[{"awards": "1440435 Ducklow, Hugh; 0636696 DeVries, Arthur; None TBD; 1344502 Ducklow, Hugh; 2026045 Schofield, Oscar; 1142158 Cheng, Chi-Hing; 1543383 Postlethwait, John; 2224611 Schofield, Oscar", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 11 Mar 2025 00:00:00 GMT", "description": "Since 1990, Palmer LTER (PAL) research has been guided by the hypothesis that variability in the polar marine ecosystem is mechanistically coupled to changes in the annual advance, retreat and spatial extent of sea ice. Since that time, the hypothesis has been modified to incorporate climate migration, i.e. the displacement of a cold, dry polar climate by a warm, moist climate regime in the northern component of the PAL region, producing fundamental changes in food web structure and elemental cycling. The observed northern changes are affecting all trophic levels and elemental cycling, and the primary mechanism of change involves match-mismatch dynamics. The proposed research builds on previous findings, with a new emphasis on process studies and modeling to elucidate the mechanistic links between teleconnections, climate change, physical oceanographic forcing and ecosystem dynamics. The proposed research will examine the hypothesis that regional warming and sea ice decline associated with historical and on-going climate migration in the northern part of the study area have altered key phenological relationships, leading to changes in species distributions, increasing trophic mismatches and changes in habitat, food availability, ecosystem dynamics and biogeochemical cycling. Through targeted process studies linked to numerical model simulations, the research also will test the hypothesis that deep cross-shelf canyons characterizing the core study region are focal areas for ecosystem processes that result in predictable, elevated food resources for top-predators. The effort includes the addition of 3 new PIs: a zooplankton ecologist with expertise in biogeochemical fluxes, a phytoplankton ecologist focusing on bio-optics and autonomous observations using gliders, and a numerical simulation modeler specializing in coupled global models of ocean circulation, plankton ecology and biogeochemical cycles. The program will add trace metal sampling and analysis, moored physical oceanographic sensors, a moored sediment trap in the south, drifting sediment traps and stable carbon (del 13C) and nitrogen (del 15N) isotope analyses. Missions lasting up to 45 days using gliders deployed before, during and after summer cruises will, along with moorings and satellite remote sensing of sea ice, ocean color, sea surface temperatures and wind fields, greatly extend the observational program in space and time. Since its inception, PAL has been a leader in Information Management to enable knowledge-building within and beyond the Antarctic, oceanographic and LTER communities. PAL has designed and deployed a new information infrastructure with a relational database architecture to facilitate data distribution and sharing. The Education and Outreach program capitalizes on the public\u0027s fascination with Antarctica to promote scientific literacy from kindergarten students to adult citizens concerned with climate change and environmental sustainability. Through communicating results to the public and working with scientific assessment bodies (e.g., IPCC) and Antarctic Treaty parties to protect Earth\u0027s last frontier, PAL researchers contribute to the national scientific agenda and the greater public benefit.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Cryonotothenioid; R/V LMG; Bellingshausen Sea; Southern Ocean; Notothenioid; FISHERIES", "locations": "Bellingshausen Sea; Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Corso, Andrew; Desvignes, Thomas; McDowell, Jan; Cheng, Chi-Hing; Biesack, Ellen; Steinberg, Deborah; Hilton, Eric", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repositories": null, "science_programs": "LTER", "south": -90.0, "title": "LTER Palmer, Antarctica (PAL): Land-Shelf-Ocean Connectivity, Ecosystem Resilience and Transformation in a Sea-Ice Influenced Pelagic Ecosystem", "uid": "p0010494", "west": -180.0}, {"awards": "2448649 Brooks, Cassandra", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 10 Mar 2025 00:00:00 GMT", "description": "Marine protected areas (MPAs) are protected areas of seas, oceans, and estuaries. They need coordinated research and monitoring for informed management to fulfill their conservation potential. Coordination is challenging, however, often due to knowledge gaps caused by inadequate access to data and resources, compounded by insufficient communication between scientists and managers. This Research Coordinating Network (RCN) uses the world\u2019s largest MPA in the Ross Sea, Antarctica, as a model system to create an international interdisciplinary network supporting policy-relevant research and monitoring that could be implemented in other remote, large-scale international MPAs. The first 10-year review of the Ross Sea MPA in 2027 will present a critical opportunity to coordinate across science, policy, and other partner communities to ensure the 2027 review (and subsequent reviews) are well grounded in robust scientific data, analyses, and streamlined inputs into policy. Many Antarctic research, policy, and conservation groups exist, some are even already focused on the Ross Sea, but there is not yet a formalized framework for coordination. Hence, the need for an RCN which can formalize connections among policy, research, and other communities focused specifically on research and monitoring of the Ross Sea region MPA. The RCN also provides an example of how to bring together diverse interdisciplinary participants towards an effective, integrated science-policy collaboration. To fulfill their conservation potential and provide safeguards for biodiversity, Marine Protected Areas (MPAs) need coordinated research and monitoring for informed management through effective evaluation of ecosystem dynamics. The Ross Sea MPA in Antarctica is the world\u2019s largest MPA and the only one on the high seas. The Research Coordination Network (RCN) will connect three key components: (i) policy engagement, (ii) community partner engagement, and (iii) integrated science. The science component comprises three themes: data science and cyberinfrastructure; biophysical modeling; and observations that include monitoring and process studies. Guided by clear research questions across the three components, the RCN will lead to new knowledge about the barriers to science-policy engagement and strategies to overcome them; strategies for effectively engaging diverse community partners; and science needed to better understand the Ross Sea ecosystem structure and function, including strategies for international coordination. The three science themes inform understanding of the ecosystem, and thus, the potential efficacy of the Ross Sea region MPA. Data science and cyberinfrastructure provide essential structures for coordinated research. Biophysical modeling is critical for evaluating ecosystem metrics and can be illustrative for understanding changes in ecosystem structure and function. Observations and process studies are needed for addressing knowledge gaps and informing cyberinfrastructure tools and biophysical modeling efforts. The science integration component will advance knowledge while also advancing transformative interdisciplinary collaboration across data science, modeling, and observations. The RCN will build new connections and collaborations among scientists, policymakers and community partners, internationally and across disciplines, while integrating science and policy in novel ways. The RCN will operate through regular engagement across the network communities, including meetings and targeted activities with specific products and outcomes. The RCN increases diversity, science diplomacy, knowledge exchange, and conservation and five early- to mid-career researchers have leading roles. The contributions from this RCN will facilitate significant advances in the ability to understand high latitude marine ecosystems and how these systems respond to competing stressors, including climate change and fishing. Further, lessons learned through the RCN could offer guidance on how other large-scale international MPAs are monitored and assessed. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "BENTHIC; Southern Ocean; Ross Sea; AQUATIC SCIENCES; COMMUNITY DYNAMICS; ECOSYSTEM FUNCTIONS; Antarctica", "locations": "Ross Sea; Southern Ocean; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Brooks, Cassandra", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "RCN: Building a Coordinated Network for Research and Monitoring in Large-Scale International Marine Protected Areas: The Ross Sea Region as a Model System", "uid": "p0010503", "west": null}, {"awards": "2418105 Zoet, Lucas", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 10 Oct 2024 00:00:00 GMT", "description": "Glaciers move in response to gravity pulling them downhill and much of the resistance to this motion is supplied by the bedrock that they sit on. For fast moving glaciers this motion is largely the result of basal ice sliding over and around bedrock bumps, and the specific processes at the ice-bed interface that facilitate this sliding play a dominant role in setting the glacier speed. Sliding atop the ice-bed interface is known to create cavities (pockets of water) downstream of bedrock bumps. These cavities facilitate water flow, control areas of ice-bed contact, regulate basal drag, dictate subglacial erosion, and affect ice mechanics in general. Thus, the length and shape of cavities (geometry) as they separate from the bed is of fundamental importance in glaciology. This project will determine the fundamental processes that set the shapes of those cavities. This work will benefit the scientific community by producing improved estimates to basal sliding and subglacial hydrology which are two of the main uncertainties in glacier-flow modeling. It will also lead to a better understanding of subglacial erosion which effectively controls the basal bump geometries. This in turn will lead to improved understanding of the fundamentals of glacier and ice-sheet dynamics. Therefore, the outcome of the project could ultimately improve future projections of sea-level rise, benefitting society at large. In addition, this project will train a postdoctoral researcher and undergraduate students from tribal institutions. This project will: 1) Use a novel experimental device to generate a cavity geometry data set for a range of independent controls; and 2) Use the results from part one to constrain numerical models that will allow for the exploration of a greater range of parameter space than is possible in the physical experiments alone. Using a novel cryogenic ring-shear device, this project will systematically assess three likely controls on cavity geometry: effective stress, sliding speed, and bump geometry, while simultaneously tracking strain indicators within the ice and the geometry of the cavity through the transparent walls of the device. These experiments will be conducted with the University of Wisconsin-Madison, state-of-the-art ring-shear device and represent the first instance where all three parameters\u2019 effects on the resultant cavity geometry can be measured simultaneously. The lab experiment findings of cavity geometry and strain rates within the ice will be used to help constrain the process-based numerical modeling of cavity formation. The numerical simulations of ice flow around obstacles will provide information about the stress and strain distribution within the ice, and from this data we can explore the ability of existing theories to predict cavity geometry for fast-flowing ice. The physics within the numerical model will be updated as needed to incorporate processes such as a stress dependent ice rheology or changes in the ice-bed contact physics that are currently unaccounted for. Outcomes will be 1) a detailed understanding of the physics that govern cavity geometry and 2) a simple parameterization of the lab and modeling results that can be easily incorporated into glaciological models for improved estimates of subglacial sliding, hydrology, and erosion. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; Madison, WI", "locations": "Madison, WI", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Zoet, Lucas", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Determining the Controls on Subglacial Cavity Geometry", "uid": "p0010481", "west": null}, {"awards": "2332479 MacAyeal, Douglas", "bounds_geometry": "POLYGON((161 -76,162.4 -76,163.8 -76,165.2 -76,166.6 -76,168 -76,169.4 -76,170.8 -76,172.2 -76,173.6 -76,175 -76,175 -76.3,175 -76.6,175 -76.9,175 -77.2,175 -77.5,175 -77.8,175 -78.1,175 -78.4,175 -78.7,175 -79,173.6 -79,172.2 -79,170.8 -79,169.4 -79,168 -79,166.6 -79,165.2 -79,163.8 -79,162.4 -79,161 -79,161 -78.7,161 -78.4,161 -78.1,161 -77.8,161 -77.5,161 -77.2,161 -76.9,161 -76.6,161 -76.3,161 -76))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 08 Oct 2024 00:00:00 GMT", "description": "Non-Technical Abstract: This project explores the areas or crash-zones where floating ice shelves in Antarctica compressively flow against obstructions such as islands and plugs of stagnant ice frozen to the sea bed. The significance of these crash-zones is that they are responsible for generating the resistive forces that allow ice shelves to slow down the flow of ice farther inland into the ocean. Ice conditions within these boundaries thus determine how Antarctica\u2019s ice sheets contribute to sea-level rise. The research will feature on-the-ice glaciological and geophysical field measurements near pressure ridges near Scott Base and the transition to the ice road where large wave-like pressure ridges form on the ice-shelf surface. This field area is along the coast of Ross Island adjacent to major logistical stations of the US and New Zealand Antarctic programs. Thus the research will help station managers better preserve one of the key roadways that connects the stations to the major runway used to fly to virtually all other parts of Antarctica. The research will also interact with educational programs such as featured in the long-standing Juneau Icefield Research Project as well as potential involvement of an artist from the US Antarctic Program\u2019s Polar STEAM in the second field season. Technical Abstract: This project explores the dynamics of boundaries where ice shelves compressively flow against obstructions such as islands and areas of grounded ice. The significance of these boundaries is that they are responsible for generating the resistive forces that allow ice shelves to impede or slow down the flow of grounded inland ice into the ocean. Ice conditions within these boundaries thus determine how Antarctica\u2019s ice sheets contribute to sea-level rise. The research will feature glaciological and geophysical field surveys in a compressive boundary area near pressure ridges adjacent to Scott Base and the transition to the ice road along the coast of Ross Island, an area affecting access to major logistical hubs of the US and New Zealand Antarctic programs. Field data will be combined with remote sensing, numerical modeling and theory development to answer key questions about the dynamics of compressive boundaries such as: is there a limit to compressive stress due to ice fracture and the bending of the ice shelf into sinusoidal pressure ridges? Over what time scales does this compressive stress build, fluctuate and decay, and how is it related to the processes that form rumples? Are there ways in which the ridges actually protect the compressive boundary from damage such as by setting up a means to scatter ocean swell impinging from the open ocean? How should compressive ice-shelf boundaries be represented in large scale ice-sheet/shelf models for the prediction of future sea-level rise? A variety of broader impact work will be done both specifically targeting the research field area and more broadly addressing scientific and societal concerns. The field area contains a critical logistics roadway that connects McMurdo Station, Scott Base and a runway essential for continent-wide air logistics. The project will inform how to stabilize the roadway against excessive damage from summer ablation and other factors. Other broader impacts include: (a) Open-Science evaluation of climate systems engineering strategies for glacial geoengineering mitigation of sea-level rise, (b) cooperation with the Juneau Icefield Research Program (JIRP) education component, (c) support and facilitation of an online FieldSafe workshop and associated panel discussion to support early-career Antarctic field teams to mitigate environmental and interpersonal risks in remote field sites, and (d) potential involvement of an artist from the US Antarctic Program\u2019s Polar STEAM in the second field season. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 175.0, "geometry": "POINT(168 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Ice Shelf Dynamics; McMurdo Sound", "locations": "McMurdo Sound", "north": -76.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas; Banwell, Alison; Campbell, Seth; Schild, Kristin; Cassoto, Ryan", "platforms": null, "repositories": null, "science_programs": null, "south": -79.0, "title": "Collaborative Research: Ice-Shelf Rumpling and its Influence on Ice-Shelf Buttressing Processes.", "uid": "p0010478", "west": 161.0}, {"awards": "2336328 Larochelle, Stacy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 08 Oct 2024 00:00:00 GMT", "description": "Ice sheets lose ice mass through gravity-driven flow to the ocean where ice breaks into icebergs and melts, contributing to global sea level rise. Water commonly found at the base of ice sheets facilitates this process by lubricating the ice-rock interface. The recent discovery of vast, kilometer-thick groundwater reservoirs beneath the Antarctic Ice Sheet thus raises important questions about the potential impact of groundwater on ice flow. It has been hypothesized that groundwater flow to the ice-sheet bed may accelerate ice flow as the ice sheet shrinks in response to global warming. Evaluating this hypothesis is challenging due to poorly understood interactions between water, ice, and rock, but is crucial for anticipating the response of ice sheets and sea level to climate change. Understanding how groundwater responds to a changing ice sheet also has important implications for the heat, chemical elements, and microorganisms it stores and transports. To assess the impact of groundwater processes on ice dynamics, a new idealized modeling framework will be developed, incorporating several novel hydromechanical couplings between ice sheets, subglacial drainage systems, and groundwater aquifers. This framework will enable testing the hypotheses that (1) aquifers decelerate ice mass loss in the absence of a well-developed subglacial drainage system, but that (2) an efficient, channelized drainage system can reduce and even reverse this decelerating effect, and that (3) the impact of these phenomena is most pronounced for steep ice flowing rapidly over thick sedimentary basins and depends in a complex way on aquifer permeability. Existing geodetic, seismic, and other geophysical datasets at well-studied Thwaites Glacier and Whillans Ice Stream will be used to constrain model parameters and investigate the impact of groundwater processes in contrasting glaciologic settings. This work will help rule out or highlight subglacial groundwater as one of the next major challenges for efforts to predict the future of the Antarctic Ice Sheet and sea-level rise on decadal to millennial timescales. The project will contribute to educating the next generation of scientists by supporting an early-career PI and a graduate student, as well as participation in a field and research educational program in Alaska and the production of chapters for an online, open-source, free interactive textbook. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND WATER; GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Larochelle, Stacy; Kingslake, Jonathan", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Modeling the Coupled Dynamics of Groundwater, Subglacial Hydrology and Ice Sheets", "uid": "p0010479", "west": null}, {"awards": "2332062 Kim, Heather", "bounds_geometry": "POLYGON((-80 -59,-76.8 -59,-73.6 -59,-70.4 -59,-67.2 -59,-64 -59,-60.8 -59,-57.599999999999994 -59,-54.4 -59,-51.2 -59,-48 -59,-48 -60.6,-48 -62.2,-48 -63.8,-48 -65.4,-48 -67,-48 -68.6,-48 -70.2,-48 -71.8,-48 -73.4,-48 -75,-51.2 -75,-54.4 -75,-57.6 -75,-60.8 -75,-64 -75,-67.2 -75,-70.4 -75,-73.6 -75,-76.8 -75,-80 -75,-80 -73.4,-80 -71.8,-80 -70.2,-80 -68.6,-80 -67,-80 -65.4,-80 -63.8,-80 -62.2,-80 -60.6,-80 -59))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 05 Aug 2024 00:00:00 GMT", "description": "The West Antarctic Peninsula (WAP) is experiencing significant environmental changes, including warming temperatures, reduced sea ice, and glacier retreat. These changes could impact marine ecosystems and biological and chemical processes, particularly the biological pump, which is the process by which carbon is transported from the ocean surface to the deep sea, playing a crucial role in regulating atmospheric carbon dioxide levels. This project aims to understand how climate change affects the biological pump in the WAP region. Using a combination of advanced modeling techniques and data from long-term research programs, the project will investigate the processes governing the biological pump and its climate feedback. The findings will provide insights into the future dynamics of the WAP region and contribute to our understanding of climate change impacts on polar marine ecosystems. This research is important as it will enhance knowledge of how polar regions respond to climate change, which is vital for predicting global climate patterns and informing conservation efforts. Furthermore, the project supports the development of early-career researchers and promotes diversity in science through collaborations with educational programs and outreach to underrepresented communities. This project focuses on the WAP, a region undergoing rapid environmental changes. The goal is to investigate and quantify the factors controlling the biological pump and its feedback to climate change and variability. A novel hybrid modeling framework will be developed, integrating observational data from the Palmer Long-Term Ecological Research program and the Rothera Oceanographic and Biological Time-Series into a sophisticated one-dimensional mechanistic biogeochemical model. This framework will utilize Artificial Intelligence and Machine Learning techniques for data assimilation and parameter optimization. By incorporating complementary datasets and optimizing model parameters, the project aims to reduce uncertainties in modeling biological pump processes. The study will also use climate scenarios from the Coupled Model Intercomparison Project Phase 6 to assess the impacts of future climate conditions on the biological pump. Additionally, the project will examine the role of vertical mixing of dissolved organic matter in total export production, providing a comprehensive understanding of the WAP carbon cycle. The outcomes will improve temporal resolution and data assimilation, advancing the mechanistic understanding of the interplay between ocean dynamics and biogeochemical processes in the changing polar environment. The project will also leverage unique datasets and make the model framework and source codes publicly available, facilitating collaboration and benefiting the broader scientific community. Outreach efforts include engaging with educational programs and promoting diversity in Polar Science through collaborations with institutions serving underrepresented groups. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -48.0, "geometry": "POINT(-64 -67)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctic; BIOGEOCHEMICAL CYCLES; PELAGIC; ECOSYSTEM FUNCTIONS", "locations": "West Antarctic", "north": -59.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Kim, Heather", "platforms": null, "repositories": null, "science_programs": null, "south": -75.0, "title": "Projecting the Biological Carbon Pump and Climate Feedback in the Rapidly Changing West Antarctic Peninsula: A Hybrid Modeling Study", "uid": "p0010474", "west": -80.0}, {"awards": "2336354 Juarez Rivera, Marisol", "bounds_geometry": "POLYGON((160 -76.5,160.45 -76.5,160.9 -76.5,161.35 -76.5,161.8 -76.5,162.25 -76.5,162.7 -76.5,163.15 -76.5,163.6 -76.5,164.05 -76.5,164.5 -76.5,164.5 -76.7,164.5 -76.9,164.5 -77.1,164.5 -77.3,164.5 -77.5,164.5 -77.7,164.5 -77.9,164.5 -78.1,164.5 -78.3,164.5 -78.5,164.05 -78.5,163.6 -78.5,163.15 -78.5,162.7 -78.5,162.25 -78.5,161.8 -78.5,161.35 -78.5,160.9 -78.5,160.45 -78.5,160 -78.5,160 -78.3,160 -78.1,160 -77.9,160 -77.7,160 -77.5,160 -77.3,160 -77.1,160 -76.9,160 -76.7,160 -76.5))", "dataset_titles": "Lake Fryxell 2022-2023 benthic microbial mat thickness and number of laminae", "datasets": [{"dataset_uid": "601839", "doi": "10.15784/601839", "keywords": "Antarctica; Cryosphere; Dry Valleys; Lake Fryxell; Laminae; Microbial Mat; Thickness", "people": "Juarez Rivera, Marisol; Mackey, Tyler; Paul, Ann; Hawes, Ian; Sumner, Dawn", "repository": "USAP-DC", "science_program": null, "title": "Lake Fryxell 2022-2023 benthic microbial mat thickness and number of laminae", "url": "https://www.usap-dc.org/view/dataset/601839"}], "date_created": "Fri, 05 Jul 2024 00:00:00 GMT", "description": "Perennially ice-covered lakes in the McMurdo Dry Valleys of Antarctica contain abundant microbial mats, and the export of this mat material can fertilize the surrounding polar desert ecosystems. These desert soils are one of the most organic-poor on earth yet host a community of microorganisms. Microbial mat material is exported from the shallow, gas-supersaturated regions of the lakes when gas bubbles form in the mats, lifting them to the ice cover; the perennial ice cover maintains gas supersaturation. These mats freeze in and are exported to the surrounding soils through ice ablation. The largest seasonal decrease and thinnest ice cover in the history of Lake Fryxell was recorded during the 2022-2023 Austral summer. In this thin ice year, the water column dissolved oxygen increased over prior observations, and the lake bottom surface area with bubble-disrupted mat was more than double that observed in 1980-1981 and 2006-2007. This work will constrain mat mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning to understand how future changing regional climate and predicted seasonal loss of lake ice cover will affect nutrient transport in the McMurdo Dry Valleys. Exceptional years of mat export are hypothesized to have the most significant impact on nutrient export to soil communities; variability in mat liftoff may thus play a role in the McMurdo Dry Valleys ecosystem response to changing climate. The perennial ice cover of lakes in the McMurdo Dry Valleys of Antarctica modulates the transfer of gasses, organic and inorganic material, between the lakes and surrounding soils. The export of biomass in these lakes is driven by the supersaturation of atmospheric gasses in the shallow regions under perennial ice cover. Gas bubbles nucleate in the mats, producing buoyancy that lifts them to the bottom of the ice, where they freeze in and are exported to the surrounding soils through ice ablation. These mats represent a significant source of biomass and nutrients to the McMurdo Dry Valleys soils, which are among the most organic-poor on earth. Nevertheless, this biomass remains unaccounted for in organic carbon cycling models for the McMurdo Dry Valleys. Ice cover data from the McMurdo Dry Valleys Long Term Ecological Research Project shows that the ice thickness has undergone cyclical variation over the last 40 years, reaching the largest seasonal decrease and thinnest ice-cover in the recorded history of Lake Fryxell during the 2022-2023 austral summer. Preliminary work shows that the surface area with mat liftoff at Lake Fryxell is more than double that observed in 1980-1981 and 2006-2007, coinciding with this unprecedented thinning of the ice-cover and an increase in the water column dissolved O2. This research will constrain biomass mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning. The researchers hypothesize that a thinner ice cover promotes more biomass mobilization by 1) stimulating additional production of gas bubbles from the existing gas-supersaturated waters during summertime photosynthesis to create microbial mat liftoff and 2) promoting mat liftoff in deeper, thicker microbial mats, and 3) that this biomass can be traced into the soils by characterizing its chemistry and modeling the most likely depositional settings. This work will use microbial mat samples, lake dissolved oxygen and photosynthetically active radiation data and underwater drone footage documenting the depth distribution of liftoff mats in January 2023, and long-term ice cover thickness, photosynthetically active radiation, and lake level change data collected by the McMurdo Dry Valleys Long Term Ecological Research Project to test hypotheses 1-3. The dispersal of the liftoff mat exposed at Lake Fryxell surface will be modeled using a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Exceptional liftoff years like the present are hypothesized to have the most significant impact on the soil communities as the rates of soil respiration increase with the addition of carbon. However, continued warming in the next 10 - 40 years may result in seasonal loss of the ice cover and cessation of liftoff mat export. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 164.5, "geometry": "POINT(162.25 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; MINERALS; LAKE/POND; ISOTOPES; Organic Matter; McMurdo Dry Valleys; SEDIMENTARY ROCKS", "locations": "McMurdo Dry Valleys", "north": -76.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Earth Sciences", "paleo_time": null, "persons": "Juarez Rivera, Marisol", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.5, "title": "RAPID: Is Biomass Mobilization at Ice-covered Lake Fryxell, Antarctica reaching a Critical Threshold?", "uid": "p0010467", "west": 160.0}, {"awards": "2233187 Stammerjohn, Sharon", "bounds_geometry": "POLYGON((-180 -70,-177 -70,-174 -70,-171 -70,-168 -70,-165 -70,-162 -70,-159 -70,-156 -70,-153 -70,-150 -70,-150 -71,-150 -72,-150 -73,-150 -74,-150 -75,-150 -76,-150 -77,-150 -78,-150 -79,-150 -80,-153 -80,-156 -80,-159 -80,-162 -80,-165 -80,-168 -80,-171 -80,-174 -80,-177 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -79,160 -78,160 -77,160 -76,160 -75,160 -74,160 -73,160 -72,160 -71,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 28 Feb 2024 00:00:00 GMT", "description": "The Ross Sea Region Marine Protected Area (RSRMPA), one of the world\u2019s largest MPAs, encompasses one of the healthiest marine ecosystems remaining on this planet; however, it is exposed to increasing stress from ongoing climate change and fishing pressure. Numerous gaps in our understanding of the highly coupled nature of the Ross Sea marine ecosystem need to be addressed to support conservation efforts in the Ross Sea region, including informing the efficacy and management of the RSRMPA into the coming decades. The overarching goal of this research is to formulate an innovative and sustainable world-class research program aimed at better understanding, conserving, and managing the RSRMPA through the coordination of multi-faceted system-level approaches. There will be a coordinated effort to facilitate international collaboration; create education, outreach, and Diverse Equitable and Inclusive (DEI) opportunities; and increase conservation awareness. Coordinating Ross Sea marine ecosystem research will contribute to enhancing system-level global research, sustainable data networks, DEI, and climate equity. This program will also provide opportunity to develop similar frameworks for other large-scale, globally important systems. The trans-disciplinary aspiration can also serve to guide the NSF in sustaining or initiating new funding opportunities while addressing several of the 10 NSF BIG IDEAS and engaging multiple NSF Directorates. The project will help maintain NSF\u2019s mission of scientific leadership by networking the Antarctic community by providing science-based conservation plans to help mitigate environmental changes in this pristine region of the Southern Ocean. The researchers will convene a workshop to strategize the implementation of an internationally networked, world class program that is based on inter- and trans-disciplinary approaches (including bridging science, cyberinfrastructure, policy, management, and conservation), while also providing opportunities for STEM education, early career development, and core DEI principles. To effectively facilitate the prioritization of research related to the regional and global interconnectedness of the Ross Sea marine ecosystem, the workshop will involve leading experts in Ross Sea marine research and other researchers, stakeholders, and policy experts involved in the greater oceanographic, climate and ecosystem/food web modeling communities. The workshop will determine a long-term decadal plan comprising the following phases: (1) initial data synthesis and ecosystem/food web model development; (2) field observations and modeling, networked through an internationally coordinated Ross Sea Observing System; and (3) data synthesis and modeling, including a \u201csunset\u201d plan to support ongoing RSRMPA management and preservation of the Ross Sea marine ecosystem. Outcomes will include a workshop report detailing the long-term research plan, a peer-reviewed article, educational and outreach materials, and a list of proposed research topics for implementing a world class research program and Principal Investigators who will help coordinate the multiple efforts aimed at addressing major gaps in our knowledge of the Ross Sea system. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 160.0, "geometry": "POINT(-175 -75)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; PELAGIC; COASTAL; United States Of America", "locations": "United States Of America", "north": -70.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Stammerjohn, Sharon; Brooks, Cassandra", "platforms": null, "repositories": null, "science_programs": null, "south": -80.0, "title": "Planning: Formulating and Sustaining a System-Level Understanding of a Large Marine Ecosystem in the Ross Sea Region Marine Protected Area to Better Conserve and Guide Policy", "uid": "p0010452", "west": -150.0}, {"awards": null, "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 12 Feb 2024 00:00:00 GMT", "description": "Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function.\u003cbr/\u003e \u003cbr/\u003e \u003cbr/\u003eTo understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; BENTHIC; PENGUINS; FLUORESCENCE; PHYTOPLANKTON", "locations": "Palmer Station", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": null, "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Physical Mechanisms Driving Food Web Focusing in Antarctic Biological Hotspots", "uid": "p0010448", "west": null}, {"awards": "2333940 Zhong, Shijie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 08 Jan 2024 00:00:00 GMT", "description": "Satellite observations of Earth\u2019s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth\u2019s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth\u2019s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS; CRUSTAL MOTION; COMPUTERS; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE", "locations": "WAIS", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Zhong, Shijie", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Investigating Effects of Transient and Non-Newtonian Mantle Viscosity on Glacial Isostatic Adjustment Process and their Implications for GPS Observations in Antarctica", "uid": "p0010441", "west": -180.0}, {"awards": "2224760 Gooseff, Michael", "bounds_geometry": "POINT(162.87 -77)", "dataset_titles": "EDI Data Portal: McMurdo Dry Valleys LTER", "datasets": [{"dataset_uid": "200379", "doi": "", "keywords": null, "people": null, "repository": "Environmental Data Initiative (EDI)", "science_program": null, "title": "EDI Data Portal: McMurdo Dry Valleys LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=MCM"}], "date_created": "Tue, 14 Nov 2023 00:00:00 GMT", "description": "Non-technical Abstract The McMurdo Dry Valleys LTER seeks to understand how changes in the temporal variability of ecological connectivity interact with existing landscape legacies to alter the structure and functioning of this extreme polar desert ecosystem. This research has broad implications, as it will help us to understand how natural ecosystems respond to ongoing anthropogenic global change. At the same time, this project also serves an important educational and outreach function, providing immersive research and educational experiences to students and artists from diverse backgrounds, and helping to ensure a diverse and well-trained next generation of leaders in polar ecosystem science and stewardship. Ultimately, the results of this project will help us to better understand and prepare for the effects of climate change and develop scientific insights that are relevant far beyond Antarctic ecosystems. The McMurdo Dry Valleys (MDVs) make up an extreme polar desert ecosystem in the largest ice-free region of Antarctica. The organisms in this ecosystem are generally small. Bacteria, microinvertebrates, cyanobacterial mats, and phytoplankton can be found across the streams, soils, glaciers, and ice-covered lakes. These organisms have adapted to the cold and arid conditions that prevail outside of lakes for all but a brief period in the austral summer when the ecosystem is connected by liquid water. In the summer when air temperatures rise barely above freezing, soils warm and glacial meltwater flows through streams into the open moats of lakes. Most biological activity across the landscape occurs in summer. Through the winter, or polar night (6 months of darkness), glaciers, streams, and soil biota are inactive until sufficient light, heat, and liquid water return, while lake communities remain active all year. Over the past 30 years, the MDVs have been disturbed by cooling, heatwaves, floods, rising lake levels, as well as permafrost and lake ice thaw. Considering the clear ecological responses to this variation in physical drivers, and climate models predicting further warming and more precipitation, the MDV ecosystem sits at a threshold between the current extreme cold and dry conditions and an uncertain future. This project seeks to determine how important the legacy of past events and conditions versus current physical and biological interactions shape the current ecosystem. Four hypotheses will be tested, related to 1) whether the status of specific organisms are indicative ecosystem stability, 2) the relationship between legacies of past events to current ecosystem resilience (resistance to big changes), 3) carryover of materials between times of high ecosystem connectivity and activity help to maintain ecosystem stability, and 4) changes in disturbances affect how this ecosystem persists through the annual polar night (i.e., extended period of dark and cold). Technical Abstract In this iteration of the McMurdo LTER project (MCM6), the project team will test ecological connectivity and stability theory in a system subject to strong physical drivers (geological legacies, extreme seasonality, and contemporary climate change) and driven by microbial organisms. Since microorganisms regulate most of the world\u2019s critical biogeochemical functions, these insights will be relevant far beyond polar ecosystems and will inform understanding and expectations of how natural and managed ecosystems respond to ongoing anthropogenic global change. MCM6 builds on previous foundational research, both in Antarctica and within the LTER network, to consider the temporal aspects of connectivity and how it relates to ecosystem stability. The project will examine how changes in the temporal variability of ecological connectivity interact with the legacies of the existing landscape that have defined habitats and biogeochemical cycling for millennia. The project team hypothesizes that the structure and functioning of the MDV ecosystem is dependent upon legacies and the contemporary frequency, duration, and magnitude of ecological connectivity. This hypothesis will be tested with new and continuing monitoring, experiments, and analyses of long-term datasets to examine: 1) the stability of these ecosystems as reflected by sentinel taxa, 2) the relationship between ecological legacies and ecosystem resilience, 3) the importance of material carryover during periods of low connectivity to maintaining biological activity and community stability, and 4) how changes in disturbance dynamics disrupt ecological cycles through the polar night. Tests of these hypotheses will occur in field and modeling activities using new and long-term datasets already collected. New datasets resulting from field activities will be made freely available via widely-known online databases (MCM LTER and EDI). The project team has also developed six Antarctic Core Ideas that encompass themes from data literacy to polar food webs and form a consistent thread across the education and outreach activities. Building on past success, collaborations will be established with teachers and artists embedded within the science teams, who will work to develop educational modules with science content informed by direct experience and artistic expression. Undergraduate mentoring efforts will incorporate computational methods through a new data-intensive scientific training program for MCM REU students. The project will also establish an Antarctic Research Experience for Community College Students at CU Boulder, to provide an immersive educational and research experience for students from diverse backgrounds in community colleges. MCM LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science and stewardship. Historically underrepresented participation will be expanded at each level of the project. To aid in these efforts, the project has established Education \u0026 Outreach and Diversity, Equity, and Inclusion committees to lead, coordinate, support, and integrate these activities through all aspects of MCM6. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 162.87, "geometry": "POINT(162.87 -77)", "instruments": null, "is_usap_dc": true, "keywords": "COMMUNITY DYNAMICS; ABLATION ZONES/ACCUMULATION ZONES; SOIL TEMPERATURE; DIATOMS; FIELD INVESTIGATION; PERMANENT LAND SITES; BUOYS; GROUND-BASED OBSERVATIONS; SEDIMENTS; SNOW WATER EQUIVALENT; SPECIES/POPULATION INTERACTIONS; WATER-BASED PLATFORMS; FIXED OBSERVATION STATIONS; VIRUSES; PHYTOPLANKTON; ACTIVE LAYER; FIELD SURVEYS; RADIO TRANSMITTERS; DATA COLLECTIONS; ECOLOGICAL DYNAMICS; LANDSCAPE; GROUND WATER; SNOW/ICE CHEMISTRY; LAND-BASED PLATFORMS; ANIMALS/INVERTEBRATES; ECOSYSTEM FUNCTIONS; HUMIDITY; GEOCHEMISTRY; SURFACE WINDS; RIVERS/STREAM; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; SNOW; LAND RECORDS; ATMOSPHERIC PRESSURE; SURFACE TEMPERATURE; ATMOSPHERIC RADIATION; BACTERIA/ARCHAEA; AIR TEMPERATURE; GLACIERS; SNOW/ICE TEMPERATURE; SOIL CHEMISTRY; METEOROLOGICAL STATIONS; WATER QUALITY/WATER CHEMISTRY; TERRESTRIAL ECOSYSTEMS; MOORED; PROTISTS; STREAMFLOW STATION; Dry Valleys; LAKE/POND; LAKE ICE; SNOW DEPTH; AQUATIC ECOSYSTEMS; SNOW DENSITY; FIELD SITES", "locations": "Dry Valleys", "north": -77.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "Gooseff, Michael N.; Adams, Byron; Barrett, John; Diaz, Melisa A.; Doran, Peter; Dugan, Hilary A.; Mackey, Tyler; Morgan-Kiss, Rachael; Salvatore, Mark; Takacs-Vesbach, Cristina; Zeglin, Lydia H.", "platforms": "LAND-BASED PLATFORMS; LAND-BASED PLATFORMS \u003e FIELD SITES; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e RADIO TRANSMITTERS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e FIXED OBSERVATION STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e STREAMFLOW STATION; WATER-BASED PLATFORMS; WATER-BASED PLATFORMS \u003e BUOYS; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e BUOYS", "repo": "Environmental Data Initiative (EDI)", "repositories": "Environmental Data Initiative (EDI)", "science_programs": "LTER", "south": -77.0, "title": "LTER: MCM6 - The Roles of Legacy and Ecological Connectivity in a Polar Desert Ecosystem", "uid": "p0010440", "west": 162.87}, {"awards": "1149085 Bassis, Jeremy", "bounds_geometry": "POLYGON((66 -68,66.9 -68,67.8 -68,68.7 -68,69.6 -68,70.5 -68,71.4 -68,72.3 -68,73.2 -68,74.1 -68,75 -68,75 -68.6,75 -69.2,75 -69.8,75 -70.4,75 -71,75 -71.6,75 -72.2,75 -72.8,75 -73.4,75 -74,74.1 -74,73.2 -74,72.3 -74,71.4 -74,70.5 -74,69.6 -74,68.7 -74,67.8 -74,66.9 -74,66 -74,66 -73.4,66 -72.8,66 -72.2,66 -71.6,66 -71,66 -70.4,66 -69.8,66 -69.2,66 -68.6,66 -68))", "dataset_titles": "Antarctic Ice Shelf Rift Propagation Rates", "datasets": [{"dataset_uid": "601740", "doi": "10.15784/601740", "keywords": "Amery Ice Shelf; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; MODIS", "people": "Walker, Catherine; Bassis, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Shelf Rift Propagation Rates", "url": "https://www.usap-dc.org/view/dataset/601740"}], "date_created": "Fri, 13 Oct 2023 00:00:00 GMT", "description": "Bassis/1149085 This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbr\u00e4e, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.", "east": 75.0, "geometry": "POINT(70.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Amery Ice Shelf", "locations": "Amery Ice Shelf", "north": -68.0, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Bassis, Jeremy", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "CAREER: Bound to Improve - Improved Estimates of the Glaciological Contribution to Sea Level Rise", "uid": "p0010437", "west": 66.0}, {"awards": "2035078 Giometto, Marco; 2034874 Salesky, Scott", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 08 Sep 2023 00:00:00 GMT", "description": "1. A non-technical explanation of the project\u0027s broader significance and importance, that serves as a public justification for NSF funding. This part should be understandable to an educated reader who is not a scientist or engineer. Katabatic or drainage winds, carry high-density air from a higher elevation down a slope under the force of gravity. Although katabatic flows are ubiquitous in alpine and polar regions, a surface-layer similarity theory is currently lacking for these flows, undermining the accuracy of numerical weather and climate prediction models. This project is interdisciplinary, and will give graduate and undergraduate students valuable experience interacting with researchers outside their core discipline. Furthermore, this project will broaden participating in science through recruitment of students from under-represented groups at OU and CU through established programs. The Antarctic Ice Sheet drives many processes in the Earth system through its modulation of regional and global atmospheric and oceanic circulations, storage of fresh water, and effects on global albedo and climate. An understanding of the surface mass balance of the ice sheets is critical for predicting future sea level rise and for interpreting ice core records. Yet, the evolution of the ice sheets through snow deposition, erosion, and transport in katabatic winds (which are persistent across much of the Antarctic) remains poorly understood due to the lack of an overarching theoretical framework, scarcity of in situ observational datasets, and a lack of accurate numerical modeling tools. Advances in the fundamental understanding and modeling capabilities of katabatic transport processes are urgently needed in view of the future climatic and snowfall changes that are projected to occur within the Antarctic continent. This project will leverage the expertise of a multidisciplinary team of investigators (with backgrounds spanning cryospheric science, environmental fluid mechanics, and atmospheric science) to address these knowledge gaps. 2. A technical description of the project that states the problem to be studied, the goals and scope of the research, and the methods and approaches to be used. In many cases, the technical project description may be a modified version of the project summary submitted with the proposal. Using field observations and direct numerical simulations of katabatic flow, this project is expected--- for the first time---to lead to a surface-layer similarity theory for katabatic flows relating turbulent fluxes to mean vertical gradients. The similarity theory will be used to develop surface boundary conditions for large eddy simulations (LES), enabling the first accurate LES of katabatic flow. The numerical tools that the PIs will develop will allow them to investigate how the partitioning between snow redistribution, transport, and sublimation depends on the environmental parameters typically encountered in Antarctica (e.g. atmospheric stratification, surface sloping angles, and humidity profiles), and to develop simple models to infer snow transport based on satellite remote sensing and regional climate models This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "TURBULENCE; ATMOSPHERIC RADIATION; DATA COLLECTIONS; SNOW/ICE; SNOW; FIELD INVESTIGATION; AIR TEMPERATURE; HUMIDITY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Salesky, Scott; Giometto, Marco; Das, Indrani", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e DATA COLLECTIONS; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Snow Transport in Katabatic Winds and Implications for the Antarctic Surface Mass Balance: Observations, Theory, and Numerical Modeling", "uid": "p0010433", "west": null}, {"awards": "2231558 Smith, Nathan; 2231559 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 01 Sep 2023 00:00:00 GMT", "description": "The unique Antarctic environment offers insight into processes and records not seen anywhere else on Earth, and is critical to understanding our planet\u2019s history and future. The remoteness and logistics of Antarctic science brings together researchers from diverse disciplines who otherwise wouldn\u2019t be presented with opportunities for collaboration, and often rarely attend the same academic conferences. The Interdisciplinary Antarctic Earth Science (IAES) conference is a biennial gathering that supports the collaboration of U.S. bio-, cryo-, geo-, and atmospheric science researchers working in the Antarctic. This proposal will support the next two IAES conferences to be held in 2022 and 2024, as well as a paired deep-field camp planning workshop. The IAES conference is important to the mission of the NSF in supporting interdisciplinary collaboration in the Antarctic Earth sciences, but also fulfills recommendations by the National Academy for improving cross-disciplinary awareness, data sharing, and early career researcher mentoring and development. The size and scope of the IAES conference allow it to serve as a hub for novel, interdisciplinary collaboration, as well as help develop the next generation of Antarctic Earth scientists. The goals of the IAES conference are to develop and deepen scientific collaborations across the Antarctic Earth science community, and create a framework for future deep-field, as well as non-field-based research. Across a 2.5 day hybrid conference, the IAES themes will include 1) connecting surficial processes, geology, and the deep earth; 2) landscape, ice sheet, ocean and atmospheric interactions; 3) exploring the hidden continent; and 4) evolution and ecology of ancient and modern organisms, ecosystems, and environments. The conference will share science through presentations of current research and keynote talks, broaden participation through welcoming new researchers from under-represented communities and disciplines, and deepen collaboration through interdisciplinary networking highlighting potential research connections, novel mentorship activities, and promoting data re-use, and application of remote sensing and modeling. Discussions resulting from the IAES conference will be used to develop white papers on future Antarctic collaborative research and deep-field camps based on community-driven research priorities. Community surveys and feedback will be solicited throughout the project to guide the future development of the IAES conference. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GEOMORPHIC LANDFORMS/PROCESSES; GEOCHEMISTRY; California; ICE CORE RECORDS; ECOLOGICAL DYNAMICS; GLACIERS/ICE SHEETS; PALEOCLIMATE RECONSTRUCTIONS", "locations": "California", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Smith, Nathan; Tinto, Kirsty", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Conference: Interdisciplinary Antarctic Earth Science Conference \u0026 Deep-Field Planning Workshop", "uid": "p0010432", "west": -180.0}, {"awards": "2032328 Apel, Eric", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 27 Jul 2023 00:00:00 GMT", "description": "A class of small molecules, very short-lived substances (VSLS; e.g. CHBr3,CH2Br2, and CH3I) are important components in the climate system where they act as tropospheric ozone destroyers as described in the multilateral environmental Montreal Protocol on Substances that Deplete the Ozone Layer. The Southern Ocean represents a key component in the climate system and has a critical role in other global biogeochemical cycles. This project will use the NSF/NCAR Community Earth System Model (CESM) with a newly developed online air-sea exchange framework, to evaluate biogeochemical controls on the marine sources of VSLS in the Southern Ocean as well as the Southern Hemisphere. A machine-learning approach will be used to couple ocean biogeochemistry with air-sea exchange for these compounds. A variety of oceanic and atmospheric observations of VSLS will be used to evaluate a unique oceanic VSLS inventory. In particular, the recent ORCAS field campaign provides a unique opportunity to examine Southern Ocean VSLS emissions, and their impacts from ocean biogeochemistry, meteorology and sea ice cycles. The project will also support a postdoctoral early-career researcher, and a specific effort of this project is STEM education and public outreach activities. The research team will extend opportunities to high school and undergraduate students so they may gain experience in the coupled ocean and atmospheric sciences, including exposure to and experience in programming and modeling. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; HALOCARBONS AND HALOGENS", "locations": "Antarctic Peninsula", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Apel, Eric", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Southern Ocean Biogeochemistry Control on Short-Lived Ozone-Depleting Substances and Impacts on the Climate System", "uid": "p0010427", "west": -180.0}, {"awards": "2026045 Schofield, Oscar; 2224611 Schofield, Oscar", "bounds_geometry": "POLYGON((-79.65 -63.738,-77.9728 -63.738,-76.29560000000001 -63.738,-74.61840000000001 -63.738,-72.94120000000001 -63.738,-71.26400000000001 -63.738,-69.58680000000001 -63.738,-67.9096 -63.738,-66.2324 -63.738,-64.5552 -63.738,-62.878 -63.738,-62.878 -64.3683,-62.878 -64.9986,-62.878 -65.6289,-62.878 -66.25919999999999,-62.878 -66.8895,-62.878 -67.5198,-62.878 -68.1501,-62.878 -68.7804,-62.878 -69.41069999999999,-62.878 -70.041,-64.5552 -70.041,-66.2324 -70.041,-67.9096 -70.041,-69.5868 -70.041,-71.26400000000001 -70.041,-72.94120000000001 -70.041,-74.61840000000001 -70.041,-76.29560000000001 -70.041,-77.9728 -70.041,-79.65 -70.041,-79.65 -69.41069999999999,-79.65 -68.7804,-79.65 -68.1501,-79.65 -67.5198,-79.65 -66.8895,-79.65 -66.25919999999999,-79.65 -65.6289,-79.65 -64.9986,-79.65 -64.3683,-79.65 -63.738))", "dataset_titles": "Expedition Data of LMG2301; Expedition Data of NBP2113; Palmer LTER data in the Environmental Data Initiative Repository", "datasets": [{"dataset_uid": "200370", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2113", "url": "https://www.rvdata.us/search/cruise/NBP2113"}, {"dataset_uid": "200367", "doi": "", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Palmer LTER data in the Environmental Data Initiative Repository", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=PAL"}, {"dataset_uid": "200371", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of LMG2301", "url": "https://www.rvdata.us/search/cruise/LMG2301"}], "date_created": "Wed, 26 Jul 2023 00:00:00 GMT", "description": "Part 1: Non-technical description The goal of all LTER sites is to conduct policy-relevant ecosystem research for questions that require tens of years of data and cover large geographical areas. The Palmer Antarctica Long Term Ecological Research (PAL-LTER) site has been in operation since 1990 and has been studying how the marine ecosystem west of the Antarctica Peninsula (WAP) is responding to a climate that is changing as rapidly as any place on the Earth. The study is evaluating how warming conditions and decreased ice cover leading to extended periods of open water are affecting many aspects of ecosystem function. The team is using combined cutting-edge approaches including yearly ship-based research cruises, small-boat weekly sampling, autonomous vehicles, animal biologging, oceanographic floats and seafloor moorings, manipulative lab-based process studies and modeling to evaluate both seasonal and annual ecosystem responses. These combined approaches are allowing for the study the ecosystem changes at scales needed to assess both short-term and long-term drivers. The study region also includes submarine canyons that are special regions of enhanced biological activity within the WAP. This research program is paired with a comprehensive education and outreach program promoting the global significance of Antarctic science and research. In addition to training for graduate and undergraduate students, they are using newly-developed Polar Literacy Principles as a foundation in a virtual schoolyard program that shares polar instructional materials and provides learning opportunities for K-12 educators. The PAL-LTER team is also leveraging the development of Out of School Time materials for afterschool and summer camp programs, sharing Palmer LTER-specific teaching materials with University, Museum, and 4-H Special Interest Club partners. Part 2: Technical description Polar ecosystems are among the most rapidly changing on Earth. The Palmer LTER (PAL-LTER) program builds on three decades of coordinated research along the western side of the Antarctic Peninsula (WAP) to gain new mechanistic and predictive understanding of ecosystem changes in response to disturbances spanning long-term decadal (\u2018press\u2019) drivers and changes due to higher-frequency (\u2018pulse\u2019) drivers, such as large storms and extreme seasonal anomaly in sea ice cover. The influence of major natural climate modes that modulate variations in sea ice, weather, and oceanographic conditions to drive changes in ecosystem structure and function (e.g., El Ni\u00f1o Southern Oscillation and Southern Annular Mode) are being studied at multiple time scales \u2013from diel, seasonal, interannual, to decadal intervals, and space scales\u2013from hemispheric to global scale investigated by remote sensing, the regional scales. Specifically, the team is evaluating how variability of physical properties (such as vertical and alongshore connectivity processes) interact to modulate biogeochemical cycling and community ecology in the WAP region. The study is providing an evaluation of ecosystem resilience and ecological responses to long-term \u201cpress-pulse\u201d drivers and a decadal-level reversal in sea ice coverage. This program is providing fundamental understanding of population and biogeochemical responses for a marine ecosystem experiencing profound change. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.878, "geometry": "POINT(-71.26400000000001 -66.8895)", "instruments": null, "is_usap_dc": true, "keywords": "SEA ICE; PLANKTON; PELAGIC; West Antarctic Shelf; R/V NBP; OCEAN MIXED LAYER; COMMUNITY DYNAMICS; PENGUINS; R/V LMG", "locations": "West Antarctic Shelf", "north": -63.738, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Schofield, Oscar; Steinberg, Deborah", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "EDI; R2R", "science_programs": "LTER", "south": -70.041, "title": "LTER: Ecological Response and Resilience to \u201cPress-Pulse\u201d Disturbances and a Recent Decadal Reversal in Sea Ice Trends Along the West Antarctic Peninsula", "uid": "p0010426", "west": -79.65}, {"awards": "1847173 Duddu, Ravindra", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 07 Jul 2023 00:00:00 GMT", "description": "Iceberg calving is a complex natural fracture process and a dominant cause of mass loss from the floating ice shelves on the margins of the Antarctic ice sheet. There is concern that rapid changes at these ice shelves can destabilize parts of the ice sheet and accelerate their contribution to sea-level rise. The goal of this project is to understand and simulate the fracture mechanics of calving and to develop physically-consistent calving schemes for ice-sheet models. This would enable more reliable estimation of Antarctic mass loss by reducing the uncertainty in projections. The research plan is integrated with an education and outreach plan that aims to (1) enhance computational modeling skills of engineering and Earth science students through a cross-college course and a high-performance computing workshop and (2) increase participation and diversity in engineering and sciences by providing interdisciplinary research opportunities to undergraduates and by deploying new cyberlearning tools to engage local K-12 students in the Metro Nashville Public Schools in computational science and engineering, and glaciology. This project aims to provide fundamental understanding of iceberg calving by advancing the frontiers in computational fracture mechanics and nonlinear continuum mechanics and translating it to glaciology. The project investigates crevasse propagation using poro-damage mechanics models for hydrofracture that are consistent with nonlinear viscous ice rheology, along with the thermodynamics of refreezing in narrow crevasses at meter length scales. It will develop a fracture-physics based scheme to better represent calving in ice-sheet models using a multiscale method. The effort will also address research questions related to calving behavior of floating ice shelves and glaciers, with the goal of enabling more reliable prediction of calving fronts in whole-Antarctic ice-sheet simulations over decadal-to-millennial time scales. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIER MOTION/ICE SHEET MOTION", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Duddu, Ravindra", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "CAREER: Fracture Mechanics of Antarctic Ice Shelves and Glaciers - Representing Iceberg Calving in Ice Sheet Models and Developing Cyberlearning Tools for Outreach", "uid": "p0010423", "west": null}, {"awards": "1543383 Postlethwait, John; 1947040 Postlethwait, John; 2232891 Postlethwait, John", "bounds_geometry": "POLYGON((-180 -37,-144 -37,-108 -37,-72 -37,-36 -37,0 -37,36 -37,72 -37,108 -37,144 -37,180 -37,180 -42.3,180 -47.6,180 -52.9,180 -58.2,180 -63.5,180 -68.8,180 -74.1,180 -79.4,180 -84.69999999999999,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84.7,-180 -79.4,-180 -74.1,-180 -68.8,-180 -63.5,-180 -58.2,-180 -52.9,-180 -47.6,-180 -42.300000000000004,-180 -37))", "dataset_titles": "aBSREL tests for episodic diversifying selection on hemoglobin genes in notothenioids.; MEME tests of sites evolving under episodic diversifying selection in notothenioid hemoglobin genes.; Notothenioid hemoglobin protein 3D modeling.; Notothenioid species tree used in the study.; Phylogenetic trees of hemoglobin proteins in notothenioids.; Rates of hemoglobin evolution among genes and across notothenioid species.; RELAX tests for pervasive changes in strength of natural selection on hemoglobin genes in notothenioids.", "datasets": [{"dataset_uid": "601732", "doi": "10.15784/601732", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "people": "Postlethwait, John; Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Notothenioid hemoglobin protein 3D modeling.", "url": "https://www.usap-dc.org/view/dataset/601732"}, {"dataset_uid": "601721", "doi": "10.15784/601721", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Gene; Hemoglobin; Icefish; Notothenioid; Plunderfish; Sub-Antarctic", "people": "Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "Notothenioid species tree used in the study.", "url": "https://www.usap-dc.org/view/dataset/601721"}, {"dataset_uid": "601722", "doi": "10.15784/601722", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Gene; Hemoglobin; Icefish; Notothenioid; Plunderfish; Sub-Antarctic", "people": "Postlethwait, John; Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "Phylogenetic trees of hemoglobin proteins in notothenioids.", "url": "https://www.usap-dc.org/view/dataset/601722"}, {"dataset_uid": "601728", "doi": "10.15784/601728", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Gene; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "people": "Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "aBSREL tests for episodic diversifying selection on hemoglobin genes in notothenioids.", "url": "https://www.usap-dc.org/view/dataset/601728"}, {"dataset_uid": "601729", "doi": "10.15784/601729", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "people": "Desvignes, Thomas; Postlethwait, John", "repository": "USAP-DC", "science_program": null, "title": "Rates of hemoglobin evolution among genes and across notothenioid species.", "url": "https://www.usap-dc.org/view/dataset/601729"}, {"dataset_uid": "601730", "doi": "10.15784/601730", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "people": "Postlethwait, John; Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "MEME tests of sites evolving under episodic diversifying selection in notothenioid hemoglobin genes.", "url": "https://www.usap-dc.org/view/dataset/601730"}, {"dataset_uid": "601731", "doi": "10.15784/601731", "keywords": "Antarctica; Cold Adaptation; Cryonotothenioid; Dragonfish; Eleginopsioidea; Fish; Genetic Analysis; Hemoglobin; Icefish; Notothenioid; Notothenioid Fishes; Plunderfish; Sub-Antarctic", "people": "Postlethwait, John; Desvignes, Thomas", "repository": "USAP-DC", "science_program": null, "title": "RELAX tests for pervasive changes in strength of natural selection on hemoglobin genes in notothenioids.", "url": "https://www.usap-dc.org/view/dataset/601731"}], "date_created": "Wed, 03 May 2023 00:00:00 GMT", "description": "Antarctic notothenioid fishes, also known as cryonotothenioids, inhabit the icy and highly oxygenated waters surrounding the Antarctic continent after diverging from notothenioids inhabiting more temperate waters. Notothenioid hemoglobin and blood parameters are known to have evolved along with the establishment of stable polar conditions, and among Antarctic notothenioids, icefishes are evolutionary oddities living without hemoglobin following the deletion of all functional hemoglobin genes from their genomes. In this project, we investigate the evolution of hemoglobin genes and gene clusters across the notothenioid radiation until their loss in the icefish ancestor after its divergence from the dragonfish lineage to understand the forces, mechanisms, and potential causes for hemoglobin gene loss in the icefish ancestor.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "FISH; Icefish; Cryonotothenioid; Gene; Plunderfish; Eleginopsioidea; AQUATIC ECOSYSTEMS; Dragonfish; Sub-Antarctic; Notothenioid; Blood; Hemoglobin", "locations": "Sub-Antarctic", "north": -37.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Desvignes, Thomas; Postlethwait, John", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Evolution of hemoglobin genes in notothenioid fishes", "uid": "p0010417", "west": -180.0}, {"awards": "2152622 Morlighem, Mathieu", "bounds_geometry": "POLYGON((-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-103 -74,-102 -74,-101 -74,-100 -74,-100 -74.3,-100 -74.6,-100 -74.9,-100 -75.2,-100 -75.5,-100 -75.8,-100 -76.1,-100 -76.4,-100 -76.7,-100 -77,-101 -77,-102 -77,-103 -77,-104 -77,-105 -77,-106 -77,-107 -77,-108 -77,-109 -77,-110 -77,-110 -76.7,-110 -76.4,-110 -76.1,-110 -75.8,-110 -75.5,-110 -75.2,-110 -74.9,-110 -74.6,-110 -74.3,-110 -74))", "dataset_titles": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "datasets": [{"dataset_uid": "601658", "doi": "10.15784/601658", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites; Thwaites Glacier", "people": "Das, Indrani", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601658"}], "date_created": "Tue, 20 Dec 2022 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections. The project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-105 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; Amundsen Sea; ICE SHEETS", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "NOT APPLICABLE", "persons": "Morlighem, Mathieu; Das, Indrani", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "NSF-NERC: PROcesses, drivers, Predictions: Modeling the response of Thwaites Glacier over the next Century using Ice/Ocean Coupled Models (PROPHET)", "uid": "p0010400", "west": -110.0}, {"awards": "1625904 TBD", "bounds_geometry": "POLYGON((166 -77.5,166.4 -77.5,166.8 -77.5,167.2 -77.5,167.6 -77.5,168 -77.5,168.4 -77.5,168.8 -77.5,169.2 -77.5,169.6 -77.5,170 -77.5,170 -77.75,170 -78,170 -78.25,170 -78.5,170 -78.75,170 -79,170 -79.25,170 -79.5,170 -79.75,170 -80,169.6 -80,169.2 -80,168.8 -80,168.4 -80,168 -80,167.6 -80,167.2 -80,166.8 -80,166.4 -80,166 -80,166 -79.75,166 -79.5,166 -79.25,166 -79,166 -78.75,166 -78.5,166 -78.25,166 -78,166 -77.75,166 -77.5))", "dataset_titles": "Sarah PCWS unmodified ten-minute observational data, 2020 - present (ongoing).; Skomik PCWS unmodified ten-minute observational data, 2022 - present (ongoing).", "datasets": [{"dataset_uid": "200340", "doi": "https://doi.org/10.48567/h6qx-0613", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Skomik PCWS unmodified ten-minute observational data, 2022 - present (ongoing).", "url": "https://amrdcdata.ssec.wisc.edu/dataset/skomik-pcws-unmodified-ten-minute-observational-data-2022-present-ongoing"}, {"dataset_uid": "200341", "doi": "https://doi.org/10.48567/q4eh-nm67", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "Sarah PCWS unmodified ten-minute observational data, 2020 - present (ongoing).", "url": "https://amrdcdata.ssec.wisc.edu/dataset/sarah-pcws-unmodified-ten-minute-observational-data-2022-present-ongoing"}], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Our knowledge of Antarctic weather and climate relies on only a handful of direct observing stations located on this harsh and remote continent. This observing system reports meteorological measurements from an existing network of automatic weather stations (AWS) spread across a vast area. This MRI project will enable the development, testing and eventual deployment of a next generation of polar automatic climate and weather observing stations for unattended use in the Antarctic. The proposed new Automatic Weather Station (AWS) system will enhance the capabilities and accuracy of the meteorological observations, enabling climate quality measurements. This project will involve development of a more capable instrumentation core, with two major goals. The first goal is to lower the cost for an AWS electronic core to 3 times less than currently employed systems. The second is to enable an onboard temperature calibration capability, an innovative development for the Antarctic AWS. The capability for onboard calibration will add confidence in the critical climate measure of ambient temperature, along with other standard meteorological parameters. Observations made by a modernized AWS network will inform and extend future numerical climate modeling efforts, improve operational weather forecasts, capture weather phenomena, and support environmental science research in other disciplines. A theme of the project is the inclusion of community college students in all aspects of the effort. With an eye on training the next generation of research instrumentation expertise, while involving other science, technology, engineering and mathematics (STEM) fields, undergraduate students will be involved in the development, testing and deployment of new AWS systems. As well as reporting, data analysis and publication of scientific knowledge, students intending to transfer to a 4-year university, as well as those pursuing electronics or electrical engineering associate degrees will be introduced to weather and climate topics. This MRI award was supported with funds from the Division of Polar Programs and the Division of Atmospheric and Geospace Sciences, both of the Directorate of Geosciences.", "east": 170.0, "geometry": "POINT(168 -78.75)", "instruments": null, "is_usap_dc": true, "keywords": "ATMOSPHERIC WINDS; Madison Area Technical College; SNOW/ICE; SURFACE PRESSURE; ATMOSPHERIC RADIATION; HUMIDITY; AIR TEMPERATURE; METEOROLOGICAL STATIONS; WEATHER STATIONS", "locations": "Madison Area Technical College", "north": -77.5, "nsf_funding_programs": null, "paleo_time": null, "persons": "Lazzara, Matthew; Cassano, John; L\u0027\u0027Ecuyer, Tristan; Kulie, Mark", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e METEOROLOGICAL STATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e WEATHER STATIONS", "repo": "AMRDC", "repositories": "AMRDC", "science_programs": null, "south": -80.0, "title": "MRI: Development of a Modern Polar Climate and Weather Automated Observing System", "uid": "p0010396", "west": 166.0}, {"awards": "1542756 Koutnik, Michelle", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.9,-175 -78.8,-175 -79.7,-175 -80.6,-175 -81.5,-175 -82.4,-175 -83.3,-175 -84.2,-175 -85.1,-175 -86,-175.5 -86,-176 -86,-176.5 -86,-177 -86,-177.5 -86,-178 -86,-178.5 -86,-179 -86,-179.5 -86,180 -86,177.5 -86,175 -86,172.5 -86,170 -86,167.5 -86,165 -86,162.5 -86,160 -86,157.5 -86,155 -86,155 -85.1,155 -84.2,155 -83.3,155 -82.4,155 -81.5,155 -80.6,155 -79.7,155 -78.8,155 -77.9,155 -77,157.5 -77,160 -77,162.5 -77,165 -77,167.5 -77,170 -77,172.5 -77,175 -77,177.5 -77,-180 -77))", "dataset_titles": "Beardmore Glacier model in \u0027icepack\u0027", "datasets": [{"dataset_uid": "200339", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beardmore Glacier model in \u0027icepack\u0027", "url": "https://github.com/danshapero/beardmore"}], "date_created": "Mon, 12 Dec 2022 00:00:00 GMT", "description": "Reconstructions of past changes in thickness and extent of the Antarctic ice sheet are important for evaluating past and present sea-level change, and for validating numerical models necessary to make realistic predictions of changes under future climate and ocean conditions. Models estimate that the Ross Sea sector was one of the largest contributors to sea-level rise from Antarctica as the ice sheet adjusted during the past ten thousand years from the glacial period to the Holocene. In this sector, ice flow into the embayment comes through West Antarctic ice streams and through East Antarctic outlet glaciers that flow through the Transantarctic Mountains. Observational data constrain the last glacial maximum and the Holocene retreat, but models are necessary to understand the environmental conditions needed for outlet glaciers to reach observed high stands, to fit the observed patterns of retreat, and to understand how the contribution of ice from West Antarctica and from East Antarctica changed over time. The investigators will use available geological and geophysical data in combination with forward ice-flow models and inverse models to investigate the evolution of the four Transantarctic outlet glaciers where sufficient data exist. The objectives of this new modeling are to constrain the glaciological conditions necessary for these glaciers to thicken during the last glacial, thin during the Holocene, and reach their present-day state. By testing specific hypotheses this work contributes to an interdisciplinary effort to understand Holocene deglaciation of the Ross Sea Embayment. In addition, the modeling will address the resolving power of the available data to answer key questions for each target glacier. Broader impacts include mentoring a graduate student, public outreach, incorporation of research into high-school and university classes, and support of an early-career investigator.", "east": -175.0, "geometry": "POINT(170 -81.5)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS; Transantarctic Mountains; GLACIER THICKNESS/ICE SHEET THICKNESS", "locations": "Transantarctic Mountains", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Smith, Ben; Conway, Howard; Shapero, Daniel", "platforms": null, "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -86.0, "title": "Holocene Deglaciation of the Western Ross Embayment: Constraints from East Antarctic Outlet Glaciers", "uid": "p0010398", "west": 155.0}, {"awards": "1916982 Teyssier, Christian; 1917176 Siddoway, Christine; 1917009 Thomson, Stuart", "bounds_geometry": "POLYGON((-160.16 -67.15,-154.572 -67.15,-148.984 -67.15,-143.39600000000002 -67.15,-137.808 -67.15,-132.22 -67.15,-126.632 -67.15,-121.04400000000001 -67.15,-115.456 -67.15,-109.868 -67.15,-104.28 -67.15,-104.28 -68.165,-104.28 -69.18,-104.28 -70.19500000000001,-104.28 -71.21000000000001,-104.28 -72.225,-104.28 -73.24,-104.28 -74.255,-104.28 -75.27,-104.28 -76.285,-104.28 -77.3,-109.868 -77.3,-115.456 -77.3,-121.044 -77.3,-126.632 -77.3,-132.22 -77.3,-137.808 -77.3,-143.396 -77.3,-148.98399999999998 -77.3,-154.572 -77.3,-160.16 -77.3,-160.16 -76.285,-160.16 -75.27,-160.16 -74.255,-160.16 -73.24,-160.16 -72.225,-160.16 -71.21000000000001,-160.16 -70.19500000000001,-160.16 -69.18,-160.16 -68.165,-160.16 -67.15))", "dataset_titles": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock; U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "datasets": [{"dataset_uid": "200333", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "Apatite fission track thermochronology data for detrital minerals, offshore clasts, and bedrock", "url": ""}, {"dataset_uid": "200332", "doi": "", "keywords": null, "people": null, "repository": "in progress", "science_program": null, "title": "U-Pb detrital zircon geochronological data, obtained by LA-ICP-MS", "url": ""}], "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) whose temperature change as a function of rock depth happens to be significant. This strong geothermal gradient in the bedrock is favorable for determining when the bedrock experienced rapid exhumation or \"uncovering\". Analyzing the chemistry of minerals (zircon and apatite) within the eroded rocks will provide information about the rate and timing of the glacier removal of bedrock from the Antarctic continent. The research addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incision. These results will refine ice sheet history and aid the international societal response to contemporary ice sheet change and its global consequences. The project will contribute to the training of two graduate and two undergraduate students in STEM. The objective is to clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling will be applied to date and characterize episodes of glacial erosional incision. Single-grain double- and triple-dating of zircon and apatite will reveal the detailed crustal thermal evolution of the region enabling the research team to determine the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism. High-T mineral thermochronometers across Marie Byrd Land (MBL) record rapid extension-related cooling at ~100 Ma from temperatures of \u003e800 degrees C to \u0026#8804; 300 degrees C. This signature forms a reference horizon, or paleogeotherm, through which the Cenozoic landscape history using low-T thermochronometers can be explored. MBL\u0027s elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision. Students will be trained to use state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data they acquire will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction that will be tested with inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP\u0027s Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -104.28, "geometry": "POINT(-132.22 -72.225)", "instruments": null, "is_usap_dc": true, "keywords": "Marie Byrd Land; GLACIERS/ICE SHEETS; Zircon; Subglacial Topography; FIELD SURVEYS; TECTONICS; Ice Sheet; Thermochronology; Apatite; ROCKS/MINERALS/CRYSTALS; Erosion; United States Of America; LABORATORY", "locations": "United States Of America; Marie Byrd Land", "north": -67.15, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC", "persons": "Siddoway, Christine; Thomson, Stuart; Teyssier, Christian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "in progress", "repositories": "in progress", "science_programs": null, "south": -77.3, "title": "Collaborative Research: Ice sheet erosional interaction with hot geotherm in West Antarctica", "uid": "p0010386", "west": -160.16}, {"awards": "1543533 Johnson, Jesse; 1543530 van der Veen, Cornelis", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 19 Oct 2022 00:00:00 GMT", "description": "Van der Veen/1543530 The objective of this research is to gain better understanding of the West Antarctic ice flow in the transition region from grounded ice to floating ice shelves and investigate the conditions that can initiate and sustain major retreat of these glaciers. Several major Antarctic outlet glaciers and ice streams will be investigated using a suite of observational techniques and modeling tools. Glaciers include Thwaites Glacier, which has become a focal point in the discussion of West Antarctic retreat, Whillans Ice Stream as an example of the archetype ice stream, and Byrd Glacier, a major outlet glacier draining East Antarctica through the Transantarctic Mountains into the Ross Ice Shelf. This study will investigate whether the ongoing changes in these glaciers will lead to long-term mass loss (the onset of ice sheet collapse), or whether these glaciers will quickly stabilize with a new geometry. To adequately incorporate the dynamic behavior of outlet glaciers and ice streams requires inclusion of the relevant physical processes, and the development of regional models that employ a numerical grid with a horizontal grid spacing sufficiently refined to capture smaller-scale bed topographic features that may control the flow of these glaciers. This award revisits the issue of stability of marine-terminating glaciers whose grounding line is located on a retrograded bed slope. In particular, an attempt will be made to resolve the question whether observed rapid changes are the result of perturbations at the terminus or grounding line, or whether these changes reflect ice-dynamical forcing over the grounded reaches. High-resolution satellite imagery will be used to investigate ice-flow perturbations on smaller spatial scales than has been done before, to evaluate the importance of localized sites of high basal resistance on grounding-line stability. This collaborative project involves a range of modeling strategies including force-budget analysis, flow-band modeling, Full Stokes modeling for local studies, and using the Ice Sheet System Model developed at JPL for regional modeling. Broader Impacts include training two graduate students in computer simulations and ice sheet modeling algorithms. The work will also expand on a web-based interactive flowline model, so that it includes more realistic grounding line dynamics.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Ice Sheet Dynamics; MODELS; Iceberg Calving; GLACIERS/ICE SHEETS; Numerical Glacier Modeling; Basal Sliding; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "van der Veen, Cornelis; Stearns, Leigh; Paden, John", "platforms": "OTHER \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Stability and Dynamics of Antarctic Marine Outlet Glaciers", "uid": "p0010387", "west": -180.0}, {"awards": "2135184 Arrigo, Kevin; 2135186 Baumberger, Tamara; 2135185 Resing, Joseph", "bounds_geometry": "POLYGON((155 -61,156.5 -61,158 -61,159.5 -61,161 -61,162.5 -61,164 -61,165.5 -61,167 -61,168.5 -61,170 -61,170 -61.2,170 -61.4,170 -61.6,170 -61.8,170 -62,170 -62.2,170 -62.4,170 -62.6,170 -62.8,170 -63,168.5 -63,167 -63,165.5 -63,164 -63,162.5 -63,161 -63,159.5 -63,158 -63,156.5 -63,155 -63,155 -62.8,155 -62.6,155 -62.4,155 -62.2,155 -62,155 -61.8,155 -61.6,155 -61.4,155 -61.2,155 -61))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 30 Sep 2022 00:00:00 GMT", "description": "Phytoplankton blooms throughout the world\u2019s oceans support critical marine ecosystems and help remove carbon dioxide (CO2) from the atmosphere. Traditionally, it has been assumed that phytoplankton blooms in the Southern Ocean are stimulated by iron from either nearby land or sea-ice. However, recent work demonstrates that hydrothermal vents may be an additional iron source for phytoplankton blooms. This enhancement of phytoplankton productivity by different iron sources supports rich marine ecosystems and leads to the sequestration of carbon in the deep ocean. Our proposed work will uncover the importance of hydrothermal activity in stimulating a large phytoplankton bloom along the southern boundary of the Antarctic Circumpolar Current just north of the Ross Sea. It will also lead towards a better understanding of the overall impact of hydrothermal activity on the carbon cycle in the Southern Ocean, which appears to trigger local hotspots of biological activity which are a potential sink for atmospheric CO2. This project will encourage the participation of underrepresented groups in ocean sciences, as well as providing educational opportunities for high school and undergraduate students, through three different programs. Stanford University\u2019s Summer Undergraduate Research in Geoscience and Engineering (SURGE) program provides undergraduates from different US universities and diverse cultural backgrounds the opportunity to spend a summer doing a research project at Stanford. The Stanford Earth Summer Undergraduate Research Program (SESUR) is for Stanford undergraduates who want to learn more about environmental science by performing original research. Finally, Stanford\u2019s School of Earth, Energy, and Environmental Sciences High School Internship Program enables young scientists to serve as mentors, prepares high school students for college, and serves to strengthen the partnership between Stanford and local schools. Students present their results at the Fall AGU meeting as part of the AGU Bright STaRS program. This project will form the basis of at least two PhD dissertations. The Stanford student will participate in Stanford\u2019s Woods Institute Rising Environmental Leaders Program (RELP), a year-round program that helps graduate students hone their leadership and communication skills to maximize the impact of their research. The graduate student will also participate in Stanford\u2019s Grant Writing Academy where they will receive training in developing and articulating research strategies to tackle important scientific questions. This interdisciplinary program combines satellite and ship-based measurements of a large poorly understood phytoplankton bloom (the AAR bloom) in the northwestern Ross Sea sector of the Southern Ocean with a detailed modeling study of the physical processes linking deep dissolved iron (DFe) reservoirs to the surface phytoplankton bloom. Prior to the cruise, we will implement a numerical model (CROCO) for our study region so that we can better understand the circulation, plumes, turbulence, fronts, and eddy field around the AAR bloom and how they transport and mix hydrothermally produced DFe vertically. Post cruise, observations of the vertical distribution of 3He (combined with DMn and DFe), will be used as initial conditions for a passive tracer in the model, and tracer dispersal will be assessed to better quantify the role of the various turbulent processes in upwelling DFe-rich waters to the upper ocean. The satellite-based component of the program will characterize the broader sampling region before, during, and after our cruise. During the cruise, our automated software system at Stanford University will download and process images of sea ice concentration, Chl-a concentration, sea surface temperature (SST), and sea surface height (SSH) and send them electronically to the ship. Operationally, our goal is to use all available satellite data and preliminary model results to target shipboard sampling both geographically and temporally to optimize sampling of the AAR bloom. We will use available BGC-Argo float data to help characterize the AAR bloom. In collaboration with SOCCOM, we will deploy additional BGC-Argo floats (if available) during our transit through the study area to allow us to better characterize the bloom. The centerpiece of our program will be a 40-day process study cruise in austral summer. The cruise will consist of an initial \u201cradiator\u201d pattern of hydrographic surveys/sections along the AAR followed by CTDs to selected submarine volcanoes. When/if eddies are identified, they will be sampled either during or after the initial surveys. The radiator pattern, or parts thereof, will be repeated 2-3 times. Hydrographic survey stations will include vertical profiles of temperature, salinity, oxygen, oxidation-reduction potential, light scatter, and PAR (400-700 nm). Samples will be collected for trace metals, ligands, 3He, and total suspended matter. Where intense hydrothermal activity is identified, samples for pH and total CO2 will also be collected to characterize the hydrothermal system. Water samples will be collected for characterization of macronutrients, and phytoplankton physiology, abundance, species composition, and size. During transits, we will continuously measure atmospheric conditions, current speed and direction, and surface SST, salinity, pCO2, and fluorescence from the ship\u2019s systems to provide detailed maps of these parameters. The ship will be used as a platform for conducting phytoplankton DFe bioassay experiments at key stations throughout the study region both inside and outside the bloom. We will also perform detailed comparisons of algal taxonomic composition, physiology, and size structure inside and outside the bloom to determine the potential importance of each community on local biogeochemistry. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 170.0, "geometry": "POINT(162.5 -62)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; Antarctica; TRACE ELEMENTS; Hydrothermal Vent; Phytoplankton; Primary Production", "locations": "Antarctica", "north": -61.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Arrigo, Kevin; Thomas, Leif N; Baumberger, Tamara; Resing, Joseph", "platforms": null, "repositories": null, "science_programs": null, "south": -63.0, "title": "Collaborative Research: Understanding the Massive Phytoplankton Blooms over the Australian-Antarctic Ridge", "uid": "p0010381", "west": 155.0}, {"awards": "1644118 Dunbar, Robert", "bounds_geometry": "POLYGON((-108 -73,-107.3 -73,-106.6 -73,-105.9 -73,-105.2 -73,-104.5 -73,-103.8 -73,-103.1 -73,-102.4 -73,-101.7 -73,-101 -73,-101 -73.3,-101 -73.6,-101 -73.9,-101 -74.2,-101 -74.5,-101 -74.8,-101 -75.1,-101 -75.4,-101 -75.7,-101 -76,-101.7 -76,-102.4 -76,-103.1 -76,-103.8 -76,-104.5 -76,-105.2 -76,-105.9 -76,-106.6 -76,-107.3 -76,-108 -76,-108 -75.7,-108 -75.4,-108 -75.1,-108 -74.8,-108 -74.5,-108 -74.2,-108 -73.9,-108 -73.6,-108 -73.3,-108 -73))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}], "date_created": "Wed, 21 Sep 2022 00:00:00 GMT", "description": "Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt. This research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.", "east": -101.0, "geometry": "POINT(-104.5 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; WATER TEMPERATURE; SALINITY; Oxygen Isotope; Meltwater Inventory; Pine Island Bay; OCEAN CHEMISTRY", "locations": "Pine Island Bay", "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Dunbar, Robert", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater", "uid": "p0010380", "west": -108.0}, {"awards": "1924730 Lazzara, Matthew", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "AMRC Automatic Weather Station project data", "datasets": [{"dataset_uid": "200316", "doi": "10.48567/1hn2-nw60", "keywords": null, "people": null, "repository": "AMRDC", "science_program": null, "title": "AMRC Automatic Weather Station project data", "url": "https://doi.org/10.48567/1hn2-nw60"}], "date_created": "Tue, 23 Aug 2022 00:00:00 GMT", "description": "The Antarctic Automatic Weather Station network is the most extensive surficial meteorological network in the Antarctic, approaching its 30th year at several of its data stations. Its prime focus is also as a long term observational record, to measure the near surface weather and climatology of the Antarctic atmosphere. Antarctic Automatic Weather Stations measure air-temperature, pressure, wind speed and direction at a nominal surface height of ~ 2-3m. Other parameters such as relative humidity and snow accumulation may also be taken. The surface observations from the Antarctic Automatic Weather Station network are also used operationally, for forecast purposes, and in the planning of field work. Surface observations made from the network have also been used to check the validity of satellite and remote sensing observations. The proposed effort informs our understanding of the Antarctic environment and its weather and climate trends over the past few decades. The research has implications for potential future operations and logistics for the US Antarctic Program during the winter season. As a part of this endeavor, all project participants will engage in a coordinated outreach effort to bring the famous Antarctic \"cold\" to public seminars, K-12, undergraduate, and graduate classrooms, and senior citizen centers. This project proposes to use the surface conditions observed by the Antarctic Automatic Weather Station (AWS) network to determine how large-scale modes of climate variability impact Antarctic weather and climate, how the surface observations from the AWS network are linked to surface layer and boundary layer processes. Consideration will also be given to low temperature physical environments such as may be encountered during Antarctic winter, and the best ways to characterize these, and other ?cold pool? phenomena. Observational data from the AWS are collected via Iridium network, or DCS Argos aboard either NOAA or MetOp polar orbiting satellites and thus made available in near real time to operational and synoptic weather forecasters over the GTS (WMO Global Telecommunication System). Being able to support improvements in numerical weather prediction and climate modeling will have lasting impacts on Antarctic science and logistical support. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "SURFACE TEMPERATURE; ATMOSPHERIC PRESSURE; ATMOSPHERIC TEMPERATURE; Antarctica; SURFACE WINDS; HUMIDITY; AIR TEMPERATURE; ATMOSPHERIC WINDS; ATMOSPHERIC PRESSURE MEASUREMENTS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Lazzara, Matthew; Welhouse, Lee J", "platforms": null, "repo": "AMRDC", "repositories": "AMRDC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Antarctic Automatic Weather Station Program 2019-2022", "uid": "p0010370", "west": -180.0}, {"awards": null, "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 23 Aug 2022 00:00:00 GMT", "description": "The Antarctic Automatic Weather Station network is the most extensive surficial meteorological network in the Antarctic, approaching its 30th year at several of its data stations. Its prime focus is also as a long term observational record, to measure the near surface weather and climatology of the Antarctic atmosphere. Antarctic Automatic Weather Stations measure air-temperature, pressure, wind speed and direction at a nominal surface height of ~ 2-3m. Other parameters such as relative humidity and snow accumulation may also be taken. The surface observations from the Antarctic Automatic Weather Station network are also used operationally, for forecast purposes, and in the planning of field work. Surface observations made from the network have also been used to check the validity of satellite and remote sensing observations. The proposed effort informs our understanding of the Antarctic environment and its weather and climate trends over the past few decades. The research has implications for potential future operations and logistics for the US Antarctic Program during the winter season. As a part of this endeavor, all project participants will engage in a coordinated outreach effort to bring the famous Antarctic \"cold\" to public seminars, K-12, undergraduate, and graduate classrooms, and senior citizen centers.\u003cbr/\u003e\u003cbr/\u003eThis project proposes to use the surface conditions observed by the Antarctic Automatic Weather Station (AWS) network to determine how large-scale modes of climate variability impact Antarctic weather and climate, how the surface observations from the AWS network are linked to surface layer and boundary layer processes. Consideration will also be given to low temperature physical environments such as may be encountered during Antarctic winter, and the best ways to characterize these, and other ?cold pool? phenomena. Observational data from the AWS are collected via Iridium network, or DCS Argos aboard either NOAA or MetOp polar orbiting satellites and thus made available in near real time to operational and synoptic weather forecasters over the GTS (WMO Global Telecommunication System). Being able to support improvements in numerical weather prediction and climate modeling will have lasting impacts on Antarctic science and logistical support.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "HUMIDITY; SURFACE WINDS; SURFACE PRESSURE; INCOMING SOLAR RADIATION; SURFACE AIR TEMPERATURE", "locations": null, "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": null, "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Antarctic Automatic Weather Station Program 2019-2022", "uid": "p0010371", "west": null}, {"awards": "2220969 Manucharyan, Georgy; 2220968 Stewart, Andrew", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "The world ocean is continuously in motion, and a large fraction of this motion takes the form of \"eddies\", nearly-horizontal swirls of water spanning tens to hundreds of kilometers. These eddies affect the ocean by mediating large-scale currents, redistributing heat, and supplying nutrients to oceanic ecosystems. Consequently, the ocean science community has historically invested substantial effort in characterizing the properties and impact of these eddies. In polar regions, the sea ice cover inhibits observations of eddies, and the relatively small horizontal size of the eddies hampers computer simulations of their behavior. Nonetheless, previous studies have identified an active population of eddies beneath the Arctic sea ice and shown that these eddies play a crucial role in maintaining the large-scale circulation in the Arctic seas. However, there has been no systematic attempt to study such eddies under Antarctic sea ice, leaving a significant gap in our understanding of eddies and their contribution to the large-scale ocean circulation around Antarctica. The proposed research combines multiple approaches to improve our understanding of the eddy dynamics. Statistical characterizations of the sub-sea ice eddy field will be derived using hydrographic observations under Antarctic sea ice from Argo floats and instrumented seals. High-resolution global ocean and sea ice models will be used to track the simulated eddies back to their formation sites to identify the eddy formation mechanisms. Theoretical calculations will be conducted to test the hypothesis that the eddies primarily originate from hydrodynamic instabilities associated with subsurface density gradients. These theoretical, modeling, and data analysis approaches will be combined to estimate the eddies\u0027 contribution to lateral tracer transports and their impact on mean circulations of the near-Antarctic ocean. The proposed work will facilitate future scientific endeavors by providing publicly-available databases of detected eddy properties. This project will support the research of several junior scientists: an undergraduate student, two graduate students, and an early-career faculty member. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; OCEAN CURRENTS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Stewart, Andrew; Bianchi, Daniele", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Characteristics and Origins of Eddies beneath Antarctic Sea Ice", "uid": "p0010366", "west": -180.0}, {"awards": "2205008 Walker, Catherine", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "Most of the mass loss from the Antarctic Ice Sheet, a major contributor to sea level rise, occurs at its margins, where ice meets the ocean. Glaciers and ice streams flow towards the coast and can go afloat over the water, forming ice shelves. Ice shelves make up almost half of the entire Antarctic coastline, and hold back the flow of inland ice in Antarctica continent; thus they are integral to the overall stability of the Antarctic Ice Sheet. Ice shelves lose mass by two main processes: iceberg calving and basal melting. Temporal and spatial fluctuations in both are driven by various processes; a major driver of ice shelf melt is the heat provided by the neighboring Southern Ocean. Ocean heat, in turn, is driven by various aspects of the ice shelf environment. One of the most significant contributors to changes in the ocean\u2019s heat content is the presence of sea ice. This research will focus on the effects of coastal polynyas (areas of open water amidst sea ice), how they modulate the local ocean environment, and how that environment drives ice shelf basal melting. To date, the relationship between polynyas and ice shelf melt has not been characterized on an Antarctic-wide scale. Understanding the feedbacks between polynya size and duration, ocean stratification, and ice shelf melt, and the strength of those feedbacks, will improve the ability to characterize influences on the long-term stability of ice shelves, and in turn, the Antarctic Ice Sheet as a whole. A critical aspect of this study is that it will provide a framework for understanding ice shelf-ocean interaction across a diverse range of geographic settings. This, together with improvements of various models, will help interpret the impacts of future climate change on these systems, as their responses are likely quite variable and, overall, different from the large-scale response of the ice sheet. This project will also provide a broader context to better design future observational studies of specific coastal polynya and ice shelf processes. This study focuses on four main hypotheses: 1) Variations of coastal polynya extent are correlated with those of the ice shelf melt rates, and this correlation varies around Antarctica; 2) Polynya extent modulates a feedback between ice shelf melt and accretion regimes through stratification of local waters; 3) Polynya extent together with seafloor bathymetry regulate the volume of warm offshore waters that reach ice margins; and 4) The strength of the feedback between polynya and glacier ice varies with geographic setting and influences the long-term stability of the glacial system. Observational data, including ice-penetrating radar, radar and laser altimetry, and in situ hydrographic data, and derived data sets from the Southern Ocean State Estimate (SOSE) project and BedMachine Antarctica, will be used in conjunction with ocean (MIT global circulation model, MITgcm) and ice sheet (Ice sheet and Sea-level System Model, ISSM) models to reveal underlying dynamics. The joint analysis of the observational data enables an investigation of polynya, ocean, and ice shelf signals and their interplay over time across a range of settings. The results of this data analysis also provide inputs and validation data for the modeling tasks, which will allow for characterization of the feedbacks in our observations. The coupled modeling will enable us to examine the interaction between polynya circulation and ice shelves in different dynamical regimes and to understand ice and ocean feedback over time. Diagnosing and interpreting the pan-Antarctic spatial variability of the polynya-ice shelf interaction are the main objectives of this research and separates this study from other projects targeted at the interactive processes in specific regions. As such, this research focuses on seven preliminary target sites around the Antarctic coast to establish a framework for interpreting coupled ice shelf-ocean variability across a diverse range of geographic settings. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; ICE EXTENT; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Walker, Catherine; Zhang, Weifeng; Seroussi, Helene", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Investigating the Role of Coastal Polynya Variability in Modulating Antarctic Marine-Terminating Glacier Drawdown", "uid": "p0010364", "west": -180.0}, {"awards": "2147554 Chen, Nancy; 1640481 Rotella, Jay; 2147553 Rotella, Jay", "bounds_geometry": "POLYGON((162 -74.95,162.8 -74.95,163.6 -74.95,164.4 -74.95,165.2 -74.95,166 -74.95,166.8 -74.95,167.6 -74.95,168.4 -74.95,169.2 -74.95,170 -74.95,170 -75.295,170 -75.64,170 -75.985,170 -76.33,170 -76.67500000000001,170 -77.02000000000001,170 -77.36500000000001,170 -77.71000000000001,170 -78.055,170 -78.4,169.2 -78.4,168.4 -78.4,167.6 -78.4,166.8 -78.4,166 -78.4,165.2 -78.4,164.4 -78.4,163.6 -78.4,162.8 -78.4,162 -78.4,162 -78.055,162 -77.71000000000001,162 -77.36500000000001,162 -77.02000000000001,162 -76.67500000000001,162 -76.33,162 -75.985,162 -75.64,162 -75.295,162 -74.95))", "dataset_titles": "Demographic data for Weddell Seal colonies in Erebus Bay through the 2023 Antarctic field season", "datasets": [{"dataset_uid": "601837", "doi": "10.15784/601837", "keywords": "AMD; Amd/Us; Antarctica; Cryosphere; McMurdo Sound; Population Dynamics; USA/NSF; USAP-DC; Weddell Seal", "people": "Rotella, Jay", "repository": "USAP-DC", "science_program": null, "title": "Demographic data for Weddell Seal colonies in Erebus Bay through the 2023 Antarctic field season", "url": "https://www.usap-dc.org/view/dataset/601837"}], "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "Part 1: Non-technical description This is a continuation of a long-term population dynamics study (1978-present) using an intensive mark-recapture tagging of Weddell seals in Erebus Bay, Antarctica. Past work has become a global model for population studies of large animals. Results have documented strong annual variation in reproduction, abundance, and population composition. This program will add components to evaluate the demographic role of immigrant mothers, evaluate possible drivers of annual variation in overall population dynamics, assess genetic differences between immigrant and locally born mothers, and document patterns of gene flow among seal colonies in the Ross Sea region. These new aspects will focus on understanding of population structure, function, and genetics and provide key information for predicting how the seal population will respond to environmental change. The addition of genetic approaches will advance available data for multiple groups in multiple countries working on Weddell Seals. This work includes an early career scientists training program for faculty university graduate and undergraduate students and well as a defined program for data sharing. The research is paired with active education and outreach programs, social media, websites, educational resources, videos and high-profile public lecture activities. The informal science education program will expand on the project\u2019s successful efforts at producing and delivering short-form videos that have been viewed over 1.6 million times to date. In addition, the education program will add new topics such as learning about seals using genomics and how seals respond to a changing world to a multimedia-enhanced electronic book about the project\u2019s long-term research on Weddell seals, which will be freely available to the public early in the project. Part 2: Technical description Reliable predictions are needed for how populations of wild species, especially those at high latitudes, will respond to future environmental conditions. This study will use a strategic extension of the long-term demographic research program that has been conducted annually on the Erebus Bay population of Weddell seals since 1978 to help meet that need. Recent analyses of the study population indicate strong annual variation in reproduction, abundance, and population composition. The number of new immigrant mothers that join the population each year has recently grown such that most new mothers are now immigrants. Despite the growing number of immigrants, the demographic importance and geographic origins of immigrants are unknown. The research will (1) add new information on drivers of annual variation in immigrant numbers, (2) compare and combine information on the vital rates and demographic role of immigrant females and their offspring with that of locally born females, and (3) add genomic analyses that will quantify levels of genetic variation in and gene flow among the study population and other populations in the Ross Sea. The project will continue the long-term monitoring of the population at Erebus Bay and characterize population dynamics and the role of immigration using a combination of mark-recapture analyses, stochastic population modeling, and genomic analyses. The study will continue to provide detailed data on individual seals to other science teams, educate and mentor individuals in the next generation of ecologists, introduce two early-career, female scientists to Antarctic research, and add genomics approaches to the long-term population study of Erebus Bay Weddell seals. The research will be complemented with a robust program of training and an informal science education program. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 170.0, "geometry": "POINT(166 -76.67500000000001)", "instruments": null, "is_usap_dc": true, "keywords": "SPECIES/POPULATION INTERACTIONS; McMurdo Sound", "locations": "McMurdo Sound", "north": -74.95, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rotella, Jay; Chen, Nancy", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.4, "title": "Collaborative Research: The Drivers and Role of Immigration in the Dynamics of the Largest Population of Weddell Seals in Antarctica under Changing Conditions", "uid": "p0010361", "west": 162.0}, {"awards": "1744649 Christianson, Knut", "bounds_geometry": "POLYGON((-120 -85.5,-117.5 -85.5,-115 -85.5,-112.5 -85.5,-110 -85.5,-107.5 -85.5,-105 -85.5,-102.5 -85.5,-100 -85.5,-97.5 -85.5,-95 -85.5,-95 -85.62,-95 -85.74,-95 -85.86,-95 -85.98,-95 -86.1,-95 -86.22,-95 -86.34,-95 -86.46000000000001,-95 -86.58,-95 -86.7,-97.5 -86.7,-100 -86.7,-102.5 -86.7,-105 -86.7,-107.5 -86.7,-110 -86.7,-112.5 -86.7,-115 -86.7,-117.5 -86.7,-120 -86.7,-120 -86.58,-120 -86.46000000000001,-120 -86.34,-120 -86.22,-120 -86.1,-120 -85.98,-120 -85.86,-120 -85.74,-120 -85.62,-120 -85.5))", "dataset_titles": "Hercules Dome ApRES Data; Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data; Hercules Dome Ice-Penetrating Radar Swath Topographies; Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets; ITASE Impulse Radar Hercules Dome to South Pole", "datasets": [{"dataset_uid": "601711", "doi": "10.15784/601711", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Paden, John; Holschuh, Nicholas; Hoffman, Andrew; Christianson, Knut", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome Ice-Penetrating Radar Swath Topographies", "url": "https://www.usap-dc.org/view/dataset/601711"}, {"dataset_uid": "601606", "doi": "10.15784/601606", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Christianson, Knut", "repository": "USAP-DC", "science_program": null, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "url": "https://www.usap-dc.org/view/dataset/601606"}, {"dataset_uid": "601712", "doi": "10.15784/601712", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Welch, Brian; Jacobel, Robert; Hoffman, Andrew; Christianson, Knut", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "ITASE Impulse Radar Hercules Dome to South Pole", "url": "https://www.usap-dc.org/view/dataset/601712"}, {"dataset_uid": "601739", "doi": "10.15784/601739", "keywords": "Antarctica; Apres; Crystal Orientation Fabric; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hercules Dome; Ice Dynamic; Ice Penetrating Radar; Radar Interferometry; Radar Polarimetry", "people": "Horlings, Annika; Hoffman, Andrew; Hills, Benjamin; Fudge, Tyler J; Erwin, Emma; Steig, Eric J.; Christianson, Knut; Holschuh, Nicholas", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome ApRES Data", "url": "https://www.usap-dc.org/view/dataset/601739"}, {"dataset_uid": "601710", "doi": "10.15784/601710", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Hercules Dome; Ice Penetrating Radar; Snow/ice; Snow/Ice", "people": "Hills, Benjamin; Hoffman, Andrew; Christianson, Knut; O\u0027Connor, Gemma; Horlings, Annika; Holschuh, Nicholas; Christian, John", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Hercules Dome High-Frequency Impulse Ice-Penetrating Radar Data", "url": "https://www.usap-dc.org/view/dataset/601710"}], "date_created": "Tue, 02 Aug 2022 00:00:00 GMT", "description": "The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington\u0027s annual Polar Science Weekend in Seattle, and art-science collaboration. This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a \"Raymond Bump\") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -95.0, "geometry": "POINT(-107.5 -86.1)", "instruments": null, "is_usap_dc": true, "keywords": "West Antarctica; ICE DEPTH/THICKNESS; East Antarctica", "locations": "West Antarctica; East Antarctica", "north": -85.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Hoffman, Andrew; Holschuh, Nicholas", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -86.7, "title": "Ice Dynamics at the Intersection of the West and East Antarctic Ice Sheets", "uid": "p0010359", "west": -120.0}, {"awards": "2012247 Groff, Dulcinea; 2012444 Cimino, Megan; 2012365 Johnston, David", "bounds_geometry": "POLYGON((-65 -64.5,-64.8 -64.5,-64.6 -64.5,-64.4 -64.5,-64.2 -64.5,-64 -64.5,-63.8 -64.5,-63.6 -64.5,-63.4 -64.5,-63.2 -64.5,-63 -64.5,-63 -64.55,-63 -64.6,-63 -64.65,-63 -64.7,-63 -64.75,-63 -64.8,-63 -64.85,-63 -64.9,-63 -64.95,-63 -65,-63.2 -65,-63.4 -65,-63.6 -65,-63.8 -65,-64 -65,-64.2 -65,-64.4 -65,-64.6 -65,-64.8 -65,-65 -65,-65 -64.95,-65 -64.9,-65 -64.85,-65 -64.8,-65 -64.75,-65 -64.7,-65 -64.65,-65 -64.6,-65 -64.55,-65 -64.5))", "dataset_titles": "Aerial data from drone surveys of coastal habitats on the West Antarctic Peninsula during austral summer (January\u2013March 2020 and February\u2013March 2019); Data from: Terrestrial spatial distribution and summer abundance of Antarctic fur seals (Arctocephalus gazella) near Palmer Station, Antarctica, from drone surveys", "datasets": [{"dataset_uid": "200471", "doi": "10.7924/r4sf2xs2w", "keywords": null, "people": null, "repository": "Duke Research Repository", "science_program": null, "title": "Aerial data from drone surveys of coastal habitats on the West Antarctic Peninsula during austral summer (January\u2013March 2020 and February\u2013March 2019)", "url": "https://research.repository.duke.edu/concern/datasets/r207tq370?locale=en"}, {"dataset_uid": "200472", "doi": "10.5061/dryad.qv9s4mwp0", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Data from: Terrestrial spatial distribution and summer abundance of Antarctic fur seals (Arctocephalus gazella) near Palmer Station, Antarctica, from drone surveys", "url": "https://datadryad.org/dataset/doi:10.5061/dryad.qv9s4mwp0"}], "date_created": "Sun, 24 Jul 2022 00:00:00 GMT", "description": "This award is funded in whole or part under the American Rescue Plan Act of 2021 (Public Law 117-2). Part I: Non-technical description: Ad\u00e9lie penguin colonies are declining and disappearing from the western Antarctic Peninsula. However, not all colonies in a certain area decline or disappear at the same rate. This research project will evaluate the influence of terrestrial surface properties on Ad\u00e9lie penguin colonies, leveraging five decades of research on seabirds near Palmer Station where an Ad\u00e9lie colony on Litchfield Island became extinct in 2007 while other colonies nearby are still present. The researchers will combine information obtained from remote sensing, UAS (Unoccupied Aircraft System, or drones) high-resolution maps, reconstruction of past moss banks and modeling with machine learning tools to define suitable penguin and peatbank moss habitats and explore the influence of microclimate on their distributions. In particular, the researchers are asking if guano from penguin colonies could act as fertilizers of moss banks in the presence of localized wind patters that can carry airborne nitrogen to the mosses. Modeling will relate penguin and peatbank moss spatial patterns to environmental variables and provide a greater understanding of how continued environmental change could impact these communities. The project allows for documentation of terrestrial Antarctic ecosystems in support of seabirds and provisioning of such information to the broader science community that seeks to study penguins, educating graduate and undergraduate students and a post-doctoral researcher. The research team includes two young women as Principal Investigators, one of them from an under-represented ethnic minority, first time Antarctic Principal Investigator, from an EPSCoR state (Wyoming), broadening participation in Antarctic research. Researchers will serve as student mentors through the Duke Bass Connections program entitled Biogeographic Assessment of Antarctic Coastal Habitats. This program supports an interdisciplinary team of graduate and undergraduate students collaborating with project faculty and experts on cutting-edge research bridging the classroom and the real world. Part II: Technical description: This research aims to understand the changes at the microclimate scale (meters) by analyzing present and past Ad\u00e9lie penguin colonies and moss peatbanks in islands around Palmer Station in the western Antarctic Peninsula \u2013 interlinked systems that are typically considered in isolation. By integrating in situ and remote data, this project will synthesize the drivers of biogeomorphology on small islands of the Antarctic Peninsula, a region of rapid change where plants and animals often co-occur and animal presence often determines the habitation of plants. A multi-disciplinary approach combine field measurements, remote sensing, UAS (Unoccupied Aircraft Systems) maps, paleoecology and modeling with machine learning to define suitable habitats and the influence of microclimates on penguin and peatbank distributions. The link between the two aspects of this study, peatbanks and penguins, is the potential source of nutrients for peat mosses from penguin guano. Peatbank and penguin distribution will be modeled and all models will be validated using in situ information from moss samples that will identify mechanistic processes. This project leverages 5 decades of seabird research in the area and high-definition remote sensing provided by the Polar Geospatial center to study the microclimate of Litchfield Island where an Ad\u00e9lie colony became extinct in 2007 when other colonies nearby are still present. The research team includes two early career women as Principal Investigators, one of them from an under-represented ethnic minority, first time Antarctic Principal Investigator, from an EPSCoR state (Wyoming). Researchers will serve as mentors for students through the Duke Bass Connections program entitled Biogeogrpahic Assessment of Antarctic Coastal Habitats which bridges the classroom and the real world. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -63.0, "geometry": "POINT(-64 -64.75)", "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; Antarctic Peninsula; COASTAL; STABLE ISOTOPES; TOPOGRAPHIC EFFECTS; PALEOCLIMATE RECONSTRUCTIONS; MACROFOSSILS; PLANTS; PENGUINS; ISOTOPES; VISIBLE IMAGERY; RADIOCARBON; Anvers Island", "locations": "Antarctic Peninsula; Anvers Island; Palmer Station", "north": -64.5, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Groff, Dulcinea; Cimino, Megan; Johnston, David", "platforms": null, "repo": "Duke Research Repository", "repositories": "Dryad; Duke Research Repository", "science_programs": null, "south": -65.0, "title": "Collaborative Research: Common Environmental Drivers Determine the Occupation Chronology of Ad\u00e9lie Penguins and Moss Peatbanks on the Western Antarctic Peninsula", "uid": "p0010354", "west": -65.0}, {"awards": "2138277 Gallagher, Katherine", "bounds_geometry": "POLYGON((-78 -62,-76.2 -62,-74.4 -62,-72.6 -62,-70.8 -62,-69 -62,-67.2 -62,-65.4 -62,-63.6 -62,-61.8 -62,-60 -62,-60 -63,-60 -64,-60 -65,-60 -66,-60 -67,-60 -68,-60 -69,-60 -70,-60 -71,-60 -72,-61.8 -72,-63.6 -72,-65.4 -72,-67.2 -72,-69 -72,-70.8 -72,-72.6 -72,-74.4 -72,-76.2 -72,-78 -72,-78 -71,-78 -70,-78 -69,-78 -68,-78 -67,-78 -66,-78 -65,-78 -64,-78 -63,-78 -62))", "dataset_titles": "Current velocity and direction data from Regional Ocean Modeling System simulations (2006-2007 \u0026 2010-2011); Current velocity and direction data from Regional Ocean Modeling System simulations (2008-2009 \u0026 2018-2019); Passive particle trajectories from Regional Ocean Modeling System simulations 2008-2009 \u0026 2018-2019; Simulated krill trajectory data from Regional Ocean Modeling System simulations 2006-2007 \u0026 2010-2011; Simulated krill trajectory data from Regional Ocean Modeling System simulations 2008-2009 \u0026 2018-2019; Simulated marine debris trajectories along the West Antarctic Peninsula in 2008-2009 and 2018-2019", "datasets": [{"dataset_uid": "601734", "doi": "10.15784/601734", "keywords": "Antarctica; Modeling; Regional Ocean Modeling System; West Antarctic Shelf", "people": "Gallagher, Katherine", "repository": "USAP-DC", "science_program": null, "title": "Simulated marine debris trajectories along the West Antarctic Peninsula in 2008-2009 and 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601734"}, {"dataset_uid": "601655", "doi": "10.15784/601655", "keywords": "Antarctica; Antarctic Krill; Model Data; Physical Oceanography; Regional Ocean Modeling System; ROMS; West Antarctic Shelf", "people": "Gallagher, Katherine", "repository": "USAP-DC", "science_program": null, "title": "Simulated krill trajectory data from Regional Ocean Modeling System simulations 2008-2009 \u0026 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601655"}, {"dataset_uid": "601682", "doi": "10.15784/601682", "keywords": "Antarctica; Physical Oceanography; Regional Ocean Modeling System; ROMS", "people": "Gallagher, Katherine", "repository": "USAP-DC", "science_program": null, "title": "Passive particle trajectories from Regional Ocean Modeling System simulations 2008-2009 \u0026 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601682"}, {"dataset_uid": "601656", "doi": "10.15784/601656", "keywords": "Antarctica; Model Data; Ocean Currents; Physical Oceanography; Regional Ocean Modeling System; ROMS; West Antarctic Shelf", "people": "Gallagher, Katherine", "repository": "USAP-DC", "science_program": null, "title": "Current velocity and direction data from Regional Ocean Modeling System simulations (2008-2009 \u0026 2018-2019)", "url": "https://www.usap-dc.org/view/dataset/601656"}, {"dataset_uid": "601779", "doi": "10.15784/601779", "keywords": "Antarctica; Cryosphere; Model Data; Ocean Currents; Physical Oceanography; Regional Ocean Modeling System; ROMS; West Antarctic Shelf", "people": "Gallagher, Katherine", "repository": "USAP-DC", "science_program": null, "title": "Current velocity and direction data from Regional Ocean Modeling System simulations (2006-2007 \u0026 2010-2011)", "url": "https://www.usap-dc.org/view/dataset/601779"}, {"dataset_uid": "601780", "doi": "10.15784/601780", "keywords": "Antarctica; Antarctic Krill; Cryosphere; Model Data; Physical Oceanography; Regional Ocean Modeling System; ROMS; West Antarctic Shelf", "people": "Gallagher, Katherine", "repository": "USAP-DC", "science_program": null, "title": "Simulated krill trajectory data from Regional Ocean Modeling System simulations 2006-2007 \u0026 2010-2011", "url": "https://www.usap-dc.org/view/dataset/601780"}], "date_created": "Tue, 19 Jul 2022 00:00:00 GMT", "description": "Pygoscelis penguins are central place foragers during the summer while they raise their chicks. They leave and return to the same colony location after hunting for food and rely on the availability of Antarctic krill, their primary food source. This research focuses on whether penguin diets and colony location reflect the retention of prey around and near colonies on the West Antarctic Peninsula. Eddies and other oceanographic processes may facilitate prey retention at certain locations, driving penguin colony establishment and success. This project hypothesizes that Pygoscelis penguin diets will be composed of more Antarctic krill (Euphausia superba) when local prey retention is high, possibly due to subsurface eddies. This hypothesis will be tested using satellite-based estimates of Pygoscelis penguin diet composition using multispectral sensor data to estimate nitrogen values and infer trophic level. Prey retention will be calculated along the peninsula using the Regional Ocean Modeling System (ROMS). Simulated particles and diel vertical migration will be used to mimic krill behavior. These particles can be experimentally seeded across multiple depths in multiple years to assess residence times in the system. Using penguin colony data from the Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD), the PI will correlate diet and retention metrics to local penguin colony growth and persistence and build a predictive model of where colonies may form in the future. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -60.0, "geometry": "POINT(-69 -67)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Peninsula; PENGUINS; SPECIES/POPULATION INTERACTIONS; OCEAN CURRENTS", "locations": "Antarctic Peninsula", "north": -62.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Gallagher, Katherine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -72.0, "title": "OPP-PRF Pygoscelis Penguin Response to Potential Prey Retention along the West Antarctic Peninsula", "uid": "p0010349", "west": -78.0}, {"awards": "1643431 Bitz, Cecilia", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Analysis code, processed observational data and climate model output required to produce figures for Roach et al (2022); Model output: CICE experiments with varying floe and wave physics described in Roach et al. (2019); Model output from experiments (FSD-M21) described in Cooper et al 2022.; Model output from experiments (IC4M1) described in Cooper et al 2022.; Model output from experiments (IC4M2) described in Cooper et al 2022.; Model output from experiments (IC4M3rad) described in Cooper et al 2022.; Model output from experiments (IC4M4) described in Cooper et al 2022.; Model output from experiments (IC4M5) described in Cooper et al 2022.; Model output from experiments (IC4M7) described in Cooper et al 2022.; Model output: NEMO-CICE with an emergent sea ice floe size distribution described in Roach et al (2018)", "datasets": [{"dataset_uid": "200301", "doi": "10.5281/zenodo.6213441", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M1) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6213441"}, {"dataset_uid": "200304", "doi": "10. 5281/zenodo.6214555", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M4) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214555"}, {"dataset_uid": "200306", "doi": "10.5281/zenodo.6212423", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M7) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6212423"}, {"dataset_uid": "200307", "doi": "10.5281/zenodo.6212232", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (FSD-M21) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6212232"}, {"dataset_uid": "200308", "doi": "10.5281/zenodo.5913959", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Analysis code, processed observational data and climate model output required to produce figures for Roach et al (2022)", "url": "https://zenodo.org/record/5913959"}, {"dataset_uid": "200310", "doi": "10.5281/zenodo.1193930", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output: NEMO-CICE with an emergent sea ice floe size distribution described in Roach et al (2018)", "url": "https://zenodo.org/record/1193930"}, {"dataset_uid": "200302", "doi": "10.5281/zenodo.6213793", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M2) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6213793"}, {"dataset_uid": "200305", "doi": "10.5281/zenodo.6214998", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M5) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214998"}, {"dataset_uid": "200303", "doi": "10.5281/zenodo.6214364", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output from experiments (IC4M3rad) described in Cooper et al 2022.", "url": "https://zenodo.org/record/6214364"}, {"dataset_uid": "200309", "doi": "10.5281/zenodo.3463580", "keywords": null, "people": null, "repository": "Zenodo", "science_program": null, "title": "Model output: CICE experiments with varying floe and wave physics described in Roach et al. (2019)", "url": "https://zenodo.org/record/3463580"}], "date_created": "Tue, 19 Jul 2022 00:00:00 GMT", "description": "Sea-ice coverage surrounding Antarctica has expanded during the era of satellite observations, in contrast to rapidly shrinking Arctic sea ice. Most climate models predict Antarctic sea ice loss, rather than growth, indicating that there is much to learn about Antarctic sea ice in terms of its natural variability, processes and interactions affecting annual growth and retreat, and the impact of atmospheric factors such increasing greenhouse gases and stratospheric ozone depletion. This project is designed to improve model simulations of sea ice and examine the role of wind and wave forcing on changes in sea ice around Antarctica. This project seeks to explain basic interactions of the coupled atmosphere, ocean, and ice dynamics in the Antarctic climate system, especially in the region near the sea ice edge. The summer evolution of sea ice cover and the near surface heat exchange of atmosphere and ocean depend on the geometric distribution of floes and the open water surrounding them. The distribution of floes has the greatest impact on the sea ice state in the marginal seas, where the distribution itself can vary rapidly. This project would develop and implement a model of sea ice floes in the Los Alamos sea ice model, known as CICE5. This sea ice component would be coupled to the third generation WaveWatch model within the Community Climate System Model Version 2. The coupled model would be used to study sea ice-wave interactions and the role of modeling sea ice floes in the Antarctic. The broader impacts of this project include outreach, support of female scientists, and improvement of the sea-ice codes in widely used climate models.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE FLOES; Southern Ocean; SEA ICE", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bitz, Cecilia", "platforms": null, "repo": "Zenodo", "repositories": "Zenodo", "science_programs": null, "south": -90.0, "title": "The Role of Wave-sea Ice Floe Interactions in Recent Antarctic Sea Ice Change", "uid": "p0010350", "west": -180.0}, {"awards": "1745023 Hennon, Tyler; 1745009 Kohut, Josh; 1745011 Klinck, John; 1745081 Bernard, Kim; 1744884 Oliver, Matthew; 1745018 Fraser, William", "bounds_geometry": "POLYGON((-75 -60,-73 -60,-71 -60,-69 -60,-67 -60,-65 -60,-63 -60,-61 -60,-59 -60,-57 -60,-55 -60,-55 -61,-55 -62,-55 -63,-55 -64,-55 -65,-55 -66,-55 -67,-55 -68,-55 -69,-55 -70,-57 -70,-59 -70,-61 -70,-63 -70,-65 -70,-67 -70,-69 -70,-71 -70,-73 -70,-75 -70,-75 -69,-75 -68,-75 -67,-75 -66,-75 -65,-75 -64,-75 -63,-75 -62,-75 -61,-75 -60))", "dataset_titles": "Antarctic ACROBAT data; CTD Data from IFCB Sampling; Finite Time Lyapunov Exponent Results, Calculated from High Frequency Radar Observed Surface Currents; High Frequency Radar, Palmer Deep; IFCB Image Data; Relative Particle Density; SWARM AMLR moorings - acoustic data; SWARM Glider Data near Palmer Deep; WAP model float data; Winds from Joubin and Wauwerman Islands", "datasets": [{"dataset_uid": "200396", "doi": "10.26008/1912/bco-dmo.867442.2", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "WAP model float data", "url": "https://www.bco-dmo.org/dataset/867442"}, {"dataset_uid": "200390", "doi": "10.26008/1912/bco-dmo.865030.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "CTD Data from IFCB Sampling", "url": "https://www.bco-dmo.org/dataset/865030"}, {"dataset_uid": "200398", "doi": "", "keywords": null, "people": null, "repository": "IOOS Glider DAAC", "science_program": null, "title": "SWARM Glider Data near Palmer Deep", "url": "https://gliders.ioos.us/erddap/search/index.html?page=1\u0026itemsPerPage=1000\u0026searchFor=swarm"}, {"dataset_uid": "200392", "doi": "10.26008/1912/bco-dmo.917884.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "High Frequency Radar, Palmer Deep", "url": "https://www.bco-dmo.org/dataset/917884"}, {"dataset_uid": "200397", "doi": "10.26008/1912/bco-dmo.865098.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Winds from Joubin and Wauwerman Islands", "url": "https://www.bco-dmo.org/dataset/865098"}, {"dataset_uid": "200394", "doi": "10.26008/1912/bco-dmo.917926.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Relative Particle Density", "url": "https://www.bco-dmo.org/dataset/917926"}, {"dataset_uid": "200393", "doi": "10.26008/1912/bco-dmo.865002.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "IFCB Image Data", "url": "https://www.bco-dmo.org/dataset/865002"}, {"dataset_uid": "200389", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic ACROBAT data", "url": "https://www.bco-dmo.org/dataset/916046"}, {"dataset_uid": "200391", "doi": "10.26008/1912/bco-dmo.917914.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Finite Time Lyapunov Exponent Results, Calculated from High Frequency Radar Observed Surface Currents", "url": "https://www.bco-dmo.org/dataset/917914"}, {"dataset_uid": "200395", "doi": "10.26008/1912/bco-dmo.872729.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "SWARM AMLR moorings - acoustic data", "url": "https://www.bco-dmo.org/dataset/872729"}], "date_created": "Tue, 05 Jul 2022 00:00:00 GMT", "description": "Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function. To understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -55.0, "geometry": "POINT(-65 -65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CONDUCTIVITY SENSORS \u003e CONDUCTIVITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e RADIATION SENSORS", "is_usap_dc": true, "keywords": "MOORED; WATER TEMPERATURE; CONDUCTIVITY; FLUORESCENCE; UNCREWED VEHICLES; Palmer Station; PHOTOSYNTHETICALLY ACTIVE RADIATION; PELAGIC; OCEAN MIXED LAYER; SURFACE; SALINITY; WATER PRESSURE; LIVING ORGANISM; MODELS; ACOUSTIC SCATTERING", "locations": "Palmer Station", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Instrumentation and Support; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": "NOT APPLICABLE", "persons": "Bernard, Kim; Oliver, Matthew; Kohut, Josh; Fraser, William; Klinck, John M.; Statcewich, Hank", "platforms": "LIVING ORGANISM-BASED PLATFORMS \u003e LIVING ORGANISM; OTHER \u003e MODELS; WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE", "repo": "BCO-DMO", "repositories": "BCO-DMO; IOOS Glider DAAC", "science_programs": null, "south": -70.0, "title": "Collaborative Research: Physical Mechanisms Driving Food Web Focusing in Antarctic Biological Hotspots", "uid": "p0010346", "west": -75.0}, {"awards": "0003956 Burns, Jennifer; 9981683 Costa, Daniel", "bounds_geometry": "POLYGON((-70 -65,-69.5 -65,-69 -65,-68.5 -65,-68 -65,-67.5 -65,-67 -65,-66.5 -65,-66 -65,-65.5 -65,-65 -65,-65 -65.5,-65 -66,-65 -66.5,-65 -67,-65 -67.5,-65 -68,-65 -68.5,-65 -69,-65 -69.5,-65 -70,-65.5 -70,-66 -70,-66.5 -70,-67 -70,-67.5 -70,-68 -70,-68.5 -70,-69 -70,-69.5 -70,-70 -70,-70 -69.5,-70 -69,-70 -68.5,-70 -68,-70 -67.5,-70 -67,-70 -66.5,-70 -66,-70 -65.5,-70 -65))", "dataset_titles": "Crabeater seal oxygen stores", "datasets": [{"dataset_uid": "601583", "doi": "10.15784/601583", "keywords": "Antarctica; Crabeater Seal; GLOBEC; Hemoglobin; LMG0104; LMG0106; LMG0204; LMG0205; Marguerite Bay; Myoglobin; Oxygen Stores; Seals", "people": "Burns, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Crabeater seal oxygen stores", "url": "https://www.usap-dc.org/view/dataset/601583"}], "date_created": "Wed, 29 Jun 2022 00:00:00 GMT", "description": "This collaborative study between the University of California, Santa Cruz, Duke University, the University of South Florida, the University of Alaska-Anchorage, and the University of California, San Diego will examine the identification of biological and physical features associated with the abundance and distribution of individual Antarctic predators; the identification and characterization of biological \u0027hot spots\u0027 within the Western Antarctic Peninsula; and the development of temporally and spatially explicit models of krill consumption within the WAP by vertebrate predators. It is one of several data synthesis and modeling components that use the data obtained in the course of the field work of the Southern Ocean Global Ocean Ecosystems Dynamics (SO GLOBEC) experiment.\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with understanding how predators utilize \u0027hot spots\u0027, i.e. locally intense areas of biological productivity, and how \u0027hot spots\u0027 might temporally and spatially structure krill predation rates, and will be integrated with other synthesis and modeling studies that deal with the hydrography primary production, and krill dynamics.", "east": -65.0, "geometry": "POINT(-67.5 -67.5)", "instruments": null, "is_usap_dc": true, "keywords": "Marguerite Bay; MARINE ECOSYSTEMS", "locations": "Marguerite Bay", "north": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Burns, Jennifer; Costa, Daniel", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -70.0, "title": "Foraging Ecology of Crabeater Seals (Lobodon Carcinophagus)", "uid": "p0010345", "west": -70.0}, {"awards": "1744771 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities; 5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "datasets": [{"dataset_uid": "601601", "doi": "10.15784/601601", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Halberstadt, Anna Ruth; Buchband, Hannah; Balco, Gregory", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601601"}, {"dataset_uid": "601602", "doi": "10.15784/601602", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Balco, Gregory; Buchband, Hannah; Halberstadt, Anna Ruth", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601602"}], "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "The purpose of this project is to use geological data that record past changes in the Antarctic ice sheets to test computer models for ice sheet change. The geologic data mainly consist of dated glacial deposits that are preserved above the level of the present ice sheet, and range in age from thousands to millions of years old. These provide information about the size, thickness, and rate of change of the ice sheets during past times when the ice sheets were larger than present. In addition, some of these data are from below the present ice surface and therefore also provide some information about past warm periods when ice sheets were most likely smaller than present. The primary purpose of the computer model is to predict future ice sheet changes, but because significant changes in the size of ice sheets are slow and likely occur over hundreds of years or longer, the only way to determine whether these models are accurate is to test their ability to reproduce past ice sheet changes. The primary purpose of this project is to carry out such a test. The research team will compile relevant geologic data, in some cases generate new data by dating additional deposits, and develop methods and software to compare data to model simulations. In addition, this project will (i) contribute to building and sustaining U.S. science capacity through postdoctoral training in geochronology, ice sheet modeling, and data science, and (ii) improve public access to geologic data and model simulations relevant to ice sheet change through online database and website development. Technical aspects of this project are primarily focused on the field of cosmogenic-nuclide exposure-dating, which is a method that relies on the production of rare stable and radio-nuclides by cosmic-ray interactions with rocks and minerals exposed at the Earth\u0027s surface. Because the advance and retreat of ice sheets results in alternating cosmic-ray exposure and shielding of underlying bedrock and surficial deposits, this technique is commonly used to date and reconstruct past ice sheet changes. First, this project will contribute to compiling and systematizing a large amount of cosmogenic-nuclide exposure age data collected in Antarctica during the past three decades. Second, it will generate additional geochemical data needed to improve the extent and usefulness of measurements of stable cosmogenic nuclides, cosmogenic neon-21 in particular, that are useful for constraining ice-sheet behavior on million-year timescales. Third, it will develop a computational framework for comparison of the geologic data set with existing numerical model simulations of Antarctic ice sheet change during the past several million years, with particular emphasis on model simulations of past warm periods, for example the middle Pliocene ca. 3-3.3 million years ago, during which the Antarctic ice sheets are hypothesized to have been substantially smaller than present. Fourth, guided by the results of this comparison, it will generate new model simulations aimed at improving agreement between model simulations and geologic data, as well as diagnosing which processes or parameterizations in the models are or are not well constrained by the data. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "BERYLLIUM-10 ANALYSIS; AMD; ICE SHEETS; GLACIATION; Amd/Us; LABORATORY; USA/NSF; Antarctica; ALUMINUM-26 ANALYSIS; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Balco, Gregory", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Synoptic Evaluation of Long-Term Antarctic Ice Sheet Model Simulations using a Continent-Wide Database of Cosmogenic-Nuclide Measurements", "uid": "p0010342", "west": -180.0}, {"awards": "2201129 Fischer, Karen", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Crustal thicknesses in Antarctica from Sp receiver functions; Lithospheric thicknesses in Antarctica from Sp receiver functions", "datasets": [{"dataset_uid": "601899", "doi": "10.15784/601899", "keywords": "Antarctica; Cryosphere; LAB; Lithosphere; Lithospheric Thickness", "people": "Fischer, Karen; Brown, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Lithospheric thicknesses in Antarctica from Sp receiver functions", "url": "https://www.usap-dc.org/view/dataset/601899"}, {"dataset_uid": "601898", "doi": "10.15784/601898", "keywords": "Antarctica; Crust; Cryosphere; Moho", "people": "Fischer, Karen; Brown, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Crustal thicknesses in Antarctica from Sp receiver functions", "url": "https://www.usap-dc.org/view/dataset/601898"}], "date_created": "Tue, 14 Jun 2022 00:00:00 GMT", "description": "The western portion of the Antarctic continent is very active in terms of plate tectonic processes that can produce significant variations in the Earths mantle temperature as well as partial melting of the mantle. In addition to these internal processes, the ice sheet in western Antarctica is melting due to Earths warming climate and adding water to the ocean. These changes in ice mass cause adjustments in rocks within the Earth\u0027s crust, allowing the surface to rebound in some locations and fall in others, altering the geographical pattern of sea-level change. However, the solid Earth response depends strongly on the strength of the rocks at a wide range of timescales which is not well-known and varies with temperature and other rock properties. This project has three primary goals. (1) It will assess how processes such as rifting, mantle upwelling and lithospheric instability have altered the lithosphere and underlying asthenosphere of western Antarctica, contributing to a planet-wide understanding of these processes. (2) It will use new measurements of mantle and crust properties to estimate the rate at which heat from the solid Earth flows into the base of the ice, which is important for modeling the rates at which the ice melts and flows. (3) It will places bounds on mantle viscosity, which is key for modeling the interaction of the solid Earth with changing ice and water masses and their implications for sea-level rise. To accomplish these goals, new resolution of crust and mantle structure will be obtained by analyzing seismic waves from distant earthquakes that have been recorded at numerous seismic stations in Antarctica. These analyses will include new combinations of seismic wave data that provide complementary information about mantle temperature, heat flow and viscosity. This project will provide educational and career opportunities to a Brown University graduate student, undergraduates from groups underrepresented in science who will come to Brown University for a summer research program, and other undergraduates. The project will bring together faculty and students for a seminar at Brown that explores the connections between the solid Earth and ice processes in Antarctica. Project research will be incorporated in outreach to local public elementary schools and high schools. This research addresses key questions about mantle processes and properties in western Antarctica. What are the relative impacts of rifting, mantle plumes, and lithospheric delamination in the evolution of the lithosphere and asthenosphere? Where is topography isostatically compensated, and where are dynamic processes such as plate flexure or tractions from 3-D mantle flow required? What are the bounds on heat flow and mantle viscosity, which represent important inputs to models of ice sheet evolution and its feedback from the solid Earth? To address these questions, this project will measure mantle and crust properties using seismic tools that have not yet been applied in Antarctica: regional-scale measurement of mantle attenuation from surface waves; Sp body wave phases to image mantle velocity gradients such as the lithosphere-asthenosphere boundary; and surface wave amplification and ellipticity. The resulting models of seismic attenuation and velocity will be jointly interpreted to shed new light on temperature, bulk composition, volatile content, and partial melt, using a range of laboratory-derived constitutive laws, while considering data from mantle xenoliths. To test the relative roles of rifting, mantle plumes, and delamination, and to assess isostatic support for Antarctic topography, the predictions of these processes will be compared to the new models of crust and mantle properties. To improve bounds on western Antarctic heat flow, seismic attenuation and velocity will be used in empirical comparisons and in direct modeling of vertical temperature gradients. To better measure mantle viscosity at the timescales of glacial isostatic adjustment, frequency-dependent viscosity will be estimated from the inferred mantle conditions. This project will contribute to the education and career development of the following: a Brown University Ph.D. student, Brown undergraduates, and undergraduates from outside the university will be involved through the Department of Earth, Environmental and Planetary Sciences (DEEPS) Leadership Alliance NSF Research Experience for Undergraduates (REU) Site which focuses on geoscience summer research experiences for underrepresented students. The project will be the basis for a seminar at Brown that explores the connections between the solid Earth and cryosphere in Antarctica and will contribute to outreach in local public elementary and high schools. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; West Antarctica; USA/NSF; SEISMIC SURFACE WAVES; AMD; PLATE TECTONICS; Amd/Us; GLACIERS/ICE SHEETS; FIELD INVESTIGATION", "locations": "West Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Fischer, Karen; Dalton, Colleen", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Probing the Western Antarctic Lithosphere and Asthenosphere with New Approaches to Imaging Seismic Wave Attenuation and Velocity", "uid": "p0010339", "west": -180.0}, {"awards": "1745082 Beilman, David; 1745068 Booth, Robert", "bounds_geometry": "POLYGON((-64.4 -62.4,-63.910000000000004 -62.4,-63.42 -62.4,-62.93000000000001 -62.4,-62.440000000000005 -62.4,-61.95 -62.4,-61.46 -62.4,-60.97 -62.4,-60.480000000000004 -62.4,-59.99 -62.4,-59.5 -62.4,-59.5 -62.7,-59.5 -63,-59.5 -63.3,-59.5 -63.6,-59.5 -63.900000000000006,-59.5 -64.2,-59.5 -64.5,-59.5 -64.80000000000001,-59.5 -65.10000000000001,-59.5 -65.4,-59.99 -65.4,-60.480000000000004 -65.4,-60.97 -65.4,-61.46 -65.4,-61.95 -65.4,-62.440000000000005 -65.4,-62.93000000000001 -65.4,-63.42 -65.4,-63.910000000000004 -65.4,-64.4 -65.4,-64.4 -65.10000000000001,-64.4 -64.80000000000001,-64.4 -64.5,-64.4 -64.2,-64.4 -63.900000000000006,-64.4 -63.6,-64.4 -63.3,-64.4 -63,-64.4 -62.7,-64.4 -62.4))", "dataset_titles": "LMG2002 Expedtition Data", "datasets": [{"dataset_uid": "200222", "doi": "10.7284/908802", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG2002 Expedtition Data", "url": "https://www.rvdata.us/search/cruise/LMG2002"}], "date_created": "Fri, 10 Jun 2022 00:00:00 GMT", "description": "Warming on the western Antarctic Peninsula in the later 20th century has caused widespread changes in the cryosphere (ice and snow) and terrestrial ecosystems. These recent changes along with longer-term climate and ecosystem histories will be deciphered using peat deposits. Peat accumulation can be used to assess the rate of glacial retreat and provide insight into ecological processes on newly deglaciated landscapes in the Antarctic Peninsula. This project builds on data suggesting recent ecosystem transformations that are linked to past climate of the western Antarctic Peninsula and provide a timeline to assess the extent and rate of recent glacial change. The study will produce a climate record for the coastal low-elevation terrestrial region, which will refine the major climate shifts of up to 6 degrees C in the recent past (last 12,000 years). A novel terrestrial record of the recent glacial history will provide insight into observed changes in climate and sea-ice dynamics in the western Antarctic Peninsula and allow for comparison with off-shore climate records captured in sediments. Observations and discoveries from this project will be disseminated to local schools and science centers. The project provides training and career development for a postdoctoral scientist as well as graduate and undergraduate students. The research presents a new systematic survey to reconstruct ecosystem and climate change for the coastal low-elevation areas on the western Antarctic Peninsula (AP) using proxy records preserved in late Holocene peat deposits. Moss and peat samples will be collected and analyzed to generate a comprehensive data set of late-Holocene climate change and ecosystem dynamics. The goal is to document and understand the transformations of landscape and terrestrial ecosystems on the western AP during the late Holocene. The testable hypothesis is that coastal regions have experienced greater climate variability than evidenced in ice-core records and that past warmth has facilitated dramatic ecosystem and cryosphere response. A primary product of the project is a robust reconstruction of late Holocene climate changes for coastal low-elevation terrestrial areas using multiple lines of evidence from peat-based biological and geochemical proxies, which will be used to compare with climate records derived from marine sediments and ice cores from the AP region. These data will be used to test several ideas related to novel peat-forming ecosystems (such as Antarctic hairgrass bogs) in past warmer climates and climate controls over ecosystem establishment and migration to help assess the nature of the Little Ice Age cooling and cryosphere response. The chronology of peat cores will be established by radiocarbon dating of macrofossils and Bayesian modeling. The high-resolution time series of ecosystem and climate changes will help put the observed recent changes into a long-term context to bridge climate dynamics over different time scales. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -59.5, "geometry": "POINT(-61.95 -63.900000000000006)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; ISOTOPES; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; SEDIMENTS; Amd/Us; FIELD INVESTIGATION; Antarctic Peninsula; AMD; TERRESTRIAL ECOSYSTEMS; USA/NSF; RADIOCARBON", "locations": "Antarctic Peninsula", "north": -62.4, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Beilman, David; Booth, Robert", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -65.4, "title": "Collaborative Research: Reconstructing Late Holocene Ecosystem and Climate Shifts from Peat Records in the Western Antarctic Peninsula", "uid": "p0010337", "west": -64.4}, {"awards": "1951090 Stukel, Michael", "bounds_geometry": "POLYGON((-80 -63,-78.2 -63,-76.4 -63,-74.6 -63,-72.8 -63,-71 -63,-69.2 -63,-67.4 -63,-65.6 -63,-63.8 -63,-62 -63,-62 -63.7,-62 -64.4,-62 -65.1,-62 -65.8,-62 -66.5,-62 -67.2,-62 -67.9,-62 -68.6,-62 -69.3,-62 -70,-63.8 -70,-65.6 -70,-67.4 -70,-69.2 -70,-71 -70,-72.8 -70,-74.6 -70,-76.4 -70,-78.2 -70,-80 -70,-80 -69.3,-80 -68.6,-80 -67.9,-80 -67.2,-80 -66.5,-80 -65.8,-80 -65.1,-80 -64.4,-80 -63.7,-80 -63))", "dataset_titles": "BCO-DMO Project Page", "datasets": [{"dataset_uid": "200294", "doi": null, "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "BCO-DMO Project Page", "url": "https://www.bco-dmo.org/project/838048"}], "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Algae in the surface ocean convert carbon dioxide into organic carbon through photosynthesis. The biological carbon pump transports this organic carbon from the atmosphere to the deep ocean where it can be stored for tens to hundreds of years. Annually, the amount transported is similar to that humans are currently emitting by burning fossil fuels. However, at present we cannot predict how this important process will change with a warming ocean. These investigators plan to develop a 15+ year time-series of vertical carbon transfer for the Western Antarctic Peninsula; a highly productive Antarctic ecosystem. This region is also rapid transition to warmer temperatures leading to reduced sea ice coverage. This work will help researchers better understand how the carbon cycle in the Western Antarctic Peninsula will respond to climate change. The researchers will develop the first large-scale time-series of carbon flux anywhere in the ocean. This research will also support the education and training of a graduate student and support the integration of concepts in Antarctic research into two undergraduate courses designed for non-science majors and advanced earth science students. The researchers will also develop educational modules for introducing elementary and middle-school age students to important concepts such as gross and net primary productivity, feedbacks in the marine and atmospheric systems, and the differences between correlation and causation. Results from this proposal will also be incorporated into a children\u2019s book, \u201cPlankton do the Strangest Things\u201d, that is targeted at 5-7 year olds and is designed to introduce them to the incredible diversity and fascinating adaptations of microscopic marine organisms. This research seeks to leverage 6 years (2015-2020) of 234Th samples collected on Palmer LTER program, 5 years of prior measurements (2009-2010, 2012-2014), and upcoming cruises (2021-2023) to develop a time-series of summertime particle flux in the WAP that stretches for 15 years. The 238U-234Th disequilibrium approach utilizes changes in the activity of the particle-active radio-isotope 234Th relative to its parent nuclide 238U to quantify the flux of sinking carbon out of the surface ocean (over a time-scale of ~one month). This proposal will fund 234Th analyses from nine years\u2019 worth of cruises (2015-2023) and extensive analyses designed to investigate the processes driving inter-annual variability in the BCP. These include: 1) physical modeling to quantify the importance of advection and diffusion in the 234Th budget, 2) time-series analyses of particle flux, and 3) statistical modeling of the relationships between particle flux and multiple presumed drivers (biological, chemical, physical, and climate indices) measured by collaborators in the Palmer LTER program. This multi-faceted approach is critical for linking the measurements to models and for predicting responses to climate change. It will also test the hypothesis that export flux is decreasing in the northern WAP, increasing in the southern WAP, and increasing when integrated over the entire region as a result of earlier sea ice retreat and a larger ice-free zone. The project will also investigate relationships between carbon export and multiple potentially controlling factors including: primary productivity, algal biomass and taxonomic composition, biological oxygen saturation, zooplankton biomass and taxonomic composition, bacterial production, temperature, wintertime sea ice extent, date of sea ice retreat, and climate modes. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -62.0, "geometry": "POINT(-71 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; FIELD INVESTIGATION; Palmer Station; USAP-DC; BIOGEOCHEMICAL CYCLES; USA/NSF", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Stukel, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -70.0, "title": "Quantifying Processes Driving Interannual Variability in the Biological Carbon Pump in the Western Antarctic Peninsula", "uid": "p0010332", "west": -80.0}, {"awards": "2055455 Duhaime, Melissa", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Part 1: Non-technical description: It is well known that the Southern Ocean plays an important role in global carbon cycling and also receives a disproportionately large influence of climate change. The role of marine viruses on ocean productivity is largely understudied, especially in this global region. This team proposes to use combination of genomics, flow cytometry, and network modeling to test the hypothesis that viral biogeography, infection networks, and viral impacts on microbial metabolism can explain variations in net community production (NCP) and carbon cycling in the Southern Ocean. The project includes the training of a postdoctoral scholar, graduate students and undergraduate students. It also includes the development of a new Polar Sci ReachOut program in partnership with the University of Michigan Museum of Natural History especially targeted to middle-school students and teachers and the general public. The team will also produce a Science for Tomorrow (SFT) program for use in middle schools in metro-Detroit communities and lead a summer Research Experience for Teachers (RET) fellows. Part 2: Technical description: The study will leverage hundreds of existing samples collected for microbes and viruses from the Antarctic Circumpolar Expedition (ACE). These samples provide the first contiguous survey of viral diversity and microbial communities around Antarctica. Viral networks are being studied in the context of biogeochemical data to model community networks and predict net community production (NCP), which will provide a way to evaluate the role of viruses in Southern Ocean carbon cycling. Using cutting edge molecular and flow cytometry approaches, this project addresses the following questions: 1) How/why are Southern Ocean viral populations distributed across environmental gradients? 2a) Do viruses interfere with \"keystone\" metabolic pathways and biogeochemical processes of microbial communities in the Southern Ocean? 2b) Does nutrient availability or other environmental variables drive changes in virus-microbe infection networks in the Southern Ocean? Results will be used to develop and evaluate generative models of NCP predictions that incorporate the importance of viral traits and virus-host interactions. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; Amd/Us; AMD; FIELD INVESTIGATION; USA/NSF; AQUATIC SCIENCES; BACTERIA/ARCHAEA; MARINE ECOSYSTEMS; VIRUSES; USAP-DC", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Duhaime, Melissa; Zaman, Luis", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA - Viral Ecogenomics of the Southern Ocean: Unifying Omics and Ecological Networks to Advance our Understanding of Antarctic Microbial Ecosystem Function", "uid": "p0010333", "west": -180.0}, {"awards": "1744856 Bromirski, Peter; 1246151 Bromirski, Peter; 1744958 Wei, Yong; 1744759 Dunham, Eric", "bounds_geometry": null, "dataset_titles": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves; Datasets for Model Simulations of Tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Thwaites); Datasets of bathymetric model grids for model simulations of tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves; Model simulation data of tsunami propagation in the Pacific Ocean; Model simulations of tsunami propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Ross Sea); Model Tsunami Propagation Simulation From Circum-Pacific Subduction Zones to West Antarctic Ice Shelves; Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "datasets": [{"dataset_uid": "601561", "doi": "10.15784/601561", "keywords": "Amundsen Sea; Antarctica; Glaciology", "people": "Tazhimbetov, Nurbek; Dunham, Eric; Almquist, Martin", "repository": "USAP-DC", "science_program": null, "title": "Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "url": "https://www.usap-dc.org/view/dataset/601561"}, {"dataset_uid": "601924", "doi": "10.15784/601924", "keywords": "Antarctica; Cryosphere; Model Simulation; Pacific Ocean; Subduction Zone Earthquakes; Tsunami; Tsunami impact; West Antarctica Ice Shelf", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Datasets of bathymetric model grids for model simulations of tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves", "url": "https://www.usap-dc.org/view/dataset/601924"}, {"dataset_uid": "200323", "doi": "10.25740/qy001dt7463", "keywords": null, "people": null, "repository": "Stanford Digital Repository", "science_program": null, "title": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves", "url": "https://doi.org/10.25740/qy001dt7463"}, {"dataset_uid": "601923", "doi": "10.15784/601923", "keywords": "Antarctica; Cryosphere; Model Simulation; Ross Sea Ice Shelf; Thwaites Region; Tsunami; Tsunami impact; West Antarctica Ice Shelf", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Datasets for Model Simulations of Tsunami Propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Thwaites)", "url": "https://www.usap-dc.org/view/dataset/601923"}, {"dataset_uid": "601922", "doi": "10.15784/601922", "keywords": "Antarctica; Cryosphere; Model Simulation; Ross Ice Shelf; Ross Sea Ice Shelf; Subduction Zone Earthquakes; Tsunami; Tsunami impact; West Antarctica Ice Shelf", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Model simulations of tsunami propagation from Circum-Pacific Subduction Zone to West Antarctic Ice Shelves (Ross Sea)", "url": "https://www.usap-dc.org/view/dataset/601922"}, {"dataset_uid": "200424", "doi": "N/A", "keywords": null, "people": null, "repository": "NOAA Center for Tsunami Research (NCTR)", "science_program": null, "title": "Model Tsunami Propagation Simulation From Circum-Pacific Subduction Zones to West Antarctic Ice Shelves", "url": " https://nctr.pmel.noaa.gov/antarctica/ "}, {"dataset_uid": "601921", "doi": "10.15784/601921", "keywords": "Antarctica; Cryosphere; Model Output; Model Simulation; Pacific Ocean; Subduction Zone Earthquakes; Tsunami; Tsunami impact; West Antarctic Ice Sheet", "people": "Wei, Yong", "repository": "USAP-DC", "science_program": null, "title": "Model simulation data of tsunami propagation in the Pacific Ocean", "url": "https://www.usap-dc.org/view/dataset/601921"}], "date_created": "Mon, 16 May 2022 00:00:00 GMT", "description": "Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences. This project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; AMD; Amd/Us; SEA ICE; Amundsen Sea; USAP-DC; USA/NSF; Ross Ice Shelf; MODELS", "locations": "Amundsen Sea; Ross Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Dunham, Eric; Bromirski, Peter; Wei, Yong", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "NOAA Center for Tsunami Research (NCTR); Stanford Digital Repository; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Do Ocean Wave Impacts Pose a Hazard to the Stability of West Antarctic Ice Shelves?", "uid": "p0010320", "west": null}, {"awards": "1643174 Padman, Laurence; 1643285 Joughin, Ian", "bounds_geometry": "POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73))", "dataset_titles": "Beta Version of Plume Model; Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier; icepack; Pine Island Basin Scale Model", "datasets": [{"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}, {"dataset_uid": "200290", "doi": "http://hdl.handle.net/1773/46687", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier", "url": "https://doi.org/10.6069/2MZZ-6B61"}, {"dataset_uid": "200313", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beta Version of Plume Model", "url": "https://github.com/icepack/plumes"}, {"dataset_uid": "200315", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Pine Island Basin Scale Model", "url": "https://github.com/fastice/icesheetModels"}], "date_created": "Fri, 13 May 2022 00:00:00 GMT", "description": "The West Antarctic Ice Sheet contains enough ice to raise global sea levels by 3-4 meters. Ice-sheet volume falls, and sea level increases, when more ice is lost to the ocean by glacier flow than is replaced by snowfall. Glacier speed is reduced when ice shelves, which are the floating extensions of the ice sheets, are present. Processes that affect ice shelf thickness and extent therefore influence the rates of grounded ice loss and sea-level rise. West Antarctica is currently losing ice, at an accelerating rate, with most loss occurring in the Amundsen Sea region via discharge from Pine Island and Thwaites glaciers. This loss was initiated by increased circulation of relatively warm ocean water beneath these glacier\u0027s ice shelves, causing them to thin by melting. However, this melting also depends on how the changing shape of the ice shelves affects the ocean circulation beneath them and the speeds of the grounded glaciers upstream. Limited understanding of these processes leads to uncertainties in estimates of future ice loss. This interdisciplinary project brings together glaciologists and oceanographers from three US institutions to study the interactions between changing glacier flow, ice shelf shape and extent, and ocean circulation. Data and numerical models will be used to identify the key processes that determine how rapidly this region can shed ice. The project team will train postdocs and graduate students in cutting-edge modeling techniques, and educate the public about Antarctic ice loss through talks, school science fairs, and Seattle Science Center\u0027s annual Polar Science Weekend. The project team will conduct simulations, using a combination of ice-sheet and ocean models, to reduce uncertainties in projected ice loss from Pine Island and Thwaites glaciers by: (i) assessing how ice-shelf melt rates will change as the ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of sub-shelf melt rates to changes in ocean state on the nearby continental shelf. These studies will reduce uncertainty on ice loss and sea-level rise estimates, and lay the groundwork for development of future fully-coupled ice-sheet/ocean models. The project will first develop high-resolution ice-shelf-cavity circulation models driven by modern observed regional ocean state and validated with estimates of melt derived from satellite observations. Next, an ice-flow model will be used to estimate the future grounding retreat. An iterative process with the ocean-circulation and ice-flow models will then simulate melt rates at each stage of retreat. These results will help assess the validity of the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway, which was based on simplified models of melt rate. These models will also provide a better understanding of the sensitivity of melt to regional forcing such as changes in Circumpolar Deep Water temperature and wind-driven changes in thermocline height. Finally, several semi-coupled ice-ocean simulations will help determine the influence of the ocean-circulation driven melt over the next several decades. 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Washington ResearchWorks Archive", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica ", "uid": "p0010318", "west": -104.0}, {"awards": "2045880 Sokol, Eric; 2046260 Salvatore, Mark", "bounds_geometry": "POLYGON((161.88 -77.47,162.075 -77.47,162.27 -77.47,162.465 -77.47,162.66 -77.47,162.855 -77.47,163.05 -77.47,163.245 -77.47,163.44 -77.47,163.635 -77.47,163.83 -77.47,163.83 -77.501,163.83 -77.532,163.83 -77.563,163.83 -77.594,163.83 -77.625,163.83 -77.656,163.83 -77.687,163.83 -77.718,163.83 -77.749,163.83 -77.78,163.635 -77.78,163.44 -77.78,163.245 -77.78,163.05 -77.78,162.855 -77.78,162.66 -77.78,162.465 -77.78,162.27 -77.78,162.075 -77.78,161.88 -77.78,161.88 -77.749,161.88 -77.718,161.88 -77.687,161.88 -77.656,161.88 -77.625,161.88 -77.594,161.88 -77.563,161.88 -77.532,161.88 -77.501,161.88 -77.47))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 21 Apr 2022 00:00:00 GMT", "description": "Part I: Non-technical description: Water is life and nowhere is it more notable than in deserts. Within the drylands on Earth, the Antarctic deserts, represented in this study by the McMurdo Dry Valleys, exemplify life in extreme environments with scarce water, low temperatures and long periods of darkness during the polar winter. There is a scarcity of methods to determine water availability, data necessary to predict which species are successful in the drylands, unless measurements are done manually or with field instruments. This project aims to develop a new method of determining soil moisture and use the new data to identify locations suitable for life. Combining these habitats with known species distributions in the McMurdo Dry Valleys, results from this project will predict which species should be present, and also what is the expected species distribution in a changing environment. In this way the project takes advantage of a combination of methods, from recent remote sensing products, ecological models and 30 years of field collections to bring a prediction of how life might change in the McMurdo Dry Valleys in a warmer, and possibly, moister future climate. This project benefits the National Science Foundation goals of expanding fundamental knowledge of Antarctic biota and the processes that sustain life in extreme environments. The knowledge acquired in this project will be disseminated to other drylands through training of high-school curricular programming in Native American communities of the SouthWest. Part II: Technical description: Terrestrial environments in Antarctica are characterized by low liquid water supply, sub-zero temperatures and the polar night in winter months. During summer, melting of snow patches, seasonal steams from glacial melt and vicinity to lakes provide a variety of environments that maintain life, not yet studied at landscape-scale level for habitat suitability and the processes that drive them. This project proposes to integrate remote sensing, hydrological models and ecological models to establish habitat suitability for species in the McMurdo Dry Valleys based on water availability. The approach is at a landscape level in order to establish present-day and future scenarios of species distribution. There are four main objectives: remote sensing development of moisture levels in soils, combining biological and soil data, building and calibrating models of habitat suitability by combining species distribution and environmental variability and applying statistical species distribution model. The field data to develop habitat suitability and calibration of models will leverage a the 30-year dataset collected by the McMurdo Long-Term Ecological Research program. Mechanistic models developed will be essential to predict species distribution in future climate scenarios. Training of post-doctoral researchers and a graduate student will prepare for the next generation of Antarctic scientists. Results from this project will train high-school students from native American communities in the SouthWest where similar desert conditions exist. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 163.83, "geometry": "POINT(162.855 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ACTIVE LAYER; Taylor Valley; USAP-DC; Amd/Us; AMD; MODELS; USA/NSF", "locations": "Taylor Valley", "north": -77.47, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Salvatore, Mark; Gooseff, Michael N.; Sokol, Eric; Barrett, John", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -77.78, "title": "Collaborative Research: Moving Beyond the Margins: Modeling Water Availability and Habitable Terrestrial Ecosystems in the Polar Desert of the McMurdo Dry Valleys", "uid": "p0010316", "west": 161.88}, {"awards": "1341429 Ball, Becky", "bounds_geometry": "POLYGON((-68.205783 -60.706633,-65.9444531 -60.706633,-63.6831232 -60.706633,-61.4217933 -60.706633,-59.1604634 -60.706633,-56.8991335 -60.706633,-54.6378036 -60.706633,-52.3764737 -60.706633,-50.1151438 -60.706633,-47.8538139 -60.706633,-45.592484 -60.706633,-45.592484 -62.1204014,-45.592484 -63.5341698,-45.592484 -64.9479382,-45.592484 -66.3617066,-45.592484 -67.775475,-45.592484 -69.1892434,-45.592484 -70.6030118,-45.592484 -72.0167802,-45.592484 -73.4305486,-45.592484 -74.844317,-47.8538139 -74.844317,-50.1151438 -74.844317,-52.3764737 -74.844317,-54.6378036 -74.844317,-56.8991335 -74.844317,-59.1604634 -74.844317,-61.4217933 -74.844317,-63.6831232 -74.844317,-65.9444531 -74.844317,-68.205783 -74.844317,-68.205783 -73.4305486,-68.205783 -72.0167802,-68.205783 -70.6030118,-68.205783 -69.1892434,-68.205783 -67.775475,-68.205783 -66.3617066,-68.205783 -64.9479382,-68.205783 -63.5341698,-68.205783 -62.1204014,-68.205783 -60.706633))", "dataset_titles": "Climatic and environmental constraints on aboveground-belowground linkages and diversity across a latitudinal gradient in Antarctica", "datasets": [{"dataset_uid": "200289", "doi": "", "keywords": null, "people": null, "repository": "OSF - Center for Open Science", "science_program": null, "title": "Climatic and environmental constraints on aboveground-belowground linkages and diversity across a latitudinal gradient in Antarctica", "url": "https://osf.io/8xfrc/"}], "date_created": "Thu, 14 Apr 2022 00:00:00 GMT", "description": "The Antarctic Peninsula is experiencing rapid environmental changes, which will influence the community of organisms that live there. However, we know very little about the microscopic organisms living in the soil in this region. Soil biology (including bacteria, fungi, and invertebrates) are responsible for many important processes that sustain ecosystems, such as nutrient recycling. Without understanding the environmental conditions that influence soil biodiversity along the Antarctic Peninsula, our ability to predict the consequences of global change is strongly limited. This project will identify the soil community at many sites along the Antarctic Peninsula to discover how the community changes with environmental conditions from north to south. The project will also identify how the soil community at each site differs under different types of plants. Understanding more about the ways in which plant cover and climate conditions influence soil biodiversity will allow predictions of how communities will respond to future changes such as climate warming and invasive plant species. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The investigators will engage with outreach to K-12 students and the general public both directly and through a blog and will participate in workshops for K-12 teachers. Additionally, the project will provide the opportunity for many undergraduate and graduate students of diverse backgrounds to be trained in interdisciplinary research. The investigators will determine the nature and strength of plant-soil linkages in influencing soil community composition and diversity over a latitudinal gradient of environmental and climatic conditions. The goals are to (1) increase our understanding of current biogeography and diversity by providing in-depth knowledge of soil community composition and complexity as it relates to environmental and climatic characteristics; and (2) determine the nature of aboveground-belowground community linkages over varying spatial scales. The team will identify the composition and diversity of soil communities under key habitat types (grass, moss, algae, etc.). Microbial communities (bacteria, fungi, archaea) will be investigated using pyrosequencing for community composition analysis and metagenomic sequencing to identify functional capabilities. Invertebrates (nematodes, tardigrades, rotifers, microarthropods) will be extracted and identified to the lowest possible taxonomic level. Soil chemistry (pH, nutrient content, soil moisture, etc.) and climate conditions will be measured to determine the relationship between soil communities and physical and chemical properties. Structural equation modeling will be used to identify aboveground-belowground linkage pathways and quantify link strengths under varying environmental conditions.", "east": -45.592484, "geometry": "POINT(-56.8991335 -67.775475)", "instruments": null, "is_usap_dc": true, "keywords": "FUNGI; FIELD INVESTIGATION; AMD; Amd/Us; TERRESTRIAL ECOSYSTEMS; USA/NSF; ANIMALS/INVERTEBRATES; SOIL CHEMISTRY; BACTERIA/ARCHAEA; Antarctic Peninsula; ECOSYSTEM FUNCTIONS; USAP-DC", "locations": "Antarctic Peninsula", "north": -60.706633, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ball, Becky; Van Horn, David", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "OSF - Center for Open Science", "repositories": "OSF - Center for Open Science", "science_programs": null, "south": -74.844317, "title": "Collaborative Research: Climatic and Environmental Constraints on Aboveground-Belowground Linkages and Diversity across a Latitudinal Gradient in Antarctica", "uid": "p0010314", "west": -68.205783}, {"awards": "2038145 Bernard, Kim", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Winter Female Krill Oocyte Size", "datasets": [{"dataset_uid": "601919", "doi": "10.15784/601919", "keywords": "Antarctica; Biota; Cryosphere; Krill; Oceans; Southern Ocean", "people": "Bernard, Kim", "repository": "USAP-DC", "science_program": null, "title": "Winter Female Krill Oocyte Size", "url": "https://www.usap-dc.org/view/dataset/601919"}], "date_created": "Fri, 01 Apr 2022 00:00:00 GMT", "description": "Warming at the northern Antarctic Peninsula is causing fundamental changes in the marine ecosystem. Antarctic krill are small shrimp-like animals that are most abundant in that area. They are also an essential part of the marine food web of the waters surrounding Antarctica. Meanwhile, a rapidly growing international fishery has developed for krill. Understanding changes in krill populations is therefore critical both to the management of the fishery and the ability of scientists to predict changes in the Antarctic marine ecosystem. This project will have two broader societal impacts. First, the project will support the training of students for careers in oceanography. The students will be recruited from underrepresented groups in an effort to increase diversity, equity and inclusion in STEM. Second, results from this project will develop improved population models, which are essential for the effective management of the Antarctic krill fishery. In collaboration with US delegates on the Commission for the Conservation of Antarctic Marine Living Resources, the researchers will produce a report outlining the key findings from the study. Effective population modeling relies on empirical and theoretical understanding of how environment drives krill reproduction. There are two critical egg development stages in Antarctic krill that impact population growth. They are early egg development, and advanced egg development/spawning. The timing and duration of early egg development determines the number of eggs produced and the number of seasonal spawning events a female can undergo. The research team will use samples of Antarctic krill collected over the last 30 years in late winter/early spring, summer and early fall. The reproductive development stages of individual females in these samples will be assessed. These data will be modeled against climatological and oceanographic data to test three hypotheses. First, they will test if colder winter conditions correspond to early preparation for spawning. Second, they will test if favorable winter-summer conditions increase early spawning. Finally, they will test if favorable winter-summer conditions lengthen the spawning season. The study will advance current understanding of the environmental conditions that promote population increases in Antarctic krill and will fill an important gap in current knowledge of the reproductive development and output of Antarctic krill. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "FISHERIES; AMD; USAP-DC; Antarctic Peninsula; Amd/Us; USA/NSF; PELAGIC; LABORATORY", "locations": "Antarctic Peninsula", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Bernard, Kim", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Drivers of Antarctic Krill Reproductive Output", "uid": "p0010312", "west": -180.0}, {"awards": "2148517 Hancock, Cathrine", "bounds_geometry": "POLYGON((-60 -55,-51 -55,-42 -55,-33 -55,-24 -55,-15 -55,-6 -55,3 -55,12 -55,21 -55,30 -55,30 -57,30 -59,30 -61,30 -63,30 -65,30 -67,30 -69,30 -71,30 -73,30 -75,21 -75,12 -75,3 -75,-6 -75,-15 -75,-24 -75,-33 -75,-42 -75,-51 -75,-60 -75,-60 -73,-60 -71,-60 -69,-60 -67,-60 -65,-60 -63,-60 -61,-60 -59,-60 -57,-60 -55))", "dataset_titles": "Trajectories for APEX floats 9223 and 9224 from acoustic tracking using artoa4argo, Mar 2022-Feb 2023; Under ice trajectories for RAFOS enabled profiling floats in the Weddell Gyre", "datasets": [{"dataset_uid": "601652", "doi": "10.15784/601652", "keywords": "Antarctica; ANTXXIV/3; Argo Float; Artoa4argo; GPS Data; RAFOS; US Argo Program; Weddell Sea", "people": "Hancock, Cathrine", "repository": "USAP-DC", "science_program": null, "title": "Under ice trajectories for RAFOS enabled profiling floats in the Weddell Gyre", "url": "https://www.usap-dc.org/view/dataset/601652"}, {"dataset_uid": "601852", "doi": "10.15784/601852", "keywords": "Antarctica; Continental Slope; Cryosphere; Eddy; Float Trajectory; HAFOS; Weddell Sea", "people": "Boebel, Olaf; Hancock, Cathrine", "repository": "USAP-DC", "science_program": null, "title": "Trajectories for APEX floats 9223 and 9224 from acoustic tracking using artoa4argo, Mar 2022-Feb 2023", "url": "https://www.usap-dc.org/view/dataset/601852"}], "date_created": "Fri, 25 Mar 2022 00:00:00 GMT", "description": "The Weddell Gyre is one of the major components of the Southern Ocean circulation system, linking heat and carbon fluxes in the Antarctic Circumpolar Current to the continental margins. Water masses entering the Weddell Gyre are modified as they move in a great circular route around the gyre margin and change through processes involving air-sea-cryosphere interactions as well as through ocean eddies that mix properties across the gyre boundaries. Some of the denser water masses exit the gyre through pathways along the northern boundary, and ultimately ventilate the global deep ocean as Antarctic Bottom Water. While in-situ and satellite observations, as well as computer modeling efforts, provide estimates of the large-scale average flow within the gyre, details of the smaller-scale, or \"mesoscale\" eddy flow remain elusive. The proposed research will quantify mixing due to mesoscale eddies within the Weddell Gyre, as well as the transport of incoming deep water from the northeast, thought to be a result of transient eddies. Since the Weddell Gyre produces source water for about 40% of Antarctic Bottom Water formation, understanding the dynamics in this region helps to identify causes of documented changes in global bottom waters. This in turn, will give insight into how climate change is affecting global oceans, through modification of dense polar waters and Antarctic Bottom Water characteristics. This project aims to track 153 RAFOS-enabled Argo floats in the ice-covered regions of the Weddell Gyre. The resultant tracks along with all available Argo and earlier float data will be used to calculate Eulerian and Lagrangian means and eddy statistics for the Weddell Gyre. The study will link RAFOS tracks with Argo profiles under ice, allowing one to characterize the importance of eddies in water column modification at critical ice-edge boundaries and leads. With RAFOS tracks near the northeastern limit of the gyre, the project will investigate the eddy-driven processes of incoming Circumpolar Deep Water, to understand better the mechanisms and volume fluxes involved. Previous work shows that a large fraction of the mean circulation in the southern and western limits of the gyre, where it contacts the Antarctic continent, occurs in a narrow boundary layer above the slope. The research here will integrate this flow structure into a complete interior and boundary layer mean circulation synthesis. The findings and products from the proposed work will improve the positioning of Argo profiles in the polar regions, which would allow for more accurate climatological maps and derived quantities. Estimates of meso-scale mixing may serve as a foundation for the development of new parameterization schemes employed in climate models, as well as local and global ocean circulation models in polar regions. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 30.0, "geometry": "POINT(-15 -65)", "instruments": null, "is_usap_dc": true, "keywords": "OCEAN CURRENTS; WATER MASSES; BUOYS; USA/NSF; Weddell Sea; AMD; USAP-DC; Amd/Us", "locations": "Weddell Sea", "north": -55.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Hancock, Cathrine; Speer, Kevin", "platforms": "WATER-BASED PLATFORMS \u003e BUOYS \u003e MOORED \u003e BUOYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0, "title": "Weddell Gyre Mean Circulation and Eddy Statistics from Floats", "uid": "p0010310", "west": -60.0}, {"awards": "2149500 Chambers, Don", "bounds_geometry": "POLYGON((-180 -30,-144 -30,-108 -30,-72 -30,-36 -30,0 -30,36 -30,72 -30,108 -30,144 -30,180 -30,180 -36,180 -42,180 -48,180 -54,180 -60,180 -66,180 -72,180 -78,180 -84,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -84,-180 -78,-180 -72,-180 -66,-180 -60,-180 -54,-180 -48,-180 -42,-180 -36,-180 -30))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Mar 2022 00:00:00 GMT", "description": "The Southern Ocean accounts for ~40% of the total ocean uptake of anthropogenic carbon dioxide despite covering only 20% of the global ocean surface, and is particularly rich in long-lived eddies. These eddies, or large ocean whirlpools which can be observed from space, can alter air-sea fluxes of carbon dioxide in ways that are not yet fully understood. New observations from autonomous platforms measuring ocean carbon content suggest that there is significant heterogeneity in ocean carbon fluxes which can be linked to these dynamic eddy features. Due to computational and time limitations, ocean eddies are not explicitly represented in most global climate simulations, limiting our ability to understand the role eddies play in the ocean carbon cycle. This study will explore the impact of eddies on ocean carbon content and air-sea carbon dioxide fluxes in the Southern Ocean using both simulated- and observation-based strategies and the findings will improve our understanding of the ocean\u2019s role in the carbon cycle and in global climate. While this work will primarily be focused on the Southern Ocean, the results will be globally applicable. The researchers will also broaden interest in physical and chemical oceanography among middle school-age girls in the University of South Florida\u2019s Oceanography Camp for Girls by augmenting existing lessons with computational methods in oceanography. This project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite sea surface height data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls, recognized by NSF as a \u201cModel STEM Program for Women and Girls\u201d focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Southern Ocean; PH; BIOGEOCHEMICAL CYCLES; AMD; OCEAN CHEMISTRY; OCEAN MIXED LAYER; USA/NSF; NITROGEN; OCEAN CURRENTS; SALINITY/DENSITY; USAP-DC; OCEAN TEMPERATURE; MODELS; CHLOROPHYLL; DISSOLVED GASES; NUTRIENTS", "locations": "Southern Ocean", "north": -30.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Williams, Nancy; Chambers, Don; Tamsitt, Veronica", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Diagnosing the Role of Ocean Eddies in Carbon Cycling from a High-resolution Data Assimilating Ocean Biogeochemical Model", "uid": "p0010309", "west": -180.0}, {"awards": "1823135 Bromwich, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "YOPP-SH Analysis and Forecast Results. ", "datasets": [{"dataset_uid": "200287", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "YOPP-SH Analysis and Forecast Results. ", "url": "http://polarmet.osu.edu/YOPP-SH/"}], "date_created": "Mon, 14 Mar 2022 00:00:00 GMT", "description": "This research will take advantage of the greater number of Antarctic weather observations collected as part of the World Meteorological Organization\u0027s \"Year of Polar Prediction\". Researchers will use these additional observations to study new ways of incorporating data into existing weather prediction models. The primary goal of this research is to improve the accuracy of weather forecasts in Antarctica. This work is important, as the harsh weather in Antarctica greatly impacts scientific research and the support of this research. Being able to accurately predict changing weather increases the safety and efficiency of Antarctic field science and operations. The proposed effort seeks to advance goals of the World Meteorological Organization\u0027s Polar Prediction Project and its Year of Polar Prediction-Southern Hemisphere (YOPP-SH) effort. Researchers will investigate and demonstrate the forecast impact of enhanced atmospheric observations obtained from YOPP-SH\u0027s Special Observing Period on polar numerical weather prediction. This will be done by using the Antarctic Mesoscale Prediction System (AMPS). AMPS is the primary numerical weather prediction capability for the United States Antarctic Program (USAP). Modeling experimentation will assess the impact of Special Observing Period data on Antarctic forecasts and will serve as a vehicle for testing new data assimilation approaches for AMPS. The primary goal for this work is improved forecasting and numerical weather prediction tools. Outcomes will include quantification of the value of enhanced southern hemisphere atmospheric observations. This work will also help improve AMPS and its ability to support the USAP. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "VERTICAL PROFILES; Antarctica; USA/NSF; WATER VAPOR PROFILES; USAP-DC; AMD; Amd/Us; COMPUTERS; WIND PROFILES", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bromwich, David; Powers, Jordan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -90.0, "title": "Application of Year of Polar Prediction- Southern Hemisphere (YOPP-SH) Observations for Improvement of Antarctic Numerical Weather Prediction", "uid": "p0010308", "west": -180.0}, {"awards": "2149501 Mazloff, Matthew", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 04 Mar 2022 00:00:00 GMT", "description": "The Southern Ocean accounts for ~40% of the total ocean uptake of anthropogenic carbon dioxide despite covering only 20% of the global ocean surface, and is particularly rich in long-lived eddies. These eddies, or large ocean whirlpools which can be observed from space, can alter air-sea fluxes of carbon dioxide in ways that are not yet fully understood. New observations from autonomous platforms measuring ocean carbon content suggest that there is significant heterogeneity in ocean carbon fluxes which can be linked to these dynamic eddy features. Due to computational and time limitations, ocean eddies are not explicitly represented in most global climate simulations, limiting our ability to understand the role eddies play in the ocean carbon cycle. This study will explore the impact of eddies on ocean carbon content and air-sea carbon dioxide fluxes in the Southern Ocean using both simulated- and observation-based strategies and the findings will improve our understanding of the ocean\u2019s role in the carbon cycle and in global climate. While this work will primarily be focused on the Southern Ocean, the results will be globally applicable. The researchers will also broaden interest in physical and chemical oceanography among middle school-age girls in the University of South Florida\u2019s Oceanography Camp for Girls by augmenting existing lessons with computational methods in oceanography. This project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite sea surface height data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls, recognized by NSF as a \u201cModel STEM Program for Women and Girls\u201d focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; AMD; USA/NSF; USAP-DC; MODELS; BIOGEOCHEMICAL CYCLES; Amd/Us", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Mazloff, Matthew", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Diagnosing the role of ocean eddies in carbon cycling from a high- resolution data assimilating ocean biogeochemical model", "uid": "p0010304", "west": -180.0}, {"awards": "1643917 Fricker, Helen", "bounds_geometry": "POLYGON((-163.646 -84.186,-162.58715 -84.186,-161.5283 -84.186,-160.46945 -84.186,-159.4106 -84.186,-158.35175 -84.186,-157.2929 -84.186,-156.23405 -84.186,-155.1752 -84.186,-154.11635 -84.186,-153.0575 -84.186,-153.0575 -84.20871,-153.0575 -84.23142,-153.0575 -84.25413,-153.0575 -84.27684,-153.0575 -84.29955,-153.0575 -84.32226,-153.0575 -84.34497,-153.0575 -84.36768,-153.0575 -84.39039,-153.0575 -84.4131,-154.11635 -84.4131,-155.1752 -84.4131,-156.23405 -84.4131,-157.2929 -84.4131,-158.35175 -84.4131,-159.4106 -84.4131,-160.46945 -84.4131,-161.5283 -84.4131,-162.58715 -84.4131,-163.646 -84.4131,-163.646 -84.39039,-163.646 -84.36768,-163.646 -84.34497,-163.646 -84.32226,-163.646 -84.29955,-163.646 -84.27684,-163.646 -84.25413,-163.646 -84.23142,-163.646 -84.20871,-163.646 -84.186))", "dataset_titles": "Wideband magnetotelluric responses from Whillans Ice Stream, West Antarctica", "datasets": [{"dataset_uid": "601526", "doi": "10.15784/601526", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Stream; Magnetotelluric; Subglacial; Whillans Ice Stream", "people": "Fricker, Helen; Gustafson, Chloe; Key, Kerry; Siegfried, Matthew", "repository": "USAP-DC", "science_program": null, "title": "Wideband magnetotelluric responses from Whillans Ice Stream, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601526"}], "date_created": "Sat, 26 Feb 2022 00:00:00 GMT", "description": "The Antarctic ice sheet is underlain by a dynamic water system that lubricates the flow of ice streams and outlet glaciers, provides a habitat for a diverse microbial ecosystem, and delivers freshwater and nutrients to the Southern Ocean. However, imaging this subglacial environment is difficult: Antarctica is a vast continent with ice up to four kilometers (2.5 miles) thick. To detect water at the ice-bed interface and in deeper groundwater reservoirs, this project will adapt a technique called electromagnetic sounding that is well-established on land and in the ocean for imaging fluids beneath the surface. Groundwater is estimated to be a significant part of the subglacial water budget in Antarctica, yet previous observational approaches have been unable to characterize its volume and distribution. This project will thus yield critical information about how ice-rock-water-ocean systems interact and inform our understanding of ice-sheet processes, global nutrient cycles, and freshwater flux to the ocean. The project will provide cross-disciplinary training for a graduate student and postdoctoral scientist, and develop an educational outreach program through the Birch Aquarium. Standard geophysical surveying techniques used in glaciology to image subglacial water (radio-echo sounding and active-source seismology) are not directly sensitive to water content. In contrast, ground-based electromagnetic (EM) methods are sensitive to water content through its impact on bulk conductivity. Although EM methods are well-established for high-precision mapping of hydrology in other geological environments, their application on ice sheets is in its infancy. The proposed work will adapt both passive- and active-source EM techniques to glaciological questions to quantify the three-dimensional structure of subglacial water beneath an ice stream and in a grounding zone. The project will perform a suite of synthetic inversion studies to determine the range of applications of EM techniques in glaciology and execute a field experiment on the Whillans Ice Plain to investigate two hypotheses about the subglacial water system based on previous observational and modeling results: (1) Subglacial Lake Whillans is underlain by a deep, saline groundwater reservoir; and (2) there is an estuary-like zone of mixing between fresh subglacial water and seawater near, and possibly landward, of the grounding line.", "east": -153.0575, "geometry": "POINT(-158.35175 -84.29955)", "instruments": null, "is_usap_dc": true, "keywords": "Whillans Ice Stream; GROUND WATER; USA/NSF; USAP-DC; AMD; GEOMAGNETIC INDUCTION; Amd/Us; FIELD SURVEYS", "locations": "Whillans Ice Stream", "north": -84.186, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Key, Kerry; Fricker, Helen; Siegfried, Matthew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.4131, "title": "Mapping Antarctic Subglacial Water with Novel Electromagnetic Techniques", "uid": "p0010300", "west": -163.646}, {"awards": "0342484 Harwood, David", "bounds_geometry": "POINT(167.083333 -77.888889)", "dataset_titles": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601451", "doi": "10.15784/601451", "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; McMurdo Sound; Miocene; Paleoclimate; Particle Size", "people": "Passchier, Sandra; Candice, Falk", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601451"}], "date_created": "Fri, 04 Feb 2022 00:00:00 GMT", "description": "ANDRILL is a scientific drilling program to investigate Antarctica\u0027s role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica\u0027s climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth\u0027s ocean-climate system. \u003cbr/\u003e\u003cbr/\u003eThis award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica\u0027s major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.\u003cbr/\u003e\u003cbr/\u003eThe South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area\u0027s complex tectonic history.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society\u0027s understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. \u003cbr/\u003e\u003cbr/\u003eAs key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica\u0027s ice sheets are important to society\u0027s understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth\u0027s climatic future.", "east": 167.083333, "geometry": "POINT(167.083333 -77.888889)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; FIELD SURVEYS; ICE SHEETS; USA/NSF; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; Ross Ice Shelf; SEDIMENTS", "locations": "Ross Ice Shelf", "north": -77.888889, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harwood, David; Levy, Richard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.888889, "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "uid": "p0010297", "west": 167.083333}, {"awards": "1946326 Doran, Peter", "bounds_geometry": "POLYGON((161 -77.4,161.3 -77.4,161.6 -77.4,161.9 -77.4,162.2 -77.4,162.5 -77.4,162.8 -77.4,163.1 -77.4,163.4 -77.4,163.7 -77.4,164 -77.4,164 -77.46,164 -77.52,164 -77.58,164 -77.64,164 -77.7,164 -77.76,164 -77.82,164 -77.88,164 -77.94,164 -78,163.7 -78,163.4 -78,163.1 -78,162.8 -78,162.5 -78,162.2 -78,161.9 -78,161.6 -78,161.3 -78,161 -78,161 -77.94,161 -77.88,161 -77.82,161 -77.76,161 -77.7,161 -77.64,161 -77.58,161 -77.52,161 -77.46,161 -77.4))", "dataset_titles": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: Infrared Stimulated Luminescence data; EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: in situ 14C data", "datasets": [{"dataset_uid": "601520", "doi": "10.15784/601520", "keywords": "Antarctica; Sample/collection Description; Sample/Collection Description; Sample Location; Taylor Valley", "people": "Doran, Peter; Stone, Michael", "repository": "USAP-DC", "science_program": "LTER", "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: Infrared Stimulated Luminescence data", "url": "https://www.usap-dc.org/view/dataset/601520"}, {"dataset_uid": "601521", "doi": "10.15784/601521", "keywords": "Antarctica; Carbon-14; Sample/collection Description; Sample/Collection Description; Sample Location; Taylor Valley", "people": "Doran, Peter; Stone, Michael", "repository": "USAP-DC", "science_program": null, "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers: in situ 14C data", "url": "https://www.usap-dc.org/view/dataset/601521"}], "date_created": "Mon, 31 Jan 2022 00:00:00 GMT", "description": "Correlating ecosystem responses to past climate forcing is highly dependent on the use of reliable techniques for establishing the age of events (dating techniques). In Antarctic dry regions (land areas without glaciers), carbon-14 dating has been used to assess the ages of organic deposits left behind by ancient lakes. However, the reliability of the ages is debatable because of possible contamination with \"old carbon\" from the surrounding landscape. The proposed research will attempt to establish two alternate dating techniques, in situ carbon-14 cosmogenic radionuclide exposure dating and optically stimulated luminescence (OSL), as reliable alternate dating methods for lake history in Antarctic dry areas that are not contaminated by the old carbon. The end goal will be to increase scientific understanding of lake level fluctuation in the lakes of Taylor Valley, Antarctica so that inference about past climate, glacier, and ecosystem response can be inferred. The results of this study will provide a coarse-scale absolute chronology for lake level history in Taylor Valley, demonstrate that exposure dating and OSL are effective means to understand the physical dynamics of ancient water bodies, and increase the current understanding of polar lacustrine and ice sheet responses to past and present climatic changes. These chronologies will allow polar lake level fluctuations to be correlated with past changes in global and regional climate, providing information critical for understanding and modeling the physical responses of these environments to modern change. This research supports a PhD student; the student will highlight this work with grade school classes in the United States. This research aims to establish in situ carbon-14 exposure dating and OSL as reliable alternate (to carbon-14 of organic lake deposits) geochronometers that can be used to settle the long-disputed lacustrine history and chronology of Taylor Valley, Antarctica and elsewhere. Improved lake level history will have significant impacts for the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) site as the legacy of fluctuating lake levels of the past affects the distribution of organic matter and nutrients, and impacts biological connectivity valley-wide. This work will provide insight into the carbon reservoir of large glacial lakes in the late Holocene and have implications for previously reported radiocarbon chronologies. OSL samples will be analyzed in the Desert Research Institute Luminescence Laboratory in Reno, NV. For the in situ carbon-14 work, rock samples extracted from boulders and bedrock surfaces will be prepared at Tulane University. The prepared in situ carbon-14 samples will be analyzed at the National Ocean Sciences Accelerator Mass Spectrometry laboratory in Woods Hole, MA. The two datasets will be combined to produce a reliable, coarse scale chronology for late Quaternary lake level fluctuations in Taylor Valley. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 164.0, "geometry": "POINT(162.5 -77.7)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; Taylor Valley; AGE DETERMINATIONS; USA/NSF; AMD; USAP-DC", "locations": "Taylor Valley", "north": -77.4, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Earth Sciences", "paleo_time": null, "persons": "Doran, Peter", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "LTER", "south": -78.0, "title": "EAGER: Refining glacial lake history in Taylor Valley, East Antarctica with alternative geochronometers", "uid": "p0010294", "west": 161.0}, {"awards": "1744800 Adcroft, Alistair; 1744835 Wagner, Till", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Model of iceberg drift and decay including breakup", "datasets": [{"dataset_uid": "601510", "doi": "10.15784/601510", "keywords": "Antarctica; Footloose Mechanism; Iceberg Breakup; Iceberg Decay; Model; Southern Ocean", "people": "Wagner, Till; England, Mark", "repository": "USAP-DC", "science_program": null, "title": "Model of iceberg drift and decay including breakup", "url": "https://www.usap-dc.org/view/dataset/601510"}], "date_created": "Tue, 18 Jan 2022 00:00:00 GMT", "description": "Icebergs are a component of the Antarctic climate system, yet a comprehensive representation of their dynamics in climate models has remained elusive. Representing the role of icebergs in global climate models (GCMs) poses a formidable challenge to the scientific community. The most striking shortcoming of current iceberg models is arguably that they do not represent giant tabular icebergs, even though giant icebergs carry most of the freshwater stored in icebergs in the Southern Ocean. This lack of large icebergs in models is mostly due to the difficulties associated with adequately modeling iceberg decay. In particular, fracturing and breakup are not typically considered in iceberg models, despite being dominant iceberg decay processes. Investigators are to address these issues using a hierarchy of iceberg models, ranging from an idealized analytical model to a comprehensive GCM, in concert with recent observational data. The main objective of this study is to develop a new iceberg model that: (i) accounts for iceberg breakup and fracturing processes that have been neglected to date, (ii) improves on the representation of iceberg decay processes that were considered in previous models, (iii) explicitly represents large tabular icebergs. The primary broader impact of the proposed work will be through a K-12 teacher workshop series showcasing this project as an example of how scientists develop physical models. Ongoing changes in the California K-12 science standards will enable the teachers to creatively use this material in their classrooms. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; ICEBERGS; USA/NSF; Southern Ocean; AMD; USAP-DC; COMPUTERS", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Wagner, Till; Eisenman, Ian", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Modeling Giant Icebergs and Their Decay", "uid": "p0010290", "west": -180.0}, {"awards": "2031554 Chartier, Alex; 2032421 Kim, Hyomin", "bounds_geometry": "POLYGON((-180 -75,-144 -75,-108 -75,-72 -75,-36 -75,0 -75,36 -75,72 -75,108 -75,144 -75,180 -75,180 -76.5,180 -78,180 -79.5,180 -81,180 -82.5,180 -84,180 -85.5,180 -87,180 -88.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88.5,-180 -87,-180 -85.5,-180 -84,-180 -82.5,-180 -81,-180 -79.5,-180 -78,-180 -76.5,-180 -75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 31 Dec 2021 00:00:00 GMT", "description": "This award is funded in whole or part under the American Rescue Plan Act of 2021 (Public Law 117-2). The Geospace environment comprises a complex system of the incoming solar wind plasma flow interacting with the Earth\u0027s magnetic field and transferring its energy and momentum into the magnetosphere. This interaction takes place mainly on the Earth\u0027s dayside, where reconnecting geomagnetic field line might be \"open\" and directly connected to the interplanetary magnetic field lines, thus providing direct pathways for the solar wind energy to be transferred down to the ionosphere and upper atmosphere. The spatial extent of the polar cap areas controlled by the ionospheric plasma convection demarcate the so-called \"Open-Closed Boundary\" where solar wind particles reach down polar ionospheres. Observations of that boundary serve the important role in validating geomagnetic field modeling and help studying space weather. Motivated by the compelling Geospace research in the polar regions, this award will allow scientists to investigate magnetosphere-ionosphere coupling processes and ionospheric irregularities inside the polar caps and their space weather impacts by establishing a new ground-based network that will be deployed in the Antarctic polar cap region. This will be achieved using three new instrumented platforms (next generation of Automatic Geophysical Observatories) along the snow traverse route from the Korean Antarctic Station Jang Bogo toward to the Concordia Station at Dome C by the Korea Polar Research Institute\u0027s (KOPRI) team. Geospace data collected by these three platforms will be shared by the U.S. and Korean researchers, as well as will be made available to other scientists. The research involves early-career researchers, as well as train students who will build and operate remote Antarctic platforms, as well as analyze collected data to investigate space weather events and validate models. This project expands the U.S. institutions partnership with the KOPRI scientists and logistical support personnel. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; USA/NSF; Jang Bogo Station; Jang Bogo Station And A Traverse Route On The Antarctic Plateau; USAP-DC; FIELD SURVEYS; MAGNETIC FIELDS/MAGNETIC CURRENTS; AURORAE; AMD", "locations": "Jang Bogo Station And A Traverse Route On The Antarctic Plateau; Jang Bogo Station", "north": -75.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Astrophysics and Geospace Sciences; Antarctic Astrophysics and Geospace Sciences", "paleo_time": null, "persons": "Kim, Hyomin; Perry, Gareth; Chartier, Alex", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Investigation of Deep Polar Cap Dynamics Using an Autonomous Instrument Network", "uid": "p0010288", "west": -180.0}, {"awards": "2039419 Swanger, Kate", "bounds_geometry": "POLYGON((161 -77.3,161.2 -77.3,161.4 -77.3,161.6 -77.3,161.8 -77.3,162 -77.3,162.2 -77.3,162.4 -77.3,162.6 -77.3,162.8 -77.3,163 -77.3,163 -77.35,163 -77.4,163 -77.45,163 -77.5,163 -77.55,163 -77.6,163 -77.65,163 -77.7,163 -77.75,163 -77.8,162.8 -77.8,162.6 -77.8,162.4 -77.8,162.2 -77.8,162 -77.8,161.8 -77.8,161.6 -77.8,161.4 -77.8,161.2 -77.8,161 -77.8,161 -77.75,161 -77.7,161 -77.65,161 -77.6,161 -77.55,161 -77.5,161 -77.45,161 -77.4,161 -77.35,161 -77.3))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 16 Dec 2021 00:00:00 GMT", "description": "The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina. The PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master\u2019s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 163.0, "geometry": "POINT(162 -77.55)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; SEDIMENTS; USA/NSF; AMD; Dry Valleys; USAP-DC", "locations": "Dry Valleys", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -77.8, "title": "Collaborative Research: Holocene and Late Pleistocene Stream Deposition in the McMurdo Dry Valleys, Antarctica as a Proxy for Glacial Meltwater and Paleoclimate", "uid": "p0010285", "west": 161.0}, {"awards": "1643394 Buizert, Christo", "bounds_geometry": "POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65))", "dataset_titles": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "200257", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "GISP2 and WAIS Divide Ice Cores 60,000 Year Surface Temperature Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/34133"}, {"dataset_uid": "200255", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/32632"}, {"dataset_uid": "200256", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncei.noaa.gov/access/paleo-search/study/24530"}], "date_created": "Wed, 10 Nov 2021 00:00:00 GMT", "description": "Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ISOTOPES; Antarctica; USA/NSF; AMD; ICE CORE RECORDS; USAP-DC; VOLCANIC DEPOSITS; MODELS; Amd/Us", "locations": "Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Buizert, Christo; Wettstein, Justin", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw in Antarctica from Synchronized Ice Cores", "uid": "p0010279", "west": -180.0}, {"awards": "2138556 Halberstadt, Anna Ruth", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities; 5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "datasets": [{"dataset_uid": "601602", "doi": "10.15784/601602", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Balco, Gregory; Buchband, Hannah; Halberstadt, Anna Ruth", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"sensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601602"}, {"dataset_uid": "601601", "doi": "10.15784/601601", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Modeling; Marine Ice Margin Instability; Model Output", "people": "Halberstadt, Anna Ruth; Buchband, Hannah; Balco, Gregory", "repository": "USAP-DC", "science_program": null, "title": "5 million year transient Antarctic ice sheet model run with \"desensitized\" marine ice margin instabilities", "url": "https://www.usap-dc.org/view/dataset/601601"}], "date_created": "Tue, 09 Nov 2021 00:00:00 GMT", "description": "Geologic data provide crucial insights into Antarctic Ice Sheet dynamics; for example, progressive exposure of mountain peaks emerging from the ice sheet reveal ice elevation changes, and the past \u2018footprint\u2019 of marine-based ice sheets is imprinted on the seafloor. Numerical ice sheet simulations can link these geologic records in space and time to make larger-scale inferences about continent-wide ice sheet evolution. This work integrates both marine and terrestrial geologic datasets with numerical simulations to investigate Antarctic Ice Sheet behavior (and contribution to global sea level) throughout the last deglaciation, ~20,000 years ago until present. Specifically, this research addresses two issues regarding the relationship between simulations and data and their use in reconstructing past ice-sheet behavior: (1) Geologic records from the modern seafloor suggest significantly earlier retreat of marine-based ice compared to terrestrial records of mountain peak exposure (ice thinning). Computer experiments investigate several hypotheses for this mismatch in timing. (2) Exposure age data (terrestrial measurements recording ice elevation changes) are often interpreted to reflect ice dynamics hundreds of kilometers away from the study site. This work uses simulations to explore the linkage between ice elevation changes \u2018upstream\u2019 as glaciers flow through mountainous regions and ice dynamics further \u2018downstream\u2019 where ice contacts the ocean. This work will produce a publicly available, customizable, and easily accessible toolkit for comparing simulations and data, including a database of geologic records to use as constraints. The project is interdisciplinary, bridging a communication gap between the ice-sheet simulations and geologic data-collecting communities. This project combines numerical simulations and geologic data to explore fundamental knowledge gaps regarding the interpretation and use of marine and terrestrial datasets. This work will produce an ensemble of continent-wide coupled ice sheet and glacial isostatic adjustment simulations, constrained with comprehensive existing geologic data, to reproduce a history of deglacial Antarctic Ice Sheet evolution that is compatible with the geologic record as well as glaciologically and gravitationally self-consistent. Comparison between simulations and data is improved through high-resolution nested ice sheet modeling techniques, which provide unprecedented context for exposure age data generally located in regions of complex topography. Numerical simulations will be performed with systematically varied parameters and boundary conditions, and can thus support an investigation of (1) chronological mismatches between terrestrial thinning and marine ice sheet retreat during the mid-Holocene, and (2) how marine grounding-line dynamics are propagated upstream to coastal outlet glaciers and further interior under a variety of different scenarios. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; GLACIERS/ICE SHEETS; USAP-DC; USA/NSF; MODELS; AMD; Amd/Us", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Halberstadt, Anna Ruth", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "OPP-PRF: High-resolution Nested Antarctic Ice Sheet Modeling to Reconcile Marine and Terrestrial Geologic Data", "uid": "p0010278", "west": -180.0}, {"awards": "2136938 Tedesco, Marco; 2136940 Newman, Dava; 2136939 Cervone, Guido", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Surface melt-related multi-source remote-sensing and climate model data over Helheim Glacier, Greenland for segmentation and machine learning applications; Surface melt-related multi-source remote-sensing and climate model data over Larsen C Ice Shelf, Antarctica for segmentation and machine learning applications", "datasets": [{"dataset_uid": "601841", "doi": "10.15784/601841", "keywords": "Antarctica; Climate Modeling; Cryosphere; Downscaling; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland; Ice Sheet; Machine Learning; MAR; Remote Sensing; Sea Level Rise; Snow/ice; Snow/Ice; Surface Melt", "people": "Alexander, Patrick; Antwerpen, Raphael; Cervone, Guido; Fettweis, Xavier; L\u00fctjens, Bj\u00f6rn; Tedesco, Marco", "repository": "USAP-DC", "science_program": null, "title": "Surface melt-related multi-source remote-sensing and climate model data over Helheim Glacier, Greenland for segmentation and machine learning applications", "url": "https://www.usap-dc.org/view/dataset/601841"}, {"dataset_uid": "601842", "doi": "10.15784/601842", "keywords": "Antarctica; Climate Modeling; Cryosphere; Downscaling; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Larsen C Ice Shelf; Machine Learning; MAR; Remote Sensing; Sea Level Rise; Snow/ice; Snow/Ice; Surface Melt", "people": "Alexander, Patrick; Tedesco, Marco; L\u00fctjens, Bj\u00f6rn; Fettweis, Xavier; Cervone, Guido; Antwerpen, Raphael", "repository": "USAP-DC", "science_program": null, "title": "Surface melt-related multi-source remote-sensing and climate model data over Larsen C Ice Shelf, Antarctica for segmentation and machine learning applications", "url": "https://www.usap-dc.org/view/dataset/601842"}], "date_created": "Mon, 08 Nov 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Climate change is promoting increased melting in Greenland and Antarctica, contributing to the global sea level rise. Understanding what drives the increase and the amount of meltwater from the ice sheets is paramount to improve our skills to project future sea level rise and associated consequences. Melting in Antarctica mostly occurs along ice shelves (tongues of ice floating in the water). They do not contribute directly to sea level when they melt but their disappearance allows the glaciers at the top to flow faster towards the ocean, increasing the contribution of Antarctica to sea level rise. Satellite data can only offer a partial view of what is happening, either because of limited coverage or because of the presence of clouds, which often obstruct the view in this part of the world. Models, on the other hand, can provide estimates but the spatial detail they can provide is still limited by many factors. This project will use artificial intelligence to overcome these problems and to merge satellite data and model outputs to generate daily maps of surface melting with unprecedented detail. These techniques are similar to those used in cell phones to sharpen images or to create landscapes that look \u201creal\u201d but are only existing in the \u201ccomputer world,\u201d but they have never been applied to melting in Antarctica for improving estimates of sea level rise. Meltwater in Antarctica has been shown to impact ice shelf stability through the fracturing and flexural processes. Image scarcity has often forced the community to use general climate and regional climate models to explore hydrological features. Notwithstanding models having been considerably refined over the past years, they still require improvements in capturing the processes driving the energy balance and, most importantly, the feedback among the drivers and the energy balance terms that drive the hydrological processes. Moreover, spatial resolution is still too coarse to properly capture hydrological processes, especially over ice shelves. Machine learning (ML) tools can help in this regard, especially when it is computationally infeasible to run physics-based models at desired resolutions in space and time, like in the case of ice shelf surface hydrology. This project will train Generative Adversarial Networks (GANs) with the outputs of a regional climate model and remote sensing data to generate unprecedented, high-resolution (100 m) maps of surface melting. Beside improving the spatial resolution, and hence providing a long-needed and crucial dataset to the polar community, the tool here proposed will be able to provide satellite-like maps on a daily basis, hence addressing also those issues related to the lack of spatial coverage. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; Amd/Us; AMD; USA/NSF; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; USAP-DC; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Polar Cyberinfrastructure; Polar Cyberinfrastructure; Polar Cyberinfrastructure", "paleo_time": null, "persons": "Tedesco, Marco", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: EAGER: Generation of high resolution surface melting maps over Antarctica using regional climate models, remote sensing and machine learning", "uid": "p0010277", "west": -180.0}, {"awards": "2139002 Huth, Alexander", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Simulations of ice-shelf rifting on Larsen C Ice Shelf", "datasets": [{"dataset_uid": "601718", "doi": "10.15784/601718", "keywords": "Antarctica; Glaciology; Iceberg; Ice Shelf Dynamics; Larsen C Ice Shelf; Model Data; Modeling", "people": "Huth, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Simulations of ice-shelf rifting on Larsen C Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601718"}], "date_created": "Fri, 05 Nov 2021 00:00:00 GMT", "description": "Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models. In this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; ICEBERGS; AMD; Antarctic Ice Sheet; USA/NSF; GLACIERS/ICE SHEETS; Amd/Us; MODELS", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Post Doc/Travel", "paleo_time": null, "persons": "Huth, Alex", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "OPP-PRF Calving, Icebergs, and Climate", "uid": "p0010276", "west": -180.0}, {"awards": "1744949 Campbell, Seth; 1744927 Mitrovica, Jerry; 1745015 Zimmerer, Matthew", "bounds_geometry": "POLYGON((-145 -74,-141.6 -74,-138.2 -74,-134.8 -74,-131.4 -74,-128 -74,-124.6 -74,-121.2 -74,-117.8 -74,-114.4 -74,-111 -74,-111 -74.6,-111 -75.2,-111 -75.8,-111 -76.4,-111 -77,-111 -77.6,-111 -78.2,-111 -78.8,-111 -79.4,-111 -80,-114.4 -80,-117.8 -80,-121.2 -80,-124.6 -80,-128 -80,-131.4 -80,-134.8 -80,-138.2 -80,-141.6 -80,-145 -80,-145 -79.4,-145 -78.8,-145 -78.2,-145 -77.6,-145 -77,-145 -76.4,-145 -75.8,-145 -75.2,-145 -74.6,-145 -74))", "dataset_titles": "Mt. Waesche ground-penetrating radar data 2018-2019", "datasets": [{"dataset_uid": "601490", "doi": "10.15784/601490", "keywords": "Antarctica; GPR; Mt. Waesche", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": null, "title": "Mt. Waesche ground-penetrating radar data 2018-2019", "url": "https://www.usap-dc.org/view/dataset/601490"}], "date_created": "Fri, 22 Oct 2021 00:00:00 GMT", "description": "This study will collect a novel dataset to determine how the West Antarctic Ice Sheet (WAIS) responded to a warmer climate during the last interglacial period (~125,000 years ago) by reconstructing the glacial history at the Mt. Waesche volcano. Reconstructing WAIS geometry when the ice sheet was smaller than present is difficult and data are lacking because the evidence lies beneath the present ice sheet. This study will drill through the ice sheet and recover bedrock that can be analyzed for its surface exposure history to help determine when the surface became overridden by the ice sheet. This study will provide constraints on the past maximum and minimum spatial extent of WAIS during the last glacial-interglacial cycle. Understanding the geometry of a reduced WAIS during intervals when the planet was warmer than present may provide a possible analogue for future environmental conditions given predicted temperature trends. A reduction of WAIS results in rising sea levels which threatens coastal communities across the globe. The data will help improve numerical ice sheet models to better predict WAIS response to current and future climate trends. The project supports a teacher educational workshop and the training of graduate and undergraduate students. The goal of this project is to obtain rock samples from beneath the WAIS through shallow (\u003c80 m) drilling at Mt. Waesche, a volcano in Marie Byrd Land, near an ice dome of WAIS (2000 m elevation). The lithologies of lava flows exposed on the flank of the volcano are well-suited for cosmogenic 3He and 36Cl as well as 40Ar/39Ar measurements which will establish eruption and exposure age. Existing 40Ar/39Ar data indicate basaltic lava flows on the volcano flank as young as 350 ka. Thus, measured cosmogenic nuclides measured in rock cores from beneath the ice surface will be indicative of relatively recent exposure during periods of reduced ice elevation, most likely, during the last interglacial. The first field season is focused on identifying appropriate locations for drilling and a ground penetrating radar (GPR) survey of the subglacial topography \u003c100m under the blue ice area. Mapping and dating the adjacent exposed lava flows will allow tracing of lava flows of known age and composition below the ice margin that will be targeted for drilling the following year. The second field season activities include drilling 8 boreholes (two transects) through blue ice with the Winkie drill near the ice margin to 80 m depth to obtain rock cores from the sub-ice lava flows. 3He exposure ages will constrain the duration and minimum extent of past surface lowering of the WAIS in Marie Byrd Land. Deeper GPR imaging (up to 700 m) will hope to reveal additional evidence of lava/ice interactions that would independently place constraints on lower ice levels during past eruptions. Results from this study will be compared with the modeled ice elevation histories at Mt. Waesche to validate ice sheet modeling efforts. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -111.0, "geometry": "POINT(-128 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Mt. Waesche; USA/NSF; SNOW/ICE; GLACIER THICKNESS/ICE SHEET THICKNESS; PALEOCLIMATE RECONSTRUCTIONS; LABORATORY; LAVA COMPOSITION/TEXTURE; Amd/Us; AMD; USAP-DC", "locations": "Mt. Waesche", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Braddock, Scott; Campbell, Seth; Ackert, Robert; Zimmerer, Matthew; Mitrovica, Jerry", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: Constraining West Antarctic Ice Sheet elevation during the last interglacial", "uid": "p0010272", "west": -145.0}, {"awards": "2035637 Tabor, Clay; 2035580 Aarons, Sarah", "bounds_geometry": null, "dataset_titles": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area; Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.; Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "datasets": [{"dataset_uid": "601821", "doi": "10.15784/601821", "keywords": "ALHIC1903; Allan Hills; Antarctica; Blue Ice; Cryosphere; Dust; Leach; Rare Earth Element", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Rare earth elemental concentrations of leached ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601821"}, {"dataset_uid": "601820", "doi": "10.15784/601820", "keywords": "ALHIC1903; Allan Hills; Antarctica; Cryosphere; Dust; Ice Core Data; Isotope; Nd; Neodymium; Sr; Strontium", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": null, "title": "Strontium and neodymium isotope compositions of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601820"}, {"dataset_uid": "601822", "doi": "10.15784/601822", "keywords": "ALHIC1903; Allan Hills; Antarctica; Cryosphere; Deuterium; Hydrogen; Ice; Ice Core Data; Isotope; Oxygen; Water", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Oxygen and hydrogen isotope compositions and associated d-excess of ice from ALHIC1903 drilled at the Allan Hills Blue Ice Area.", "url": "https://www.usap-dc.org/view/dataset/601822"}, {"dataset_uid": "601825", "doi": "10.15784/601825", "keywords": "Accumulation Rate; ALHIC1903; Allan Hills; Antarctica; Blue Ice; Concentration; Cryosphere; Dust; Flux", "people": "Carter, Austin", "repository": "USAP-DC", "science_program": null, "title": "Concentration and flux of ice core dust from ALHIC1903 drilled at the Allan Hills Blue Ice Area", "url": "https://www.usap-dc.org/view/dataset/601825"}], "date_created": "Wed, 06 Oct 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The spatial extent of the West Antarctic Ice Sheet during the last interglacial period (129,000 to 116,000 years ago) is currently unknown, yet this information is fundamental to projections of the future stability of the ice sheet in a warming climate. Paleoclimate records and proxy evidence such as dust can inform on past environmental conditions and ice-sheet coverage. This project will combine new, high-sensitivity geochemical measurements of dust from Antarctic ice collected at Allan Hills with existing water isotope records to document climate and environmental changes through the last interglacial period. These changes will then be compared with Earth-system model simulations of dust and water isotopes to determine past conditions and constrain the sensitivity of the West Antarctic Ice Sheet to warming. The project will test the hypothesis that the uncharacteristically volcanic dust composition observed at another peripheral ice core site at Taylor Glacier during the last interglacial period is related to changes in the spatial extent of the West Antarctic Ice Sheet. This project aims to characterize mineral dust transport during the penultimate glacial-interglacial transition. The team will apply high-precision geochemical techniques to the high-volume, high-resolution ice core drilled at the Allan Hills site in combination with Earth system model simulations to: (1) determine if the volcanic dust signature found in interglacial ice from Taylor Glacier is also found at Allan Hills, (2) determine the likely dust source(s) to this site during the last interglacial, and (3) probe the atmospheric and environmental changes during the last interglacial with a diminished West Antarctic Ice Sheet. The team will develop a suite of measurements on previously drilled ice from Allan Hills, including isotopic compositions of Strontium and Neodymium, trace element concentrations, dust-size distribution, and imaging of ice-core dust to confirm the original signal observed and provide a broader spatial reconstruction of dust transport. In tandem, the team will conduct Earth system modeling with prognostic dust and water-isotope capability to test the sensitivity of dust transport under several plausible ice-sheet and freshwater-flux configurations. By comparing dust reconstruction and model simulations, the team aims to elucidate the driving mechanisms behind dust transport during the last interglacial period. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "MICROPARTICLE CONCENTRATION; FIELD SURVEYS; GEOCHEMISTRY; ICE EXTENT; Amd/Us; USA/NSF; PALEOCLIMATE RECONSTRUCTIONS; AMD; Allan Hills; ICE CORE RECORDS; USAP-DC", "locations": "Allan Hills", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Aarons, Sarah; Tabor, Clay", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Peripheral East Antarctic ice as a unique recorder of climate variability during the Last Interglacial", "uid": "p0010270", "west": null}, {"awards": "1916665 Mahon, Andrew; 1916661 Halanych, Kenneth; 2225144 Halanych, Kenneth", "bounds_geometry": "POLYGON((-72 -61,-69.8 -61,-67.6 -61,-65.4 -61,-63.2 -61,-61 -61,-58.8 -61,-56.6 -61,-54.4 -61,-52.2 -61,-50 -61,-50 -61.8,-50 -62.6,-50 -63.4,-50 -64.2,-50 -65,-50 -65.8,-50 -66.6,-50 -67.4,-50 -68.2,-50 -69,-52.2 -69,-54.4 -69,-56.6 -69,-58.8 -69,-61 -69,-63.2 -69,-65.4 -69,-67.6 -69,-69.8 -69,-72 -69,-72 -68.2,-72 -67.4,-72 -66.6,-72 -65.8,-72 -65,-72 -64.2,-72 -63.4,-72 -62.6,-72 -61.8,-72 -61))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 22 Sep 2021 00:00:00 GMT", "description": "Antarctica is among the most rapidly warming places on the planet, and some reports suggest the Antarctic environment is approaching, or possibly beyond, the tipping point for ice shelf collapse. The loss of ice around Antarctica is dramatically changing habitat availability for marine fauna, particularly benthic marine invertebrate species. Building on past studies, this research will provide insights into how changing climate impacts species distribution and community structure. Geological data suggests that during periods when ice extent was much reduced relative to modern levels, marine seaways connected the Ross and Weddell Seas on either side of Antarctica. However, most theories about the origins of current marine invertebrate distribution patterns fail to consider this transantarctic connection. This research will use molecular genomic tools to probe the DNA of Antarctic marine invertebrates and explore alternative hypotheses about factors that may have shaped current patterns of animal biodiversity in the Southern Ocean. Research will inform predictions about how species distributions may change as Antarctic ice sheets continue to deteriorate and provide critical information on how organisms adjust their ranges in response to environmental change. This work includes several specific outreach activities including presentations in K-8 classrooms, several short-format videos on Antarctic genomics and field work, and two 3-day workshops on bioinformatics approaches. A minimum of 4 graduate students, a postdoc and several undergraduates will also be trained during this project. The overarching goal of this research is to understand environmental factors that have shaped patterns of present-day diversity in Antarctic benthic marine invertebrates. Evidence from sediment cores and modeling suggests ice shelf collapses have occurred multiple times in the last few million years. During these periods, transantarctic seaways connected the Ross and Weddell Seas. This research will assess whether the presence of transantarctic waterways helps explain observed similarities between the Ross and Weddell Seas benthic marine invertebrate fauna better than other current hypotheses (e.g., dispersal by the Antarctic Circumpolar Current, or expansion from common glacial refugia). Seven Antarctic benthic invertebrate taxa will be targeted to test alternative hypothesis about the origins of population genetic structure in the Southern Ocean using Single Nucleotide Polymorphism (SNP) markers that sample thousands of loci across the genome. Additionally, research will test the current paradigm that divergence between closely related, often cryptic, species is the result of population bottlenecks caused by glaciation. Specifically, SNP data will be mapped on to draft genomes of three of our target taxa to assess the degree of genetic divergence and look for signs of selection. Research findings may be applicable to other marine ecosystems around the planet. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -50.0, "geometry": "POINT(-61 -65)", "instruments": null, "is_usap_dc": true, "keywords": "Marguerite Bay; USA/NSF; AMD; Weddell Sea; USAP-DC; FIELD SURVEYS; Amd/Us; MARINE ECOSYSTEMS; ANIMALS/INVERTEBRATES", "locations": "Weddell Sea; Marguerite Bay", "north": -61.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Halanych, Kenneth; Mahon, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -69.0, "title": "Collaborative Research: Have transantarctic dispersal corridors impacted Antarctic marine biodiversity?", "uid": "p0010266", "west": -72.0}, {"awards": "2039432 Grapenthin, Ronni", "bounds_geometry": "POLYGON((165.5 -77.1,165.91 -77.1,166.32 -77.1,166.73 -77.1,167.14 -77.1,167.55 -77.1,167.96 -77.1,168.37 -77.1,168.78 -77.1,169.19 -77.1,169.6 -77.1,169.6 -77.18,169.6 -77.26,169.6 -77.34,169.6 -77.42,169.6 -77.5,169.6 -77.58,169.6 -77.66,169.6 -77.74,169.6 -77.82,169.6 -77.9,169.19 -77.9,168.78 -77.9,168.37 -77.9,167.96 -77.9,167.55 -77.9,167.14 -77.9,166.73 -77.9,166.32 -77.9,165.91 -77.9,165.5 -77.9,165.5 -77.82,165.5 -77.74,165.5 -77.66,165.5 -77.58,165.5 -77.5,165.5 -77.42,165.5 -77.34,165.5 -77.26,165.5 -77.18,165.5 -77.1))", "dataset_titles": "Erebus GPS timeseries ", "datasets": [{"dataset_uid": "601471", "doi": "10.15784/601471", "keywords": "Antarctica; GPS; Mount Erebus; Ross Island", "people": "Grapenthin, Ronni", "repository": "USAP-DC", "science_program": null, "title": "Erebus GPS timeseries ", "url": "https://www.usap-dc.org/view/dataset/601471"}], "date_created": "Fri, 03 Sep 2021 00:00:00 GMT", "description": "Nontechnical Abstract Mount Erebus volcano on Ross Island, Antarctica, is the southernmost active volcano on the planet. It provides a natural laboratory to study a volcanic system that has been in a continuous state of activity with a persistent lava lake over at least the last 40 years. Worldwide only four other volcanoes with such long-lived lava lakes exist: Erta Ale, Ethiopia; Kilauea, Hawaii; Nyiragongo, Congo; and Ambrym, Vanuatu. These volcanoes are a rare anomaly that provide a window into the underlying magmatic system and behavior. Erebus is of particular interest as it cycles through phases of very explosive activity every 20 thousand years. This project will investigate interactions between the magmatic system, the rift it is located in, and the impact of the gravitational load the volcano imposes on the underlying crust and its own magmatic system. Possible interactions between these factors may explain the changes in activity. The project will analyze geophysical data that have been collected at Erebus over at least the last two decades. The results of this work will be available to the public and scientific community and inform geodynamic models in this region. The project funds an early-career scientist and a graduate student at New Mexico Tech and contributes to the development of the next generation of scientists. Technical Abstract The proposed work targets scientific questions recently formulated by the community during the 2016 NSF-sponsored Scientific Drivers and Future of Mount Erebus Volcano Observatory workshop. The location and geometry of the magmatic plumbing from vent to lower crust system remain poorly constrained, particularly below 1 km depth. The style and causes for changes in volcanic and magmatic activity over the short term (minutes to hours) and on the decadal scale remains enigmatic. Two decades of campaign and continuous GPS data on Ross Island will inform about the longer term dynamics of both, Ross Island growing within the Terror Rift, and Erebus? deeper magmatic system. This project will organize and analyze all existing GPS data for Ross Island, and interpret any anomalies in the resulting time series. These activities require organization, consistent processing and interpretation/modeling of the existing ~20 years of GPS data, which include campaign, continuous, and high-rate GPS observations. We will generate these position time series in a consistent local reference frame and make the results, including models of transient deformation available to the community. Volcanic, tectonic and isostatic adjustment related deformation will be modeled to place Erebus in a broad volcano-tectonic framework of West Antarctica. During the data analysis phase, the utility of existing GPS data for reflection studies of snow and sea-level dynamics will also be evaluated.", "east": 169.6, "geometry": "POINT(167.55 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Ross Island; TECTONICS; USAP-DC; Amd/Us; AMD; CRUSTAL MOTION; USA/NSF; FIELD SURVEYS", "locations": "Ross Island", "north": -77.1, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Grapenthin, Ronni", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.9, "title": "Collaborative Research: Multi-Parameter Geophysical Constraints on Volcano Dynamics of Mt. Erebus and Ross Island, Antarctica", "uid": "p0010255", "west": 165.5}, {"awards": "2114839 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": "Argon thermochronological data on Pliocene ice-rafted detrital mineral grains from IODP Expedition 379 in the Amundsen Sea sector; Grain-size data for the Pliocene section at IODP Site U1533, Amundsen Sea", "datasets": [{"dataset_uid": "601900", "doi": "10.15784/601900", "keywords": "Amundsen Sea Sector; Antarctica; Cryosphere; Glaciation; Grain Size; Pliocene; Sediment Core Data; Sedimentology", "people": "Passchier, Sandra; Mino-Moreira, Lisbeth", "repository": "USAP-DC", "science_program": null, "title": "Grain-size data for the Pliocene section at IODP Site U1533, Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601900"}, {"dataset_uid": "601907", "doi": "10.15784/601907", "keywords": "40Ar/39Ar; Amundsen Sea; Amundsen Sea Sector; Antarctica; Cryosphere; Ice-Rafted Detritus; IODP; Paleoclimate; Pliocene; Provenance; Sedimentology", "people": "Hemming, Sidney R.; Passchier, Sandra", "repository": "USAP-DC", "science_program": null, "title": "Argon thermochronological data on Pliocene ice-rafted detrital mineral grains from IODP Expedition 379 in the Amundsen Sea sector", "url": "https://www.usap-dc.org/view/dataset/601907"}], "date_created": "Wed, 25 Aug 2021 00:00:00 GMT", "description": "The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students. The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of \u003e 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current \u201cicehouse\u201d period ~3.3 Ma. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; TERRIGENOUS SEDIMENTS; Amd/Us; SEDIMENTS; FIELD SURVEYS; Amundsen Sea; USAP-DC; AMD", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum", "uid": "p0010252", "west": null}, {"awards": "1643871 van Gestel, Natasja; 1947562 van Gestel, Natasja", "bounds_geometry": "POLYGON((-65 -64.5,-64.8 -64.5,-64.6 -64.5,-64.4 -64.5,-64.2 -64.5,-64 -64.5,-63.8 -64.5,-63.6 -64.5,-63.4 -64.5,-63.2 -64.5,-63 -64.5,-63 -64.55,-63 -64.6,-63 -64.65,-63 -64.7,-63 -64.75,-63 -64.8,-63 -64.85,-63 -64.9,-63 -64.95,-63 -65,-63.2 -65,-63.4 -65,-63.6 -65,-63.8 -65,-64 -65,-64.2 -65,-64.4 -65,-64.6 -65,-64.8 -65,-65 -65,-65 -64.95,-65 -64.9,-65 -64.85,-65 -64.8,-65 -64.75,-65 -64.7,-65 -64.65,-65 -64.6,-65 -64.55,-65 -64.5))", "dataset_titles": "2022-2023 Palmer Station terrestrial carbon fluxes - field warming experiment; Soil moisture and soil temperature data (0-5 cm) near Palmer Station, Antarctica", "datasets": [{"dataset_uid": "601877", "doi": "10.15784/601877", "keywords": "Antarctica; Antarctic Peninsula; Conductivity; Cryosphere; Palmer Station; Soil; Temperature", "people": "van Gestel, Natasja", "repository": "USAP-DC", "science_program": null, "title": "Soil moisture and soil temperature data (0-5 cm) near Palmer Station, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601877"}, {"dataset_uid": "601853", "doi": "10.15784/601853", "keywords": "Antarctica; CO2; Cryosphere; Field Investigations; Palmer Station", "people": "van Gestel, Natasja", "repository": "USAP-DC", "science_program": null, "title": "2022-2023 Palmer Station terrestrial carbon fluxes - field warming experiment", "url": "https://www.usap-dc.org/view/dataset/601853"}], "date_created": "Sat, 21 Aug 2021 00:00:00 GMT", "description": "Part I: Non-technical description: Earth\u2019s terrestrial ecosystems have the potential to either slow down or hasten the pace of climate change. The direction depends in part on both plant and microbial responses to warming. This study uses Antarctica as a model ecosystem to study the carbon balance of a simplified ecosystem (simplified compared to terrestrial ecosystems elsewhere) in response to a warming treatment. Carbon balance is dictated by sequestered carbon (through photosynthesis) and released carbon (plant and microbial respiration). Hence, to best assess plant and microbial responses to warming, this study uses a plant gradient that starts at the glacier (no plants, only soil microbes) to an old site entirely covered by plants. Experimental warming in the field is achieved by open-top chambers that warm the air and soil inside. The net ecosystem carbon exchange, the net result of sequestered and released carbon, will be measured in warmed and control plots with a state-of-the art gas exchange machine. Laboratory temperature incubation studies will supplement field work to attribute changes in carbon fluxes to individual plant species and soil microbial taxa (i.e., \u201cspecies\u201d). Data from this study will feed into earth system climate change models. The importance of this study will be shared with the broader community through the production of a video series created by an award-winning science media production company, an Antarctic blog, and through interactions with schools in the United States (on-site through Skype and in-person visits). Part II: Technical description: Responses of the carbon balance of terrestrial ecosystems to warming will feed back to the pace of climate change, but the size and direction of this feedback are poorly constrained. Least known are the effects of warming on carbon losses from soil, and clarifying the major microbial controls is an important research frontier. This study uses a series of experiments and observations to investigate microbial, including autotrophic taxa, and plant controls of net ecosystem productivity in response to warming in intact ecosystems. Field warming is achieved using open-top chambers paired with control plots, arrayed along a productivity gradient. Along this gradient, incoming and outgoing carbon fluxes will be measured at the ecosystem-level. The goal is to tie warming-induced shifts in net ecosystem carbon balance to warming effects on soil microbes and plants. The field study will be supplemented with lab temperature incubations. Because soil microbes dominate biogeochemical cycles in Antarctica, a major focus of this study is to determine warming responses of bacteria, fungi and archaea. This is achieved using a cutting-edge stable isotope technique, quantitative stable isotope probing (qSIP) developed by the proposing research team, that can identify the taxa that are active and involved in processing new carbon. This technique can identify individual microbial taxa that are actively participating in biogeochemical cycling of nutrients (through combined use of 18O-water and 13C-bicarbonate) and thus can be distinguished from those that are simply present (cold-preserved). The study further assesses photosynthetic uptake of carbon by the vegetation and their sensitivity to warming. Results will advance research in climate change, plant and soil microbial ecology, and ecosystem modeling. Science communication will be achieved through an informative video series, a daily Antarctic blog, and online- and in-person visits to schools in the United States. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -63.0, "geometry": "POINT(-64 -64.75)", "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; TERRESTRIAL ECOSYSTEMS; USA/NSF; AMD; Amd/Us; USAP-DC; FIELD SURVEYS", "locations": "Palmer Station", "north": -64.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science", "paleo_time": null, "persons": "van Gestel, Natasja", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -65.0, "title": "Antarctica as a Model System for Responses of Terrestrial Carbon Balance to Warming", "uid": "p0010251", "west": -65.0}, {"awards": "2122248 Waters, Laura", "bounds_geometry": "POLYGON((-127.143608 -77.1380528,-127.1012394 -77.1380528,-127.0588708 -77.1380528,-127.0165022 -77.1380528,-126.9741336 -77.1380528,-126.931765 -77.1380528,-126.8893964 -77.1380528,-126.8470278 -77.1380528,-126.8046592 -77.1380528,-126.7622906 -77.1380528,-126.719922 -77.1380528,-126.719922 -77.14809141,-126.719922 -77.15813002,-126.719922 -77.16816863,-126.719922 -77.17820724,-126.719922 -77.18824585,-126.719922 -77.19828446,-126.719922 -77.20832307,-126.719922 -77.21836168,-126.719922 -77.22840029,-126.719922 -77.2384389,-126.7622906 -77.2384389,-126.8046592 -77.2384389,-126.8470278 -77.2384389,-126.8893964 -77.2384389,-126.931765 -77.2384389,-126.9741336 -77.2384389,-127.0165022 -77.2384389,-127.0588708 -77.2384389,-127.1012394 -77.2384389,-127.143608 -77.2384389,-127.143608 -77.22840029,-127.143608 -77.21836168,-127.143608 -77.20832307,-127.143608 -77.19828446,-127.143608 -77.18824585,-127.143608 -77.17820724,-127.143608 -77.16816863,-127.143608 -77.15813002,-127.143608 -77.14809141,-127.143608 -77.1380528))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 19 Aug 2021 00:00:00 GMT", "description": "This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The geologic record reveals that volcanic activity increases when glaciers retreat and major ice sheets thin. This relationship produces a positive feedback mechanism where the uptick in volcanism increases greenhouse gasses concentrations, leading to climate warming and further deglaciation. Although the pattern between volcanism and deglaciation is observed in the geologic record, the exact mechanism(s) by which glaciers impact a volcanic plumbing system is unknown. This project focuses on Mount Waesche, a volcano in West Antarctica, that frequently erupts during warm, interglacial periods and undergoes a period of less activity during cold, glacial periods. This project will examine compositions of the rocks and minerals from Mount Waesche to determine magma storage depths, allowing the investigators to understand how magma plumbing systems change in response to glacial cycles. These results will be compared with geodynamic simulations to understand the physics behind the effects of deglaciation on the magmatic plumbing systems within Earth\u2019s crust. The investigators will additionally partner with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche\u2019s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -126.719922, "geometry": "POINT(-126.931765 -77.18824585)", "instruments": null, "is_usap_dc": true, "keywords": "Mt. Waesche; GEOCHEMISTRY; LITHOSPHERIC PLATE MOTION; STRESS; Amd/Us; West Antarctica; Executive Committee Range; NOT APPLICABLE; USAP-DC; AMD; MAJOR ELEMENTS; USA/NSF; ROCKS/MINERALS/CRYSTALS", "locations": "West Antarctica; Mt. Waesche; Executive Committee Range", "north": -77.1380528, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Waters, Laura; Naliboff, John; Zimmerer, Matthew", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -77.2384389, "title": "Integrating petrologic records and geodynamics: Quantifying the effects of glaciation on crustal stress and eruptive patterns at Mt. Waesche, Executive Committee Range, Antarctica", "uid": "p0010248", "west": -127.143608}, {"awards": "1954241 O\u0027\u0027Brien, Kristin", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 17 Aug 2021 00:00:00 GMT", "description": "Part 1: Non-technical description: Global climate warming is increasing the frequency and severity of low oxygen events in marine and freshwater environments worldwide, and these events threaten the health of aquatic ecosystems and the viability of fish populations. The Southern Ocean surrounding Antarctica has historically been a stable, icy-cold, and oxygen-rich environment, but is now warming at an unprecedented rate and faster than all other regions in the Southern hemisphere. Antarctic fishes have evolved in sub-zero temperatures that have been stable over long periods of time with traits allowing them to thrive in frigid waters, but with diminished resilience to warming temperatures. Presently little is known about the ability of Antarctic fishes to withstand hypoxic, or low-oxygen, conditions that often accompany warming. This research will investigate the hypoxia tolerance of four species of Antarctic fishes, including two species of icefishes that lack the oxygen-carrying protein, hemoglobin, which may compromise their ability to oxygenate tissues under hypoxic conditions. The hypoxia tolerance of four Antarctic fish species will be compared to that of a related fish species inhabiting warmer coastal regions of South America. Physiological and biochemical responses to hypoxia will be evaluated and compared amongst the five species to bolster our predictions of the capacity of Antarctic fishes to cope with a changing environment. This research will provide training opportunities for undergraduate and graduate students, and a postdoctoral research fellow. A year-long seminar series hosted by the Aquarium of the Pacific will feature female scientists who work in Antarctica to inspire youth in the greater Los Angeles area to pursue careers in science. Part 2: Technical description: The overarching hypothesis to be tested in this project is that the long evolution of Antarctic notothenioid fishes in a cold, oxygen-rich environment has reduced their capacity to mount a robust physiological, biochemical, and molecular response to hypoxia compared to related, cold-temperate fish species. Hypoxia tolerance will be compared among the red-blooded Antarctic notothenioids, Notothenia coriiceps and Notothenia rossii; the hemoglobinless Antarctic icefishes, Chaenocephalus aceratus and Chionodraco rastrospinosus; and the basal, cold-temperate notothenioid, Eleginops maclovinus, a species that has never inhabited waters south of the Polar Front. The minimum level of oxygen required to sustain maintenance metabolic requirements (O2crit) will be quantified. Animals will then be exposed to 65% of O2crit for 48 hours, and responses to hypoxia will be evaluated by measuring hematocrit and hemoglobin levels, as well as metabolites in brain, liver, glycolytic and cardiac muscles. Maximal activities of key enzymes of aerobic and anaerobic metabolism will be quantified to assess capacities for synthesizing ATP in hypoxic conditions. Gill remodeling will be analyzed using light and scanning electron microscopy. The molecular response to hypoxia will be characterized in liver and brains by quantifying levels of the master transcriptional regulator of oxygen homeostasis, hypoxia-inducible factor-1 (HIF-1), and hypoxic gene expression will be quantified using RNA-Seq. Cell cultures will be used to determine if a previously identified insertion mutation in notothenioid HIF-1 affects the ability of HIF-1 to drive gene expression and thus, hypoxia tolerance. The results of this project will provide the most comprehensive assessment of the hypoxia tolerance of Antarctic fishes to date. Broader impacts include research training opportunities for undergraduate and graduate students and a postdoctoral research associate, with a focus on involving Native Alaskan students in research. In partnership with the Aquarium of the Pacific, a year-long public seminar series will be held, showcasing the research and careers of 9 women who conduct research in Antarctica. The goal of the series is to cultivate and empower a community of middle and high school students in the greater Los Angeles area to pursue their interests in science and related fields, and to enhance the public engagement capacities of research scientists so that they may better inspire youth and early career scientists in STEM fields. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Palmer Station; FIELD SURVEYS; USAP-DC; AMD; USA/NSF; Amd/Us; FISH", "locations": "Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "O\u0027Brien, Kristin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "ANT LIA: Hypoxia Tolerance in Notothenioid Fishes", "uid": "p0010246", "west": null}, {"awards": "1644171 Blackburn, Terrence", "bounds_geometry": "POLYGON((162 -77.5,162.2 -77.5,162.4 -77.5,162.6 -77.5,162.8 -77.5,163 -77.5,163.2 -77.5,163.4 -77.5,163.6 -77.5,163.8 -77.5,164 -77.5,164 -77.525,164 -77.55,164 -77.575,164 -77.6,164 -77.625,164 -77.65,164 -77.675,164 -77.7,164 -77.725,164 -77.75,163.8 -77.75,163.6 -77.75,163.4 -77.75,163.2 -77.75,163 -77.75,162.8 -77.75,162.6 -77.75,162.4 -77.75,162.2 -77.75,162 -77.75,162 -77.725,162 -77.7,162 -77.675,162 -77.65,162 -77.625,162 -77.6,162 -77.575,162 -77.55,162 -77.525,162 -77.5))", "dataset_titles": "Isotopic ratios for subglacial precipitates from East Antarctica; U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "601806", "doi": "10.15784/601806", "keywords": "Antarctica; Cryosphere; Erosion; Isotope Data; Major Elements; Soil; Taylor Glacier; Taylor Valley", "people": "Piccione, Gavin; Tulaczyk, Slawek; Blackburn, Terrence; Edwards, Graham", "repository": "USAP-DC", "science_program": null, "title": "U-Th isotopes and major elements in sediments from Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601806"}, {"dataset_uid": "200240", "doi": "10.26022/IEDA/111548 ", "keywords": null, "people": null, "repository": "EarthChem", "science_program": null, "title": "Isotopic ratios for subglacial precipitates from East Antarctica", "url": "https://doi.org/10.26022/IEDA/111548"}], "date_created": "Fri, 13 Aug 2021 00:00:00 GMT", "description": "A\u00a0nontechnical\u00a0description of the project The primary scientific goal of the project is to test whether Taylor Valley, Antarctica has been eroded significantly by glaciers in the last ~2 million years (Ma). Taylor Valley is one of the Dry Valleys of the Transantarctic Mountains, which are characterized by low mean annual temperatures, low precipitation, and limited erosion. These conditions have allowed fragile glacial landforms to be preserved for up to 15 Ma. Sediment eroded and deposited by glaciers is found on the valley walls and floors, with progressively younger deposits preserved at lower elevations. Scientists can date glacial deposits to understand the process and timing of past glacial erosion. Previous work in the Dry Valleys region suggested that extremely cold glaciers like Taylor Glacier, a major outlet glacier entering the valleys, were not erosive during the last several million years. This research will test a new hypothesis that glacial erosion and sediment production beneath Taylor Glacier have been active in the last few million years. This hypothesis will be tested using a new isotopic dating method called \"comminution dating\u0027 which determines when fine-grained sediment particles called silt were formed. If the sediment age is young, then the results will suggest that glacial processes have been more dynamic than previously thought. Overall, this study will increase our understanding of the nature and extent of past glaciations in Antarctica. Because the silt produced by erosion sediment is a nutrient for local ecosystems, the results will also shed light on delivery of nutrients to soils, streams, and coastal zones in high polar regions. This project will be led by an early career scientist and includes training of a Ph.D. student. A\u00a0technical description of the project There is a long-standing scientific controversy about the stability of the East Antarctic Ice Sheet with much evidence centered in the Dry Valleys region of South Victoria Land. A prevailing view of geomorphologists is that the landscape has been very stable and that the effects of glaciation have been minimal for the past ~15 Ma. This project will distinguish between two end-member scenarios of glacial erosion and deposition by Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet that terminates in Taylor Valley in the Dry Valleys region of Antarctica. In the first scenario, all valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen ancient river channels. In this case, younger glacial deposits record advances of cold-based glaciers of decreasing ice volume and limited glacial erosion, and sediment generation resulted in glacial deposits composed primarily of older recycled sediments. In the second scenario, selective erosion of the valley floor has continued to deepen Taylor Valley but has not affected the adjacent peaks over the last 2 Ma. In this scenario, the \"bathtub rings\" of Quaternary glacial deposits situated at progressively lower elevations through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of new sediment which is now incorporated into these deposits. While either scenario would result in the present-day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. The two scenarios will be tested by placing time constraints on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in fine-grained particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss. The timing of comminution and particle size controls the magnitude of 234U loss. While this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that the preliminary modeling and measured data show is readily resolved.", "east": 164.0, "geometry": "POINT(163 -77.625)", "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Taylor Valley", "locations": "Taylor Valley", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence; Tulaczyk, Slawek", "platforms": null, "repo": "USAP-DC", "repositories": "EarthChem; USAP-DC", "science_programs": null, "south": -77.75, "title": "U-Series Comminution Age Constraints on Taylor Valley Erosion", "uid": "p0010243", "west": 162.0}, {"awards": null, "bounds_geometry": null, "dataset_titles": "Common-era black carbon deposition and atmospheric modeling for 6 Antarctic ice cores", "datasets": [{"dataset_uid": "601464", "doi": "10.15784/601464", "repository": "USAP-DC", "science_program": null, "title": "Common-era black carbon deposition and atmospheric modeling for 6 Antarctic ice cores", "url": "http://www.usap-dc.org/view/dataset/601464"}], "date_created": "Fri, 16 Jul 2021 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Antarctica; Antarctic Peninsula; Biomass Burning; Black Carbon; Dronning Maud Land; East Antarctic Plateau; Ice Core", "locations": "Antarctica; Antarctic Peninsula; Dronning Maud Land; East Antarctic Plateau", "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "McConnell, Joseph; Chellman, Nathan", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "2000992 Romans, Brian", "bounds_geometry": "POINT(-172.873074 -74.274008)", "dataset_titles": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "datasets": [{"dataset_uid": "601807", "doi": "10.15784/601807", "keywords": "Antarctica; Cryosphere; Grain Size; Ross Sea", "people": "Romans, Brian W.; Varela, Natalia", "repository": "USAP-DC", "science_program": null, "title": "Grain size of Plio-Pleistocene continental slope and rise sediments, Hillary Canyon, Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601807"}], "date_created": "Tue, 06 Jul 2021 00:00:00 GMT", "description": "Part I: Non-technical description: Predicting how polar ice sheets will respond to future global warming is difficult because all the processes that contribute to their melting are not well understood. This is important because the more ice on land that melts, the higher sea levels will rise. The most significant uncertainty in current estimates of sea-level rise in the coming decades is the potential contribution from the Antarctic Ice Sheet. One way to increase our knowledge about how large ice sheets respond to climate change in response to natural factors is to examine the geologic past. Natural global warming (and cooling) events in Earth\u2019s history provide examples that we can use to better understand processes, interactions, and responses we can\u2019t directly observe today. One such time period, approximately three million years ago (known as the Pliocene), was the last time atmospheric carbon dioxide levels were as high as they are today and, therefore, represents a time period to study to better understand the ice sheet response to a warming climate. Specifically, this project is interested in understanding how ocean currents near Antarctica, which transport heat and store carbon, behaved during these past climate events. The history of past ice sheet-ocean interactions are recorded in sediments that were deposited, layer upon layer, in the deep sea offshore Antarctica. In January-February 2018, a team of scientists and crew set sail to the Ross Sea, offshore west Antarctica, on the scientific ocean drilling vessel JOIDES Resolution to recover such sediment archives. This project focuses on a sediment core from that expedition, which captures the relatively warm Pliocene time interval, as well as the subsequent transition into cooler climates typical of the past two million years. The researchers will analyze the sediment with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more. These analyses will be done by the research team, including several students, at their respective laboratories and will then integrated into a unified record of ice sheet-ocean interactions. Ultimately, the results will be used to improve modeled projections of how the Antarctic Ice Sheet could respond to future climate change. Part II: Technical description: Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. The researchers hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, they plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. To test their hypothesis, they will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) They will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. They will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) They will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) They will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. All of these data will be integrated with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -172.873074, "geometry": "POINT(-172.873074 -74.274008)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; LABORATORY; AMD; USA/NSF; SEDIMENTS; Amd/Us; Ross Sea", "locations": "Ross Sea", "north": -74.274008, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.274008, "title": "COLLABORATIVE RESEARCH: Orbital-scale Variability of the West Antarctic Ice Sheet and the Formation of Bottom Water in the Ross Sea during the Pliocene-Pleistocene", "uid": "p0010227", "west": -172.873074}, {"awards": "2023244 Stewart, Andrew; 2023259 Thompson, Andrew; 2023303 Purkey, Sarah", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Code for reproducing the ocean-biogeochemical experiments in Sun et al. (2024); Hydrographic data collected from the Bellingshausen and Amundsen seas (NCEI Accession 0210639); Ocean CFC reconstructed data product", "datasets": [{"dataset_uid": "200427", "doi": "10.6084/m9.figshare.26787751", "keywords": null, "people": null, "repository": "Figshare (open repository)", "science_program": null, "title": "Code for reproducing the ocean-biogeochemical experiments in Sun et al. (2024)", "url": "https://doi.org/10.6084/m9.figshare.26787751"}, {"dataset_uid": "200428", "doi": "", "keywords": null, "people": null, "repository": "NOAA\u0027s National Centers for Environmental Information (NCEI)", "science_program": null, "title": "Hydrographic data collected from the Bellingshausen and Amundsen seas (NCEI Accession 0210639)", "url": "https://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:0210639"}, {"dataset_uid": "601752", "doi": "10.15784/601752", "keywords": "Antarctica; CFCs; GLODAP; Ocean Model; Ocean Ventilation; Southern Ocean", "people": "Cimoli, Laura; Gebbie, Jack; Purkey, Sarah", "repository": "USAP-DC", "science_program": null, "title": "Ocean CFC reconstructed data product", "url": "https://www.usap-dc.org/view/dataset/601752"}], "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "Part 1: Because of the manner in which it is formed at high latitudes in the Antarctic ice, Antarctic Bottom Water (AABW) is the coldest, saltiest and densest water on the planet. The global circulation of is often quanti\ufb01ed via the transport in a two-dimensional, latitude/depth coordinate space. However, AABW formation, northward \ufb02ow and distribution between the Atlantic, Indian and Paci\ufb01c basins are fundamentally three-dimensional processes. AABW is formed in a handful of distinct sites around the Antarctic coast, notably the southern Weddell Sea, the western Ross Sea, along the Ad\u00b4elie coast, and in Prydz Bay. AABW is one of the key components of the global ocean overturning circulation, and plays a critical role in regulating Earth\u0027s climate, on multi-decadal-to-millennial time scales. Part 2: Mapping of AABW transport to northern basins is not well constrained, with conflicting conclusions drawn in previous studies. At one extreme the ACC has been suggested to be a \u201cconduit\" that simply allows each variety of AABW to transit directly northward. At the other extreme, it has been suggested that the ACC \u201cblends\" all shelf AABW sources together before they reach the northern basins. To close the gap in understanding, this collaborative project draws on three complementary analytical tools: process-oriented modeling of AABW export across the ACC, a high-resolution global ocean model, and an observationally-constrained estimate of the global circulation. The proposed identification and mechanistic understanding of AABW pathways. This project will also advance the careers of three postdoctoral researchers and two early-career faculty members, and will continue collaborative links between the PI and a foreign investigator. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "AMD; MODELS; USAP-DC; WATER MASSES; Southern Ocean; Amd/Us; OCEAN CURRENTS; COMPUTERS; Antarctic Circumpolar Current; USA/NSF", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Stewart, Andrew; Thompson, Andrew; Purkey, Sarah", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "Figshare (open repository)", "repositories": "Figshare (open repository); NOAA\u0027s National Centers for Environmental Information (NCEI); USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters?", "uid": "p0010220", "west": -180.0}, {"awards": "1947882 Robel, Alexander", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "Uncertainty in projections of future sea level rise comes, in part, from ice-sheet melting under the influence of unpredictable variations in ocean and atmospheric temperature near ice sheets. Using state-of-the-art modeling techniques, the Antarctic Ice Sheet Large Ensemble (AISLENS) Project will estimate the range of possible Antarctic Ice Sheet melt during the recent past and over the next several centuries that could result from such climate variations. The AISLENS Project will also facilitate research by providing modeling output as an open product to the broader climate and glaciology communities. The project will support an early career faculty member, and interdisciplinary training for a graduate student, postdoctoral fellow and undergraduate student. As a part of this project, an undergraduate course on \"Sea Level Rise and Coastal Engineering\" will be also developed, bringing together Earth Science and Civil Engineering students in an interdisciplinary setting and contributing to their education in sea level science and coastal adaptation. This will be done in the geographic context of the Southeastern US, the region of most concentrated vulnerability to sea-level rise in the US. The primary goal of the proposed research is to understand and quantify the role of internal climate variability in driving ice loss from the Antarctic Ice Sheet over the recent past and into the future. The AISLENS Project will encompass hundreds of simulations of Antarctic ice sheet evolution from 1950 to 2300 forced by realistic variations in climate, including snowfall and melt from fluctuating oceanic and atmospheric temperatures. Plausible realizations of Antarctic climate forcing will be generated from stochastic emulation of output from the Energy Exascale Earth System Model (E3SM) under past and future emissions scenarios. These realizations of variable climate will be used to force the MPAS Albany Land Ice (MALI) model, a state-of-the-art model of ice flow in the Antarctic Ice Sheet. In this project, AISLENS will be used to conduct uncertainty and attribution analyses. In the uncertainty analysis, the evolution of ensemble spread in simulations of the future evolution of the Antarctic Ice Sheet will be systematically decomposed to determine which temporal and spatial scales of climate variability contribute the most to future ice-sheet projection uncertainty. In the attribution analysis, a range of satellite-based observations of recent Antarctic ice loss will be compared to the envelope of internal variability of Antarctic ice loss simulated in AISLENS simulations encompassing the recent past. This analysis will provide context to recent observations indicating significant variability of Antarctic climate forcing and provide a possible path forward for conducting robust statistical inference studies for observed ice-sheet changes. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "ICE SHEETS; Antarctica; Antarctic Ice Sheet; AMD; USAP-DC; USA/NSF; MODELS; Amd/Us", "locations": "Antarctic Ice Sheet; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Robel, Alexander", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repositories": null, "science_programs": null, "south": null, "title": "The Antarctic Ice Sheet Large Ensemble (AISLENS) Project: Assessing the Role of Climate Variability in Past and Future Ice Sheet Mass Loss", "uid": "p0010223", "west": null}, {"awards": "1851022 Fudge, Tyler; 1851094 Baker, Ian", "bounds_geometry": null, "dataset_titles": "Code for calculating mean gradient for EDC sulfate data; EPICA Dome C Sulfate Data 7-3190m; Forward Diffusion Model used to calculate widening of volcanic layer widths; Volcanic Widths in Dome C Interglacials and Glacials", "datasets": [{"dataset_uid": "601855", "doi": "10.15784/601855", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Volcanic Widths in Dome C Interglacials and Glacials", "url": "https://www.usap-dc.org/view/dataset/601855"}, {"dataset_uid": "601759", "doi": "10.15784/601759", "keywords": "Antarctica", "people": "Fudge, T. J.; Severi, Mirko", "repository": "USAP-DC", "science_program": "COLDEX", "title": "EPICA Dome C Sulfate Data 7-3190m", "url": "https://www.usap-dc.org/view/dataset/601759"}, {"dataset_uid": "601857", "doi": "10.15784/601857", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Forward Diffusion Model used to calculate widening of volcanic layer widths", "url": "https://www.usap-dc.org/view/dataset/601857"}, {"dataset_uid": "601856", "doi": "10.15784/601856", "keywords": "Antarctica; Cryosphere", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Code for calculating mean gradient for EDC sulfate data", "url": "https://www.usap-dc.org/view/dataset/601856"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "The ice of the polar ice sheets is among the purest substances on Earth, yet the small amount of impurities --such as acids-- are important to how the ice flows and what can be learned from ice cores about past climate. The goal of this project is to understand the role of such acids on the deformation of polycrystalline ice by comparing the deformation behavior of pure and sulfuric acid-doped samples. Sulfuric acid was chosen both because of its importance for interpreting past climate and because it can lead to water veins in ice at low temperatures. This work will focus on the location, movement, and impact of acids in polycrystalline ice that are more complex than in single crystals of ice. By deforming samples and performing microstructural characterization, the role of acids on deformation rate, grain evolution, and the movement of the acids themselves, will be assessed. The work will lead to the education of a Ph.D. student at Dartmouth College, introduce undergraduate students to research at both the University of Washington and Dartmouth College. Despite the ubiquitous use of the constitutive relation for ice commonly referred to as \"Glen\u0027s Flow Law\", significant uncertainty exists particularly with regard to the role of impurities and the development of oriented fabrics. The aim of this project is to improve the constitutive relationship for ice by performing deformation tests and microstructural characterization of pure and sulfuric acid-doped ice. The project will focus on sulfuric acid\u0027s impact on ice viscosity, fabric evolution, and diffusivity. Sulfuric acid can have both direct and indirect effects on the mechanical properties of polycrystalline ice. The direct effects change the dislocation velocity and/or density, and the indirect effects change the grain size and fabric. The complexity and interaction of these effects means that it is not possible to understand the effects of sulfuric acid by simply examining ice core specimens. In this project, the team will deform four types of ice: lab-grown ice samples doped with similar-to-natural concentrations of sulfuric acid, lab-grown high-purity ice, layered doped and pure ice, and natural ice from Antarctic ice cores. Deformation will be performed in both uniaxial compression and simple shear. The addition of simple shear tests is critical for relating the laboratory-observed deformation behavior to the behavior of polar ice sheets where the shear strain dominates ice motion in basal ice. After deformation to strains from 5 percent up to 25 percent, the microstructural development will be assessed with methods including a variety of scanning electron microscope techniques, Raman microscopy, synchrotron-based Nano-X-ray fluorescence, and ion chromatography. These analysis techniques will allow the determination of 1) the segregation and movement of impurities, 2) the rate of grain-boundary migration, 3) the number of recrystallized grains; and 4) the full orientation of the ice crystals. The results will enable both microstructural modeling of the effects of sulfuric acid and numerical modeling of diffusion in ice cores. The net result will be a better understanding of ice deformation that improves ice-core interpretation and ice-sheet modeling. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; Polycrystalline Ice; LABORATORY; Epica Dome C; SNOW/ICE; USA/NSF; USAP-DC; Ice Core; Amd/Us", "locations": "Epica Dome C", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Science and Technology; Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "uid": "p0010211", "west": null}, {"awards": "1643455 Enderlin, Ellyn; 1933764 Enderlin, Ellyn", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Crane Glacier centerline observations and modeling results ; Remotely-sensed iceberg geometries and meltwater fluxes", "datasets": [{"dataset_uid": "601679", "doi": "10.15784/601679", "keywords": "Antarctica; Elevation; Glaciology; Iceberg; Meltwater; Submarine Melt", "people": "Dickson, Adam; Enderlin, Ellyn; Miller, Emily; Dryak, Mariama; Oliver, Caitlin; Aberle, Rainey", "repository": "USAP-DC", "science_program": null, "title": "Remotely-sensed iceberg geometries and meltwater fluxes", "url": "https://www.usap-dc.org/view/dataset/601679"}, {"dataset_uid": "601617", "doi": "10.15784/601617", "keywords": "Antarctica; Antarctic Peninsula; Crane Glacier; Glacier Dynamics; Glacier Mass Discharge; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling; Model Output", "people": "Marshall, Hans-Peter; Aberle, Rainey; Enderlin, Ellyn; Kopera, Michal; Meehan, Tate", "repository": "USAP-DC", "science_program": null, "title": "Crane Glacier centerline observations and modeling results ", "url": "https://www.usap-dc.org/view/dataset/601617"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "Enderlin/1643455 This award supports a project that will use a novel remote sensing method, which was initially developed to investigate melting of icebergs around Greenland, to examine spatial and temporal variations in ocean forcing around the Antarctic ice sheet periphery. Nearly three-quarters of the Antarctic ice sheet is fringed by regions of floating glacier ice called ice shelves. These ice shelves play an important role in modulating the flow of ice from the ice sheet interior towards the coast, similar to how dams regulate the downstream flow of water from reservoirs. Therefore, a reduction in ice shelf size due to changing air and ocean temperatures can have serious implications for the flux of glacier ice reaching the Antarctic coast, and thus, sea level change. Observations of recent ocean warming in the Amundsen Sea, thinning of the ice shelves, and increased ice flux from the West Antarctic ice sheet interior suggests that ice shelf destabilization triggered by ocean warming may already be underway in some regions. Although detailed observations are available in the Amundsen Sea region, our understanding of spatial and temporal variations in ocean conditions and their influence on ice shelf stability is limited by the scarceness of observations spanning the ice sheet periphery. The project will yield insights into variability in the submarine melting of ice shelves and will help advance the career of a female early-career scientist in a male-dominated field. The project will use repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images will be used to construct maps of iceberg surface elevation, which will be differenced in time to derive time series of iceberg volume change and area-averaged melt rates. Where ocean data are available, the melt rates will be compared to these data to assess whether variations in ocean temperature can explain observed iceberg melt variability. Large spatial gradients in melt rates will be compared to estimates of iceberg drift rates, which will be inferred from the repeat satellite images as well as numerically modeled drift rates produced by (unfunded) collaborators, to quantify the effects of water shear on iceberg melt rates. Spatial and temporal patterns in iceberg melting will also be compared to independently derived ice shelf thickness datasets. Overall, the analysis should yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amery Ice Shelf; FIELD SURVEYS; Totten Glacier; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; USAP-DC; Antarctic Peninsula; ICEBERGS; Mertz Glacier; OCEAN TEMPERATURE; USA/NSF; Amd/Us; Amundsen Sea; Ronne Ice Shelf; Filchner Ice Shelf; AMD", "locations": "Antarctic Peninsula; Totten Glacier; Ronne Ice Shelf; Filchner Ice Shelf; Amery Ice Shelf; Mertz Glacier; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Enderlin, Ellyn", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Antarctic Submarine Melt Variability from Remote Sensing of Icebergs", "uid": "p0010210", "west": -180.0}, {"awards": "1914668 Aschwanden, Andy; 1914698 Hansen, Samantha; 1914767 Winberry, Paul; 1914743 Becker, Thorsten", "bounds_geometry": "POLYGON((90 -65,99 -65,108 -65,117 -65,126 -65,135 -65,144 -65,153 -65,162 -65,171 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,171 -90,162 -90,153 -90,144 -90,135 -90,126 -90,117 -90,108 -90,99 -90,90 -90,90 -87.5,90 -85,90 -82.5,90 -80,90 -77.5,90 -75,90 -72.5,90 -70,90 -67.5,90 -65))", "dataset_titles": "East Antarctic Seismicity from different Automated Event Detection Algorithms; Full Waveform Ambient Noise Tomography for East Antarctica", "datasets": [{"dataset_uid": "601762", "doi": "10.15784/601762", "keywords": "Antarctica; Geoscientificinformation; Machine Learning; Seismic Event Detection; Seismology; Seismometer", "people": "Walter, Jacob; Hansen, Samantha; Ho, Long", "repository": "USAP-DC", "science_program": null, "title": "East Antarctic Seismicity from different Automated Event Detection Algorithms", "url": "https://www.usap-dc.org/view/dataset/601762"}, {"dataset_uid": "601763", "doi": "10.15784/601763", "keywords": "Ambient Noise; Antarctica; East Antarctica; Geoscientificinformation; Seismic Tomography; Seismology", "people": "Hansen, Samantha; Emry, Erica", "repository": "USAP-DC", "science_program": null, "title": "Full Waveform Ambient Noise Tomography for East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601763"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "Part I: Nontechnical Earths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California\u0027s Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. In particular, ice-sheets sitting above warm Earth will collapse more quickly during warming climate. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica\u0027s potential for future sea-level. Part II: Technical Description In polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(135 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "TECTONICS; AMD; Wilkes Subglacial Basin; ICE SHEETS; USA/NSF; Amd/Us; SEISMOLOGICAL STATIONS; SEISMIC SURFACE WAVES; East Antarctica; USAP-DC", "locations": "East Antarctica; Wilkes Subglacial Basin", "north": -65.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Becker, Thorsten; Binder, April; Hansen, Samantha; Aschwanden, Andy; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Resolving earth structure influence on ice-sheet stability in the Wilkes\r\nSubglacial Basin (RESISSt)", "uid": "p0010204", "west": 90.0}, {"awards": "1643120 Iverson, Neal", "bounds_geometry": null, "dataset_titles": "Ice permeameter experimental parameters and results; Softening of temperate ice by interstitial water; Tertiary creep rates if temperate ice containing greater than 0.7% liquid water", "datasets": [{"dataset_uid": "601833", "doi": "10.15784/601833", "keywords": "Antarctica; Cryosphere", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Tertiary creep rates if temperate ice containing greater than 0.7% liquid water", "url": "https://www.usap-dc.org/view/dataset/601833"}, {"dataset_uid": "601460", "doi": "10.15784/601460", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Stream; Lab Experiment; Rheology; Snow/ice; Snow/Ice; Water Content", "people": "Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Softening of temperate ice by interstitial water", "url": "https://www.usap-dc.org/view/dataset/601460"}, {"dataset_uid": "601515", "doi": "10.15784/601515", "keywords": "Antarctica; Glacier Flow; Glacier Hydrology; Glaciological Instruments And Methods; Glaciology; Ice Physics; Ice Stream; Snow/ice; Snow/Ice", "people": "Fowler, Jacob; Iverson, Neal", "repository": "USAP-DC", "science_program": null, "title": "Ice permeameter experimental parameters and results", "url": "https://www.usap-dc.org/view/dataset/601515"}], "date_created": "Wed, 23 Jun 2021 00:00:00 GMT", "description": "Iverson/1643120 This award supports a project to study temperate ice, using both experimental methods and modeling, in order to determine the effect of water on its flow resistance and structure and to study the mobility of water within the ice. A new mathematical model of ice stream flow and temperature is developed in conjunction with these experiments. The model includes water production, storage, and movement in deforming ice and their effects on flow resistance at ice stream margins and on water availability for lubrication of ice stream beds. Results will improve estimates of the evolution of ice stream speed and geometry in a warming climate, and so improve the accuracy of assessments of the contribution of the Antarctic ice sheet to sea level rise over the next century. Ice streams are zones of rapid flow within the Antarctic ice sheet and are primarily responsible for its discharge of ice to the ocean and major effect on sea-level rise. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is \"temperate\", meaning that it is at its melting temperature and thus contains intercrystalline water that significantly softens the ice. Two postdoctoral researchers will be supported, trained, and mentored for academic careers, and three undergraduates will be introduced to research in the geosciences. This award is part the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University in the United States and Oxford University in the United Kingdom. The two-phase deformation of temperate ice will be studied, with the objective of determining its effect on the flow of Antarctic ice streams. The project has two components that reinforce each other. First there will be laboratory experiments in which a rotary device at Iowa State University will be used to determine relationships between the water content of temperate ice and its rheology and permeability. The second component will involve the development at Oxford University of a two-phase, fluid-dynamical theory of temperate ice and application of this theory in models of ice-stream dynamics. Results of the experiments will guide the constitutive rules and parameter ranges considered in the theory, and application of elements of the theory will improve interpretations of the experimental results. The theory and resultant models will predict the coupled distributions of temperate ice, water, stress, deformation, and basal slip that control the evolution of ice-stream speed and geometry. The modeling will result in parameterizations that allow ice streaming to be included in continental-scale models of ice sheets in a simplified but physically defensible way.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; Rheology; Antarctica; LABORATORY; Ice Stream; USA/NSF; USAP-DC; Lab Experiment; Water Content", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Iverson, Neal; Zoet, Lucas", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "NSFGEO-NERC: Collaborative Research: Two-Phase Dynamics of Temperate Ice", "uid": "p0010197", "west": null}, {"awards": "1744970 Shevenell, Amelia", "bounds_geometry": "POLYGON((120 -66,120.1 -66,120.2 -66,120.3 -66,120.4 -66,120.5 -66,120.6 -66,120.7 -66,120.8 -66,120.9 -66,121 -66,121 -66.1,121 -66.2,121 -66.3,121 -66.4,121 -66.5,121 -66.6,121 -66.7,121 -66.8,121 -66.9,121 -67,120.9 -67,120.8 -67,120.7 -67,120.6 -67,120.5 -67,120.4 -67,120.3 -67,120.2 -67,120.1 -67,120 -67,120 -66.9,120 -66.8,120 -66.7,120 -66.6,120 -66.5,120 -66.4,120 -66.3,120 -66.2,120 -66.1,120 -66))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 22 Jun 2021 00:00:00 GMT", "description": "Glacial retreat in West Antarctica is correlated with ocean warming; however, less is known about the ocean\u0027s effect on East Antarctica\u0027s glaciers including Totten Glacier located on the Sabrina Coast. The retreat of Totten Glacier has global significance as the glacier drains a sector of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels by as much as 3.5 meters. This study looks to determine the influence of ocean temperatures on East Antarctic glaciers, including Totten Glacier, over the last ~18,000 years by studying seafloor sediment around Antarctica. These sediments, or muds, include the remains of microscopic marine organisms as well as tiny particles originating from eroded Antarctic bedrock. These muds provide a record of past environmental changes including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers will refine and test new methods for measuring ocean temperature from the sediments to better understand the influence of ocean temperatures on East Antarctic glacier response. Results will be integrated into ice sheet and climate models to improve the accuracy of ice sheet modeling efforts and subsequent sea level predictions. Results from this project will be disseminated at scientific conferences, in the scientific literature, and more broadly to the general public via the St. Petersburg Science Festival and at the Oceanography Camp for Girls. The influence of ocean temperatures on East Antarctic glaciers is largely unknown. This research focuses on ice-proximal Antarctic margin paleoceanographic proxy calibration and validation, which will improve understanding of past ocean-ice sheet interactions on a variety of timescales. In this project, researchers from the University of South Florida will (1) further develop and refine two ocean temperature proxies, foraminifer Mg/Ca and TEX86, for use in ice-proximal Antarctic continental margin sediments and (2) investigate deglacial to present (~18-0 ka) ocean-ice interactions at the outlet of the climatically sensitive Aurora Subglacial Basin. The proposed research utilizes sediment trap, sediment core, and physical oceanographic data previously collected from the Sabrina Coast continental shelf during NSF-funded cruise NBP14-02. Studies of existing sediment cores will integrate multiple paleotemperature, meltwater/salinity, nutrient, bottom water oxygen, and sea ice proxies with geophysical and lithologic data to understand past regional ocean-ice interactions. While the recent international Antarctic research focus has been on understanding the drivers of West Antarctic Ice Sheet retreat, models suggest it would be imprudent to ignore the East Antarctic Ice Sheet, which is proving more sensitive to climate perturbations than previously realized. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 121.0, "geometry": "POINT(120.5 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; FIELD INVESTIGATION; USA/NSF; USAP-DC; PALEOCLIMATE RECONSTRUCTIONS; Sabrina Coast; AMD; Amd/Us", "locations": "Sabrina Coast", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Shevenell, Amelia", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -67.0, "title": "Deglacial to Recent Paleoceanography of the Sabrina Coast, East Antarctica: A Multi-proxy Study of Ice-ocean Interactions at the Outlet of the Aurora Subglacial Basin", "uid": "p0010194", "west": 120.0}, {"awards": "1443556 Thomson, Stuart; 1443342 Licht, Kathy", "bounds_geometry": null, "dataset_titles": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "datasets": [{"dataset_uid": "601462", "doi": "10.15784/601462", "keywords": "Antarctica; Beardmore Glacier; Erosion; Landscape Evolution; Shackleton Glacier; Transantarctic Mountains; (U-Th)/He", "people": "Licht, Kathy; Thomson, Stuart; He, John; Reiners, Peter; Hemming, Sidney R.", "repository": "USAP-DC", "science_program": null, "title": "Apatite (U-Th)/He and TREE Data Central Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601462"}], "date_created": "Wed, 09 Jun 2021 00:00:00 GMT", "description": "Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth\u0027s last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media. The main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100\u00b0E-160\u00b0E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; LANDSCAPE; AGE DETERMINATIONS; FIELD INVESTIGATION; GLACIAL PROCESSES; Transantarctic Mountains; USA/NSF; Thermochronology; Amd/Us; USAP-DC; TRACE ELEMENTS; Provenance Analysis; AMD; LANDFORMS; GLACIAL LANDFORMS", "locations": "Transantarctic Mountains", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Thomson, Stuart; Reiners, Peter; Licht, Kathy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: East Antarctic Glacial Landscape Evolution (EAGLE): A Study using Combined Thermochronology, Geochronology and Provenance Analysis", "uid": "p0010188", "west": null}, {"awards": "1935438 McCarthy, Christine", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 03 Jun 2021 00:00:00 GMT", "description": "The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change\u2014the quantity relevant for estimating the ice sheet\u2019s sea-level contribution\u2014requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores. This project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (\u003e 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; LABORATORY; USA/NSF; COMPUTERS; USAP-DC; FIRN; Antarctic Ice Sheet; Amd/Us", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Arctic Natural Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "McCarthy, Christine M.; Kingslake, Jonathan", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Understanding Firn Rheology Through Laboratory Compaction Experiments and Radar Data", "uid": "p0010185", "west": null}, {"awards": "1643355 Steig, Eric; 1643394 Buizert, Christo", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctica 40,000 Year Temperature and Elevation Reconstructions; Layer and Thinning based Accumulation Rate Reconstructions; WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "datasets": [{"dataset_uid": "200220", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "WAIS Divide 67-6ka nssS Data and EDML, EDC and TALDICE Volcanic Tie Points", "url": "https://www.ncdc.noaa.gov/paleo/study/24530"}, {"dataset_uid": "200219", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Antarctica 40,000 Year Temperature and Elevation Reconstructions", "url": "https://www.ncdc.noaa.gov/paleo-search/study/32632"}, {"dataset_uid": "601448", "doi": "10.15784/601448", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Snow/ice; Snow/Ice", "people": "Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Layer and Thinning based Accumulation Rate Reconstructions", "url": "https://www.usap-dc.org/view/dataset/601448"}], "date_created": "Fri, 28 May 2021 00:00:00 GMT", "description": "Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Steig, Eric J.; Buizert, Christo", "platforms": null, "repo": "NCEI", "repositories": "NCEI; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Timing and Spatial Expression of the Bipolar Seesaw", "uid": "p0010183", "west": -180.0}, {"awards": "1643652 Hofmann, Eileen; 1643618 Arrigo, Kevin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic biological model output; Antarctic dFe model dyes", "datasets": [{"dataset_uid": "200211", "doi": "10.26008/1912/bco-dmo.858663.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic biological model output", "url": "https://www.bco-dmo.org/dataset/858663"}, {"dataset_uid": "200210", "doi": "10.26008/1912/bco-dmo.782848.1", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Antarctic dFe model dyes", "url": "https://www.bco-dmo.org/dataset/782848"}], "date_created": "Thu, 29 Apr 2021 00:00:00 GMT", "description": "Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail. This project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings. The project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts. Polynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers. In this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for \u003e50% of the total Antarctic polynya production. The research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent? The Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Trace Metal; AMD; PELAGIC; POLYNYAS; PHYTOPLANKTON; MODELS; Amd/Us; USAP-DC; MICROALGAE; USA/NSF; Polynya; TRACE ELEMENTS; ICE SHEETS; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "van Dijken, Gert; Arrigo, Kevin; Dinniman, Michael; Hofmann, Eileen", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Elucidating Environmental Controls of Productivity in Polynas and the Western Antarctic Peninsula", "uid": "p0010175", "west": -180.0}, {"awards": "1246151 Bromirski, Peter; 1246416 Stephen, Ralph", "bounds_geometry": "POLYGON((-180 -77,-179.5 -77,-179 -77,-178.5 -77,-178 -77,-177.5 -77,-177 -77,-176.5 -77,-176 -77,-175.5 -77,-175 -77,-175 -77.4,-175 -77.8,-175 -78.2,-175 -78.6,-175 -79,-175 -79.4,-175 -79.8,-175 -80.2,-175 -80.6,-175 -81,-175.5 -81,-176 -81,-176.5 -81,-177 -81,-177.5 -81,-178 -81,-178.5 -81,-179 -81,-179.5 -81,180 -81,179 -81,178 -81,177 -81,176 -81,175 -81,174 -81,173 -81,172 -81,171 -81,170 -81,170 -80.6,170 -80.2,170 -79.8,170 -79.4,170 -79,170 -78.6,170 -78.2,170 -77.8,170 -77.4,170 -77,171 -77,172 -77,173 -77,174 -77,175 -77,176 -77,177 -77,178 -77,179 -77,-180 -77))", "dataset_titles": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ; Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "datasets": [{"dataset_uid": "200207", "doi": "10.7914/SN/XH_2014", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-Induced Vibrations and Collaborative Research: Mantle Structure and Dynamics of the Ross Sea from a Passive Seismic Deployment on the Ross Ice Shelf. International Federation of Digital Seismograph Networks. ", "url": "http://www.fdsn.org/networks/detail/XH_2014/"}, {"dataset_uid": "200209", "doi": "10.7283/58E3-GA46", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations 2015/2016, UNAVCO, Inc., GPS/GNSS Observations Dataset", "url": "https://doi.org/10.7283/58E3-GA46"}], "date_created": "Thu, 15 Apr 2021 00:00:00 GMT", "description": "Bromirski/1246151 This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is \"locally\" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.", "east": 170.0, "geometry": "POINT(177.5 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; GLACIER MOTION/ICE SHEET MOTION; USAP-DC; Amd/Us; AMD; USA/NSF; Iris; Ross Ice Shelf", "locations": "Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Bromirski, Peter; Gerstoft, Peter; Stephen, Ralph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS; UNAVCO", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Dynamic Response of the Ross Ice Shelf to Wave-induced Vibrations", "uid": "p0010169", "west": -175.0}, {"awards": "1643353 Christianson, Knut; 1643301 Gerbi, Christopher", "bounds_geometry": null, "dataset_titles": "ImpDAR: an impulse radar processor; SeidarT; South Pole Lake ApRES Radar; South Pole Lake GNSS; South Pole Lake: ground-based ice-penetrating radar", "datasets": [{"dataset_uid": "200203", "doi": "", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "South Pole Lake: ground-based ice-penetrating radar", "url": "http://hdl.handle.net/1773/45293"}, {"dataset_uid": "601503", "doi": "10.15784/601503", "keywords": "Antarctica; Apres; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; South Pole; Subglacial Lakes; Vertical Velocity", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake ApRES Radar", "url": "https://www.usap-dc.org/view/dataset/601503"}, {"dataset_uid": "200244", "doi": " https://zenodo.org/badge/latestdoi/382590632", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "SeidarT", "url": "https://github.com/UMainedynamics/SeidarT"}, {"dataset_uid": "601502", "doi": "10.15784/601502", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GNSS; GPS; GPS Data; South Pole; Subglacial Lakes", "people": "Hills, Benjamin", "repository": "USAP-DC", "science_program": null, "title": "South Pole Lake GNSS", "url": "https://www.usap-dc.org/view/dataset/601502"}, {"dataset_uid": "200202", "doi": "http://doi.org/10.5281/zenodo.3833057", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "ImpDAR: an impulse radar processor", "url": "https://www.github.com/dlilien/ImpDAR"}], "date_created": "Wed, 17 Feb 2021 00:00:00 GMT", "description": "Gerbi/1643301 This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; GLACIERS/ICE SHEETS; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; South Pole; USA/NSF; AMD; GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; FIELD SURVEYS; Amd/Us", "locations": "South Pole; United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Christianson, Knut; Gerbi, Christopher; Campbell, Seth; Vel, Senthil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "Uni. Washington ResearchWorks Archive", "repositories": "GitHub; Uni. Washington ResearchWorks Archive; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Computational Methods Supporting Joint Seismic and Radar Inversion for Ice Fabric and Temperature in Streaming Flow", "uid": "p0010160", "west": null}, {"awards": "1443144 Steig, Eric; 1443448 Schaefer, Joerg", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Simulations of 10Be over Antarctica; South Pole ice Core 10Be CE", "datasets": [{"dataset_uid": "601431", "doi": "10.15784/601431", "keywords": "Antarctica; South Pole", "people": "Steig, Eric J.; Ding, Qinghua; Schaefer, Joerg", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Simulations of 10Be over Antarctica", "url": "https://www.usap-dc.org/view/dataset/601431"}, {"dataset_uid": "601535", "doi": "10.15784/601535", "keywords": "Antarctica; South Pole", "people": "Schaefer, Joerg", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice Core 10Be CE", "url": "https://www.usap-dc.org/view/dataset/601535"}], "date_created": "Thu, 04 Feb 2021 00:00:00 GMT", "description": "This project will acquire measurements of the concentration of beryllium-10 (10Be) from an ice core from the South Pole, Antarctica. An isotope of the element beryllium, 10Be, is produced in the atmosphere by high-energy protons (cosmic rays) that enter Earth\u0027s atmosphere from space. It is removed from the atmosphere by settling or by scavenging by rain or snowfall. Hence, concentrations of 10Be in snow at the South Pole reflect the production rate of 10Be in the atmosphere. Because the rate of production of 10Be over Antarctica depends primarily on the strength of the Sun\u0027s magnetic field, measurements of 10Be in the South Pole ice core will provide a record of changes in solar activity. The South Pole ice core will reach an age of 40,000 years at the bottom. The project will result in measurements of 10Be at annual resolution for the last 100 years and selected periods in the more distant past, such as the Maunder Minimum, a period during the late 17th century during which no sunspots were observed, or the last glacial cold period, about 20,000 years ago. A climate model that can simulate the production of 10Be in the atmosphere, it\u0027s transport through the atmosphere, and its deposition at the snow surface in Antarctica will be used to aid in using the 10Be data to determine past changes in solar activity from decadal to millennial scale, and in turn to evaluate the role of the Sun in Earth?s climate from a new perspective. The production of 10Be in Earth\u0027s atmosphere results from the spallation of oxygen and nitrogen in the atmosphere by cosmic rays. Cosmic ray variations in the high latitudes are primarily modulated by solar variability. Time-series records of 10Be from ice cores are therefore important for deriving variations in solar activity through time, which is fundamental to understanding climate variability. Deposition of 10Be to the ice surface is also influenced by variability in atmospheric circulation and deposition processes, and South Pole is the best available location for minimizing the influence of variable atmospheric circulation on 10Be deposition. To date, only one record of 10Be exists from South Pole; that record is widely used in solar forcing estimates used in climate models, but covers only the last millennium and ends in CE 1982. We will obtain 10Be concentration measurements in a 1500-m, 40000-year long ice core from the South Pole. This will extend the existing record both further back in time and forward to the present, providing overlap with the modern instrumental record of solar and climate variability. High resolution (annual to biannual) measurements will be made in targeted areas of interest, including the last 100 years, the Maunder Minimum (CE 1650-1715), and the last glacial maximum. The novel data will be used in conjunction with climate model experiments that incorporate 10Be production, transport, and deposition physics. Together, data and modeling will create an updated record of atmospheric 10Be production and hence of solar activity.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "COSMIC RAYS; LABORATORY; BERYLLIUM-10 ANALYSIS; SNOW/ICE; South Pole; GLACIERS; ICE CORE RECORDS", "locations": "South Pole", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Schaefer, Joerg; Steig, Eric J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A High-sensitivity Beryllium-10 Record from an Ice Core at South Pole", "uid": "p0010158", "west": -180.0}, {"awards": "1842049 Kim, Sora; 1842059 Huber, Matthew; 1842176 Bizimis, Michael; 1842115 Jahn, Alexandra", "bounds_geometry": "POLYGON((-56.693516 -64.209061,-56.6823452 -64.209061,-56.6711744 -64.209061,-56.6600036 -64.209061,-56.6488328 -64.209061,-56.637662 -64.209061,-56.6264912 -64.209061,-56.6153204 -64.209061,-56.6041496 -64.209061,-56.5929788 -64.209061,-56.581808 -64.209061,-56.581808 -64.2143344,-56.581808 -64.2196078,-56.581808 -64.2248812,-56.581808 -64.2301546,-56.581808 -64.235428,-56.581808 -64.2407014,-56.581808 -64.2459748,-56.581808 -64.2512482,-56.581808 -64.2565216,-56.581808 -64.261795,-56.5929788 -64.261795,-56.6041496 -64.261795,-56.6153204 -64.261795,-56.6264912 -64.261795,-56.637662 -64.261795,-56.6488328 -64.261795,-56.6600036 -64.261795,-56.6711744 -64.261795,-56.6823452 -64.261795,-56.693516 -64.261795,-56.693516 -64.2565216,-56.693516 -64.2512482,-56.693516 -64.2459748,-56.693516 -64.2407014,-56.693516 -64.235428,-56.693516 -64.2301546,-56.693516 -64.2248812,-56.693516 -64.2196078,-56.693516 -64.2143344,-56.693516 -64.209061))", "dataset_titles": "Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota", "datasets": [{"dataset_uid": "200183", "doi": "https://doi.org/10.6071/M34T1Z", "keywords": null, "people": null, "repository": "Dryad", "science_program": null, "title": "Data from: Probing the ecology and climate of the Eocene Southern Ocean with sand tiger sharks Striatolamia macrota", "url": "https://datadryad.org/stash/dataset/doi:10.6071/M34T1Z"}], "date_created": "Tue, 15 Dec 2020 00:00:00 GMT", "description": "The Earth\u0027s climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from \u0027greenhouse\u0027 to \u0027icehouse\u0027 conditions. During the Eocene, a shift to cooler temperatures at high latitudes resulted in the inception of polar glaciation. This in turn affected the environment for living organisms. This project looks to uncover the interaction between biological, oceanographic, and climate systems for the Eocene in Antarctica using chemical analysis of fossil shark teeth collected during past expeditions. The combination of paleontological and geochemical analyses will provide insight to the past ecology and ocean conditions; climate models will be applied to test the role of tectonics, greenhouse gas concentration and ocean circulation on environmental change during this time period. The study contributes to understanding the interaction of increased atmospheric carbon dioxide and ocean circulation. This project also seeks to improve diversity, equity, and inclusion within the geosciences workforce with efforts targeted to undergraduate, graduate, postdoctoral, and early career faculty. The research goal is to elucidate the processes leading from the Eocene greenhouse to Oligocene icehouse conditions. Previous explanations for this climate shift centers on Antarctica, where tectonic configurations influenced oceanic gateways, ocean circulation reduced heat transport, and/or greenhouse gas declines prompted glaciation. The team will reconstruct watermass, current, and climate fluctuations proximal to the Antarctic Peninsula using geochemical indicators (oxygen and neodymium isotope composition) from fossil shark teeth collected from Seymour Island. The approach builds on previous shark paleontological studies, incorporates geochemical analyses for environmental reconstruction (i.e., temperature gradients and ocean circulation), and tests hypotheses on Earth System dynamics using novel global climate model simulations with geochemical tracers. This project will advance global climate modeling capabilities with experiments that consider Eocene tectonic configuration within isotope-enabled climate model simulations. A comparison of geochemical results from Eocene climate simulations and empirical records of shark teeth will reveal processes and mechanisms central to the Eocene Antarctic climatic shift. This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -56.581808, "geometry": "POINT(-56.637662 -64.235428)", "instruments": null, "is_usap_dc": true, "keywords": "FISH; USA/NSF; OXYGEN ISOTOPE ANALYSIS; WATER MASSES; Amd/Us; AMD; USAP-DC; OXYGEN ISOTOPES; LABORATORY; Seymour Island; Sharks; Striatolamia Macrota", "locations": "Seymour Island", "north": -64.209061, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE \u003e EOCENE", "persons": "Kim, Sora; Scher, Howard; Huber, Matthew; Jahn, Alexandra", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "Dryad", "repositories": "Dryad", "science_programs": null, "south": -64.261795, "title": "Collaborative Research: Integrating Eocene Shark Paleoecology and Climate Modeling to reveal Southern Ocean Circulation and Antarctic Glaciation", "uid": "p0010146", "west": -56.693516}, {"awards": "1542885 Dunham, Eric", "bounds_geometry": null, "dataset_titles": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "datasets": [{"dataset_uid": "601320", "doi": "10.15784/601320", "keywords": "Antarctica; Computer Model; Glaciology; Model Data; Shear Stress; Solid Earth; Whillans Ice Stream", "people": "Abrahams, Lauren", "repository": "USAP-DC", "science_program": null, "title": "Earthquake Sequence Dynamics at the Interface Between an Elastic Layer and Underlying Half-Space in Antiplane Shear", "url": "https://www.usap-dc.org/view/dataset/601320"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth\u0027s ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students. Simulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOGRAPHS", "is_usap_dc": true, "keywords": "SEISMIC PROFILE; AMD; Antarctica; GROUND-BASED OBSERVATIONS; USA/NSF; USAP-DC; Amd/Us", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Dunham, Eric", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Characterizing Brittle Failure and Fracture Propagation in Fast Ice Sliding with Dynamic Rupture Models based on Whillans Ice Stream Seismic/Geodetic Data", "uid": "p0010138", "west": null}, {"awards": "1443433 Licht, Kathy; 1443213 Kaplan, Michael", "bounds_geometry": "POLYGON((159 -83.8,159.5 -83.8,160 -83.8,160.5 -83.8,161 -83.8,161.5 -83.8,162 -83.8,162.5 -83.8,163 -83.8,163.5 -83.8,164 -83.8,164 -83.87,164 -83.94,164 -84.01,164 -84.08,164 -84.15,164 -84.22,164 -84.29,164 -84.36,164 -84.43,164 -84.5,163.5 -84.5,163 -84.5,162.5 -84.5,162 -84.5,161.5 -84.5,161 -84.5,160.5 -84.5,160 -84.5,159.5 -84.5,159 -84.5,159 -84.43,159 -84.36,159 -84.29,159 -84.22,159 -84.15,159 -84.08,159 -84.01,159 -83.94,159 -83.87,159 -83.8))", "dataset_titles": "10Be and 26Al cosmogenic nuclide surface exposure data; 3He input data", "datasets": [{"dataset_uid": "601375", "doi": "10.15784/601375", "keywords": "Antarctica; Cosmogenic Dating; Transantarctic Mountains", "people": "Winckler, Gisela; Schaefer, Joerg; Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "10Be and 26Al cosmogenic nuclide surface exposure data", "url": "https://www.usap-dc.org/view/dataset/601375"}, {"dataset_uid": "601376", "doi": "10.15784/601376", "keywords": "Antarctica; Transantarctic Mountains", "people": "Schaefer, Joerg; Winckler, Gisela; Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "3He input data", "url": "https://www.usap-dc.org/view/dataset/601376"}], "date_created": "Tue, 29 Sep 2020 00:00:00 GMT", "description": "Licht/1443433 Sediments deposited by the Antarctic ice sheet are an archive of its history with time and help geologists to determine how the remote interior of the ice sheet has changed over the past several hundred thousand years. This project will focus on the formation and dynamics of moraines (accumulations of dirt and rocks that are incorporated in the glacier surface or have been pushed along by the glacier as it moves) near the blue ice area of Mt. Achernar in the central Transantarctic Mountains in Antarctica.. The study will improve basic understanding of the formation of these moraines. Fieldwork at the site will focus on imaging the internal structure of the moraine to determine the processes by which it, and others like it, form over time. Additional analyses will include measurements of ice flow and collection of rock samples to determine the timing of debris deposition and the changes in the sources of sediments from deep within the Antarctic continent. The project will provide both graduate and undergraduate students training in paleoclimate studies, geology, and numerical modeling approaches. The broader impacts of the proposed work include hands on training in the Earth Sciences for graduate and undergraduate students, collaboration with colleagues in New Zealand and Sweden to provide an international research experience for students from the US, and three educational modules to be delivered by student researchers regarding Antarctica\u0027s role in global environments. The research is societally relevant and multidisciplinary and the topics are ideal for sharing with the public. All research findings will be made publicly available to others via timely publication in high-impact, peer-reviewed journals and all data will be submitted to the National Snow and Ice Data Center, and excess samples will be provided to the U.S. Polar Rock Repository. Direct observations of ice sheet history from the margins of Antarctica\u0027s polar plateau are essential for testing numerical ice sheet models, and the laterally extensive, blue-ice moraines of the Mt. Achernar Moraine complex in the central Transantarctic Mountains contain a unique and nearly untapped direct, quasi-continuous record of ice sheet change over multiple glacial cycles. The project objectives include improved understanding of processes and rates of blue ice moraine formation, as well as identifying the topographic, glaciological, and climatic controls on their evolution. Data to be collected with fieldwork in Antarctica include: imaging of internal ice structure with ground-penetrating radar, measurement of ice flow velocity and direction with a global positioning system (GPS) array, analysis of debris concentration and composition in glacier ice, state-of-the-art cosmogenic multi-nuclide analyses to determine exposure ages of moraine debris, mapping of trimlines and provenance analysis. Numerical model simulations, constrained by field data, will be used to evaluate the factors influencing changes in glacier flow that potentially impact the accumulation of the moraine debris. All together, the new data and modeling efforts will improve conceptual models of blue ice moraine formation, and thereby make them a more valuable proxy for developing a better understanding of the history of the ice sheet.", "east": 164.0, "geometry": "POINT(161.5 -84.15)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; GLACIAL PROCESSES; Mt. Achernar; ABLATION ZONES/ACCUMULATION ZONES; GLACIER ELEVATION/ICE SHEET ELEVATION; Antarctica; Antarctic Ice Sheet; Transantarctic Mountains; GLACIATION; USAP-DC; ICE MOTION; AMD; LABORATORY; Amd/Us", "locations": "Transantarctic Mountains; Antarctic Ice Sheet; Mt. Achernar; Antarctica", "north": -83.8, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Kaplan, Michael; Schaefer, Joerg; Winckler, Gisela; Licht, Kathy", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Collaborative Research: Multidisciplinary Analysis of Antarctic Blue Ice Moraine Formation and their Potential as Climate Archives over Multiple Glacial Cycles", "uid": "p0010131", "west": 159.0}, {"awards": "0125252 Padman, Laurence; 0125602 Padman, Laurence", "bounds_geometry": "POLYGON((-180 -40.231,-144 -40.231,-108 -40.231,-72 -40.231,-36 -40.231,0 -40.231,36 -40.231,72 -40.231,108 -40.231,144 -40.231,180 -40.231,180 -45.2079,180 -50.1848,180 -55.1617,180 -60.1386,180 -65.1155,180 -70.0924,180 -75.0693,180 -80.0462,180 -85.0231,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.0231,-180 -80.0462,-180 -75.0693,-180 -70.0924,-180 -65.1155,-180 -60.1386,-180 -55.1617,-180 -50.1848,-180 -45.2079,-180 -40.231))", "dataset_titles": "Antarctic Tide Gauge Database, version 1; AntTG_Database_Tools; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; pyTMD; TMD_Matlab_Toolbox_v2.5", "datasets": [{"dataset_uid": "200158", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "pyTMD", "url": "https://github.com/tsutterley/pyTMD"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Sutterley, Tyler; Howard, Susan L.; Greene, Chad A.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}, {"dataset_uid": "200156", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "AntTG_Database_Tools", "url": "https://github.com/EarthAndSpaceResearch/AntTG_Database_Tools"}, {"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "200157", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "TMD_Matlab_Toolbox_v2.5", "url": "https://github.com/EarthAndSpaceResearch/TMD_Matlab_Toolbox_v2.5"}, {"dataset_uid": "601358", "doi": "10.15784/601358", "keywords": "Antarctica; Oceans; Sea Surface Height; Tide Gauges; Tides", "people": "Howard, Susan L.; Padman, Laurence; King, Matt", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Tide Gauge Database, version 1", "url": "https://www.usap-dc.org/view/dataset/601358"}], "date_created": "Tue, 07 Jul 2020 00:00:00 GMT", "description": "The ocean tide is a large component of total variability of ocean surface height and currents in the seas surrounding Antarctica, including under the floating ice shelves. Maximum tidal height range exceeds 7 m (near the grounding line of Rutford Ice Stream) and maximum tidal currents exceed 1 m/s (near the shelf break in the northwest Ross Sea). Tides contribute to several important climate and ecosystems processes including: ocean mixing, production of dense bottom water, flow of warm Circumpolar Deep Water onto the continental shelves, melting at the bases of ice shelves, fracturing of the ice sheet near a glacier or ice stream\u2019s grounding line, production and decay of sea ice, and sediment resuspension. Tide heights and, in particular, currents can change as the ocean background state changes, and as the geometry of the coastal margins of the Antarctic Ice Sheet varies through ice shelf thickness changes and ice-front and grounding-line advances or retreats. For satellite-based studies of ocean surface height and ice shelf thickness changes, tide heights are a source of substantial noise that must be removed. Similarly, tidal currents can also be a substantial noise signal when trying to estimate mean ocean currents from short-term measurements such as from acoustic Doppler current profilers mounted on ships and CTD rosettes. Therefore, tide models play critical roles in understanding current and future ocean and ice states, and as a method for removing tides in various measurements. A paper in Reviews of Geophysics (Padman, Siegfried and Fricker, 2018, see list of project-related publications below) provides a detailed review of tides and tidal processes around Antarctica.\r\n\nThis project provides a gateway to tide models and a database of tide height coefficients at the Antarctic Data Center, and links to toolboxes to work with these models and data.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e GAUGES \u003e TIDE GAUGES", "is_usap_dc": true, "keywords": "Tide Gauges; OCEAN CURRENTS; Sea Surface Height; USAP-DC; GLACIER MOTION/ICE SHEET MOTION; Tides; Antarctica; MODELS; FIELD INVESTIGATION", "locations": "Antarctica", "north": -40.231, "nsf_funding_programs": "Arctic System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana; King, Matt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e MODELS", "repo": "GitHub", "repositories": "GitHub; USAP-DC", "science_programs": null, "south": -90.0, "title": "Ocean Tides around Antarctica and in the Southern Ocean", "uid": "p0010116", "west": -180.0}, {"awards": "1341658 Mukhopadhyay, Sujoy", "bounds_geometry": "POLYGON((-116.45 -84.786,-116.443 -84.786,-116.436 -84.786,-116.429 -84.786,-116.422 -84.786,-116.415 -84.786,-116.408 -84.786,-116.401 -84.786,-116.394 -84.786,-116.387 -84.786,-116.38 -84.786,-116.38 -84.7864,-116.38 -84.7868,-116.38 -84.7872,-116.38 -84.7876,-116.38 -84.788,-116.38 -84.7884,-116.38 -84.7888,-116.38 -84.7892,-116.38 -84.7896,-116.38 -84.79,-116.387 -84.79,-116.394 -84.79,-116.401 -84.79,-116.408 -84.79,-116.415 -84.79,-116.422 -84.79,-116.429 -84.79,-116.436 -84.79,-116.443 -84.79,-116.45 -84.79,-116.45 -84.7896,-116.45 -84.7892,-116.45 -84.7888,-116.45 -84.7884,-116.45 -84.788,-116.45 -84.7876,-116.45 -84.7872,-116.45 -84.7868,-116.45 -84.7864,-116.45 -84.786))", "dataset_titles": "Ohio Range Subglacial rock core cosmogenic nuclide data", "datasets": [{"dataset_uid": "601351", "doi": "10.15784/601351", "keywords": "Aluminum-26; Antarctica; Beryllium-10; Cosmogenic Dating; Cosmogenic Radionuclides; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Fluctuations; Ohio Range; Rocks", "people": "Mukhopadhyay, Sujoy", "repository": "USAP-DC", "science_program": null, "title": "Ohio Range Subglacial rock core cosmogenic nuclide data", "url": "https://www.usap-dc.org/view/dataset/601351"}], "date_created": "Sun, 28 Jun 2020 00:00:00 GMT", "description": "Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare. The investigators propose to collect geochemical data from the Ohio Range and Scott Glacier to quantify past variability in the height of the WAIS. Limited available cosmogenic nuclide data are broadly consistent with a model indicating that Pliocene WAIS elevations and volumes were smaller than at present, and that WAIS collapse was common. The PIs will use geologic observations and cosmogenic nuclide concentrations from bedrock samples at multiple locations and at multiple elevations, including sub-ice samples, to constrain WAIS ice volume changes in a \"dipstick\" like fashion. Data obtained from the proposed research will provide targets for data-ice sheet model comparisons to accurately characterize Plio-Pleistocene and future WAIS behavior. As part of this project, the investigators will work with the Natural History Museum and the Earth \u0026 Planetary Science department at Harvard to develop an exhibit that will become part of the Museum\u0027s recently opened Earth and Planetary Science Gallery. The project involves mentoring of a female graduate student as well as an undergraduate student.", "east": -116.38, "geometry": "POINT(-116.415 -84.788)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ROCK CORERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Sheet Fluctuations; ALUMINUM-26 ANALYSIS; BERYLLIUM-10 ANALYSIS; Cosmogenic Radionuclides; USAP-DC; FIELD INVESTIGATION; AMD; Ohio Range; GLACIER THICKNESS/ICE SHEET THICKNESS; ICE SHEETS; LABORATORY", "locations": "Ohio Range", "north": -84.786, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Mukhopadhyay, Sujoy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.79, "title": "Constraining Plio-Pleistocene West Antarctic Ice Sheet Behavior from the Ohio Range and Scott Glacier", "uid": "p0010113", "west": -116.45}, {"awards": "1551195 Burdige, David", "bounds_geometry": "POLYGON((-71 -64,-70.1 -64,-69.2 -64,-68.3 -64,-67.4 -64,-66.5 -64,-65.6 -64,-64.7 -64,-63.8 -64,-62.9 -64,-62 -64,-62 -64.4,-62 -64.8,-62 -65.2,-62 -65.6,-62 -66,-62 -66.4,-62 -66.8,-62 -67.2,-62 -67.6,-62 -68,-62.9 -68,-63.8 -68,-64.7 -68,-65.6 -68,-66.5 -68,-67.4 -68,-68.3 -68,-69.2 -68,-70.1 -68,-71 -68,-71 -67.6,-71 -67.2,-71 -66.8,-71 -66.4,-71 -66,-71 -65.6,-71 -65.2,-71 -64.8,-71 -64.4,-71 -64))", "dataset_titles": "Expedition data of NBP1601; Project: Organic Carbon Oxidation and Iron Remobilization by West Antarctic Shelf Sediments", "datasets": [{"dataset_uid": "200148", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Project: Organic Carbon Oxidation and Iron Remobilization by West Antarctic Shelf Sediments", "url": "https://www.bco-dmo.org/project/806864"}, {"dataset_uid": "002665", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1601", "url": "https://www.rvdata.us/search/cruise/NBP1601"}], "date_created": "Tue, 16 Jun 2020 00:00:00 GMT", "description": "General Statement: The continental shelf region west of the Antarctic Peninsula has recently undergone dramatic changes and ecosystem shifts, and the community of organisms that live in, or feed off, the sea floor sediments is being impacted by species invasions from the north. Previous studies of these sediments indicate that this community may consume much more of the regional productivity than previously estimated, suggesting that sediments are a rich and important component of this ecosystem and one that may be ripe for dramatic change. Furthermore, under richer sediment conditions, iron is mobilized and released back to the water column. Since productivity in this ecosystem is thought to be limited by the availability of iron, increased rates of iron release from these sediments could stimulate productivity and promote greater overall ecosystem change. In this research, a variety of sites across the shelf region will be sampled to accurately evaluate the role of sediments in consuming ecosystem productivity and to estimate the current level of iron release from the sediments. This project will provide a baseline set of sediment results that will present a more complete picture of the west Antarctic shelf ecosystem, will allow for comparison with water column measurements and for evaluation of the fundamental workings of this important ecosystem. This is particularly important since high latitude systems may be vulnerable to the effects of climate fluctuations. Both graduate and undergraduate students will be trained. Presentations will be made at scientific meetings, at other universities, and at outreach events. A project web site will present key results to the public and explain how this new information improves understanding of Antarctic ecosystems. Technical Description of Project: In order to determine the role of sediments within the west Antarctic shelf ecosystem, this project will determine the rates of sediment organic matter oxidation at a variety of sites across the Palmer Long Term Ecosystem Research (LTER) study region. To estimate the rates of release of iron and manganese from the sediments, these same sites will be sampled for detailed vertical distributions of the concentrations of these metals both in the porewaters and in important mineral phases. Since sediment sampling will be done at LTER sites, the sediment data can be correlated with the rich productivity data set from the LTER. In detail, the project: a) will determine the rates of oxygen consumption, organic carbon oxidation, nutrient release, and iron mobilization by shelf sediments west of the Antarctic Peninsula; b) will investigate the vertical distribution of diagenetic reactions within the sediments; and c) will assess the regional importance of these sediment rates. Sediment cores will be used to determine sediment-water fluxes of dissolved oxygen, total carbon dioxide, nutrients, and the vertical distributions of these dissolved compounds, as well as iron and manganese in the pore waters. Bulk sediment properties of porosity, organic carbon and nitrogen content, carbonate content, biogenic silica content, and multiple species of solid-phase iron, manganese, and sulfur species will also be determined. These measurements will allow determination of total organic carbon oxidation and denitrification rates, and the proportion of aerobic versus anaerobic respiration at each site. Sediment diagenetic modeling will link the processes of organic matter oxidation to metal mobilization. Pore water and solid phase iron and manganese distributions will be used to model iron diagenesis in these sediments and to estimate the iron flux from the sediments to the overlying waters. Finally, the overall regional average and distribution of the sediment processes will be compared with the distributions of seasonally averaged chlorophyll biomass and productivity.", "east": -62.0, "geometry": "POINT(-66.5 -66)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; Iron Remobilization; R/V NBP; NBP1601; SEDIMENT CHEMISTRY; USAP-DC; West Antarctic Shelf", "locations": "West Antarctic Shelf", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Burdige, David; Christensen, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "BCO-DMO", "repositories": "BCO-DMO; R2R", "science_programs": null, "south": -68.0, "title": "Organic carbon oxidation and iron remobilization by West Antarctic shelf sediments ", "uid": "p0010108", "west": -71.0}, {"awards": "1443576 Panter, Kurt", "bounds_geometry": "POLYGON((-154.1 -86.9,-154.03 -86.9,-153.96 -86.9,-153.89 -86.9,-153.82 -86.9,-153.75 -86.9,-153.68 -86.9,-153.61 -86.9,-153.54 -86.9,-153.47 -86.9,-153.4 -86.9,-153.4 -86.92,-153.4 -86.94,-153.4 -86.96,-153.4 -86.98,-153.4 -87,-153.4 -87.02,-153.4 -87.04,-153.4 -87.06,-153.4 -87.08,-153.4 -87.1,-153.47 -87.1,-153.54 -87.1,-153.61 -87.1,-153.68 -87.1,-153.75 -87.1,-153.82 -87.1,-153.89 -87.1,-153.96 -87.1,-154.03 -87.1,-154.1 -87.1,-154.1 -87.08,-154.1 -87.06,-154.1 -87.04,-154.1 -87.02,-154.1 -87,-154.1 -86.98,-154.1 -86.96,-154.1 -86.94,-154.1 -86.92,-154.1 -86.9))", "dataset_titles": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "datasets": [{"dataset_uid": "601331", "doi": "10.15784/601331", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochronology; Glacial Volcanism; Magma Differentiation; Major Elements; Mantle Melting; Solid Earth; Trace Elements; Transantarctic Mountains", "people": "Panter, Kurt", "repository": "USAP-DC", "science_program": null, "title": "Volcanological and Petrological measurements on Mt. Early and Sheridan Bluff volcanoes, upper Scott Glacier, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601331"}], "date_created": "Fri, 05 Jun 2020 00:00:00 GMT", "description": "Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world?s largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student?s research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise ?snapshots? of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.", "east": -153.4, "geometry": "POINT(-153.75 -87)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Mantle Melting; Magma Differentiation; Geochronology; Glacial Volcanism; GEOCHEMISTRY; Major Elements; ISOTOPES; Trace Elements; Transantarctic Mountains; LABORATORY; LAVA COMPOSITION/TEXTURE; USAP-DC; LAND RECORDS", "locations": "Transantarctic Mountains", "north": -86.9, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Panter, Kurt", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.1, "title": "Investigating Early Miocene Sub-ice Volcanoes in Antarctica for Improved Modeling and understanding of a Large Magmatic Province", "uid": "p0010105", "west": -154.1}, {"awards": "9319877 Finn, Carol; 9319854 Bell, Robin; 9319369 Blankenship, Donald", "bounds_geometry": "POLYGON((-155 -77.5,-150 -77.5,-145 -77.5,-140 -77.5,-135 -77.5,-130 -77.5,-125 -77.5,-120 -77.5,-115 -77.5,-110 -77.5,-105 -77.5,-105 -78.2,-105 -78.9,-105 -79.6,-105 -80.3,-105 -81,-105 -81.7,-105 -82.4,-105 -83.1,-105 -83.8,-105 -84.5,-110 -84.5,-115 -84.5,-120 -84.5,-125 -84.5,-130 -84.5,-135 -84.5,-140 -84.5,-145 -84.5,-150 -84.5,-155 -84.5,-155 -83.8,-155 -83.1,-155 -82.4,-155 -81.7,-155 -81,-155 -80.3,-155 -79.6,-155 -78.9,-155 -78.2,-155 -77.5))", "dataset_titles": "SOAR-BSB Airborne gravity data for the CASERTZ/WAIS project; SOAR-IRE airborne gravity data for the CASERTZ/WAIS project; SOAR-TKD airborne gravity data for the CASERTZ/WAIS project; SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project", "datasets": [{"dataset_uid": "601288", "doi": "10.15784/601288", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-BSB Airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601288"}, {"dataset_uid": "601289", "doi": "10.15784/601289", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-TKD airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601289"}, {"dataset_uid": "601290", "doi": "10.15784/601290", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Bell, Robin; Arko, Robert A.", "repository": "USAP-DC", "science_program": null, "title": "SOAR-IRE airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601290"}, {"dataset_uid": "601291", "doi": "10.15784/601291", "keywords": "Aerogeophysics; Airborne Gravity; Airplane; Antarctica; Free Air Gravity; Glaciers/ice Sheet; Glaciers/Ice Sheet; Gravimeter; Gravity; Gravity Data; Marie Byrd Land; Potential Field; Solid Earth; WAIS", "people": "Arko, Robert A.; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "SOAR-WAZ Airborne gravity data for the CASERTZ/WAIS project", "url": "https://www.usap-dc.org/view/dataset/601291"}], "date_created": "Fri, 24 Apr 2020 00:00:00 GMT", "description": "Blankenship: 9319369 Bell: 9319854 Behrendt: 9319877 This award supports a project to conduct an integrated geophysical survey over a large portion of the West Antarctic Ice Sheet (WAIS) toward an understanding of the dynamic behavior of the ice sheet and the nature of the lithosphere beneath the ice sheet. West Antarctica is characterized by two kinds of the Earth s most dynamic systems, a continental rift (the West Antarctic Rift System) and a marine based ice sheet (the WAIS). Active continental rift systems, caused by divergent plate motions, result in thinned continental crust. Associated with the thin crust are fault-bounded sedimentary basins, active volcanism, and elevated heat flow. Marine ice sheets are characterized by rapidly moving streams of ice, penetrating and draining a slowly moving ice reservoir. Evidence left by past marine ice sheets indicates that they may have a strongly non- linear response to long-term climate change which results in massive and rapid discharges of ice. Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding this non-linear response. Subglacial geology and ice dynamics are generally studied in isolation, but evidence is mounting that the behavior of the West Antarctic ice streams may be closely linked to the nature of the underlying West Antarctic rift system. The fast moving ice streams appear to glide on a lubricating layer of water-saturated till. This till requires easily eroded sediment and a source of water, both of which may be controlled by the geology of the rift system; the sediments from the fault-bounded basins and the water from the elevated heat flux associated with active lithospheric extension. This project represents an interdisciplinary aerogeophysical study to characterize the lithosphere of the West Antarctic rift system beneath critical regions of the WAIS. The objective is to determine the effects of the rift architect ure, as manifested by the distribution of sedimentary basins and volcanic constructs, on the ice stream system. The research tool is a unique geophysical aircraft with laser altimetry, ice penetrating radar, aerogravity, and aeromagnetic systems integrated with a high precision kinematic GPS navigation system. It is capable of imaging both the surface and bed of the ice sheet while simultaneously measuring the gravity and magnetic signature of the subglacial lithosphere. Work to be done under this award will build on work already completed in the southern sector of central West Antarctica and it will focus on the region of the Byrd Subglacial Basin and Ice Stream D. The ice sheet in these regions is completely covered by satellite imagery and so this project will be integrated with remote sensing studies of the ice stream. The changing dynamics of Ice Stream D, as with other West Antarctic ice streams, seem to be correlated with changes in the morphological provinces of the underlying rift system. The experimental targets proceed from the divide of the interior ice, downstream through the onset of streaming to the trunk of Ice Stream D. This study will be coordinated with surface glaciological investigations of Ice Stream D and will be used to guide cooperative over-snow seismic investigations of the central West Antarctic rift system. The data will also be used to select a site for future deep ice coring along the crest of the WAIS. These data represent baseline data for long term global change monitoring work and represent crucial boundary conditions for ice sheet modeling efforts.", "east": -105.0, "geometry": "POINT(-130 -81)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": true, "keywords": "USAP-DC; MAGNETIC FIELD; GRAVITY FIELD; Antarctica; GLACIERS/ICE SHEETS; Marie Byrd Land; Airborne Gravity", "locations": "Marie Byrd Land; Antarctica", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Bell, Robin; Blankenship, Donald D.; Finn, C. A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -84.5, "title": "Collaborative Research: Lithospheric Controls on the Behavior of the West Antarctic Ice Sheet: Corridor Aerogeophysics of Eastern Ross Transect Zone", "uid": "p0010094", "west": -155.0}, {"awards": "1643550 Sletten, Ronald", "bounds_geometry": "POLYGON((160.5 -77.3,160.67 -77.3,160.84 -77.3,161.01 -77.3,161.18 -77.3,161.35 -77.3,161.52 -77.3,161.69 -77.3,161.86 -77.3,162.03 -77.3,162.2 -77.3,162.2 -77.35,162.2 -77.4,162.2 -77.45,162.2 -77.5,162.2 -77.55,162.2 -77.6,162.2 -77.65,162.2 -77.7,162.2 -77.75,162.2 -77.8,162.03 -77.8,161.86 -77.8,161.69 -77.8,161.52 -77.8,161.35 -77.8,161.18 -77.8,161.01 -77.8,160.84 -77.8,160.67 -77.8,160.5 -77.8,160.5 -77.75,160.5 -77.7,160.5 -77.65,160.5 -77.6,160.5 -77.55,160.5 -77.5,160.5 -77.45,160.5 -77.4,160.5 -77.35,160.5 -77.3))", "dataset_titles": "Timelapse photography of Don Juan Pond and surrounding basin", "datasets": [{"dataset_uid": "601487", "doi": "10.15784/601487", "keywords": "Antarctica; Brine; CaCl2; Don Juan Pond; Dry Valleys; Salt", "people": "Toner, Jonathan; Sletten, Ronald S.; Mushkin, Amit", "repository": "USAP-DC", "science_program": null, "title": "Timelapse photography of Don Juan Pond and surrounding basin", "url": "https://www.usap-dc.org/view/dataset/601487"}], "date_created": "Thu, 21 Nov 2019 00:00:00 GMT", "description": "This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment. Past research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.", "east": 162.2, "geometry": "POINT(161.35 -77.55)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA", "is_usap_dc": true, "keywords": "Amd/Us; AMD; Antarctica; USA/NSF; USAP-DC; SOIL CHEMISTRY; FIELD INVESTIGATION", "locations": "Antarctica", "north": -77.3, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sletten, Ronald S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.8, "title": "Formation and Characteristics of Brine-rich Water in the Dry Valleys, Antarctica", "uid": "p0010069", "west": 160.5}, {"awards": "1443190 Parizek, Byron", "bounds_geometry": "POLYGON((-130 -73,-125.5 -73,-121 -73,-116.5 -73,-112 -73,-107.5 -73,-103 -73,-98.5 -73,-94 -73,-89.5 -73,-85 -73,-85 -73.9,-85 -74.8,-85 -75.7,-85 -76.6,-85 -77.5,-85 -78.4,-85 -79.3,-85 -80.2,-85 -81.1,-85 -82,-89.5 -82,-94 -82,-98.5 -82,-103 -82,-107.5 -82,-112 -82,-116.5 -82,-121 -82,-125.5 -82,-130 -82,-130 -81.1,-130 -80.2,-130 -79.3,-130 -78.4,-130 -77.5,-130 -76.6,-130 -75.7,-130 -74.8,-130 -73.9,-130 -73))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 16 Sep 2019 00:00:00 GMT", "description": "Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region. We will test an ice-sheet model against existing observations, improve treatment of key processes in the model, and make projections with uncertainty assessments. This is a three-year modeling study using the open-source Ice Sheet System Model in coordination with other models to improve projections of future sea-level change. Project goals are to: 1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance; 2. improve the model by utilizing sensitivity studies with regional process-oriented models to create numerically efficient parameterizations for key sub-grid-scale processes; 3. project a range of likely evolutions of the Amundsen Sea Embayment sector and their respective contributions to sea level in the next several centuries; 4. attribute sources of errors in the hindcast and provide an assessment of the uncertainties in the projections, including a range of likely outcomes given various forcings and inclusion or omission of physical processes in the model. At present, the long-term stability of the Amundsen Sea Embayment is unknown, with both theory (the \"marine ice sheet instability hypothesis\") and observations (rapid thinning and grounding-line retreat approaching regions where the bed deepens inland) suggesting that collapse is possible. But incompletely understood physical processes (e.g., basal hydrology, rheology, and sliding; tidal effects; ice-ocean interaction along the shelf and within the grounding zone) and lack of resolution in basal topography datasets making the ultimate outcome uncertain. Thus, there is a pressing need for high-resolution simulations of this region that include numerical representations of controlling physical processes (many of which are applicable elsewhere) within a higher-order ice-sheet model capable of assimilating recent observations and providing uncertainty analyses associated with model and data limitations. By focusing on the Amundsen Sea Embayment as a connected region across the 10-10,000-meter scales using a hierarchy of one, two, and three-dimensional models along with the sensitivity analysis tools built into the Ice Sheet System Model, this project aims to produce (1) the most reliable results to date when compared with studies that consider only one ice stream or the entire ice sheet and (2) estimates of differing dynamic responses arising from errors in data, model parameterizations, and forcings. Given the uncertainties, the project will produce a range of predictions with characteristic trends that can be recognized within future observational data sets. As new data become available, some predicted rates of change could be culled from the predictive paths generated by this study.", "east": -85.0, "geometry": "POINT(-107.5 -77.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; GLACIER MOTION/ICE SHEET MOTION; NOT APPLICABLE", "locations": "Antarctica", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pollard, David; Parizek, Byron R.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -82.0, "title": "Collaborative Research: Evaluating Retreat in the Amundsen Sea Embayment: Assessing Controlling Processes, Uncertainties, and Projections", "uid": "p0010054", "west": -130.0}, {"awards": "1643901 Zhang, Weifeng; 1643735 Li, Yun; 2021245 Li, Yun", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Dynamic fine-scale sea-icescape shapes adult emperor penguin foraging habitat in East Antarctica; Monthly Stratification Climatology (1978-2021) in Antarctic Coastal Polynyas", "datasets": [{"dataset_uid": "601628", "doi": "10.15784/601628", "keywords": "Antarctic; Antarctica; Antarctic Coastal Polynyas; Polynya", "people": "Zhang, Weifeng; Li, Yun; Shunk, Nathan", "repository": "USAP-DC", "science_program": null, "title": "Monthly Stratification Climatology (1978-2021) in Antarctic Coastal Polynyas", "url": "https://www.usap-dc.org/view/dataset/601628"}, {"dataset_uid": "601209", "doi": "10.15784/601209", "keywords": "Animal Behavior Observation; Antarctica; Biota; East Antarctica; GPS; Oceans; Penguin; Southern Ocean", "people": "Kirkwood, Roger; Ropert-Coudert, Yan; Resinger, Ryan; Jonsen, Ian; Porter-Smith, Rick; Barbraud, Christophe; Wienecke, Barbara; Bost, Charles-Andr\u00e9; Ji, Rubao; Pinaud, David; Jenouvrier, Stephanie; Tamura, Takeshi; Sumner, Michael; Fraser, Alexander; Labrousse, Sara", "repository": "USAP-DC", "science_program": null, "title": "Dynamic fine-scale sea-icescape shapes adult emperor penguin foraging habitat in East Antarctica", "url": "https://www.usap-dc.org/view/dataset/601209"}], "date_created": "Wed, 07 Aug 2019 00:00:00 GMT", "description": "During winter, sea-ice coverage along the Antarctic coast is punctuated by numerous polynyas--isolated openings of tens to hundreds of kilometer wide. These coastal polynyas are hotspots of sea ice production and the primary source regions of the bottom water in the global ocean. They also host high levels of biological activities and are the feeding grounds of Emperor penguins and marine mammals. The polynyas are a key component of the Antarctic coastal system and crucial for the survival of penguins and many other species. These features also differ dramatically from each other in timing of formation, duration, phytoplankton growth season, and overall biological productivity. Yet, the underlying reasons for differences among them are largely unknown. This project studies the fundamental biophysical processes at a variety of polynyas, examines the connection between the physical environment and the phytoplankton and penguin ecology, and investigates the mechanisms behind polynya variability. The results of this interdisciplinary study will provide a context for interpretation of field measurements in Antarctic coastal polynyas, set a baseline for future polynya studies, and examine how polynya ecosystems may respond to local and large-scale environmental changes. The project will include educational and outreach activities that convey scientific messages to a broad audience. It aims to increase public awareness of the interconnection between large-scale environmental change and Antarctic coastal systems. The main objectives of this study are to form a comprehensive understanding of the temporal and spatial variability of Antarctic coastal polynyas and the physical controls of polynya ecosystems. The project takes an interdisciplinary approach and seeks to establish a modeling system centered on the Regional Ocean Modeling System. This system links the ice and ocean conditions to the plankton ecology and penguin population. Applications of the modeling system in representative polynyas, in conjunction with analysis of existing observations, will determine the biophysical influences of individual forcing factors. In particular, this study will test a set of hypothesized effects of winds, offshore water intrusion, ice-shelf melting, sea-ice formation, glacier tongues, and ocean stratification on the timing of polynya phytoplankton bloom and the overall polynya biological productivity. The project will also examine how changing polynya state affects penguin breeding success, adult survival, and population growth. The team will conduct idealized sensitivity analysis to explore implications of forcing variability, including local and large-scale environmental change, on Antarctic coastal ecosystems.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Southern Ocean; Animal Behavior; Penguin; FIELD INVESTIGATION; USAP-DC; COASTAL; PENGUINS; SEA ICE; Antarctica; OCEAN MIXED LAYER", "locations": "Southern Ocean; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Zhang, Weifeng; Ji, Rubao; Jenouvrier, Stephanie; Maksym, Edward; Li, Yun", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Polynyas in Coastal Antarctica (PICA): Linking Physical Dynamics to Biological Variability", "uid": "p0010044", "west": -180.0}, {"awards": "1443534 Bell, Robin; 1443677 Padman, Laurence; 1443498 Fricker, Helen; 1443497 Siddoway, Christine", "bounds_geometry": "POLYGON((-180 -77,-177 -77,-174 -77,-171 -77,-168 -77,-165 -77,-162 -77,-159 -77,-156 -77,-153 -77,-150 -77,-150 -77.9,-150 -78.8,-150 -79.7,-150 -80.6,-150 -81.5,-150 -82.4,-150 -83.3,-150 -84.2,-150 -85.1,-150 -86,-153 -86,-156 -86,-159 -86,-162 -86,-165 -86,-168 -86,-171 -86,-174 -86,-177 -86,180 -86,178.1 -86,176.2 -86,174.3 -86,172.4 -86,170.5 -86,168.6 -86,166.7 -86,164.8 -86,162.9 -86,161 -86,161 -85.1,161 -84.2,161 -83.3,161 -82.4,161 -81.5,161 -80.6,161 -79.7,161 -78.8,161 -77.9,161 -77,162.9 -77,164.8 -77,166.7 -77,168.6 -77,170.5 -77,172.4 -77,174.3 -77,176.2 -77,178.1 -77,-180 -77))", "dataset_titles": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data; CATS2008: Circum-Antarctic Tidal Simulation version 2008; CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023; Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice); LiDAR Nadir and Swath Data from Ross Ice Shelf, Antarctica (ROSETTA-Ice); ROSETTA-Ice data page; Ross Sea ocean model simulation used to support ROSETTA-Ice ; Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "datasets": [{"dataset_uid": "601788", "doi": null, "keywords": "Antarctica; Cryosphere; Ross Ice Shelf", "people": "Boghosian, Alexandra; Bertinato, Christopher; Locke, Caitlin; Dhakal, Tejendra; Becker, Maya K; Starke, Sarah", "repository": "USAP-DC", "science_program": null, "title": "LiDAR Nadir and Swath Data from Ross Ice Shelf, Antarctica (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601788"}, {"dataset_uid": "601794", "doi": null, "keywords": "Antarctica; Cryosphere; Remote Sensing; Ross Ice Shelf", "people": "Cordero, Isabel; Wearing, Martin; Spergel, Julian; Packard, Sarah; Dong, LingLing; Das, Indrani; Bell, Robin; Bertinato, Christopher; Chu, Winnie; Dhakal, Tejendra; Frearson, Nicholas; Keeshin, Skye", "repository": "USAP-DC", "science_program": null, "title": "Shallow Ice Radar (SIR) Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601794"}, {"dataset_uid": "601789", "doi": null, "keywords": "Airborne Radar; Antarctica; Cryosphere; Ice Thickness; Remote Sensing; Ross Ice Shelf", "people": "Millstein, Joanna; Cordero, Isabel; Frearson, Nicholas; Dhakal, Tejendra; Bertinato, Christopher; Wilner, Joel; Dong, LingLing; Das, Indrani; Spergel, Julian; Chu, Winnie; Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "Deep ICE (DICE) Radar Dataset from Ross Ice Shelf (ROSETTA-Ice)", "url": "https://www.usap-dc.org/view/dataset/601789"}, {"dataset_uid": "601772", "doi": "10.15784/601772", "keywords": "Antarctica; Cryosphere; Inverse Modeling; Model Data; Ocean Currents; Oceans; Sea Surface; Southern Ocean; Tide Model; Tides", "people": "Sutterley, Tyler; Howard, Susan L.; Greene, Chad A.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008_v2023: Circum-Antarctic Tidal Simulation 2008, version 2023", "url": "https://www.usap-dc.org/view/dataset/601772"}, {"dataset_uid": "200100", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "ROSETTA-Ice data page", "url": "http://wonder.ldeo.columbia.edu/data/ROSETTA-Ice/"}, {"dataset_uid": "601235", "doi": "10.15784/601235", "keywords": "Antarctica; Inverse Modeling; Model Data; Ocean Currents; Sea Surface; Tidal Models; Tides", "people": "Howard, Susan L.; Padman, Laurence; Erofeeva, Svetlana", "repository": "USAP-DC", "science_program": null, "title": "CATS2008: Circum-Antarctic Tidal Simulation version 2008", "url": "https://www.usap-dc.org/view/dataset/601235"}, {"dataset_uid": "601242", "doi": "10.15784/601242", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Penetrating Radar; Ice-Shelf Basal Melting; Radar Echo Sounder; Radar Echo Sounding; Snow/ice; Snow/Ice", "people": "Mosbeux, Cyrille; Cordero, Isabel; Tinto, Kirsty; Siegfried, Matthew; Siddoway, Christine; Dhakal, Tejendra; Das, Indrani; Bell, Robin; Padman, Laurence; Fricker, Helen; Frearson, Nicholas; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Basal Melt, Ice thickness and structure of the Ross Ice Shelf using airborne radar data", "url": "https://www.usap-dc.org/view/dataset/601242"}, {"dataset_uid": "601255", "doi": "10.15784/601255", "keywords": "Antarctica; Basal Melt; Ice Shelf; Model Output; Ocean Circulation Model; Ross Ice Shelf; Ross Sea", "people": "Howard, Susan L.; Springer, Scott; Padman, Laurence", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea ocean model simulation used to support ROSETTA-Ice ", "url": "https://www.usap-dc.org/view/dataset/601255"}], "date_created": "Wed, 03 Jul 2019 00:00:00 GMT", "description": "The Ross Ice Shelf is the largest existing ice shelf in Antarctica, and is currently stabilizing significant portions of the land ice atop the Antarctic continent. An ice shelf begins where the land ice goes afloat on the ocean, and as such, the Ross Ice Shelf interacts with the ocean and seafloor below, and the land ice behind. Currently, the Ross Ice Shelf slows down, or buttresses, the fast flowing ice streams of the West Antarctic Ice Sheet (WAIS), a marine-based ice sheet, which if melted, would raise global sea level by 3-4 meters. The Ross Ice Shelf average ice thickness is approximately 350 meters, and it covers approximately 487,000 square kilometers, an area slightly larger than the state of California. The Ross Ice Shelf has disappeared during prior interglacial periods, suggesting in the future it may disappear again. Understanding the dynamics, stability and future of the West Antarctic Ice Sheet therefore requires in-depth knowledge of the Ross Ice Shelf. The ROSETTA-ICE project brings together scientists from 4 US institutions and from the Institute of Geological and Nuclear Sciences Limited, known as GNS Science, New Zealand. The ROSETTA-ICE data on the ice shelf, the water beneath the ice shelf, and the underlying rocks, will allow better predictions of how the Ross Ice Shelf will respond to changing climate, and therefore how the WAIS will behave in the future. The interdisciplinary ROSETTA-ICE team will train undergraduate and high school students in cutting edge research techniques, and will also work to educate the public via a series of vignettes integrating ROSETTA-ICE science with the scientific and human history of Antarctic research. The ROSETTA-ICE survey will acquire gravity and magnetics data to determine the water depth beneath the ice shelf. Radar, LIDAR and imagery systems will be used to map the Ross Ice Shelf thickness and fine structure, crevasses, channels, debris, surface accumulation and distribution of marine ice. The high resolution aerogeophysical data over the Ross Ice Shelf region in Antarctica will be acquired using the IcePod sensor suite mounted externally on an LC-130 aircraft operating from McMurdo Station, Antarctica. Field activities will include ~36 flights on LC-130 aircraft over two field seasons in Antarctica. The IcePod instrument suite leverages the unique experience of the New York Air National Guard operating in Antarctica for NSF scientific research as well as infrastructure and logistics. The project will answer questions about the stability of the Ross Ice Shelf in future climate, and the geotectonic evolution of the Ross Ice Shelf Region, a key component of the West Antarctic Rift system. The comprehensive benchmark data sets acquired will enable broad, interdisciplinary analyses and modeling, which will also be performed as part of the project. ROSETTA-ICE will illuminate Ross ice sheet-ice shelf-ocean dynamics as the system nears a critical juncture but still is intact. Through interacting with an online data visualization tool, and comparing the ROSETTA-ICE data and results from earlier studies, we will engage students and young investigators, equipping them with new capabilities for the study of critical earth systems that influence global climate.", "east": 161.0, "geometry": "POINT(-174.5 -81.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LIDAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e PROTON MAGNETOMETER", "is_usap_dc": true, "keywords": "Airborne Radar; LIDAR; Ross Ice Shelf; SALINITY; SALINITY/DENSITY; CONDUCTIVITY; ICE DEPTH/THICKNESS; Tidal Models; GRAVITY ANOMALIES; Ross Sea; Antarctica; BATHYMETRY; C-130; MAGNETIC ANOMALIES; USAP-DC; Airborne Gravity", "locations": "Ross Sea; Antarctica; Ross Ice Shelf", "north": -77.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bell, Robin; Frearson, Nicholas; Das, Indrani; Fricker, Helen; Padman, Laurence; Springer, Scott; Siddoway, Christine; Tinto, Kirsty", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e C-130", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -86.0, "title": "Collaborative Research: Uncovering the Ross Ocean and Ice Shelf Environment and Tectonic setting Through Aerogeophysical Surveys and Modeling (ROSETTA-ICE)", "uid": "p0010035", "west": -150.0}, {"awards": "1637708 Gooseff, Michael", "bounds_geometry": "POLYGON((160 -77.25,160.5 -77.25,161 -77.25,161.5 -77.25,162 -77.25,162.5 -77.25,163 -77.25,163.5 -77.25,164 -77.25,164.5 -77.25,165 -77.25,165 -77.375,165 -77.5,165 -77.625,165 -77.75,165 -77.875,165 -78,165 -78.125,165 -78.25,165 -78.375,165 -78.5,164.5 -78.5,164 -78.5,163.5 -78.5,163 -78.5,162.5 -78.5,162 -78.5,161.5 -78.5,161 -78.5,160.5 -78.5,160 -78.5,160 -78.375,160 -78.25,160 -78.125,160 -78,160 -77.875,160 -77.75,160 -77.625,160 -77.5,160 -77.375,160 -77.25))", "dataset_titles": "EDI Data Portal: McMurdo Dry Valleys LTER; McMurdo Dry Valleys LTER Data Repository", "datasets": [{"dataset_uid": "200036", "doi": "", "keywords": null, "people": null, "repository": "LTER", "science_program": null, "title": "McMurdo Dry Valleys LTER Data Repository", "url": "http://mcm.lternet.edu/power-search/data-set"}, {"dataset_uid": "200037", "doi": "", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "EDI Data Portal: McMurdo Dry Valleys LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=MCM"}], "date_created": "Fri, 31 May 2019 00:00:00 GMT", "description": "The McMurdo Dry Valleys, Antarctica, are a mosaic of terrestrial and aquatic ecosystems in a cold desert. The McMurdo Long Term Ecological Research (LTER) project has been observing these ecosystems since 1993 and this award will support key long-term measurements, manipulation experiments, synthesis, and modeling to test current theories on ecosystem structure and function. Data collection is focused on meteorology and physical and biological dimensions of soils, streams, lakes, glaciers, and permafrost. The long-term measurements show that biological communities have adapted to the seasonally cold, dark, and arid conditions that prevail for all but a short period in the austral summer. Physical (climate and geological) drivers impart a dynamic connectivity among portions of the Dry Valley landscape over seasonal to millennial time scales. For instance, lakes and soils have been connected through cycles of lake-level rise and fall over the past 20,000 years while streams connect glaciers to lakes over seasonal time scales. Overlaid upon this physical system are biotic communities that are structured by the environment and by the movement of individual organisms within and between the glaciers, streams, lakes, and soils. The new work to be conducted at the McMurdo LTER site will explore how the layers of connectivity in the McMurdo Dry Valleys influence ecosystem structure and function. This project will test the hypothesis that increased ecological connectivity following enhanced melt conditions within the McMurdo Dry Valleys ecosystem will amplify exchange of biota, energy, and matter, homogenizing ecosystem structure and functioning. This hypothesis will be tested with new and continuing experiments that examine: 1) how climate variation alters connectivity among landscape units, and 2) how biota are connected across a heterogeneous landscape using state-of-the-science tools and methods including automated sensor networks, analysis of seasonal satellite imagery, biogeochemical analyses, and next-generation sequencing. McMurdo LTER education programs and outreach activities will be continued, and expanded with new programs associated with the 200th anniversary of the first recorded sightings of Antarctica. These activities will advance societal understanding of how polar ecosystems respond to change. McMurdo LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science, and lead the development of international environmental stewardship protocols for human activities in the region.", "east": 165.0, "geometry": "POINT(162.5 -77.875)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; NOT APPLICABLE; Antarctica; RIVERS/STREAM; USAP-DC; TERRESTRIAL ECOSYSTEMS; LAKE/POND; Polar", "locations": "Antarctica; Polar", "north": -77.25, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Gooseff, Michael N.; Takacs-Vesbach, Cristina; Howkins, Adrian; McKnight, Diane; Doran, Peter; Adams, Byron; Barrett, John; Morgan-Kiss, Rachael; Priscu, John", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "LTER", "repositories": "EDI; LTER", "science_programs": "LTER", "south": -78.5, "title": "LTER: Ecosystem Response to Amplified Landscape Connectivity in the McMurdo Dry Valleys, Antarctica", "uid": "p0010031", "west": 160.0}, {"awards": "1543031 Ivany, Linda", "bounds_geometry": null, "dataset_titles": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ; Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ; Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "datasets": [{"dataset_uid": "601175", "doi": "10.15784/601175 ", "keywords": "Antarctica; Atmosphere; Climate Model; Computer Model; Eocene; Genesis; Global Circulation Model; Modeling; Model Output; Seasonality; Temperature", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "NetCDF outputs from middle Eocene climate simulation using the GENESIS global circulation model ", "url": "https://www.usap-dc.org/view/dataset/601175"}, {"dataset_uid": "601173", "doi": "10.15784/601173 ", "keywords": "Antarctica; Carbon Isotopes; Driftwood; Eocene; Geochemistry; Geochronology; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Organic Carbon Isotopes; Seasonality; Seymour Island; Wood", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Organic carbon isotope data from serially sampled Eocene driftwood from the La Meseta Fm., Seymour ", "url": "https://www.usap-dc.org/view/dataset/601173"}, {"dataset_uid": "601174", "doi": "10.15784/601174", "keywords": "Antarctica; Biota; Bivalves; Cucullaea; Eocene; Glaciers/ice Sheet; Glaciers/Ice Sheet; Isotope Data; La Meseta Formation; Mass Spectrometer; Mass Spectrometry; Oxygen Isotope; Paleotemperature; Retrotapes; Seasonality; Seymour Island", "people": "Judd, Emily", "repository": "USAP-DC", "science_program": null, "title": "Oxygen isotope data from serially sampled Eocene bivalves from the La Meseta Fm., Seymour Island, Antarctica ", "url": "https://www.usap-dc.org/view/dataset/601174"}], "date_created": "Tue, 23 Apr 2019 00:00:00 GMT", "description": "In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth\u0027s past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth\u0027s ancient climate and what we can learn from it. Antarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.", "east": -56.0, "geometry": "POINT(-56.5 -64.25)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "PALEOCLIMATE RECONSTRUCTIONS; USAP-DC; ISOTOPES; NOT APPLICABLE; MACROFOSSILS; Antarctica", "locations": "Antarctica", "north": -64.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Ivany, Linda; Lu, Zunli; Junium, Christopher; Samson, Scott", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.5, "title": "Seasonality, Summer Cooling, and Calibrating the Approach of the Icehouse in Late Eocene Antarctica", "uid": "p0010025", "west": -57.0}, {"awards": "1443680 Smith, Craig; 1443733 Winsor, Peter; 1443705 Vernet, Maria", "bounds_geometry": "POLYGON((-66 -64,-65.6 -64,-65.2 -64,-64.8 -64,-64.4 -64,-64 -64,-63.6 -64,-63.2 -64,-62.8 -64,-62.4 -64,-62 -64,-62 -64.1,-62 -64.2,-62 -64.3,-62 -64.4,-62 -64.5,-62 -64.6,-62 -64.7,-62 -64.8,-62 -64.9,-62 -65,-62.4 -65,-62.8 -65,-63.2 -65,-63.6 -65,-64 -65,-64.4 -65,-64.8 -65,-65.2 -65,-65.6 -65,-66 -65,-66 -64.9,-66 -64.8,-66 -64.7,-66 -64.6,-66 -64.5,-66 -64.4,-66 -64.3,-66 -64.2,-66 -64.1,-66 -64))", "dataset_titles": "Andvord Bay Glacier Timelapse; Andvord Bay sediment core data collected during the FjordEco project (LMG1510 and NBP1603); Expedition Data; Expedition data of LMG1702; FjordEco Phytoplankton Ecology Dataset in Andvord Bay ; Fjord-Eco Sediment OrgC OrgN Data - Craig Smith; LMG1510 Expedition data; NBP1603 Expedition data; Sediment macrofaunal abundance and family richness from inner Andvord Bay to the open continental shelf", "datasets": [{"dataset_uid": "200040", "doi": "10.7284/907085", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "LMG1510 Expedition data", "url": "https://www.rvdata.us/search/cruise/LMG1510"}, {"dataset_uid": "601158", "doi": "10.15784/601158", "keywords": "Antarctica; Antarctic Peninsula; Biota; Ecology; Fjord; Phytoplankton", "people": "Forsch, Kiefer; Vernet, Maria; Manck, Lauren; Pan, B. Jack", "repository": "USAP-DC", "science_program": "FjordEco", "title": "FjordEco Phytoplankton Ecology Dataset in Andvord Bay ", "url": "https://www.usap-dc.org/view/dataset/601158"}, {"dataset_uid": "601111", "doi": "10.15784/601111", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iceberg; Photo; Photo/video; Photo/Video", "people": "Truffer, Martin; Winsor, Peter", "repository": "USAP-DC", "science_program": "FjordEco", "title": "Andvord Bay Glacier Timelapse", "url": "https://www.usap-dc.org/view/dataset/601111"}, {"dataset_uid": "002733", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1702", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "200039", "doi": "10.7284/907205", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1603 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1603"}, {"dataset_uid": "601236", "doi": "10.15784/601236", "keywords": "Abundance; Andvord Bay; Antarctica; Antarctic Peninsula; Biota; Fjord; LMG1510; Marine Sediments; Oceans; Polychaete; Polychaete Family Richness; R/v Laurence M. Gould; Sediment Core Data; Sediment Macrofauna", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "FjordEco", "title": "Sediment macrofaunal abundance and family richness from inner Andvord Bay to the open continental shelf", "url": "https://www.usap-dc.org/view/dataset/601236"}, {"dataset_uid": "000402", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601193", "doi": "10.15784/601193", "keywords": "Antarctica; Geochronology; Grain Size; LMG1510; NBP1603; Sediment; Sediment Core Data", "people": "Nittrouer, Charles; Eidam, Emily; Homolka, Khadijah; Smith, Craig", "repository": "USAP-DC", "science_program": null, "title": "Andvord Bay sediment core data collected during the FjordEco project (LMG1510 and NBP1603)", "url": "https://www.usap-dc.org/view/dataset/601193"}, {"dataset_uid": "001366", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1702"}, {"dataset_uid": "601157", "doi": "10.15784/601157", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Snow/ice; Snow/Ice", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "FjordEco", "title": "Fjord-Eco Sediment OrgC OrgN Data - Craig Smith", "url": "https://www.usap-dc.org/view/dataset/601157"}], "date_created": "Wed, 13 Feb 2019 00:00:00 GMT", "description": "Marine communities along the western Antarctic Peninsula are highly productive ecosystems which support a diverse assemblage of charismatic animals such as penguins, seals, and whales as well as commercial fisheries such as that on Antarctic krill. Fjords (long, narrow, deep inlets of the sea between high cliffs) along the central coast of the Peninsula appear to be intense, potentially climate sensitive, hotspots of biological production and biodiversity, yet the structure and dynamics of these fjord ecosystems are very poorly understood. Because of this intense biological activity and the charismatic fauna it supports, these fjords are also major destinations for a large Antarctic tourism industry. This project is an integrated field and modeling program to evaluate physical oceanographic processes, glacial inputs, water column community dynamics, and seafloor bottom community structure and function in these important yet little understood fjord systems. These Antarctic fjords have characteristics that are substantially different from well-studied Arctic fjords, likely yielding much different responses to climate warming. This project will provide major new insights into the dynamics and climate sensitivity of Antarctic fjord ecosystems, highlighting contrasts with Arctic sub-polar fjords, and potentially transforming our understanding of the ecological role of fjords in the rapidly warming west Antarctic coastal marine landscape. The project will also further the NSF goal of training new generations of scientists, providing scientific training for undergraduate, graduate, and postdoctoral students. This includes the unique educational opportunity for undergraduates to participate in research cruises in Antarctica and the development of a novel summer graduate course on fjord ecosystems. Internet based outreach activities will be enhanced and extended by the participation of a professional photographer who will produce magazine articles, websites, radio broadcasts, and other forms of public outreach on the fascinating Antarctic ecosystem. This project will involve a 15-month field program to test mechanistic hypotheses concerning oceanographic and glaciological forcing, and phytoplankton and benthic community response in the Antarctic fjords. Those efforts will be followed by a coupled physical/biological modeling effort to evaluate the drivers of biogeochemical cycles in the fjords and to explore their potential sensitivity to enhanced meltwater and sediment inputs. Fieldwork over two oceanographic cruises will utilize moorings, weather stations, and glacial, sea-ice and seafloor time-lapse cameras to obtain an integrated view of fjord ecosystem processes. The field team will also make multiple shipboard measurements and will use towed and autonomous underwater vehicles to intensively evaluate fjord ecosystem structure and function during spring/summer and autumn seasons. These integrated field and modeling studies are expected to elucidate fundamental properties of water column and sea bottom ecosystem structure and function in the fjords, and to identify key physical-chemical-glaciological forcing in these rapidly warming ecosystems.", "east": -62.0, "geometry": "POINT(-64 -64.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "OCEAN CURRENTS; Bellingshausen Sea; LMG1702; COMMUNITY DYNAMICS; FJORDS; R/V LMG; MARINE ECOSYSTEMS; USAP-DC; ECOSYSTEM FUNCTIONS; ANIMALS/INVERTEBRATES; SEDIMENTATION; NOT APPLICABLE; BENTHIC", "locations": "Bellingshausen Sea", "north": -64.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Winsor, Peter; Truffer, Martin; Smith, Craig; Powell, Brian; Merrifield, Mark; Vernet, Maria; Kohut, Josh", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": "FjordEco", "south": -65.0, "title": "Collaborative Research: Fjord Ecosystem Structure and Function on the West Antarctic Peninsula - Hotspots of Productivity and Biodiversity? (FjordEco)", "uid": "p0010010", "west": -66.0}, {"awards": "1443347 Condron, Alan; 1443394 Pollard, David", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios; Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming; Simulated changes in Southern Ocean salinity", "datasets": [{"dataset_uid": "601449", "doi": "10.15784/601449", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Meltwater", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Future climate response to Antarctic Ice Sheet melt caused by anthropogenic warming", "url": "https://www.usap-dc.org/view/dataset/601449"}, {"dataset_uid": "601154", "doi": "10.15784/601154 ", "keywords": "Antarctic; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Ice Sheet Model; Meltwater; Model Data; Modeling; Model Output", "people": "Pollard, David", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Sheet simulations for role of freshwater in future warming scenarios", "url": "https://www.usap-dc.org/view/dataset/601154"}, {"dataset_uid": "601442", "doi": "10.15784/601442", "keywords": "Antarctica; Computer Model; Freshwater; Glaciers/ice Sheet; Glaciers/Ice Sheet; Model Data; Ocean Model; Oceans; Salinity", "people": "Condron, Alan", "repository": "USAP-DC", "science_program": null, "title": "Simulated changes in Southern Ocean salinity", "url": "https://www.usap-dc.org/view/dataset/601442"}], "date_created": "Mon, 04 Feb 2019 00:00:00 GMT", "description": "There is compelling historical evidence that the West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse. Recent observations, compared to observations made 20-30 years before, indicate that both ice shelves (thick ice with ocean below) and land ice (thick ice with land below), are now melting at a much faster rate. Some numerical models suggest that significant ice retreat may begin within many of our lifetimes, starting with the abrupt collapse of Pine Island and Thwaites Glaciers in the next 50 years. This may be followed by retreat of much of the WAIS and then the collapse of parts of the East Antarctic ice sheet (EAIS). This research project will assess the extent to which global ocean circulation and climate will be impacted if enormous volumes of fresh water and ice flow into the Southern Ocean. It will establish whether a rapid collapse of WAIS in the near-future poses any significant threat to the stability of modern-day climate and human society. This is a topic that has so far received little attention as most prior research has focused on the response of climate to melting the Greenland ice sheet. Yet model simulations predict that the volumes of fresh water and ice released from Antarctica in the next few centuries could be up at least ten-times larger than from Greenland. The Intellectual Merit of this project stems from its ability to establish a link between the physical Antarctic system (ice sheet dynamics, fresh water discharge and iceberg calving) and global climate. The PIs (Principal Investigators) will assess the sensitivity of ocean circulation and climate to increased ice sheet melt using a combination of ocean, iceberg, ice sheet and climate models. Results from this study will help identify areas of the ice sheet that are vulnerable to collapse and also regions of the ocean where a significant freshening will have a considerable impact on climate, and serve to guide the deployment of an observational monitoring system capable of warning us when ice and fresh water discharge start to approach levels capable of disrupting ocean circulation and global climate. This project will support and train two graduate students, and each PI will be involved with local primary and secondary schools, making presentations, mentoring science fair projects, and contributing to curriculum development. A novel, web-based, interactive, cryosphere learning tool will be developed to help make school children more aware of the importance of the Polar Regions in global climate, and this software will be introduced to science teachers at a half day workshop organized by the UMass STEM Education Institute. Recent numerical simulations using a continental ice sheet/shelf model show the potential for more rapid and greater Antarctic ice sheet retreat in the next 50-300 years (under the full range of IPCC RCP (Intergovernmental Panel on Climate Change, Representative Concentration Pathways) future warming scenarios) than previously projected. Exactly how the release of enormous volumes of ice and fresh water to the Southern Ocean will impact global ocean circulation and climate has yet to be accurately assessed. This is in part because previous model simulations were too coarse to accurately resolve narrow coastal boundary currents, shelf breaks, fronts, and mesoscale eddies that are all very important for realistically simulating fresh water transport in the ocean. In this award, future projections of fresh water discharge and iceberg calving from Antarctic will be used to force a high resolution eddy-resolving ocean model (MITgcm) coupled to a new iceberg module and a fully-coupled global climate model (CCSM4). High resolution ocean/iceberg simulations will determine the role of mesoscale eddies in freshwater transport and give new insight into how fresh water is advected to far-field locations, including deep water formation sites in the North Atlantic. These simulations will provide detailed information about subsurface temperatures and changes in ocean circulation close to the ice front and grounding line. An accompanying set of fully coupled climate model simulations (NCAR CCSM4) will identify multidecadal-to-centennial changes in the climate system triggered by increased high-latitude Southern Ocean freshwater forcing. Particular attention will be given to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC), wind stress, sea ice formation, and global temperatures. In doing so, this project will more accurately determine whether abrupt and potentially catastrophic changes in global climate are likely to be triggered by changes in the Antarctic system in the near-future.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; AMD; MODELS; Amd/Us; Antarctica; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Pollard, David; Condron, Alan; DeConto, Robert", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Assessing the Global Climate Response to Melting of the Antarctic Ice Sheet", "uid": "p0010007", "west": -180.0}, {"awards": "1443464 Sowers, Todd; 1443472 Brook, Edward J.; 1443710 Severinghaus, Jeffrey", "bounds_geometry": "POINT(0 -90)", "dataset_titles": "South Pole CH4 data for termination; South Pole Ice Core Isotopes of N2 and Ar; South Pole ice core (SPC14) discrete methane data; South Pole ice core total air content; South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2; SP19 Gas Chronology", "datasets": [{"dataset_uid": "601152", "doi": "10.15784/601152", "keywords": "Antarctica; Antarctic Ice Sheet; Chemistry:gas; Chemistry:Gas; Chemistry:ice; Chemistry:Ice; Delta 18O; Dole Effect; Firn Thickness; Gas Isotopes; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Gravitational Settling; Ice; Ice Core Chemistry; Ice Core Data; Ice Core Gas Records; Ice Core Records; Inert Gases; Nitrogen; Nitrogen Isotopes; Oxygen; Oxygen Isotope; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole (SPICECORE) 15N, 18O, O2/N2 and Ar/N2", "url": "https://www.usap-dc.org/view/dataset/601152"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601517", "doi": "10.15784/601517", "keywords": "Antarctica; Argon; Argon Isotopes; Firn; Firn Temperature Gradient; Firn Thickness; Gas Isotopes; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Nitrogen; Nitrogen Isotopes; South Pole; SPICEcore", "people": "Severinghaus, Jeffrey P.; Morgan, Jacob", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Isotopes of N2 and Ar", "url": "https://www.usap-dc.org/view/dataset/601517"}, {"dataset_uid": "601230", "doi": "10.15784/601230", "keywords": "Antarctica; Atmospheric CH4; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Data; Methane; Methane Concentration; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole CH4 data for termination", "url": "https://www.usap-dc.org/view/dataset/601230"}, {"dataset_uid": "601231", "doi": "10.15784/601231", "keywords": "Air Content; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Snow/ice; Snow/Ice; South Pole; SPICEcore", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core total air content", "url": "https://www.usap-dc.org/view/dataset/601231"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Aydin, Murat; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}], "date_created": "Sat, 02 Feb 2019 00:00:00 GMT", "description": "Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today\u0027s concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. This award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole. The project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. The increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general.", "east": 0.0, "geometry": "POINT(0 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; AMD; LABORATORY; Antarctica; NITROGEN ISOTOPES; USA/NSF; METHANE; Amd/Us; FIELD INVESTIGATION", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Sowers, Todd A.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: Inert Gas and Methane Based Climate Records throughout the South Pole Deep Ice Core", "uid": "p0010005", "west": 0.0}, {"awards": "1341440 Jin, Meibing; 1341558 Ji, Rubao; 1341547 Stroeve, Julienne", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic MIZ, Pack Ice and Polynya Maps from Passive Microwave Satellite Data; Ice-ocean-ecosystem model output; Sea ice chlorophyll concentrations in Antarctic coastal polynyas and seasonal ice zones", "datasets": [{"dataset_uid": "601136", "doi": "10.15784/601136", "keywords": "Antarctica; Biota; Model Data; Oceans; Southern Ocean", "people": "Jin, Meibing", "repository": "USAP-DC", "science_program": null, "title": "Ice-ocean-ecosystem model output", "url": "https://www.usap-dc.org/view/dataset/601136"}, {"dataset_uid": "601219", "doi": "10.15784/601219", "keywords": "Antarctica; Biota; Chlorophyll; Chlorophyll Concentration; Oceans; Polynya; Sea Ice Concentration; Seasonal Ice Zone; Southern Ocean", "people": "Ji, Rubao", "repository": "USAP-DC", "science_program": null, "title": "Sea ice chlorophyll concentrations in Antarctic coastal polynyas and seasonal ice zones", "url": "https://www.usap-dc.org/view/dataset/601219"}, {"dataset_uid": "601115", "doi": "10.15784/601115", "keywords": "Antarctica; Pack Ice; Polynya; Sea Ice; Southern Ocean", "people": "Stroeve, Julienne", "repository": "USAP-DC", "science_program": null, "title": "Antarctic MIZ, Pack Ice and Polynya Maps from Passive Microwave Satellite Data", "url": "https://www.usap-dc.org/view/dataset/601115"}], "date_created": "Tue, 20 Nov 2018 00:00:00 GMT", "description": "The aim of study is to understand how climate-related changes in snow and ice affect predator populations in the Antarctic, using the Ad\u00e9lie penguin as a focal species due to its long history as a Southern Ocean \u0027sentinel\u0027 species and the number of long-term research programs monitoring its abundance, distribution, and breeding biology. Understanding the environmental factors that control predator population dynamics is critically important for projecting the state of populations under future climate change scenarios, and for designing better conservation strategies for the Antarctic ecosystem. For the first time, datasets from a network of observational sites for the Ad\u00e9lie penguin across the entire Antarctic will be combined and analyzed, with a focus on linkages among the ice environment, primary production, and the population responses of Ad\u00e9lie penguins. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The results of this project can be used to illustrate intuitively to the general public the complex interactions between ice, ocean, pelagic food web and top predators. This project also offers an excellent platform to demonstrate the process of climate-change science - how scientists simulate climate change scenarios and interpret model results. This project supports the training of undergraduate and graduate students in the fields of polar oceanography, plankton and seabird ecology, coupled physical-biological modeling and mathematical ecology. The results will be broadly disseminated to the general oceanographic research community through scientific workshops, conferences and peer-reviewed journal articles, and to undergraduate and graduate education communities, K-12 schools and organizations, and the interested public through web-based servers using existing infrastructure at the investigators\u0027 institutions. The key question to be addressed in this project is how climate impacts the timing of periodic biological events (phenology) and how interannual variation in this periodic forcing influences the abundance of penguins in the Antarctic. The focus will be on the timing of ice algae and phytoplankton blooms because the high seasonality of sea ice and associated pulsed primary productivity are major drivers of the Antarctic food web. This study will also examine the responses of Ad\u00e9lie penguins to changes in sea ice dynamics and ice algae-phytoplankton phenology. Ad\u00e9lie penguins, like many other Antarctic seabirds, are long-lived, upper trophic-level predators that integrate the effects of sea ice on the food web at regional scales, and thus serve as a reliable biological indicator of environmental changes. The proposed approach is designed to accommodate the limits of measuring and modeling the intermediate trophic levels between phytoplankton and penguins (e.g., zooplankton and fish) at the pan-Antarctic scale, which are important but latent variables in the Southern Ocean food web. Through the use of remotely sensed and in situ data, along with state of the art statistical approaches (e.g. wavelet analysis) and numerical modeling, this highly interdisciplinary study will advance our understanding of polar ecosystems and improve the projection of future climate change scenarios.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; MARINE ECOSYSTEMS; NOT APPLICABLE; Antarctica", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Jin, Meibing; Stroeve, Julienne; Ji, Rubao", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Phytoplankton Phenology in the Antarctic: Drivers, Patterns, and Implications for the Adelie Penguin", "uid": "p0000001", "west": -180.0}, {"awards": "1245915 Ray, Laura", "bounds_geometry": null, "dataset_titles": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "datasets": [{"dataset_uid": "601102", "doi": "10.15784/601102", "keywords": "Antarctica; Firn; Folds; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Snow/ice; Snow/Ice", "people": "Ray, Laura; Arcone, Steven; Kaluzienski, Lynn; Koons, Peter; Lever, Jim; Walker, Ben", "repository": "USAP-DC", "science_program": null, "title": "Ground Penetrating Radar Grid Survey of the McMurdo Shear Zone", "url": "https://www.usap-dc.org/view/dataset/601102"}], "date_created": "Thu, 27 Sep 2018 00:00:00 GMT", "description": "Hamilton/1246400 This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth\u0027s current NSF GK-12 program, build on faculty-educator relationships established during University of Maine\u0027s recent GK-12 program, and incorporate project results into University of Maine\u0027s IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Ray, Laura", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Flow and Fracture Dynamics in an Ice Shelf Lateral Margin: Observations and Modeling of the McMurdo Shear Zone", "uid": "p0000701", "west": null}, {"awards": "1341311 Timmermann, Axel", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "784 ka transient Antarctic ice-sheet model simulation data", "datasets": [{"dataset_uid": "000247", "doi": "", "keywords": null, "people": null, "repository": "IBS Center for Climate Physics ICCP", "science_program": null, "title": "784 ka transient Antarctic ice-sheet model simulation data", "url": "http://climatedata.ibs.re.kr/grav/data/psu-love/antarctic-ice-sheet"}], "date_created": "Tue, 26 Jun 2018 00:00:00 GMT", "description": "Timmerman/1341311 This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth\u0027s orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Timmermann, Axel", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "IBS Center for Climate Physics ICCP", "repositories": "IBS Center for Climate Physics ICCP", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Bipolar Coupling of late Quaternary Ice Sheet Variability", "uid": "p0000379", "west": -180.0}, {"awards": "1341585 Sorlien, Christopher", "bounds_geometry": "POLYGON((-180 -73.33,-179.1 -73.33,-178.2 -73.33,-177.3 -73.33,-176.4 -73.33,-175.5 -73.33,-174.6 -73.33,-173.7 -73.33,-172.8 -73.33,-171.9 -73.33,-171 -73.33,-171 -73.864,-171 -74.398,-171 -74.932,-171 -75.466,-171 -76,-171 -76.534,-171 -77.068,-171 -77.602,-171 -78.136,-171 -78.67,-171.9 -78.67,-172.8 -78.67,-173.7 -78.67,-174.6 -78.67,-175.5 -78.67,-176.4 -78.67,-177.3 -78.67,-178.2 -78.67,-179.1 -78.67,180 -78.67,178.5 -78.67,177 -78.67,175.5 -78.67,174 -78.67,172.5 -78.67,171 -78.67,169.5 -78.67,168 -78.67,166.5 -78.67,165 -78.67,165 -78.136,165 -77.602,165 -77.068,165 -76.534,165 -76,165 -75.466,165 -74.932,165 -74.398,165 -73.864,165 -73.33,166.5 -73.33,168 -73.33,169.5 -73.33,171 -73.33,172.5 -73.33,174 -73.33,175.5 -73.33,177 -73.33,178.5 -73.33,-180 -73.33))", "dataset_titles": "Ross Sea unconformities digital grids in depth and two-way time", "datasets": [{"dataset_uid": "601098", "doi": "10.15784/601098", "keywords": "Antarctica; Continental Margin; Geology/Geophysics - Other; Marine Geoscience; Miocene; Oligocene; Seismic Reflection", "people": "Wilson, Douglas S.; Sorlien, Christopher", "repository": "USAP-DC", "science_program": null, "title": "Ross Sea unconformities digital grids in depth and two-way time", "url": "https://www.usap-dc.org/view/dataset/601098"}], "date_created": "Fri, 25 May 2018 00:00:00 GMT", "description": "Intellectual Merit: This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances. Broader impacts: The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.", "east": -171.0, "geometry": "POINT(177 -76)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.33, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Sorlien, Christopher; Luyendyk, Bruce P.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.67, "title": "Subsidence, Tilting, Sedimentation, and Oligocene-middle Miocene paleo-depth of Ross Sea", "uid": "p0000271", "west": 165.0}, {"awards": "2023425 Schofield, Oscar; 1440435 Ducklow, Hugh", "bounds_geometry": "POLYGON((-80 -63,-78.3 -63,-76.6 -63,-74.9 -63,-73.2 -63,-71.5 -63,-69.8 -63,-68.1 -63,-66.4 -63,-64.7 -63,-63 -63,-63 -63.8,-63 -64.6,-63 -65.4,-63 -66.2,-63 -67,-63 -67.8,-63 -68.6,-63 -69.4,-63 -70.2,-63 -71,-64.7 -71,-66.4 -71,-68.1 -71,-69.8 -71,-71.5 -71,-73.2 -71,-74.9 -71,-76.6 -71,-78.3 -71,-80 -71,-80 -70.2,-80 -69.4,-80 -68.6,-80 -67.8,-80 -67,-80 -66.2,-80 -65.4,-80 -64.6,-80 -63.8,-80 -63))", "dataset_titles": "Environmental Data Initiative Repository, Supporting LTER; Expedition Data; Expedition data of LMG1501; Expedition data of LMG1601; Expedition data of LMG1701; Expedition data of LMG1801; Expedition data of LMG1901; Metadata associated with the description of Akarotaxis gouldae n. sp. (Bathydraconidae); UAV images and video of whales in the Antarctic Penisula during LMG1802", "datasets": [{"dataset_uid": "200125", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1901", "url": "https://www.rvdata.us/search/cruise/LMG1901"}, {"dataset_uid": "001367", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1701"}, {"dataset_uid": "601811", "doi": null, "keywords": "Antarctica; Bellingshausen Sea; Cryosphere; Southern Ocean", "people": "Biesack, Ellen; Corso, Andrew; Desvignes, Thomas; McDowell, Jan; Cheng, Chi-Hing; Steinberg, Deborah; Hilton, Eric", "repository": "USAP-DC", "science_program": "LTER", "title": "Metadata associated with the description of Akarotaxis gouldae n. sp. (Bathydraconidae)", "url": "https://www.usap-dc.org/view/dataset/601811"}, {"dataset_uid": "601318", "doi": "10.15784/601318", "keywords": "Aerial Imagery; Antarctica; Antarctic Peninsula; Biota; Camera; Humpback Whales; LMG1802; LTER; Minke Whales; Oceans; Palmer Station; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould; Species Size; UAV; Video Data; Whales", "people": "Bierlich, KC; Dale, Julian; Friedlaender, Ari; Nowacek, Douglas; Boyer, Keyvi", "repository": "USAP-DC", "science_program": "LTER", "title": "UAV images and video of whales in the Antarctic Penisula during LMG1802", "url": "https://www.usap-dc.org/view/dataset/601318"}, {"dataset_uid": "002729", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1701", "url": "https://www.rvdata.us/search/cruise/LMG1701"}, {"dataset_uid": "200124", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1801", "url": "https://www.rvdata.us/search/cruise/LMG1801"}, {"dataset_uid": "200122", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1501", "url": "https://www.rvdata.us/search/cruise/LMG1501"}, {"dataset_uid": "200123", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1601", "url": "https://www.rvdata.us/search/cruise/LMG1601"}, {"dataset_uid": "000246", "doi": "", "keywords": null, "people": null, "repository": "EDI", "science_program": null, "title": "Environmental Data Initiative Repository, Supporting LTER", "url": "https://portal.edirepository.org/nis/browseServlet?searchValue=PAL"}], "date_created": "Fri, 11 May 2018 00:00:00 GMT", "description": "The Palmer Antarctica LTER (Long Term Ecological Research) site has been in operation since 1990. The goal of all the LTER sites is to conduct policy-relevant research on ecological questions that require tens of years of data, and cover large geographical areas. For the Palmer Antarctica LTER, the questions are centered around how the marine ecosystem west of the Antarctica peninsula is responding to a climate that is changing as rapidly as any place on the Earth. For example, satellite observations over the past 35 years indicate the average duration of sea ice cover is now ~90 days (3 months!) shorter than it was. The extended period of open water has implications for many aspects of ecosystem research, with the concurrent decrease of Ad\u00e8lie penguins within this region regularly cited as an exemplar of climate change impacts in Antarctica. Cutting edge technologies such as autonomous underwater (and possibly airborne) vehicles, seafloor moorings, and numerical modeling, coupled with annual oceanographic cruises, and weekly environmental sampling, enables the Palmer Antarctica LTER to expand and bridge the time and space scales needed to assess climatic impacts. This award includes for the first time study of the roles of whales as major predators in the seasonal sea ice zone ecosystem. The team will also focus on submarine canyons, special regions of enhanced biological activity, along the Western Antarctic Peninsula (WAP). The current award\u0027s overarching research question is: How do seasonality, interannual variability, and long term trends in sea ice extent and duration influence the structure and dynamics of marine ecosystems and biogeochemical cycling? Specific foci within the broad question include: 1. Long-term change and ecosystem transitions. What is the sensitivity or resilience of the ecosystem to external perturbations as a function of the ecosystem state? 2. Lateral connectivity and vertical stratification. What are the effects of lateral transports of freshwater, heat and nutrients on local ocean stratification and productivity and how do they drive changes in the ecosystem? 3. Top-down controls and shifting baselines. How is the ecosystem responding to the cessation of whaling and subsequent long-term recovery of whale stocks? 4. Foodweb structure and biogeochemical processes. How do temporal and spatial variations in foodweb structure influence carbon and nutrient cycling, export, and storage? The broader impacts of the award leverage local educational partnerships including the Sandwich, MA STEM Academy, the New England Aquarium, and the NSF funded Polar Learning and Responding (PoLAR) Climate Change Education Partnership at Columbia\u0027s Earth Institute to build new synergies between Arctic and Antarctic, marine and terrestrial scientists and students, governments and NGOs. The Palmer Antarctic LTER will also conduct appropriate cross LTER site comparisons, and serve as a leader in information management to enable knowledge-building within and beyond the Antarctic, oceanographic, and LTER communities.", "east": -63.0, "geometry": "POINT(-71.5 -67)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "PELAGIC; USAP-DC; R/V LMG; NOT APPLICABLE; Palmer Station; LMG1701", "locations": "Palmer Station", "north": -63.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ducklow, Hugh; Martinson, Doug; Schofield, Oscar", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "EDI; R2R; USAP-DC", "science_programs": "LTER", "south": -71.0, "title": "LTER Palmer, Antarctica (PAL): Land-Shelf-Ocean Connectivity, Ecosystem Resilience and Transformation in a Sea-Ice Influenced Pelagic Ecosystem", "uid": "p0000133", "west": -80.0}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}, {"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"awards": "1245899 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Region Climate Model Output Plio-Pleistocene", "datasets": [{"dataset_uid": "601080", "doi": "10.15784/601080", "keywords": "Antarctica; Climate Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; McMurdo; Paleoclimate; Ross Sea", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Region Climate Model Output Plio-Pleistocene", "url": "https://www.usap-dc.org/view/dataset/601080"}], "date_created": "Tue, 16 Jan 2018 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica. Broader impacts: Results from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: West Antarctic Ice Sheet stability, Alpine Glaciation, and Climate Variability: a Terrestrial Perspective from Cosmogenic-nuclide Dating in McMurdo Sound", "uid": "p0000391", "west": 160.0}, {"awards": "1425989 Sarmiento, Jorge", "bounds_geometry": "POLYGON((-180 -52.6153,-168.67689 -52.6153,-157.35378 -52.6153,-146.03067 -52.6153,-134.70756 -52.6153,-123.38445 -52.6153,-112.06134 -52.6153,-100.73823 -52.6153,-89.41512 -52.6153,-78.09201 -52.6153,-66.7689 -52.6153,-66.7689 -55.18958,-66.7689 -57.76386,-66.7689 -60.33814,-66.7689 -62.91242,-66.7689 -65.4867,-66.7689 -68.06098,-66.7689 -70.63526,-66.7689 -73.20954,-66.7689 -75.78382,-66.7689 -78.3581,-78.09201 -78.3581,-89.41512 -78.3581,-100.73823 -78.3581,-112.06134 -78.3581,-123.38445 -78.3581,-134.70756 -78.3581,-146.03067 -78.3581,-157.35378 -78.3581,-168.67689 -78.3581,180 -78.3581,178.62318 -78.3581,177.24636 -78.3581,175.86954 -78.3581,174.49272 -78.3581,173.1159 -78.3581,171.73908 -78.3581,170.36226 -78.3581,168.98544 -78.3581,167.60862 -78.3581,166.2318 -78.3581,166.2318 -75.78382,166.2318 -73.20954,166.2318 -70.63526,166.2318 -68.06098,166.2318 -65.4867,166.2318 -62.91242,166.2318 -60.33814,166.2318 -57.76386,166.2318 -55.18958,166.2318 -52.6153,167.60862 -52.6153,168.98544 -52.6153,170.36226 -52.6153,171.73908 -52.6153,173.1159 -52.6153,174.49272 -52.6153,175.86954 -52.6153,177.24636 -52.6153,178.62318 -52.6153,-180 -52.6153))", "dataset_titles": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC; Expedition Data; Model output NOAA GFDL CM2_6 Cant Hant storage", "datasets": [{"dataset_uid": "000208", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Biogeochemical profiling float data from the Southern Ocean Carbon and Climate Observation and Modeling (SOCCOM) program.UCSD Research Data Collections DOI:10.6075/J09021PC", "url": "http://library.ucsd.edu/dc/object/bb66239018"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "601144", "doi": "10.15784/601144", "keywords": "Antarctica; Anthropogenic Heat; Atmosphere; Carbon Storage; Climate Change; Eddy; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Heat Budget; Modeling; Model Output; Oceans; Paleoclimate; Snow/ice; Snow/Ice; Southern Ocean", "people": "Chen, Haidi", "repository": "USAP-DC", "science_program": null, "title": "Model output NOAA GFDL CM2_6 Cant Hant storage", "url": "https://www.usap-dc.org/view/dataset/601144"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate. Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future. In order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs: * Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model. * Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA\u0027s Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate. Led by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will: * communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal; * train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists; * transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.", "east": -66.7689, "geometry": "POINT(-130.26855 -65.4867)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; R/V NBP; NBP1701; CLIMATE MODELS", "locations": null, "north": -52.6153, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science", "paleo_time": null, "persons": "Sarmiento, Jorge; Rynearson, Tatiana", "platforms": "OTHER \u003e MODELS \u003e CLIMATE MODELS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "PI website", "repositories": "PI website; R2R; USAP-DC", "science_programs": null, "south": -78.3581, "title": "Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM)", "uid": "p0000197", "west": 166.2318}, {"awards": "1543245 Rynearson, Tatiana", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP1701; NCBI Popset of 43 Southern Ocean diatom isolates, including accessions ON678208.1 - ON678250.1; Specific growth rate measurements for 43 Southern Ocean diatoms", "datasets": [{"dataset_uid": "601586", "doi": "10.15784/601586", "keywords": "Antarctica; Biota; NBP1701; Phytoplankton; R/v Nathaniel B. Palmer; Specific Growth Rate; Thermal Optimum Temperature", "people": "Bishop, Ian", "repository": "USAP-DC", "science_program": null, "title": "Specific growth rate measurements for 43 Southern Ocean diatoms", "url": "https://www.usap-dc.org/view/dataset/601586"}, {"dataset_uid": "002661", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1701", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "200328", "doi": "", "keywords": null, "people": null, "repository": "NCBI", "science_program": null, "title": "NCBI Popset of 43 Southern Ocean diatom isolates, including accessions ON678208.1 - ON678250.1", "url": "https://www.ncbi.nlm.nih.gov/popset/?term=2248543458"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}], "date_created": "Fri, 29 Dec 2017 00:00:00 GMT", "description": "The research will examine how diatoms (an important group of plankton in the Southern Ocean) adapt to environmental change. Diatoms will be sampled from different regions of the Southern Ocean, including the Drake Passage, the Pacific Sector of the Southern Ocean and the Ross Sea and examined to determine the range of genetic variation among diatoms in these regions. Experiments on a range of diatoms will be conducted in home laboratories and will be aimed at measuring shifts in physiological capacities over many generations in response to directional changes in the environment (temperature and pH). The information on the genetic diversity of field populations combined with information on potential rates of adaptability and genome changes will provide insight into ways in which polar marine diatoms populations may respond to environmental changes that may occur in surface oceans in the future or may have occurred during past climate conditions. Such information allows better modeling of biogeochemical cycles in the ocean as well as improves our abilities to interpret records of past ocean conditions. The project will support a doctoral student and a postdoctoral researcher as well as several undergraduate students. These scientists will learn the fundamentals of experimental evolution, a skill set that is being sought in the fields of biology and oceanography. The project also includes a collaboration with the Metcalf Institute for Marine and Environmental Reporting that will design and facilitate a session focused on current research related to evolution and climate change to be held at the annual conference of the National Association of Science Writers (NASW). Both physiological and genetic variation are key parameters for understanding evolutionary processes in phytoplankton but they are essentially unknown for Southern Ocean diatoms. The extent to which these two factors determine plasticity and adaptability in field populations and the interaction between them will influence how and whether cold-adapted diatoms can respond to changing environments. This project includes a combination of field work to identify genetic diversity within diatoms using molecular approaches and experiments in the lab to assess the range of physiological variation in contemporary populations of diatoms and evolution experiments in the lab to assess how the combination of genetic diversity and physiological variation influence the evolutionary potential of diatoms under a changing environment. This research will uncover general relationships between physiological variation, genetic diversity, and evolutionary potential that may apply across microbial taxa and geographical regions, substantially improving efforts to predict shifts in marine ecosystems. Results from this study can be integrated into developing models that incorporate evolution to predict ecosystem changes under future climate change scenarios.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; NBP1701; R/V NBP; AMD; USA/NSF; Amd/Us; DIATOMS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rynearson, Tatiana; Bishop, Ian", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "NCBI; R2R; USAP-DC", "science_programs": null, "south": null, "title": "NSFGEO-NERC: Evolutionary Response of Southern Ocean Diatoms to Environmental Change", "uid": "p0000850", "west": null}, {"awards": "1443444 Yuan, Xiaojun", "bounds_geometry": "POLYGON((65.4503 -63.5143,67.2063 -63.5143,68.9623 -63.5143,70.7183 -63.5143,72.4743 -63.5143,74.2303 -63.5143,75.9863 -63.5143,77.7423 -63.5143,79.4983 -63.5143,81.2543 -63.5143,83.0103 -63.5143,83.0103 -64.09423,83.0103 -64.67416,83.0103 -65.25409,83.0103 -65.83402,83.0103 -66.41395,83.0103 -66.99388,83.0103 -67.57381,83.0103 -68.15374,83.0103 -68.73367,83.0103 -69.3136,81.2543 -69.3136,79.4983 -69.3136,77.7423 -69.3136,75.9863 -69.3136,74.2303 -69.3136,72.4743 -69.3136,70.7183 -69.3136,68.9623 -69.3136,67.2063 -69.3136,65.4503 -69.3136,65.4503 -68.73367,65.4503 -68.15374,65.4503 -67.57381,65.4503 -66.99388,65.4503 -66.41395,65.4503 -65.83402,65.4503 -65.25409,65.4503 -64.67416,65.4503 -64.09423,65.4503 -63.5143))", "dataset_titles": "CTD Data Acquired by R/V Xue Long in the Prydz Bay- Amery Ice Shelf Region, 2015-2017", "datasets": [{"dataset_uid": "600174", "doi": "10.15784/600174", "keywords": "CTD Data; Oceans; Physical Oceanography; Prydz Bay; Sample/collection Description; Sample/Collection Description; Southern Ocean; Xue Long", "people": "Yuan, Xiaojun", "repository": "USAP-DC", "science_program": null, "title": "CTD Data Acquired by R/V Xue Long in the Prydz Bay- Amery Ice Shelf Region, 2015-2017", "url": "https://www.usap-dc.org/view/dataset/600174"}], "date_created": "Tue, 20 Jun 2017 00:00:00 GMT", "description": "Antarctic Bottom Water (AABW) formation is a key component in setting the global thermohaline (overturning) circulation. Recent studies infer a reduction of the AABW component from reduced volume of AABW entering global deep ocean basins around the Antarctic continent. It is important to obtain better estimates of AABW production rate in its source areas, and to investigate whether the global overturning circulation is slowing down. The project will continue fieldwork with CTD/LADCP surveys including 2 yearly repeat sections, mooring recoveries and deployments. Seasonal-interannual variability of CDW intrusion, dense shelf water accumulation and export as well as overflow from the Prydz Bay shelf will also be observed. The Prydz Bay- Amery Ice Shelf region has been suggested as a key AABW production site. USAP access to this remote region of the Antarctic continent is challenging. The project will involve fieldwork to be carried out with Danish and Chinese collaboration aboard the Chinese research vessel, Xue Long. A high-resolution regional ocean-sea ice coupled model will be developed to allow time and space continuous three-dimensional ocean state estimation. Both in-situ and remote sensing observations along with the modeling simulation results will be used to investigate (i) the local atmosphere-ocean-sea ice interaction and shelf processes that produce dense shelf water and (ii) the dynamic processes that control the shelf water export.", "east": 83.0103, "geometry": "POINT(74.2303 -66.41395)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -63.5143, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Yuan, Xiaojun", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -69.3136, "title": "Collaborative Research: Contribution of Prydz Bay Shelf Water to Antarctic Bottom Water Formation", "uid": "p0000295", "west": 65.4503}, {"awards": "1148982 Hansen, Samantha", "bounds_geometry": "POLYGON((153.327 -73.032547,154.5063012 -73.032547,155.6856024 -73.032547,156.8649036 -73.032547,158.0442048 -73.032547,159.223506 -73.032547,160.4028072 -73.032547,161.5821084 -73.032547,162.7614096 -73.032547,163.9407108 -73.032547,165.120012 -73.032547,165.120012 -73.3530275,165.120012 -73.673508,165.120012 -73.9939885,165.120012 -74.314469,165.120012 -74.6349495,165.120012 -74.95543,165.120012 -75.2759105,165.120012 -75.596391,165.120012 -75.9168715,165.120012 -76.237352,163.9407108 -76.237352,162.7614096 -76.237352,161.5821084 -76.237352,160.4028072 -76.237352,159.223506 -76.237352,158.0442048 -76.237352,156.8649036 -76.237352,155.6856024 -76.237352,154.5063012 -76.237352,153.327 -76.237352,153.327 -75.9168715,153.327 -75.596391,153.327 -75.2759105,153.327 -74.95543,153.327 -74.6349495,153.327 -74.314469,153.327 -73.9939885,153.327 -73.673508,153.327 -73.3530275,153.327 -73.032547))", "dataset_titles": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins; Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains; Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography; Upper Mantle Shear Wave Velocity Structure beneath the Northern Transantarctic Mountains", "datasets": [{"dataset_uid": "601019", "doi": "10.15784/601019", "keywords": "Antarctica; Geology/Geophysics - Other; GPS; Sample/collection Description; Sample/Collection Description; Seismology; Shearwave Spitting; Solid Earth; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Shear Wave Splitting Analysis and Seismic Anisotropy beneath the Northern Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601019"}, {"dataset_uid": "601017", "doi": "10.15784/601017", "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Upper Mantle Seismic Structure beneath the Northern Transantarctic Mountains from Regional P- and S-wave Tomography", "url": "https://www.usap-dc.org/view/dataset/601017"}, {"dataset_uid": "601018", "doi": "10.15784/601018", "keywords": "Antarctica; Geology/Geophysics - Other; Model; Seismology; Solid Earth; Tomography; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Upper Mantle Shear Wave Velocity Structure beneath the Northern Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/601018"}, {"dataset_uid": "601194", "doi": "10.15784/601194", "keywords": "Antarctica; Transantarctic Mountains", "people": "Hansen, Samantha", "repository": "USAP-DC", "science_program": null, "title": "Crustal Structure beneath the Northern Transantarctic Mountains and Wilkes Subglacial Basin: Implications for Tectonic Origins", "url": "https://www.usap-dc.org/view/dataset/601194"}], "date_created": "Sun, 04 Jun 2017 00:00:00 GMT", "description": "Intellectual Merit: To understand Antarctica\u0027s geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF\u0027s PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI\u0027s supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.", "east": 165.120012, "geometry": "POINT(159.223506 -74.6349495)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -73.032547, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Hansen, Samantha", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.237352, "title": "CAREER: Deciphering the Tectonic History of the Transantarctic Mountains and the Wilkes Subglacial Basin", "uid": "p0000300", "west": 153.327}, {"awards": "1142166 McConnell, Joseph", "bounds_geometry": "POINT(-112.1115 -79.481)", "dataset_titles": "WAIS Divide Ice-Core Aerosol Records from 1300 to 3404 m", "datasets": [{"dataset_uid": "601008", "doi": "10.15784/601008", "keywords": "Aerosol; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "McConnell, Joseph", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice-Core Aerosol Records from 1300 to 3404 m", "url": "https://www.usap-dc.org/view/dataset/601008"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "McConnell/1142166 This award supports a project to use unprecedented aerosol and continuous gas (methane, carbon monoxide) measurements of the deepest section of the West Antarctic Ice Sheet (WAIS) Divide ice core to investigate rapid climate changes in Antarctica during the ~60,000 year long Marine Isotope Stage 3 period of the late Pleistocene. These analyses, combined with others, will take advantage of the high snow accumulation of the WAIS Divide ice core to yield the highest time resolution glaciochemical and gas record of any deep Antarctic ice core for this time period. The research will expand already funded discrete gas measurements and extend currently funded continuous aerosol measurements on the WAIS Divide ice core from ~25,000 to ~60,000 years before present, spanning Heinrich events 3 to 6 and Antarctic Isotope Maximum (AIM, corresponding to the Northern Hemisphere Dansgaard-Oeschger) events 3 to 14. With other high resolution Greenland cores and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The intellectual merit of the work is that it will be used to address the science goals of the WAIS Divide project including the identification of dust and biomass burning tracers such as black carbon and carbon monoxide which reflect mid- and low-latitude climate and atmospheric circulation patterns, and fallout from these sources affects marine and terrestrial biogeochemical cycles. Similarly, sea salt and ocean productivity tracers reflect changes in sea ice extent, marine primary productivity, wind speeds above the ocean, and atmospheric circulation. Volcanic tracers address the relationship between northern, tropical, and southern climates as well as stability of the West Antarctic ice sheet and sea level change. When combined with other gas records from WAIS Divide, the records developed here will transform understanding of mid- and low-latitude drivers of Antarctic, Southern Hemisphere, and global climate rapid changes and the timing of such changes. The broader impacts of the work are that it will enhance infrastructure through expansion of continuous ice core analytical techniques, train students and support collaboration between two U.S. institutions (DRI and OSU). All data will be made available to the scientific community and the public and will include participation the WAIS Divide Outreach Program. Extensive graduate and undergraduate student involvement is planned. Student recruitment will be made from under-represented groups building on a long track record. Broad outreach will be achieved through collaborations with the global and radiative modeling communities, NESTA-related and other educational outreach efforts, and public lectures. This proposed project does not require field work in the Antarctic.", "east": -112.1115, "geometry": "POINT(-112.1115 -79.481)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.481, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "McConnell, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.481, "title": "Collaborative Research: Investigating Upper Pleistocene Rapid Climate Change using Continuous, Ultra-High-Resolution Aerosol and Gas Measurements in the WAIS Divide Ice Core", "uid": "p0000287", "west": -112.1115}, {"awards": "0539578 Alley, Richard; 0539232 Cuffey, Kurt", "bounds_geometry": "POINT(112.083 -79.467)", "dataset_titles": "Grain Size Full Population Dataset from WDC06A Core; Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole; Temperature Reconstruction at the West Antarctic Ice Sheet Divide; Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data; WAIS Divide Ice Core Vertical Thin Section Low-resolution Digital Imagery; WAIS Divide Surface and Snow-pit Data, 2009-2013; WDC 06A Mean Grain Size Data", "datasets": [{"dataset_uid": "601079", "doi": "10.15784/601079", "keywords": "Antarctica; Atmosphere; AWS; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Meteorology; Physical Properties; Snow Pit; Temperature; WAIS Divide; WAIS Divide Ice Core; Weatherstation", "people": "Alley, Richard; Fegyveresi, John", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Surface and Snow-pit Data, 2009-2013", "url": "https://www.usap-dc.org/view/dataset/601079"}, {"dataset_uid": "609656", "doi": "10.7265/N5MC8X08", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Fitzpatrick, Joan; Cravens, Eric D.", "repository": "USAP-DC", "science_program": null, "title": "WDC 06A Mean Grain Size Data", "url": "https://www.usap-dc.org/view/dataset/609656"}, {"dataset_uid": "600377", "doi": "10.15784/600377", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrogen; Paleoclimate; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Cuffey, Kurt M.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Temperature Reconstruction at the West Antarctic Ice Sheet Divide", "url": "https://www.usap-dc.org/view/dataset/600377"}, {"dataset_uid": "609655", "doi": "10.7265/N5VX0DG0", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Grain Size; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.; Fitzpatrick, Joan", "repository": "USAP-DC", "science_program": null, "title": "Grain Size Full Population Dataset from WDC06A Core", "url": "https://www.usap-dc.org/view/dataset/609655"}, {"dataset_uid": "609550", "doi": "10.7265/N5V69GJW", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Clow, Gary D.; Cuffey, Kurt M.", "repository": "USAP-DC", "science_program": null, "title": "Temperature Profile of the West Antarctic Ice Sheet Divide Deep Borehole", "url": "https://www.usap-dc.org/view/dataset/609550"}, {"dataset_uid": "609654", "doi": "10.7265/N5GM858X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Photo/video; Photo/Video; Thin Sections; WAIS Divide; WAIS Divide Ice Core", "people": "Cravens, Eric D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Vertical Thin Section Low-resolution Digital Imagery", "url": "https://www.usap-dc.org/view/dataset/609654"}, {"dataset_uid": "601224", "doi": "10.15784/601224", "keywords": "Antarctic; Antarctica; Bubble Number Density; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; NSF-ICF Microtome and Photography Stage; Paleoclimate; Physical Properties; Snow/ice; Snow/Ice; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Voigt, Donald E.; Fegyveresi, John; Fitzpatrick, Joan; Spencer, Matthew; Alley, Richard", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Updated (2017) bubble number-density, size, shape, and modeled paleoclimate data", "url": "https://www.usap-dc.org/view/dataset/601224"}], "date_created": "Thu, 12 Jan 2017 00:00:00 GMT", "description": "0539578\u003cbr/\u003eAlley \u003cbr/\u003eThis award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.", "east": 112.083, "geometry": "POINT(112.083 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "LABORATORY; WAIS Divide; Ice Core; Temperature Profiles; FIELD SURVEYS; Bubble Number Density; GROUND-BASED OBSERVATIONS; Wais Divide-project", "locations": "WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Fitzpatrick, Joan; Alley, Richard; Fegyveresi, John; Clow, Gary D.; Cuffey, Kurt M.; Cravens, Eric D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Physical Properties of the WAIS Divide Deep Core", "uid": "p0000038", "west": 112.083}, {"awards": "1043554 Willenbring, Jane", "bounds_geometry": "POINT(161.5 -77.5)", "dataset_titles": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "datasets": [{"dataset_uid": "600379", "doi": "10.15784/600379", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic Radionuclides; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope; Sample/collection Description; Sample/Collection Description; Transantarctic Mountains", "people": "Willenbring, Jane", "repository": "USAP-DC", "science_program": null, "title": "Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "url": "https://www.usap-dc.org/view/dataset/600379"}], "date_created": "Wed, 09 Nov 2016 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events. Broader impacts: This study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K 12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete.", "east": 161.5, "geometry": "POINT(161.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Willenbring, Jane", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.5, "title": "Collaborative Research: Activation of high-elevation alluvial fans in the Transantarctic Mountains - a proxy for Plio-Pleistocene warmth along East Antarctic ice margins", "uid": "p0000429", "west": 161.5}, {"awards": "1043018 Pollard, David; 1043485 Curtice, Josh; 1043517 Clark, Peter", "bounds_geometry": "POLYGON((163.5 -77.57,163.685 -77.57,163.87 -77.57,164.055 -77.57,164.24 -77.57,164.425 -77.57,164.61 -77.57,164.795 -77.57,164.98 -77.57,165.165 -77.57,165.35 -77.57,165.35 -77.645,165.35 -77.72,165.35 -77.795,165.35 -77.87,165.35 -77.945,165.35 -78.02,165.35 -78.095,165.35 -78.17,165.35 -78.245,165.35 -78.32,165.165 -78.32,164.98 -78.32,164.795 -78.32,164.61 -78.32,164.425 -78.32,164.24 -78.32,164.055 -78.32,163.87 -78.32,163.685 -78.32,163.5 -78.32,163.5 -78.245,163.5 -78.17,163.5 -78.095,163.5 -78.02,163.5 -77.945,163.5 -77.87,163.5 -77.795,163.5 -77.72,163.5 -77.645,163.5 -77.57))", "dataset_titles": "A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea; Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation", "datasets": [{"dataset_uid": "600123", "doi": "10.15784/600123", "keywords": "Antarctica; Cosmogenic Dating; Ross Sea; Sample/collection Description; Sample/Collection Description; Southern Ocean; WAIS", "people": "Kurz, Mark D.; Curtice, Josh", "repository": "USAP-DC", "science_program": null, "title": "A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/600123"}, {"dataset_uid": "609639", "doi": "10.7265/N5NC5Z53", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model", "people": "Pollard, David", "repository": "USAP-DC", "science_program": null, "title": "Ice Sheet Model Output, West Antarctic Ice Sheet Deglaciation", "url": "https://www.usap-dc.org/view/dataset/609639"}], "date_created": "Sat, 15 Oct 2016 00:00:00 GMT", "description": "1043517/Clark This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.", "east": 165.35, "geometry": "POINT(164.425 -77.945)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "Ocean Depth; Not provided; Bed Elevation; Model Output; Sea Level Rise; Surface Accumulation Rate; Surface Melt Rate; Ocean Melt Rate; Total Ice Volume; Modeling; Calving Rate; Total Ice Area; LABORATORY", "locations": null, "north": -77.57, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pollard, David; Curtice, Josh; Clark, Peter; Kurz, Mark D.", "platforms": "Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.32, "title": "Collaborative Research: A New Reconstruction of the Last West Antarctic Ice Sheet Deglaciation in the Ross Sea", "uid": "p0000194", "west": 163.5}, {"awards": "1043092 Steig, Eric; 1043167 White, James", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Resampling of Deep Polar Ice Cores using Information Theory; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core; WAIS Divide Ice Core Discrete CH4 (80-3403m)", "datasets": [{"dataset_uid": "600169", "doi": "10.15784/600169", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/600169"}, {"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Brook, Edward J.; Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601365", "doi": "10.15784/601365", "keywords": "Antarctica; Delta 18O; Isotope; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Jones, Tyler R.; Vaughn, Bruce; White, James; Morris, Valerie; Garland, Joshua", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Resampling of Deep Polar Ice Cores using Information Theory", "url": "https://www.usap-dc.org/view/dataset/601365"}, {"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Jones, Tyler R.; Bradley, Elizabeth; Morris, Valerie; Price, Michael; White, James; Vaughn, Bruce; Garland, Joshua", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}], "date_created": "Thu, 15 Sep 2016 00:00:00 GMT", "description": "Steig/1043092 This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": -79.47, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "White, James; Vaughn, Bruce; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000078", "west": -112.08}, {"awards": "1043580 Reusch, David", "bounds_geometry": "POLYGON((-180 -47,-144 -47,-108 -47,-72 -47,-36 -47,0 -47,36 -47,72 -47,108 -47,144 -47,180 -47,180 -51.3,180 -55.6,180 -59.9,180 -64.2,180 -68.5,180 -72.8,180 -77.1,180 -81.4,180 -85.7,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -85.7,-180 -81.4,-180 -77.1,-180 -72.8,-180 -68.5,-180 -64.2,-180 -59.9,-180 -55.6,-180 -51.3,-180 -47))", "dataset_titles": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "datasets": [{"dataset_uid": "600166", "doi": "10.15784/600166", "keywords": "Antarctica; Atmosphere; Climate Model; Meteorology; Surface Melt", "people": "Reusch, David", "repository": "USAP-DC", "science_program": null, "title": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "url": "https://www.usap-dc.org/view/dataset/600166"}, {"dataset_uid": "600386", "doi": "10.15784/600386", "keywords": "Antarctica; Atmosphere; Atmospheric Model; Climate Model; Meteorology; Paleoclimate", "people": "Reusch, David", "repository": "USAP-DC", "science_program": null, "title": "Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "url": "https://www.usap-dc.org/view/dataset/600386"}], "date_created": "Thu, 28 Jul 2016 00:00:00 GMT", "description": "The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes. Using contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change. The previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -47.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Reusch, David; Lampkin, Derrick", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Decoding \u0026 Predicting Antarctic Surface Melt Dynamics with Observations, Regional Atmospheric Modeling and GCMs", "uid": "p0000447", "west": -180.0}, {"awards": "1043481 Creyts, Timothy", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 17 Jun 2016 00:00:00 GMT", "description": "1043481/Creyts This award supports a project to develop models of subglacial hydrology in order to understand dynamics of water movement, lake drainage, and how drainage affects ice slip over deformable till with the goal of understanding present and future behavior of fast flowing regions of Antarctica. Drainage of subglacial water falls into two broad categories: distributed and channelized. In distributed systems, water is forced out along the ice?bed interface. Conversely, in channelized systems water is drawn toward a few major arteries. Observations of lake filling and draining sup- port changes in subglacial water flow and suggest a switch from a low to high discharge state or vice versa. Filling or draining can move the subglacial system from one type of drainage morphology to the other. A switch of drainage type will affect slip along the ice-bed interface because distributed morphologies tend to cause enhanced sliding whereas channelized morphologies tend to cause enhanced coupling of the ice-bed interface. Conditions beneath fast flowing ice streams of West Antarctica are ideal for switching between subglacial drainage morphologies. Fast flowing ice in West Antarctica commonly rests on sub- glacial tills and is coincident, in some areas, with observed subglacial lake filling and draining. The goal of the work is to develop the next generation of spatially distributed hydraulic models that capture lake filling and draining phenomena and investigate the effects on subglacial till. Models will be theoretical, process-based descriptions of water drainage and till failure along fast flowing ice streams. Models will be based on balance of mass, momentum, and energy. Building on previous studies, we will incorporate two dimensional movement of water to investigate distributed basal hydrology, distributed basal hydrology coupled to channels, and couple these models with till deformation. These models will provide a framework for determining how lake draining and filling affects ice discharge by providing a constraints on ice?bed coupling. The intellectual merit of the work is that it will advance knowledge about drainage of water subglacially beneath Antarctica and how water affects ice motion. Our modeling provides a unique opportunity to understand the role subglacial hydrology plays in the dynamics of key outlet glaciers and ice streams. The broader impacts of the work include training for one postdoctoral scientist and training for a summer student in simple laboratory techniques for analog experiments. In addition, the proposal dovetails into an existing polar education and outreach plan by including a component of physical, numerical, and scale models in programs developed for high school and middle school classroom visits, teacher workshops and community events. Additionally, because knowledge of glacial hydrology is increasing rapidly, we will convene a workshop on observations and models of subglacial hydrology to facilitate transfer of knowledge and ideas.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Creyts, Timothy; Bell, Robin", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -90.0, "title": "Subglacial drainage and slip modeling in Antarctica: relating lakes to ice discharge", "uid": "p0000345", "west": -180.0}, {"awards": "1043750 Chen, Jianli", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "datasets": [{"dataset_uid": "600159", "doi": "10.15784/600159", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; GRACE; Potential Field; Satellite Data", "people": "Chen, Jianli", "repository": "USAP-DC", "science_program": null, "title": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "url": "https://www.usap-dc.org/view/dataset/600159"}], "date_created": "Fri, 13 May 2016 00:00:00 GMT", "description": "1043750/Chen This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e LASER RANGING \u003e GRACE LRR", "is_usap_dc": true, "keywords": "SATELLITES; GRACE; Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Chen, Jianli; Wilson, Clark; Blankenship, Donald D.; Tapley, Byron", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NASA EARTH SYSTEM SCIENCE PATHFINDER \u003e GRACE; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "uid": "p0000415", "west": -180.0}, {"awards": "1141326 Rotella, Jay", "bounds_geometry": "POLYGON((163.1 -70.3,163.59 -70.3,164.08 -70.3,164.57 -70.3,165.06 -70.3,165.55 -70.3,166.04 -70.3,166.53 -70.3,167.02 -70.3,167.51 -70.3,168 -70.3,168 -70.98,168 -71.66,168 -72.34,168 -73.02,168 -73.7,168 -74.38,168 -75.06,168 -75.74,168 -76.42,168 -77.1,167.51 -77.1,167.02 -77.1,166.53 -77.1,166.04 -77.1,165.55 -77.1,165.06 -77.1,164.57 -77.1,164.08 -77.1,163.59 -77.1,163.1 -77.1,163.1 -76.42,163.1 -75.74,163.1 -75.06,163.1 -74.38,163.1 -73.7,163.1 -73.02,163.1 -72.34,163.1 -71.66,163.1 -70.98,163.1 -70.3))", "dataset_titles": "Demographic data for Weddell Seal colonies in Erebus Bay through the 2017 Antarctic field season", "datasets": [{"dataset_uid": "601125", "doi": "10.15784/601125", "keywords": "Antarctica; Biota; Sea Ice", "people": "Rotella, Jay", "repository": "USAP-DC", "science_program": null, "title": "Demographic data for Weddell Seal colonies in Erebus Bay through the 2017 Antarctic field season", "url": "https://www.usap-dc.org/view/dataset/601125"}], "date_created": "Mon, 08 Feb 2016 00:00:00 GMT", "description": "Abstract The Erebus Bay population of Weddell seals in Antarctica?s Ross Sea is the most southerly breeding population of mammal in the world, closely associated with persistent shore-fast ice, and one that has been intensively studied since 1968. The resulting long-term database, which includes data for 20,586 marked individuals, contains detailed population information that provides an excellent opportunity to study linkages between environmental conditions and demographic processes in the Antarctic. The population?s location is of special interest as the Ross Sea is one of the most productive areas of the Southern Ocean, one of the few pristine marine environments remaining on the planet, and, in contrast to the Antarctic Peninsula and Arctic, is undergoing a gradual lengthening of the sea-ice season. The work to be continued here capitalizes on (1) long-term data for individual seals and their polar environment; (2) experience collecting and analyzing data from the extensive study population; and (3) recent statistical advances in hierarchical modeling that allow for rigorous treatment of individual heterogeneity (in mark-recapture and body mass data) and inclusion of diverse covariates hypothesized to explain variation in fitness components. Covariates to be considered include traits of individuals and their mothers and environmental conditions throughout life. The study will continue to (1) provide detailed data on known-age individuals to other science projects and (2) educate and mentor the next generation of ecologists through academic and professional training and research experiences.", "east": 168.0, "geometry": "POINT(165.55 -73.7)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.3, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rotella, Jay; Garrott, Robert", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.1, "title": "The Demographic Consequences of Environmental Variability and Individual Heterogeneity in Life-history Tactics of a Long-lived Antarctic Marine Predator", "uid": "p0000299", "west": 163.1}, {"awards": "0948247 Pettit, Erin", "bounds_geometry": "POINT(-123.35 -75.1)", "dataset_titles": null, "datasets": null, "date_created": "Wed, 06 Jan 2016 00:00:00 GMT", "description": "Pettit/0948247\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study of the relationship between fabric and climate for the ice near the EPICA Dome C ice core site, East Antarctica. The work builds on an ongoing study at Siple Dome, West Antarctica and takes advantage of collaborations with European scientists and access to the Dome C borehole to make measurements of sonic velocity. The intellectual merit of the project is that a better understanding of how fabric preserves past climate information can improve models of the ice flow near ice core sites and the interpreta-tion of ice core data (particularly paleo-accumulation), and it may allow us to extract climate information directly from fabric data. In addition, because ice deformation is sensitive to the orientation of crystals, ice flow patterns are sensitive to the fabric. Thus, variations in the fabric between glacial and interglacial ice can affect how ice deforms and how fabric in the ice sheet develops. The Dome C site is particularly important for answering these questions, because the ice core shows evidence of eight glacial cycles, not just one as found at Siple Dome or the Greenland sites. The research will improve the understanding of the proxy relationship between sonic-velocity data and fabric; will help to model the pattern of ice flow caused by the fabric variation between glacial and interglacial time periods using these data, existing ice core chemistry and existing and new thin section data, improved surface strain data, and borehole deformation data; and will help to better understand the positive feedback mechanism that enhances fabric (and corresponding rheological) variability through a focused study of several climate transitions and the associated fabric changes. Borehole compressional-wave sonic-velocity will be measured which will complement the sonic-velocity data that already exist for boreholes in Greenland and West Antarctica. These will be the first sonic-velocity measurements in East Antarctica and the first measurements that extend for more than a single glacial/interglacial transition. The project will ultimately contribute to better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. This project will also strengthen the international collaborations within the paleoclimate and ice sheet modeling communities. This project will partially support a graduate student at the University of Alaska Fairbanks who is currently working on modeling ice including anisotropy and it will support the growth of a young scientist through a Post-Doc position. This Post Doc will gain important experience collaborating with the EPICA scientists in studying the climate-fabric relationship. Erin Pettit is active in field-science education for high school students, under-graduates, teachers, and adults. This project will help support the continued development and enhancement of Girls on Ice a program that encourages young women to explore science and the natural world.", "east": -123.35, "geometry": "POINT(-123.35 -75.1)", "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; Crystals; Deformation; FIELD INVESTIGATION; Model; Sonic Logger; Ice Flow; Rheology; FIELD SURVEYS; Borehole; Climate; Ice Fabric; Antarctica; Interglacial", "locations": "Antarctica", "north": -75.1, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Hansen, Sharon", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -75.1, "title": "The Relationship between Climate and Ice Rheology at Dome C, East Antarctica", "uid": "p0000708", "west": -123.35}, {"awards": "1043724 Swanger, Kate", "bounds_geometry": "POLYGON((160.3 -77.4,160.52 -77.4,160.74 -77.4,160.96 -77.4,161.18 -77.4,161.4 -77.4,161.62 -77.4,161.84 -77.4,162.06 -77.4,162.28 -77.4,162.5 -77.4,162.5 -77.44,162.5 -77.48,162.5 -77.52,162.5 -77.56,162.5 -77.6,162.5 -77.64,162.5 -77.68,162.5 -77.72,162.5 -77.76,162.5 -77.8,162.28 -77.8,162.06 -77.8,161.84 -77.8,161.62 -77.8,161.4 -77.8,161.18 -77.8,160.96 -77.8,160.74 -77.8,160.52 -77.8,160.3 -77.8,160.3 -77.76,160.3 -77.72,160.3 -77.68,160.3 -77.64,160.3 -77.6,160.3 -77.56,160.3 -77.52,160.3 -77.48,160.3 -77.44,160.3 -77.4))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 05 Dec 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to investigate the impact of earth surface processes on the application of cosmogenic exposure dating in Antarctica by combining multi-nuclide techniques, detailed field experiments, rock-mechanic studies, and climate modeling. They will analyze cosmogenic-nuclide inventories for a suite of six alpine-moraine systems in inland regions of the McMurdo Dry Valleys. This area is ideally suited for this study because 1) the targeted alpine moraine sequences are critically important in helping to reconstruct past temperature and precipitation values over the last several million years, 2) the production rates for cosmogenic nuclides are typically high and well-known, and 3) the complexity of surface processes is relatively low. Their work has two specific goals: to evaluate the effects of episodic geomorphic events in modulating cosmogenic inventories in surface rocks in polar deserts and to generate an alpine glacier chronology that will serve as a robust record of regional climate variation over the last several million years. A key objective is to produce a unique sampling strategy that yields consistent exposure-age results by minimizing the effects of episodic geomorphic events that obfuscate cosmogenic-nuclide chronologies. They will link their moraine chronology with regional-scale atmospheric models developed by collaborators at University of Massachusetts Amherst. Broader impacts: This research is interdisciplinary and includes two early career scientists. Results of this work will be used to enhance undergraduate education by engaging two female students in Antarctic field and summer research projects. Extended outreach includes development of virtual Antarctic field trips for Colgate University?s Ho Tung Visualization Laboratory and Boston University?s Antarctic Digital Image Analyses Laboratory. The PIs will continue to work with the Los Angeles Valley Community College, which serves students of mostly Hispanic origin as part of the PolarTREC program. This project will contribute to the collaboration between LDEO and several New York City public high schools within the Lamont-Doherty Secondary School Field Program.", "east": 162.5, "geometry": "POINT(161.4 -77.6)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.4, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Swanger, Kate", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -77.8, "title": "Collaborative Research: Multi-nuclide approach to systematically evaluate the scatter in surface exposure ages in Antarctica and to develop consistent alpine glacier chronologies", "uid": "p0000406", "west": 160.3}, {"awards": "1039982 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Seismological Data at IRIS (full data link not provided)", "datasets": [{"dataset_uid": "000170", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Seismological Data at IRIS (full data link not provided)", "url": "http://ds.iris.edu/"}], "date_created": "Mon, 23 Nov 2015 00:00:00 GMT", "description": "Intellectual Merit: Knowledge of englacial and subglacial conditions are critical for ice sheet models and predictions of sea-level change. Some of the critical variables that are poorly known but essential for improving flow models and predictions of sea-level change are: basal roughness, subglacial sedimentary and hydrologic conditions, and the temporal and spatial variability of the ice sheet flow field. Seismic reflection and refraction imaging and dense arrays of continuously operating GPS receivers can determine these parameters. The PIs propose to develop a network of wirelessly interconnected geophysical sensors (geoPebble) that will allow glaciologists to carry out these experiments simultaneously. This sensor web will provide a new way of imaging the ice sheet that is not possible with current instruments. With this sensor web, the PIs will extend the range of existing instruments from 2D to 3D, from low resolution to high resolution, but more importantly, all the geophysical measurements will be conducted synchronously. By the end of the proposal period the PIs will produce a network of 150-200 geoPebbles that will be available for NSF-sponsored glaciology research projects. Broader impacts: Improved knowledge of the flow law of ice, the sliding of glaciers and ice streams, and paleoclimate history will contribute to assessments of the potential for abrupt ice-sheet mass change, with consequent sea-level effects and significant societal impacts. This improved modeling ability will be a direct consequence of better knowledge of the physical properties of ice sheets, which this project will facilitate. The development effort will be integrated with the undergraduate education program via the capstone design classes in EE and the senior thesis requirement in Geoscience. The PIs will also form a cohort of first-year and sophomore students who will work in their labs from the beginning of the project to develop specifications through the commissioning of the network.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Anandakrishnan, Sridhar; Bilen, Sven; Urbina, Julio", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -90.0, "title": "MRI: Development of a Wirelessly-Connected Network of Seismometers and GPS Instruments for Polar and Geophysical Research", "uid": "p0000405", "west": -180.0}, {"awards": "1043706 Marchant, David", "bounds_geometry": "POLYGON((160 -76.5,160.45 -76.5,160.9 -76.5,161.35 -76.5,161.8 -76.5,162.25 -76.5,162.7 -76.5,163.15 -76.5,163.6 -76.5,164.05 -76.5,164.5 -76.5,164.5 -76.7,164.5 -76.9,164.5 -77.1,164.5 -77.3,164.5 -77.5,164.5 -77.7,164.5 -77.9,164.5 -78.1,164.5 -78.3,164.5 -78.5,164.05 -78.5,163.6 -78.5,163.15 -78.5,162.7 -78.5,162.25 -78.5,161.8 -78.5,161.35 -78.5,160.9 -78.5,160.45 -78.5,160 -78.5,160 -78.3,160 -78.1,160 -77.9,160 -77.7,160 -77.5,160 -77.3,160 -77.1,160 -76.9,160 -76.7,160 -76.5))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 23 Oct 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to investigate the impact of earth surface processes on the application of cosmogenic exposure dating in Antarctica by combining multi-nuclide techniques, detailed field experiments, rock-mechanic studies, and climate modeling. They will analyze cosmogenic-nuclide inventories for a suite of six alpine-moraine systems in inland regions of the McMurdo Dry Valleys. This area is ideally suited for this study because 1) the targeted alpine moraine sequences are critically important in helping to reconstruct past temperature and precipitation values over the last several million years, 2) the production rates for cosmogenic nuclides are typically high and well-known, and 3) the complexity of surface processes is relatively low. Their work has two specific goals: to evaluate the effects of episodic geomorphic events in modulating cosmogenic inventories in surface rocks in polar deserts and to generate an alpine glacier chronology that will serve as a robust record of regional climate variation over the last several million years. A key objective is to produce a unique sampling strategy that yields consistent exposure-age results by minimizing the effects of episodic geomorphic events that obfuscate cosmogenic-nuclide chronologies. They will link their moraine chronology with regional-scale atmospheric models developed by collaborators at University of Massachusetts Amherst. Broader impacts: This research is interdisciplinary and includes two early career scientists. Results of this work will be used to enhance undergraduate education by engaging two female students in Antarctic field and summer research projects. Extended outreach includes development of virtual Antarctic field trips for Colgate University?s Ho Tung Visualization Laboratory and Boston University?s Antarctic Digital Image Analyses Laboratory. The PIs will continue to work with the Los Angeles Valley Community College, which serves students of mostly Hispanic origin as part of the PolarTREC program. This project will contribute to the collaboration between LDEO and several New York City public high schools within the Lamont-Doherty Secondary School Field Program.", "east": 164.5, "geometry": "POINT(162.25 -77.5)", "instruments": null, "is_usap_dc": false, "keywords": "McMurdo Dry Valleys; Rock Weathering; Not provided", "locations": "McMurdo Dry Valleys", "north": -76.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Marchant, David", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -78.5, "title": "Collaborative Research: Multi-nuclide approach to systematically evaluate the scatter in surface exposure ages in Antarctica and to develop consistent alpine glacier chronologies", "uid": "p0000269", "west": 160.0}, {"awards": "1343649 Levy, Joseph", "bounds_geometry": "POLYGON((162.852 -77.6111,162.9893 -77.6111,163.1266 -77.6111,163.2639 -77.6111,163.4012 -77.6111,163.5385 -77.6111,163.6758 -77.6111,163.8131 -77.6111,163.9504 -77.6111,164.0877 -77.6111,164.225 -77.6111,164.225 -77.65331,164.225 -77.69552,164.225 -77.73773,164.225 -77.77994,164.225 -77.82215,164.225 -77.86436,164.225 -77.90657,164.225 -77.94878,164.225 -77.99099,164.225 -78.0332,164.0877 -78.0332,163.9504 -78.0332,163.8131 -78.0332,163.6758 -78.0332,163.5385 -78.0332,163.4012 -78.0332,163.2639 -78.0332,163.1266 -78.0332,162.9893 -78.0332,162.852 -78.0332,162.852 -77.99099,162.852 -77.94878,162.852 -77.90657,162.852 -77.86436,162.852 -77.82215,162.852 -77.77994,162.852 -77.73773,162.852 -77.69552,162.852 -77.65331,162.852 -77.6111))", "dataset_titles": "Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "600139", "doi": "10.15784/600139", "keywords": "Antarctica; Chemistry:soil; Chemistry:Soil; Critical Zone; Dry Valleys; Permafrost; Sample/collection Description; Sample/Collection Description; Well Measurements", "people": "Levy, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600139"}], "date_created": "Mon, 05 Oct 2015 00:00:00 GMT", "description": "Intellectual Merit: The PIs propose to quantify the hillslope water, solute, and carbon budgets for Taylor Valley in the McMurdo Dry Valleys, using water tracks to investigate near-surface geological processes and challenge the paradigm that shallow groundwater is minimal or non-exixtant. Water tracks are linear zones of high soil moisture that route shallow groundwater downslope in permafrost dominated soils. Four hypotheses will be tested: 1) water tracks are important pathways for water and solute transport; 2) water tracks transport more dissolved silica than streams in Taylor Valley indicating they are the primary site of chemical weathering for cold desert soils and bedrock; 3) water tracks that drain highland terrains are dominated by humidity-separated brines while water tracks that drain lowland terrains are dominated by marine aerosols; 4) water tracks are the sites of the highest terrestrial soil carbon concentrations and the strongest CO2 fluxes in Taylor Valley and their carbon content increases with soil age, while carbon flux decreases with age. To test these hypotheses the PIs will carry out a suite of field measurements supported by modeling and remote sensing. They will install shallow permafrost wells in water tracks that span the range of geological, climatological, and topographic conditions in Taylor Valley. Multifrequency electromagnetic induction sounding of the upper ~1 m of the permafrost will create the first comprehensive map of soil moisture in Taylor Valley, and will permit direct quantification of water track discharge across the valley. The carbon contents of water track soils will be measured and linked to global carbon dynamics. Broader impacts: Non-science majors at Oregon State University will be integrated into the proposed research through a new Global Environmental Change course focusing on the scientific method in Antarctica. Three undergraduate students, members of underrepresented minorities, will be entrained in the research, will contribute to all aspects of field and laboratory science, and will present results at national meetings.", "east": 164.225, "geometry": "POINT(163.5385 -77.82215)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.6111, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Levy, Joseph", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0332, "title": "Cryptic Hydrology of the McMurdo Dry Valleys: Water Track Contributions to Water and Geochemical Budgets in Taylor Valley, Antarctica", "uid": "p0000407", "west": 162.852}, {"awards": "0632282 Jacobs, Stanley", "bounds_geometry": "POLYGON((-129.6 -54.2,-124.44 -54.2,-119.28 -54.2,-114.12 -54.2,-108.96 -54.2,-103.8 -54.2,-98.64 -54.2,-93.48 -54.2,-88.32 -54.2,-83.16 -54.2,-78 -54.2,-78 -56.29,-78 -58.38,-78 -60.47,-78 -62.56,-78 -64.65,-78 -66.74,-78 -68.83,-78 -70.92,-78 -73.01,-78 -75.1,-83.16 -75.1,-88.32 -75.1,-93.48 -75.1,-98.64 -75.1,-103.8 -75.1,-108.96 -75.1,-114.12 -75.1,-119.28 -75.1,-124.44 -75.1,-129.6 -75.1,-129.6 -73.01,-129.6 -70.92,-129.6 -68.83,-129.6 -66.74,-129.6 -64.65,-129.6 -62.56,-129.6 -60.47,-129.6 -58.38,-129.6 -56.29,-129.6 -54.2))", "dataset_titles": "Amundsen Sea Continental Shelf Mooring Data (2006-2007); Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. 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Palmer expedition NBP0901", "datasets": [{"dataset_uid": "000128", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP07-09 processed CTD data", "url": "http://accession.nodc.noaa.gov/0120761"}, {"dataset_uid": "000130", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP09-01 processed CTD data", "url": "http://accession.nodc.noaa.gov/0071179"}, {"dataset_uid": "000129", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP09-01 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0901"}, {"dataset_uid": "000127", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP07-09 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0709"}, {"dataset_uid": "601350", "doi": null, "keywords": "Amundsen Sea; Antarctic; Antarctica; CTD; CTD Data; Current Measurements; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; Pine Island Glacier; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Jacobs, Stanley; Huber, Bruce", "repository": "USAP-DC", "science_program": null, "title": "Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601350"}, {"dataset_uid": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Giulivi, Claudia F.; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}, {"dataset_uid": "601349", "doi": null, "keywords": "Amundsen Sea; Antarctica; Current Measurements; LADCP; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; R/v Nathaniel B. Palmer; Southern Ocean", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601349"}], "date_created": "Fri, 25 Sep 2015 00:00:00 GMT", "description": "The Office of Polar Programs, Antarctic Science Division, Ocean \u0026 Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. \u003cbr/\u003eThe region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. \u003cbr/\u003eBroader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.", "east": -78.0, "geometry": "POINT(-103.8 -64.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "Not provided; R/V NBP", "locations": null, "north": -54.2, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "NCEI", "repositories": "NCEI; R2R; USAP-DC", "science_programs": null, "south": -75.1, "title": "Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise - IPY/ASEP", "uid": "p0000332", "west": -129.6}, {"awards": "0944165 McGillicuddy, Dennis; 0944254 Smith, Walker", "bounds_geometry": "POLYGON((168 -65,168.2 -65,168.4 -65,168.6 -65,168.8 -65,169 -65,169.2 -65,169.4 -65,169.6 -65,169.8 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,170 -65,169.8 -65,169.6 -65,169.4 -65,169.2 -65,169 -65,168.8 -65,168.6 -65,168.4 -65,168.2 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65,168 -65))", "dataset_titles": "Data from expdition NBP1201; Expedition Data; Project data: Processes Regulating Iron Supply at the Mesoscale - Ross Sea", "datasets": [{"dataset_uid": "000155", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Project data: Processes Regulating Iron Supply at the Mesoscale - Ross Sea", "url": "http://www.bco-dmo.org/project/2155"}, {"dataset_uid": "000156", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Data from expdition NBP1201", "url": "http://www.bco-dmo.org/deployment/506350"}, {"dataset_uid": "001442", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1201"}], "date_created": "Wed, 08 Jul 2015 00:00:00 GMT", "description": "The Ross Sea continental shelf is one of the most productive areas in the Southern Ocean, and may comprise a significant, but unaccounted for, oceanic CO2 sink, largely driven by phytoplankton production. The processes that control the magnitude of primary production in this region are not well understood, but data suggest that iron limitation is a factor. Field observations and model simulations indicate four potential sources of dissolved iron to surface waters of the Ross Sea: (1) circumpolar deep water intruding from the shelf edge; (2) sediments on shallow banks and nearshore areas; (3) melting sea ice around the perimeter of the polynya; and (4) glacial meltwater from the Ross Ice Shelf. The principal investigators hypothesize that hydrodynamic transport via mesoscale currents, fronts, and eddies facilitate the supply of dissolved iron from these four sources to the surface waters of the Ross Sea polynya. These hypotheses will be tested through a combination of in situ observations and numerical modeling, complemented by satellite remote sensing. In situ observations will be obtained during a month-long cruise in the austral summer. The field data will be incorporated into model simulations, which allow quantification of the relative contributions of the various hypothesized iron supply mechanisms, and assessment of their impact on primary production. The research will provide new insights and a mechanistic understanding of the complex oceanographic phenomena that regulate iron supply, primary production, and biogeochemical cycling. The research will thus form the basis for predictions about how this system may change in a warming climate. The broader impacts include training of graduate and undergraduate students, international collaboration, and partnership with several ongoing outreach programs that address scientific research in the Southern Ocean. The research also will contribute to the goals of the international research programs ICED (Integrated Climate and Ecosystem Dynamics) and GEOTRACES (Biogeochemical cycling and trace elements in the marine environment).", "east": 170.0, "geometry": "POINT(169 -65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker; McGillicuddy, Dennis", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "BCO-DMO", "repositories": "BCO-DMO; R2R", "science_programs": null, "south": -65.0, "title": "Collaborative Research: Impact of Mesoscale Processes on Iron Supply and Phytoplankton Dynamics in the Ross Sea", "uid": "p0000330", "west": 168.0}, {"awards": "0229314 Stone, John", "bounds_geometry": null, "dataset_titles": "Reedy Glacier Exposure Ages, Antarctica", "datasets": [{"dataset_uid": "609601", "doi": "10.7265/N5MG7MF1", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Cosmogenic; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Reedy Glacier; Sample/collection Description; Sample/Collection Description", "people": "Stone, John", "repository": "USAP-DC", "science_program": null, "title": "Reedy Glacier Exposure Ages, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609601"}], "date_created": "Mon, 30 Mar 2015 00:00:00 GMT", "description": "The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation and grounding-line retreat. However, previous work in the Ross Sea Embayment was based on data from just three locations that are all far to the north of the present grounding line. Additional data from farther south in the Ross Sea Embayment are needed to investigate whether recession has ended, or if the rate and pattern of deglaciation inferred from our previous study still apply to the present grounding line. This award provides support to reconstruct the evolution of Reedy Glacier, in the southern Transantarctic Mountains, since the Last Glacial Maximum (LGM). Because Reedy Glacier emerges from the mountains above the grounding line, its surface slope and elevation should record changes in thickness of grounded ice in the Ross Sea up to the present day. The deglaciation chronology of Reedy Glacier therefore can indicate whether Holocene retreat of the WAIS ended thousands of years ago, or is still continuing at present. This integrated glaciologic, glacial-geologic, and cosmogenic-isotope exposure- dating project will reconstruct past levels of Reedy Glacier. Over two field seasons, moraines will be mapped, dated and correlated at sites along the length of the glacier. Radar and GPS measurements will be made to supplement existing ice thickness and velocity data, which are needed as input for a model of glacier dynamics. The model will be used to relate geologic measurements to the grounding-line position downstream. Ultimately, the mapping, dating and ice-modeling components of the study will be integrated into a reconstruction that defines changes in ice thickness in the southern Ross Sea since the LGM, and relates these changes to the history of grounding-line retreat. This work directly addresses key goals of the West Antarctic Ice Sheet Initiative, which are to understand the dynamics, recent history and possible future behavior of the West Antarctic Ice Sheet.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "Surface Exposure Dates; FIELD SURVEYS; Aluminum-26; Erosion; Rock Samples; Beryllium-10; Exposure Age", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stone, John", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Late Quaternary History of Reedy Glacier", "uid": "p0000029", "west": null}, {"awards": "0944727 Arrigo, Kevin", "bounds_geometry": "POLYGON((-118.3 -71.6,-117.57 -71.6,-116.84 -71.6,-116.11 -71.6,-115.38 -71.6,-114.65 -71.6,-113.92 -71.6,-113.19 -71.6,-112.46 -71.6,-111.73 -71.6,-111 -71.6,-111 -71.86,-111 -72.12,-111 -72.38,-111 -72.64,-111 -72.9,-111 -73.16,-111 -73.42,-111 -73.68,-111 -73.94,-111 -74.2,-111.73 -74.2,-112.46 -74.2,-113.19 -74.2,-113.92 -74.2,-114.65 -74.2,-115.38 -74.2,-116.11 -74.2,-116.84 -74.2,-117.57 -74.2,-118.3 -74.2,-118.3 -73.94,-118.3 -73.68,-118.3 -73.42,-118.3 -73.16,-118.3 -72.9,-118.3 -72.64,-118.3 -72.38,-118.3 -72.12,-118.3 -71.86,-118.3 -71.6))", "dataset_titles": "Dataset: Chlorophyll a", "datasets": [{"dataset_uid": "000172", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Chlorophyll a", "url": "http://www.bco-dmo.org/dataset/546372"}], "date_created": "Fri, 30 Jan 2015 00:00:00 GMT", "description": "ASPIRE is an NSF-funded project that will examine the ecology of the Amundsen Sea during the Austral summer of 2010. ASPIRE includes an international team of trace metal and carbon chemists, phytoplankton physiologists, microbial and zooplankton ecologists, and physical oceanographers, that will investigate why and how the Amundsen Sea Polynya is so much more productive than other polynyas and whether interannual variability can provide insight to climate-sensitive mechanisms driving carbon fluxes. This project will compliment the existing ASPIRE effort by using 1) experimental manipulations to understand photoacclimation of the dominant phytoplankton taxa under conditions of varying light and trace metal abundance, 2) nutrient addition bioassays to determine the importance of trace metal versus nitrogen limitation of phytoplankton growth, and 3) a numerical ecosystem model to understand the importance of differences in mixing regime, flow field, and Fe sources in controlling phytoplankton bloom dynamics and community composition in this unusually productive polynya system. The research strategy will integrate satellite remote sensing, field-based experimental manipulations, and numerical modeling. Outreach and education include participation in Stanford\u0027s Summer Program for Professional Development for Science Teachers, Stanford\u0027s School of Earth Sciences high school internship program, and development of curriculum for local science training centers, including the Chabot Space and Science Center. Undergraduate participation and training will include support for both graduate students and undergraduate assistants.", "east": -111.0, "geometry": "POINT(-114.65 -72.9)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -71.6, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Arrigo, Kevin", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -74.2, "title": "ASPIRE: Amundsen Sea Polynya International Research Expedition", "uid": "p0000348", "west": -118.3}, {"awards": "0944087 Hamilton, Gordon", "bounds_geometry": "POLYGON((145 -80,147 -80,149 -80,151 -80,153 -80,155 -80,157 -80,159 -80,161 -80,163 -80,165 -80,165 -80.035,165 -80.07,165 -80.105,165 -80.14,165 -80.175,165 -80.21,165 -80.245,165 -80.28,165 -80.315,165 -80.35,163 -80.35,161 -80.35,159 -80.35,157 -80.35,155 -80.35,153 -80.35,151 -80.35,149 -80.35,147 -80.35,145 -80.35,145 -80.315,145 -80.28,145 -80.245,145 -80.21,145 -80.175,145 -80.14,145 -80.105,145 -80.07,145 -80.035,145 -80))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 23 Jan 2015 00:00:00 GMT", "description": "This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier\u0027s flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society\u0027s need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.", "east": 165.0, "geometry": "POINT(155 -80.175)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "Sea Level Rise; FIELD INVESTIGATION; Glacier; LABORATORY; Outlet Glaciers; Boundary Conditions; Model; Numerical Model; FIELD SURVEYS; Antarctica; COMPUTERS; Not provided; Flow Dynamics", "locations": "Antarctica", "north": -80.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Stearns, Leigh; Hamilton, Gordon S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -80.35, "title": "Collaborative Research: Byrd Glacier Flow Dynamics", "uid": "p0000319", "west": 145.0}, {"awards": "0838849 Bender, Michael; 0838843 Kurbatov, Andrei", "bounds_geometry": "POLYGON((159.16667 -76.66667,159.19167 -76.66667,159.21667 -76.66667,159.24167 -76.66667,159.26667 -76.66667,159.29167 -76.66667,159.31667 -76.66667,159.34167 -76.66667,159.36667 -76.66667,159.39167 -76.66667,159.41667 -76.66667,159.41667 -76.673336,159.41667 -76.680002,159.41667 -76.686668,159.41667 -76.693334,159.41667 -76.7,159.41667 -76.706666,159.41667 -76.713332,159.41667 -76.719998,159.41667 -76.726664,159.41667 -76.73333,159.39167 -76.73333,159.36667 -76.73333,159.34167 -76.73333,159.31667 -76.73333,159.29167 -76.73333,159.26667 -76.73333,159.24167 -76.73333,159.21667 -76.73333,159.19167 -76.73333,159.16667 -76.73333,159.16667 -76.726664,159.16667 -76.719998,159.16667 -76.713332,159.16667 -76.706666,159.16667 -76.7,159.16667 -76.693334,159.16667 -76.686668,159.16667 -76.680002,159.16667 -76.673336,159.16667 -76.66667))", "dataset_titles": "Allan Hills Stable Water Isotopes; Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "datasets": [{"dataset_uid": "609541", "doi": "10.7265/N5NP22DF", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Isotope", "people": "Kurbatov, Andrei V.; Introne, Douglas; Mayewski, Paul A.; Spaulding, Nicole", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Allan Hills Stable Water Isotopes", "url": "https://www.usap-dc.org/view/dataset/609541"}, {"dataset_uid": "600099", "doi": "10.15784/600099", "keywords": "Allan Hills; Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Ice Core Records; Paleoclimate; Solid Earth", "people": "Bender, Michael", "repository": "USAP-DC", "science_program": "Allan Hills", "title": "Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "url": "https://www.usap-dc.org/view/dataset/600099"}], "date_created": "Wed, 10 Dec 2014 00:00:00 GMT", "description": "This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an \"International Climate Park\" in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica.", "east": 159.41667, "geometry": "POINT(159.29167 -76.7)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; LABORATORY; Deuterium Isotopes; Not provided; Oxygen Isotope", "locations": null, "north": -76.66667, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Spaulding, Nicole; Introne, Douglas; Bender, Michael; Kurbatov, Andrei V.; Mayewski, Paul A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Allan Hills", "south": -76.73333, "title": "Collaborative Research: Exploring A 2 Million + Year Ice Climate Archive-Allan Hills Blue Ice Area (2MBIA)", "uid": "p0000046", "west": 159.16667}, {"awards": "1043092 Steig, Eric; 1043167 White, James", "bounds_geometry": null, "dataset_titles": "17O excess from WAIS Divide, 0 to 25 ka BP; WAIS Divide Ice Core Discrete CH4 (80-3403m); WAIS Divide WDC06A Oxygen Isotope Record", "datasets": [{"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Brook, Edward J.; Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601413", "doi": "10.15784/601413", "keywords": "Antarctica; Ice Core; Oxygen Isotope; WAIS Divide", "people": "Schoenemann, Spruce; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "17O excess from WAIS Divide, 0 to 25 ka BP", "url": "https://www.usap-dc.org/view/dataset/601413"}, {"dataset_uid": "609629", "doi": "10.7265/N5GT5K41", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide WDC06A Oxygen Isotope Record", "url": "https://www.usap-dc.org/view/dataset/609629"}], "date_created": "Sat, 06 Dec 2014 00:00:00 GMT", "description": "This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e INFRARED LASER SPECTROSCOPY", "is_usap_dc": true, "keywords": "AMD; ANALYTICAL LAB; USAP-DC; Amd/Us; LABORATORY; ICE CORE RECORDS; Antarctica; Wais Divide-project; FIELD SURVEYS; USA/NSF", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000010", "west": null}, {"awards": "0944615 Brown, Michael; 0944600 Siddoway, Christine", "bounds_geometry": "POLYGON((-146.5 -76,-145.95 -76,-145.4 -76,-144.85 -76,-144.3 -76,-143.75 -76,-143.2 -76,-142.65 -76,-142.1 -76,-141.55 -76,-141 -76,-141 -76.15,-141 -76.3,-141 -76.45,-141 -76.6,-141 -76.75,-141 -76.9,-141 -77.05,-141 -77.2,-141 -77.35,-141 -77.5,-141.55 -77.5,-142.1 -77.5,-142.65 -77.5,-143.2 -77.5,-143.75 -77.5,-144.3 -77.5,-144.85 -77.5,-145.4 -77.5,-145.95 -77.5,-146.5 -77.5,-146.5 -77.35,-146.5 -77.2,-146.5 -77.05,-146.5 -76.9,-146.5 -76.75,-146.5 -76.6,-146.5 -76.45,-146.5 -76.3,-146.5 -76.15,-146.5 -76))", "dataset_titles": "Rock Samples collected from bedrock exposures, Ford Ranges, MBL", "datasets": [{"dataset_uid": "200415", "doi": "", "keywords": null, "people": null, "repository": "Polar Rock Repository", "science_program": null, "title": "Rock Samples collected from bedrock exposures, Ford Ranges, MBL", "url": "http://bprc.osu.edu/rr/"}], "date_created": "Thu, 09 Oct 2014 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eThe northern Ford ranges in Marie Byrd Land, Antarctica, record events and processes that transformed a voluminous succession of Lower Paleozoic turbidites intruded by calc-alkaline plutonic rocks into differentiated continental crust along the margin of Gondwana. In this study the Fosdick migmatite?granite complex will be used to investigate crustal evolution through an integrated program of fieldwork, structural geology, petrology, mineral equilibria modeling, geochronology and geochemistry. The PIs propose detailed traverses at four sites within the complex to investigate Paleozoic and Mesozoic orogenic cycles. They will use petrological associations, structural geometry, and microstructures of host gneisses and leucogranites to distinguish the migration and coalescence patterns for remnant melt flow networks, and carry out detailed sampling for geochronology, geochemistry and isotope research. Mafic plutonic phases will be sampled to acquire information about mantle contributions at the source. Mineral equilibria modeling of source rocks and granite products, combined with in situ mineral dating, will be employed to resolve the P?T?t trajectories arising from thickening/thinning of crust during orogenic cycles and to investigate melting and melt loss history. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis work involves research and educational initiatives for an early career female scientist, as well as Ph.D. and undergraduate students. Educational programs for high school audiences and undergraduate courses on interdisciplinary Antarctic science will be developed.", "east": -141.0, "geometry": "POINT(-143.75 -76.75)", "instruments": null, "is_usap_dc": true, "keywords": "Tectonic; TECTONICS; Transcurrent Faults; MAJOR ELEMENTS; Migmatite; Structural Geology; Gneiss Dome; Geochronology; AGE DETERMINATIONS; Detachment Faults; Marie Byrd Land", "locations": "Marie Byrd Land", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Siddoway, Christine; Brown, Mike", "platforms": null, "repo": "Polar Rock Repository", "repositories": "Polar Rock Repository", "science_programs": null, "south": -77.5, "title": "Collaborative research: Polyphase Orogenesis and Crustal Differentiation in West Antarctica", "uid": "p0000259", "west": -146.5}, {"awards": "1043700 Harry, Dennis", "bounds_geometry": "POLYGON((-180 -70,-176.5 -70,-173 -70,-169.5 -70,-166 -70,-162.5 -70,-159 -70,-155.5 -70,-152 -70,-148.5 -70,-145 -70,-145 -71,-145 -72,-145 -73,-145 -74,-145 -75,-145 -76,-145 -77,-145 -78,-145 -79,-145 -80,-148.5 -80,-152 -80,-155.5 -80,-159 -80,-162.5 -80,-166 -80,-169.5 -80,-173 -80,-176.5 -80,180 -80,177.5 -80,175 -80,172.5 -80,170 -80,167.5 -80,165 -80,162.5 -80,160 -80,157.5 -80,155 -80,155 -79,155 -78,155 -77,155 -76,155 -75,155 -74,155 -73,155 -72,155 -71,155 -70,157.5 -70,160 -70,162.5 -70,165 -70,167.5 -70,170 -70,172.5 -70,175 -70,177.5 -70,-180 -70))", "dataset_titles": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History; Ross Sea post-middle Miocene seismic interpretation", "datasets": [{"dataset_uid": "600128", "doi": "10.15784/600128", "keywords": "Andrill; Antarctica; Continental Rift; Geology/Geophysics - Other; Lithosphere; Model; Ross Sea; Solid Earth; Tectonic; Transantarctic Mountains", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "url": "https://www.usap-dc.org/view/dataset/600128"}, {"dataset_uid": "601227", "doi": "10.15784/601227", "keywords": "Andrill; Antarctica; Marine Geoscience; Ross Sea; Seismic Interpretation; Seismic Reflection; Stratigraphy; Subsidence; Victoria Land Basin", "people": "Harry, Dennis L.", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Ross Sea post-middle Miocene seismic interpretation", "url": "https://www.usap-dc.org/view/dataset/601227"}], "date_created": "Sun, 31 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.", "east": -145.0, "geometry": "POINT(-175 -75)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; MARINE GEOPHYSICS; Antarctica; NOT APPLICABLE", "locations": "Antarctica", "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harry, Dennis L.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -80.0, "title": "Geodynamic Models of Subsidence and Lithospheric Flexure at the ANDRILL Drill Sites: Implications for Cenozoic Tectonics and Ice Sheet History", "uid": "p0000467", "west": 155.0}, {"awards": "1354231 Kowalewski, Douglas", "bounds_geometry": "POLYGON((-180 -70,-174 -70,-168 -70,-162 -70,-156 -70,-150 -70,-144 -70,-138 -70,-132 -70,-126 -70,-120 -70,-120 -71.5,-120 -73,-120 -74.5,-120 -76,-120 -77.5,-120 -79,-120 -80.5,-120 -82,-120 -83.5,-120 -85,-126 -85,-132 -85,-138 -85,-144 -85,-150 -85,-156 -85,-162 -85,-168 -85,-174 -85,180 -85,178 -85,176 -85,174 -85,172 -85,170 -85,168 -85,166 -85,164 -85,162 -85,160 -85,160 -83.5,160 -82,160 -80.5,160 -79,160 -77.5,160 -76,160 -74.5,160 -73,160 -71.5,160 -70,162 -70,164 -70,166 -70,168 -70,170 -70,172 -70,174 -70,176 -70,178 -70,-180 -70))", "dataset_titles": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "datasets": [{"dataset_uid": "600140", "doi": "10.15784/600140", "keywords": "Antarctica; Atmosphere; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Model Data; Paleoclimate; Transantarctic Mountains", "people": "Kowalewski, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "url": "https://www.usap-dc.org/view/dataset/600140"}], "date_created": "Thu, 28 Aug 2014 00:00:00 GMT", "description": "Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.", "east": -120.0, "geometry": "POINT(-160 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kowalewski, Douglas", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Validating contrasting terrestrial climate-sensitive Pliocene deposits through high resolution modeling of paleo-environments in the Transantarctic Mountains", "uid": "p0000463", "west": 160.0}, {"awards": "0944475 Kaplan, Michael", "bounds_geometry": "POLYGON((-149.7 -84.1,-118.61 -84.1,-87.52 -84.1,-56.43 -84.1,-25.34 -84.1,5.75 -84.1,36.84 -84.1,67.93 -84.1,99.02 -84.1,130.11 -84.1,161.2 -84.1,161.2 -84.43,161.2 -84.76,161.2 -85.09,161.2 -85.42,161.2 -85.75,161.2 -86.08,161.2 -86.41,161.2 -86.74,161.2 -87.07,161.2 -87.4,130.11 -87.4,99.02 -87.4,67.93 -87.4,36.84 -87.4,5.75 -87.4,-25.34 -87.4,-56.43 -87.4,-87.52 -87.4,-118.61 -87.4,-149.7 -87.4,-149.7 -87.07,-149.7 -86.74,-149.7 -86.41,-149.7 -86.08,-149.7 -85.75,-149.7 -85.42,-149.7 -85.09,-149.7 -84.76,-149.7 -84.43,-149.7 -84.1))", "dataset_titles": "Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "datasets": [{"dataset_uid": "600115", "doi": "10.15784/600115", "keywords": "Antarctica; Cosmogenic Dating; Sample/collection Description; Sample/Collection Description; Solid Earth; Transantarctic Mountains", "people": "Kaplan, Michael", "repository": "USAP-DC", "science_program": null, "title": "Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "url": "https://www.usap-dc.org/view/dataset/600115"}], "date_created": "Thu, 17 Jul 2014 00:00:00 GMT", "description": "The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica?s inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed \u003c2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time. \u003cbr/\u003e\u003cbr/\u003eBroader Impact \u003cbr/\u003eThe proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.", "east": 161.2, "geometry": "POINT(5.75 -85.75)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION", "locations": null, "north": -84.1, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kaplan, Michael", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.4, "title": "Collaborative Research: Pleistocene East Antarctic Ice Sheet History as Recorded in Sediment Provenance and Chronology of High-elevation TAM Moraines", "uid": "p0000459", "west": -149.7}, {"awards": "0934534 Sergienko, Olga", "bounds_geometry": "POLYGON((-106 -70,-105.4 -70,-104.8 -70,-104.2 -70,-103.6 -70,-103 -70,-102.4 -70,-101.8 -70,-101.2 -70,-100.6 -70,-100 -70,-100 -70.6,-100 -71.2,-100 -71.8,-100 -72.4,-100 -73,-100 -73.6,-100 -74.2,-100 -74.8,-100 -75.4,-100 -76,-100.6 -76,-101.2 -76,-101.8 -76,-102.4 -76,-103 -76,-103.6 -76,-104.2 -76,-104.8 -76,-105.4 -76,-106 -76,-106 -75.4,-106 -74.8,-106 -74.2,-106 -73.6,-106 -73,-106 -72.4,-106 -71.8,-106 -71.2,-106 -70.6,-106 -70))", "dataset_titles": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "datasets": [{"dataset_uid": "609626", "doi": "10.7265/N5XS5SBW", "keywords": "Antarctica; Arctic; Bindschadler Ice Stream; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland; Lambert Ice Stream; Macayeal Ice Stream; Pine Island Glacier; Thwaites Glacier", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "url": "https://www.usap-dc.org/view/dataset/609626"}], "date_created": "Thu, 06 Feb 2014 00:00:00 GMT", "description": "Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.", "east": -100.0, "geometry": "POINT(-103 -73)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": true, "keywords": "Not provided; Inverse Modeling; GROUND-BASED OBSERVATIONS; Basal Shear Stress", "locations": null, "north": -70.0, "nsf_funding_programs": "Arctic Natural Sciences", "paleo_time": null, "persons": "Sergienko, Olga", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "COLLABORATIVE RESEARCH: Enabling ice sheet sensitivity and stability analysis with a large-scale higher-order ice sheet model\u0027s adjoint to support sea level change assessment", "uid": "p0000048", "west": -106.0}, {"awards": "0944248 MacAyeal, Douglas", "bounds_geometry": "POLYGON((-63.72 -63.73,-62.893 -63.73,-62.066 -63.73,-61.239 -63.73,-60.412 -63.73,-59.585 -63.73,-58.758 -63.73,-57.931 -63.73,-57.104 -63.73,-56.277 -63.73,-55.45 -63.73,-55.45 -64.0876,-55.45 -64.4452,-55.45 -64.8028,-55.45 -65.1604,-55.45 -65.518,-55.45 -65.8756,-55.45 -66.2332,-55.45 -66.5908,-55.45 -66.9484,-55.45 -67.306,-56.277 -67.306,-57.104 -67.306,-57.931 -67.306,-58.758 -67.306,-59.585 -67.306,-60.412 -67.306,-61.239 -67.306,-62.066 -67.306,-62.893 -67.306,-63.72 -67.306,-63.72 -66.9484,-63.72 -66.5908,-63.72 -66.2332,-63.72 -65.8756,-63.72 -65.518,-63.72 -65.1604,-63.72 -64.8028,-63.72 -64.4452,-63.72 -64.0876,-63.72 -63.73))", "dataset_titles": "Go to the NSIDC and search for the data.; Standing Water Depth on Larsen B Ice Shelf", "datasets": [{"dataset_uid": "609584", "doi": "10.7265/N500002K", "keywords": "Antarctica; Antarctic Peninsula; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Shelf; Larsen B Ice Shelf; Sample/collection Description; Sample/Collection Description; Supraglacial Meltwater", "people": "MacAyeal, Douglas", "repository": "USAP-DC", "science_program": null, "title": "Standing Water Depth on Larsen B Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/609584"}, {"dataset_uid": "001996", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Go to the NSIDC and search for the data.", "url": "http://nsidc.org"}], "date_created": "Sat, 21 Dec 2013 00:00:00 GMT", "description": "MacAyeal/0944248\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.", "east": -55.45, "geometry": "POINT(-59.585 -65.518)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e ETM+; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS", "is_usap_dc": true, "keywords": "Supraglacial Lake; LANDSAT-7; Melt Ponds; Standing Water Depth; Ice Shelf Stability", "locations": null, "north": -63.73, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "MacAyeal, Douglas", "platforms": "SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-7", "repo": "USAP-DC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -67.306, "title": "Model Studies of Surface Water Behavior on Ice Shelves", "uid": "p0000052", "west": -63.72}, {"awards": "0537371 Nyblade, Andrew", "bounds_geometry": "POLYGON((40 -76,50 -76,60 -76,70 -76,80 -76,90 -76,100 -76,110 -76,120 -76,130 -76,140 -76,140 -76.8,140 -77.6,140 -78.4,140 -79.2,140 -80,140 -80.8,140 -81.6,140 -82.4,140 -83.2,140 -84,130 -84,120 -84,110 -84,100 -84,90 -84,80 -84,70 -84,60 -84,50 -84,40 -84,40 -83.2,40 -82.4,40 -81.6,40 -80.8,40 -80,40 -79.2,40 -78.4,40 -77.6,40 -76.8,40 -76))", "dataset_titles": "Data at IRIS Data Management Center (full data link not provided)", "datasets": [{"dataset_uid": "000233", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Data at IRIS Data Management Center (full data link not provided)", "url": "http://www.iris.edu/dms/"}], "date_created": "Wed, 04 Dec 2013 00:00:00 GMT", "description": "Abstract\u003cbr/\u003eThis award supports a seismological study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project will perform a passive seismic experiment deploying twenty-three seismic stations over the GSM to characterize the structure of the crust and upper mantle, and determine the processes driving uplift. The outcomes will also offer constraints on the terrestrial heat flux, a key variable in modeling ice sheet formation and behavior. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. \u003cbr/\u003eBecause of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this seismic experiment, NSF is also supporting an aerogeophysical survey of the GSM under award number 0632292. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach.", "east": 140.0, "geometry": "POINT(90 -80)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Nyblade, Andrew", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -84.0, "title": "Collaborative Research: A Broadband Seismic Experiment to Image the Lithosphere Beneath the Gamburtsev Mountains and Surrounding Areas, East Antarctica", "uid": "p0000657", "west": 40.0}, {"awards": "0741301 O\u0027Brien, Kristin; 1142720 Crockett, Elizabeth", "bounds_geometry": "POLYGON((-64.45 -63.29,-64.249 -63.29,-64.048 -63.29,-63.847 -63.29,-63.646 -63.29,-63.445 -63.29,-63.244 -63.29,-63.043 -63.29,-62.842 -63.29,-62.641 -63.29,-62.44 -63.29,-62.44 -63.370999999999995,-62.44 -63.452,-62.44 -63.533,-62.44 -63.614,-62.44 -63.69499999999999,-62.44 -63.775999999999996,-62.44 -63.857,-62.44 -63.937999999999995,-62.44 -64.01899999999999,-62.44 -64.1,-62.641 -64.1,-62.842 -64.1,-63.043 -64.1,-63.244 -64.1,-63.445 -64.1,-63.646 -64.1,-63.847 -64.1,-64.048 -64.1,-64.249 -64.1,-64.45 -64.1,-64.45 -64.01899999999999,-64.45 -63.937999999999995,-64.45 -63.857,-64.45 -63.775999999999996,-64.45 -63.69499999999999,-64.45 -63.614,-64.45 -63.533,-64.45 -63.452,-64.45 -63.370999999999995,-64.45 -63.29))", "dataset_titles": "Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes", "datasets": [{"dataset_uid": "600084", "doi": "10.15784/600084", "keywords": "Biota; Oceans; Pot; Southern Ocean; Trawl", "people": "O\u0027Brien, Kristin", "repository": "USAP-DC", "science_program": null, "title": "Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes", "url": "https://www.usap-dc.org/view/dataset/600084"}], "date_created": "Sat, 30 Nov 2013 00:00:00 GMT", "description": "Abstract Antarctic notothenioid fishes have evolved in the Southern Ocean for 10-14 MY under an unusual set of circumstances. Their characteristics include the complete absence of the circulating oxygen-binding protein, hemoglobin (Hb) within the Channichthyid (Icefish) family of notothenioids. Moreover, some species within the 16 members of this family have also lost the ability to express the oxygen-binding and storage protein, myoglobin (Mb) in cardiac muscle. Our previous work has determined that the loss of Hb and/or Mb is correlated with significant increases in densities of mitochondria within oxidative tissues, and extensive remodeling of these vital organelles. To date, nothing is known about how modifications in mitochondrial architecture of icefishes affect organelle function, or more importantly, how they affect organismal-level physiology. Most critical for Antarctic fishes is that mitochondrial characteristics have been linked to how well ectotherms can withstand increases in temperature. This collaborative research project will address the hypothesis that the unusual mitochondrial architecture of Antarctic Channichthyids has led to changes in function that impact their ability to withstand elevations in temperature. Specifically, the research will (1) determine if the unusual mitochondrial architecture of icefishes affects function and contributes to organismal thermal sensitivity, (2) identify differences in organismal thermal tolerance between red- and white- blooded notothenioids, (3) identify molecular mechanisms regulating changes in mitochondrial structure in icefishes. The results may establish channichthyid icefishes as a sentinel taxon for signaling the impact of global warming on the Southern Ocean. Broad impacts of this project will be realized by participation of high school biology teachers in field work through cooperation with the ARMADA project at the University of Rhode Island, as well as graduate education.", "east": -62.44, "geometry": "POINT(-63.445 -63.695)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -63.29, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Crockett, Elizabeth; O\u0027Brien, Kristin", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.1, "title": "Collaborative Research: Linkages among Mitochondrial Form, Function and Thermal Tolerance of Antarctic Notothenioid Fishes", "uid": "p0000483", "west": -64.45}, {"awards": "0948357 Measures, Christopher; 0948338 Mitchell, B. Gregory", "bounds_geometry": "POLYGON((-63 -60,-62 -60,-61 -60,-60 -60,-59 -60,-58 -60,-57 -60,-56 -60,-55 -60,-54 -60,-53 -60,-53 -60.45,-53 -60.9,-53 -61.35,-53 -61.8,-53 -62.25,-53 -62.7,-53 -63.15,-53 -63.6,-53 -64.05,-53 -64.5,-54 -64.5,-55 -64.5,-56 -64.5,-57 -64.5,-58 -64.5,-59 -64.5,-60 -64.5,-61 -64.5,-62 -64.5,-63 -64.5,-63 -64.05,-63 -63.6,-63 -63.15,-63 -62.7,-63 -62.25,-63 -61.8,-63 -61.35,-63 -60.9,-63 -60.45,-63 -60))", "dataset_titles": "Project: Blue Water Zone; Trace Metal data 2006 (ID3801); Trace Metals - 2004", "datasets": [{"dataset_uid": "000174", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Trace Metal data 2006 (ID3801)", "url": "https://www.bco-dmo.org/dataset/3801"}, {"dataset_uid": "000218", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Trace Metals - 2004", "url": "https://www.bco-dmo.org/dataset/3800"}, {"dataset_uid": "000173", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Project: Blue Water Zone", "url": "http://www.bco-dmo.org/project/2145"}], "date_created": "Fri, 22 Nov 2013 00:00:00 GMT", "description": "The ocean plays a critical role in sequestering CO2 by exporting fixed carbon to the deep ocean through the biological pump. There is a pressing need to understand the systematics of carbon export in the Southern Ocean in the context of global warming because of the sensitivity of this region to climate change, already manifested as significant temperature increases. Numerous studies have indicated that Fe supply is a primary control on phytoplankton biomass and productivity in the Southern Ocean. The results from previous cruises in Feb-Mar 2004 and Jul-Aug 2006 have revealed the major natural Fe fertilization from Fe-rich shelf waters to the Fe-limited high nutrient low chlorophyll (HNLC) Antarctic Circumpolar Current Surface Water (ASW) in the southern Drake Passage, producing a series of phytoplankton blooms. Remaining questions include: How is natural Fe transported to the euphotic zone through small-meso-large scale horizontal-vertical transport and mixing in different HNLC ACC areas? How does plankton community structure evolve in response to a natural Fe addition, how does Fe speciation respond to biogeochemical processes, and how is Fe recycled to determine the longevity of phytoplankton blooms? How does the export of POC evolve as a function of upwelling-mixing, Fe addition-recycling and bacteria-plankton structure? This synthesis proposal will address these fundamental questions using a unique dataset combining multiyear physical, Fe and biogeochemical data collected between 2004 and 2006 from 2 NSF-funded Fe fertilization experiment cruises and 3 Antarctic Marine Living Resource (AMLR) cruises in the southern Drake Passage and southwestern Scotia Sea through collaboration with scientists in the AMLR program and US Southern Ocean GLOBEC projects. All investigators involved in this study are engaged in graduate and undergraduate instruction, and mentoring of postdoctoral researchers. Each P.I. will incorporate key elements of the proposed syntheses in our lectures, problem sets and group projects. The project includes support to convene a 4-5 day international workshop on natural Fe fertilization at Woods Hole Oceanographic Institution. The workshop will include scientists from United Kingdom, France and Germany who have conducted natural Fe fertilization experiments, and Korea and China who are planning to conduct natural Fe fertilization experiments. The participation of graduate students and postdoctoral scholars will be especially encouraged. The results will be published in a Deep-Sea Research II special issue.", "east": -53.0, "geometry": "POINT(-58 -62.25)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Mitchell, B.; Azam, Farooq; Barbeau, Katherine; Gille, Sarah; Holm-Hansen, Osmund; Measures, Christopher; Selph, Karen", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -64.5, "title": "Collaborative Research: Modeling and synthesis study of a natural iron fertilization site in the Southern Drake Passage", "uid": "p0000071", "west": -63.0}, {"awards": "1043779 Mellish, Jo-Ann", "bounds_geometry": "POLYGON((165.83333 -77.51528,165.923331 -77.51528,166.013332 -77.51528,166.103333 -77.51528,166.193334 -77.51528,166.283335 -77.51528,166.373336 -77.51528,166.463337 -77.51528,166.553338 -77.51528,166.643339 -77.51528,166.73334 -77.51528,166.73334 -77.55153,166.73334 -77.58778,166.73334 -77.62403,166.73334 -77.66028,166.73334 -77.69653,166.73334 -77.73278,166.73334 -77.76903,166.73334 -77.80528,166.73334 -77.84153,166.73334 -77.87778,166.643339 -77.87778,166.553338 -77.87778,166.463337 -77.87778,166.373336 -77.87778,166.283335 -77.87778,166.193334 -77.87778,166.103333 -77.87778,166.013332 -77.87778,165.923331 -77.87778,165.83333 -77.87778,165.83333 -77.84153,165.83333 -77.80528,165.83333 -77.76903,165.83333 -77.73278,165.83333 -77.69653,165.83333 -77.66028,165.83333 -77.62403,165.83333 -77.58778,165.83333 -77.55153,165.83333 -77.51528))", "dataset_titles": "Thermoregulation in Free-Living Antarctic Seals: The Missing Link in Effective Ecological Modeling", "datasets": [{"dataset_uid": "600130", "doi": "10.15784/600130", "keywords": "Antarctica; Biota; Oceans; Ross Sea; Sea Ice; Seals; Sea Surface; Southern Ocean", "people": "Mellish, Jo-Ann", "repository": "USAP-DC", "science_program": null, "title": "Thermoregulation in Free-Living Antarctic Seals: The Missing Link in Effective Ecological Modeling", "url": "https://www.usap-dc.org/view/dataset/600130"}], "date_created": "Sun, 22 Sep 2013 00:00:00 GMT", "description": "Despite being an essential physiological component of homeotherm life in polar regions, little is known about the energetic requirements for thermoregulation in either air or water for high- latitude seals. In a joint field and modeling study, the principal investigators will quantify these costs for the Weddell seal under both ambient air and water conditions. The field research will include innovative heat flux, digestive and locomotor cost telemetry on 40 free-ranging seals combined with assessments of animal health (morphometrics, hematology and clinical chemistry panels), quantity (ultrasound) and quality (tissue biopsy) of blubber insulation, and determination of surface skin temperature patterns (infrared thermography). Field-collected data will be combined with an established individual based computational energetics model to define cost-added thresholds in body condition for different body masses. This study will fill a major knowledge gap by providing data essential to modeling all aspects of pinniped life history, in particular for ice seals. Such parameterization of energetic cost components will be essential for the accurate modeling of responses by pinnipeds to environmental variance, including direct and indirect effects driven by climate change. The study also will provide extensive opportunities in polar field work, animal telemetry, biochemical analyses and computational modeling for up to three undergraduate students and one post-doctoral researcher. Integrated education and outreach efforts will educate the public (K-12 through adult) on the importance of quantifying energetic costs of thermoregulation for marine mammals and the need to understand responses of species to environmental variance. This effort will include a custom-built, interactive hands-on mobile exhibit, and development of content for an Ocean Today kiosk.", "east": 166.73334, "geometry": "POINT(166.283335 -77.69653)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.51528, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Mellish, Jo-Ann", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.87778, "title": "Collaborative Research: THERMOREGULATION IN FREE-LIVING ANTARCTIC SEALS: THE MISSING LINK IN EFFECTIVE ECOLOGICAL MODELING", "uid": "p0000343", "west": 165.83333}, {"awards": "0838811 Sergienko, Olga", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -90,180 -87,180 -84,180 -81,180 -78,180 -75,180 -72,180 -69,180 -66,180 -63,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,180 -60,-180 -60))", "dataset_titles": "Interaction of Ice Stream Flow with Heterogeneous Beds", "datasets": [{"dataset_uid": "609583", "doi": "10.7265/N53R0QS6", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Ice Thickness; Ice Velocity", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Interaction of Ice Stream Flow with Heterogeneous Beds", "url": "https://www.usap-dc.org/view/dataset/609583"}], "date_created": "Tue, 27 Aug 2013 00:00:00 GMT", "description": "Sergienko/0838811 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to conduct a modeling study of the ice stream ? sub-glacial water system. A suite of numerical models of various dimensionality and complexity will be constructed in a sequential, hierarchical fashion to formulate and test hypotheses regarding how sub-glacial lakes form under ice streams, determine the effect of sub-glacial lakes on ice-stream flow and mass balance, and to determine feedback effects whereby the ice stream ? sub-glacial water system can elicit both stable and unstable responses to environmental perturbations. This research will address one of the only observationally verified fast-time-scale processes apparent within the Antarctic Ice Stream system. The intellectual merit of the project is that understanding the origins and consequences of near-grounding-line sub-glacial lakes is a priority in glaciological research designed to predict short-term variations in Antarctica?s near-term future mass balance. The broader impacts of the proposed work are that it will contribute to better understanding of a system that has important societal relevance through contribution to sea level rise. Participation of a graduate student in the project will provide the student?s training and education in application of the numerical modeling in geosciences.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Subglacial And Supraglacial Water Depth; Not provided; Basal Stress; Ice Stream; Direct Numerical Simulation", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Sergienko, Olga; Hulbe, Christina", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Model Investigation of Ice Stream/Subglacial Lake Systems", "uid": "p0000045", "west": 180.0}, {"awards": "0739779 Warren, Stephen; 1142963 Warren, Stephen", "bounds_geometry": "POLYGON((157 -76,158.1 -76,159.2 -76,160.3 -76,161.4 -76,162.5 -76,163.6 -76,164.7 -76,165.8 -76,166.9 -76,168 -76,168 -76.2,168 -76.4,168 -76.6,168 -76.8,168 -77,168 -77.2,168 -77.4,168 -77.6,168 -77.8,168 -78,166.9 -78,165.8 -78,164.7 -78,163.6 -78,162.5 -78,161.4 -78,160.3 -78,159.2 -78,158.1 -78,157 -78,157 -77.8,157 -77.6,157 -77.4,157 -77.2,157 -77,157 -76.8,157 -76.6,157 -76.4,157 -76.2,157 -76))", "dataset_titles": "Ice on the Oceans of Snowball Earth Project Data", "datasets": [{"dataset_uid": "000183", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Ice on the Oceans of Snowball Earth Project Data", "url": "https://digital.lib.washington.edu/researchworks/handle/1773/37320"}], "date_created": "Wed, 10 Jul 2013 00:00:00 GMT", "description": "The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling. The aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and \"blue ice\" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation.", "east": 168.0, "geometry": "POINT(162.5 -77)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Warren, Stephen; Light, Bonnie; Campbell, Adam; Carns, Regina; Dadic, Ruzica; Mullen, Peter; Brandt, Richard; Waddington, Edwin D.", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -78.0, "title": "Ocean Surfaces on Snowball Earth", "uid": "p0000402", "west": 157.0}, {"awards": "0838810 Hulbe, Christina", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 01 Jul 2013 00:00:00 GMT", "description": "Hulbe/0838810 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a modeling study of the processes in West Antarctic grounding zones, the transition from ice resting on bedrock to ice floating on the ocean surface with an eye toward understanding the interrelated causes of rapid change in grounding line configuration and outlet flow. A combination of satellite remote sensing and numerical modeling will be used to investigate both past and ongoing patterns of change. New high-resolution surface elevation maps made from a novel combination of satellite laser altimetry and remotely observed surface shape provide a unique view of grounding zones. These data will be used to diagnose events associated with the shutdown of Kamb Ice Stream, to investigate a recent discharge event on Institute Ice Stream and to investigate ongoing change at the outlet of Whillans Ice Stream, along with other modern processes around the West Antarctic. An existing numerical model of coupled ice sheet, ice stream, and ice shelf flow will be used and improved as part of the research project. The broader impacts of the project relate to the importance of understanding the role of polar ice sheets in global sea level rise. The work will contribute to the next round of deliberations for the Intergovernmental Panel on Climate Change (IPCC). Improved views, interpretations, and insights into the physical processes that govern variability in ice sheet outlet streams will help correct the shortcomings of the last IPCC report that didn?t include the role of ice sheets in sea level rise. The PIs have a strong record of public outreach, involvement in the professional community, and student training.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; Kamb Ice Stream; Grounding Line; FIELD INVESTIGATION; SATELLITES; Transition Zone; Ice Shelf Flow; Outlet Flow; Ice Sheet; Modeling; COMPUTERS; Antarctica", "locations": "Antarctica; Kamb Ice Stream", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina; Fahnestock, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Mass Transit: Controls on Grounding and Ungrounding at Marine Ice Sheet Outlets", "uid": "p0000371", "west": null}, {"awards": "0823101 Ducklow, Hugh", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG1301", "datasets": [{"dataset_uid": "002731", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG1301", "url": "https://www.rvdata.us/search/cruise/LMG1301"}, {"dataset_uid": "001425", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG1301"}], "date_created": "Mon, 24 Jun 2013 00:00:00 GMT", "description": "Since 1990, Palmer LTER (PAL) research has been guided by the hypothesis that variability in the polar marine ecosystem is mechanistically coupled to changes in the annual advance, retreat and spatial extent of sea ice. Since that time, the hypothesis has been modified to incorporate climate migration, i.e. the displacement of a cold, dry polar climate by a warm, moist climate regime in the northern component of the PAL region, producing fundamental changes in food web structure and elemental cycling. The observed northern changes are affecting all trophic levels and elemental cycling, and the primary mechanism of change involves match-mismatch dynamics. The proposed research builds on previous findings, with a new emphasis on process studies and modeling to elucidate the mechanistic links between teleconnections, climate change, physical oceanographic forcing and ecosystem dynamics. The proposed research will examine the hypothesis that regional warming and sea ice decline associated with historical and on-going climate migration in the northern part of the study area have altered key phenological relationships, leading to changes in species distributions, increasing trophic mismatches and changes in habitat, food availability, ecosystem dynamics and biogeochemical cycling. Through targeted process studies linked to numerical model simulations, the research also will test the hypothesis that deep cross-shelf canyons characterizing the core study region are focal areas for ecosystem processes that result in predictable, elevated food resources for top-predators. The effort includes the addition of 3 new PIs: a zooplankton ecologist with expertise in biogeochemical fluxes, a phytoplankton ecologist focusing on bio-optics and autonomous observations using gliders, and a numerical simulation modeler specializing in coupled global models of ocean circulation, plankton ecology and biogeochemical cycles. The program will add trace metal sampling and analysis, moored physical oceanographic sensors, a moored sediment trap in the south, drifting sediment traps and stable carbon (del 13C) and nitrogen (del 15N) isotope analyses. Missions lasting up to 45 days using gliders deployed before, during and after summer cruises will, along with moorings and satellite remote sensing of sea ice, ocean color, sea surface temperatures and wind fields, greatly extend the observational program in space and time. \u003cbr/\u003e\u003cbr/\u003eSince its inception, PAL has been a leader in Information Management to enable knowledge-building within and beyond the Antarctic, oceanographic and LTER communities. PAL has designed and deployed a new information infrastructure with a relational database architecture to facilitate data distribution and sharing. The Education and Outreach program capitalizes on the public\u0027s fascination with Antarctica to promote scientific literacy from kindergarten students to adult citizens concerned with climate change and environmental sustainability. Through communicating results to the public and working with scientific assessment bodies (e.g., IPCC) and Antarctic Treaty parties to protect Earth\u0027s last frontier, PAL researchers contribute to the national scientific agenda and the greater public benefit.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e PROFILERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ducklow, Hugh", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": "LTER", "south": null, "title": "Palmer, Antarctica Long Term Ecological Research Project", "uid": "p0000874", "west": null}, {"awards": "0636883 Bell, Robin", "bounds_geometry": "POLYGON((20 -75,23 -75,26 -75,29 -75,32 -75,35 -75,38 -75,41 -75,44 -75,47 -75,50 -75,50 -76.5,50 -78,50 -79.5,50 -81,50 -82.5,50 -84,50 -85.5,50 -87,50 -88.5,50 -90,47 -90,44 -90,41 -90,38 -90,35 -90,32 -90,29 -90,26 -90,23 -90,20 -90,20 -88.5,20 -87,20 -85.5,20 -84,20 -82.5,20 -81,20 -79.5,20 -78,20 -76.5,20 -75))", "dataset_titles": "Data portal at Lamont for airborne data", "datasets": [{"dataset_uid": "000111", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Data portal at Lamont for airborne data", "url": "http://wonder.ldeo.columbia.edu/wordpress/"}], "date_created": "Tue, 02 Apr 2013 00:00:00 GMT", "description": "Bell/0636883\u003cbr/\u003e\u003cbr/\u003eThis award support a project to study the role that subglacial water plays in the overall stability of major ice sheets. An estimated 22,000 km3 of water is currently stored within Antarctica\u0027s subglacial lakes. Movement of this water occurs through a complex and largely inferred drainage system in both East and West Antarctica. Geomorphic evidence for the catastrophic drainage of subglacial lakes documents repeated events. These major flood events appear to have drained the largest subglacial lakes situated in the relatively stable interior of the East Antarctic ice sheet. Emerging evidence suggests there is a close connection between significant subglacial lakes and the onset of the Recovery Ice Stream one of the largest in East Antarctica. Our preliminary analysis of the Recovery Lakes region, East Antarctica suggests a direct linkage between lakes and streaming ice flow, specifically the 800 km long Recovery Ice Stream and its tributaries. Located just upslope of the Recovery Ice Stream, the Recovery Lakes Region is composed of 3 well-defined lakes and a fourth, ambiguous, \u0027lake-like\u0027 feature. While other large lakes have a localized impact on ice surface slope, the Recovery Lakes Region lakes are coincident with an abrupt regional change in the ice sheet surface slope. Satellite imagery demonstrates that the downslope margin of this lake area contains distinct flow strips and crevasses: both indicative of increasing ice velocities. The discovery of a series of large lakes coincident with the onset of rapid ice flow in East Antarctica clearly links subglacial lakes and ice sheet dynamics for the first time. The evidence linking the onset of streaming in the Recovery Drainage Ice Stream to the series of large subglacial lakes raises the fundamental question: How can subglacial lakes trigger the onset of ice streaming? We advance two possible mechanisms: (i) Subglacial lakes can produce accelerated ice flow through the drainage of lake water beneath the ice sheet downslope of the lakes. (ii) Subglacial lakes can produce accelerated ice flow accelerated ice flow by modifying the basal thermal gradient via basal accretion over the lakes so when the ice sheet regrounds basal melting dominates. To evaluate the contribution of lake water and the changing basal thermal gradient, we propose an integrated program incorporating satellite imagery analysis, a series of reconnaissance aerogeophysical profiles over the Recovery Lake Region and the installation of continuous GPS sites over the Recovery Lakes. This analysis and new data will enable us (1) to produce a velocity field over the Recovery Lakes Region, (2) to map the ice thickness changes over the lakes due to acceleration triggered thinning, basal melting and freezing, (3) determine the depth and possible the tectonic origin of the Recovery Lakes and (4) determine the stability of these lakes over time. These basic data sets will enable us to advance our understanding of how subglacial lakes trigger the onset of streaming. The intellectual merit of this project is that it will be the first systematic analysis of ice streams triggering the onset of ice streams. This work has profound implications for the modeling of ice sheet behavior in the future, the geologic record of abrupt climate changes and the longevity of subglacial lakes. The broader impacts of the project are programs that will reach students of all ages through undergraduates involved in the research, formal presentations in teacher education programs and ongoing public outreach efforts at major science museums. Subglacial Antarctic lake environments are emerging as a premier, major frontier for exploration during the IPY 2007-2009.", "east": 50.0, "geometry": "POINT(35 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e AEM; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e LIDAR ALTIMETERS", "is_usap_dc": false, "keywords": "DHC-6; Basal Melting; Ice Stream; Ice Thickness; Velocity; Ice Stream Stability; Basal Freezing; Antarctica; Drainage; Aerogeophysical; Subglacial Lake; Flood Event", "locations": "Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": -90.0, "title": "Subglacial Lakes and the Onset of Ice Streaming: Recovery Lakes", "uid": "p0000702", "west": 20.0}, {"awards": "0739781 Blythe, Ann", "bounds_geometry": "POLYGON((155.77667 -79.793335,156.208836 -79.793335,156.641002 -79.793335,157.073168 -79.793335,157.505334 -79.793335,157.9375 -79.793335,158.369666 -79.793335,158.801832 -79.793335,159.233998 -79.793335,159.666164 -79.793335,160.09833 -79.793335,160.09833 -79.8578345,160.09833 -79.922334,160.09833 -79.9868335,160.09833 -80.051333,160.09833 -80.1158325,160.09833 -80.180332,160.09833 -80.2448315,160.09833 -80.309331,160.09833 -80.3738305,160.09833 -80.43833,159.666164 -80.43833,159.233998 -80.43833,158.801832 -80.43833,158.369666 -80.43833,157.9375 -80.43833,157.505334 -80.43833,157.073168 -80.43833,156.641002 -80.43833,156.208836 -80.43833,155.77667 -80.43833,155.77667 -80.3738305,155.77667 -80.309331,155.77667 -80.2448315,155.77667 -80.180332,155.77667 -80.1158325,155.77667 -80.051333,155.77667 -79.9868335,155.77667 -79.922334,155.77667 -79.8578345,155.77667 -79.793335))", "dataset_titles": "Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau", "datasets": [{"dataset_uid": "600082", "doi": "10.15784/600082", "keywords": "Antarctica; Fission Track Thermochronology; Geochemistry; Solid Earth; Transantarctic Mountains", "people": "Huerta, Audrey D.; Blythe, Ann Elizabeth", "repository": "USAP-DC", "science_program": null, "title": "Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/600082"}], "date_created": "Fri, 07 Dec 2012 00:00:00 GMT", "description": "This project studies formation of the TransAntarctic Mountains (TAM) through numerical modeling based on cooling histories of apatite mineral grains. The TAM are the highest and longest rift-related mountain range in the world. Various models for their uplift have been proposed, the most provocative of which is that they are not uplifted, but instead are the eroded remnant of a plateau. This project evaluates that hypothesis by collecting apatites from around Byrd Glacier for fission track thermochronology. Results will be combined with a kinematic and thermal model to determine the TAM?s structural evolution. The plateau model, if correct, implies that the Byrd Glacier originated not as a glacier-carved valley through the TAM, but as a river system flowing in the opposite direction. Given that the Byrd Glacier is a key drainage for the East Antarctic ice sheet, this result has important implications for ice sheet models and interpretation of both regional geology and sediment records.\u003cbr/\u003e\u003cbr/\u003eThe main broader impacts are undergraduate research and a new collaboration between a primarily undergraduate and a research institution. Students will be involved in the field program, sample analyses, and numerical modeling.", "east": 160.09833, "geometry": "POINT(157.9375 -80.1158325)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -79.793335, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Blythe, Ann Elizabeth; Huerta, Audrey D.", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.43833, "title": "Collaborative Research: Thermochronologic and modelling test for a Mesozoic West Antarctic Plateau", "uid": "p0000677", "west": 155.77667}, {"awards": "0632198 Anandakrishnan, Sridhar", "bounds_geometry": "POINT(110 -74)", "dataset_titles": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Blankenship, Donald D.; Dupont, Todd K.; Parizek, Byron R.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}], "date_created": "Wed, 29 Aug 2012 00:00:00 GMT", "description": "This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this \"pulse of activity\" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.", "east": -110.0, "geometry": "POINT(-110 -74)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": false, "keywords": "Pine Island Glacier; Bed Reflectivity; Tidal Forcing; FIELD INVESTIGATION; Not provided; Position; Thwaites; Thickness; Amundsen Sea; LABORATORY; FIELD SURVEYS; Subglacial; Ice Dynamic; Ice Sheet Modeling", "locations": "Thwaites; Pine Island Glacier; Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.", "uid": "p0000699", "west": -110.0}, {"awards": "0537752 Creyts, Timothy; 0538674 Winebrenner, Dale", "bounds_geometry": null, "dataset_titles": "Millennially Averaged Accumulation Rates for Lake Vostok; Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "datasets": [{"dataset_uid": "609500", "doi": "10.7265/N5F769HV", "keywords": "Accumulation Rate; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok", "people": "Matsuoka, Kenichi; Waddington, Edwin D.; Winebrenner, Dale; Studinger, Michael S.; Macgregor, Joseph A.", "repository": "USAP-DC", "science_program": null, "title": "Millennially Averaged Accumulation Rates for Lake Vostok", "url": "https://www.usap-dc.org/view/dataset/609500"}, {"dataset_uid": "609501", "doi": "10.7265/N59K485D", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Lake Vostok; Radar Attenuation Rate; Vostok Ice Core", "people": "Matsuoka, Kenichi; Macgregor, Joseph A.; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Modeled Radar Attenuation Rate Profile at the Vostok 5G Ice Core Site, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609501"}], "date_created": "Thu, 09 Aug 2012 00:00:00 GMT", "description": "0538674\u003cbr/\u003eMatsuoka\u003cbr/\u003eThis award supports a project to evaluate radio-echo intensities in the available SOAR ice-penetrating radar data along grids covering Lake Vostok, and along four regional tracks from Ridge B toward the lake. The project has two objectives; first, it will examine the upper surface of the lake and reflectors hypothesized to be a boundary between the meteoric and accreted ice. They will provide crucial knowledge on the dynamic evolution of the lake. Second, this project will examine a poorly understood echo-free zone within the deep ice in central East Antarctica. This zone may consist of distorted stagnant ice, while its upper boundary may be a shear zone. The SOAR radar data provide a unique resource to examine spatiotemporal water circulation patterns that should be understood in order to select the best direct-sampling strategy to the lake. The Vostok ice core provides a unique opportunity to do this work. First, the path effects, i.e. propagation loss and birefringence, will be derived at the ice-core site using ice temperature, chemistry, and fabric data. Second, lateral variations of the propagation loss will be estimated by tracking chemistry associated with radar-detected isochronous layers, and by inferring temperatures from an ice-flow model that can replicate those layers. Ice-fabric patterns will be inferred from anisotropy in the reflectivity at about 100 radar-track cross-over sites. In terms of broader impacts, a graduate student will be trained to interpret the radar data in the light of radar theory and glaciological context of Lake Vostok and summer workshops for K-12 teachers will be provided in Seattle and New York. This project will contribute to ongoing efforts to study Lake Vostok and will complement the site selection for a North Vostok ice core, which has been proposed by Russia and France as an IPY program.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Airborne Radar Sounding; DHC-6; Salinity; Lake Vostok; Antarctic Ice Sheet; Modeling; FIELD SURVEYS; Model Output; Accumulation Rate; MODELS; Numerical Model; Ice Sheet; Not provided; Hydrostatic; Aerogeophysical; Subglacial; Attenuation Rate; Radar; FIELD INVESTIGATION; Model; Circulation; LABORATORY", "locations": "Lake Vostok; Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Matsuoka, Kenichi; Winebrenner, Dale; Creyts, Timothy; Macgregor, Joseph A.; Studinger, Michael S.; Waddington, Edwin D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Deciphering the Deep Ice and the Ice-water Interface over Lake Vostok Using Existing Radar Data", "uid": "p0000090", "west": null}, {"awards": "0636584 Creyts, Timothy", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 07 Aug 2012 00:00:00 GMT", "description": "Studinger/0636584\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake\u0027s water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake\u0027s water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": false, "keywords": "Subglacial; Hydrostatic; Not provided; LABORATORY; Aerogeophysical; Numerical Model; FIELD SURVEYS; Salinity; Circulation", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Creyts, Timothy; Studinger, Michael S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Estimating the Salinity of Subglacial Lakes From Existing Aerogeophysical Data", "uid": "p0000704", "west": null}, {"awards": "0631973 Joughin, Ian; 0632031 Das, Sarah", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 20 Jun 2012 00:00:00 GMT", "description": "Joughin 0631973\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to gather data to better understand the mass balance of the West Antarctic Ice Sheet, in the Pine Island and Thwaites region, through the combination of radar altimetry and surface-based ice-core measurements of accumulation. The intellectual merit of the project is that the results of the field work will provide information on decadal-scale average accumulation extending back through the last century and will help constrain a modeling effort to determine how coastal changes propagate inland, to allow better prediction of future change. Comparison of the basin averaged accumulation with ice discharge determined using Interferometric Synthetic Aperture Radar (InSAR) velocity data will provide improved mass-balance estimates. Study of changes in flow speed will produce a record of mass balance over the last three decades. Analysis of the satellite altimeter record in conjunction with annual accumulation estimates also will provide estimates of changes and variability in mass balance. The broader impacts of the work are that it will make a significant contribution to future IPCC estimates of sea level, which are important for projection of the impacts of increased sea level on coastal communities. The research will contribute to the graduate education of students at the Universities of Washington and Kansas and will enrich K-12 education through the direct participation of the PIs in classroom activities. Informal science education includes 4-day glacier flow demonstrations at the Polar Science Weekend held annually at the Pacific Science Center in Seattle. The project also will communicate results through Center for the Remote Sensing of Ice Sheets (CReSIS) outreach effort. All field and remotely-sensed data sets will be archived and distributed by the National Snow and Ice Data Center. This project is relevant to IPY in that the West Antarctic Ice Sheet is losing mass, in large part because of rapid thinning of the Amundsen Coast glaciers so, it will directly address the NSF IPY emphasis on \"ice sheet history and dynamics.\" The project is also international in scope.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": false, "keywords": "Not provided; FIELD INVESTIGATION; Flow Speed; Antarctic; LABORATORY; Ice Sheet Accumulation Rate; Mass Balance; Accumulation; Insar; SATELLITES; FIELD SURVEYS; Ice Core; Radar Altimetry; Ice Velocity", "locations": "Antarctic", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Joughin, Ian; Medley, Brooke; Das, Sarah", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repositories": null, "science_programs": null, "south": null, "title": "IPY: Collaborative Proposal: Constraining the Mass-Balance Deficit of the Amundsen Coast\u0027s Glaciers", "uid": "p0000542", "west": null}, {"awards": "0758274 Parizek, Byron; 0636724 Blankenship, Donald", "bounds_geometry": "POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548))", "dataset_titles": "Access to data; AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica; Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; Subglacial water flow paths under Thwaites Glacier, West Antarctica; Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Roberts, Jason; Greenbaum, Jamin; Blankenship, Donald D.; Schroeder, Dustin; Siegert, Martin; van Ommen, Tas", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "609518", "doi": "10.7265/N5RJ4GC8", "keywords": "AGASEA; Airborne Radar; Antarctica; Elevation; Flow Paths; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Young, Duncan A.; Blankenship, Donald D.; Carter, Sasha P.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial water flow paths under Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609518"}, {"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Blankenship, Donald D.; Dupont, Todd K.; Parizek, Byron R.; Holt, John W.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}, {"dataset_uid": "000248", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access to data", "url": "http://nsidc.org/data/netcdf/tools.html"}, {"dataset_uid": "609334", "doi": "10.7265/N5HD7SK8", "keywords": "AGASEA; Airborne Altimetry; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Holt, John W.; Morse, David L.; Young, Duncan A.; Kempf, Scott D.", "repository": "USAP-DC", "science_program": null, "title": "Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609334"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "609517", "doi": "10.7265/N5W95730", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness", "people": "Kempf, Scott D.; Holt, John W.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609517"}, {"dataset_uid": "002536", "doi": "", "keywords": null, "people": null, "repository": "NASA", "science_program": null, "title": "Access to data", "url": "http://www.giss.nasa.gov/tools/panoply/"}], "date_created": "Tue, 15 May 2012 00:00:00 GMT", "description": "This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program\u0027s emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: \"investigation of the physics of fast glacier flow with emphasis on processes at glacier beds\"; \"investigation of ice-shelf stability\"; and \"identification and quantification of the feedback between ice dynamics and climate change\". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.", "east": -105.2773, "geometry": "POINT(-107.66765 -75.34995)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e INS", "is_usap_dc": true, "keywords": "Ice Sheet Thickness; Ice Sheet Elevation; Glacier Dynamics; Ice Stream; Numerical Model; West Antarctic; Surface Elevation; Basal Rheology; Ice Surface Velocity; Embayment Geometry; Amundsen Sea; Hydrology; FIELD SURVEYS; Antarctic Ice Sheet; Glacier; Subglacial; DHC-6; West Antarctic Ice Sheet; Model Output; Surface Climate; Glaciers; Basal Topography; Grounding Zone; Model Input Data; Airborne Laser Altimeters; FIELD INVESTIGATION; Thwaites Glacier; Airborne Laser Altimetry; Diagnostic; Ice-Shelf Buttressing; Ice Sheet; Prognostic; Glacier Surface; Airborne Radar Sounding; Digital Elevation Model; Ice Dynamic; Antarctica; Altimetry; Antarctica (agasea); Bed Elevation; Basal Stress; LABORATORY", "locations": "Antarctica; Thwaites Glacier; West Antarctic Ice Sheet; Antarctic Ice Sheet; West Antarctic; Amundsen Sea", "north": -74.0548, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "NASA; NSIDC; USAP-DC", "science_programs": null, "south": -76.6451, "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "uid": "p0000174", "west": -110.058}, {"awards": "0814241 Dupont, Todd", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 21 Mar 2012 00:00:00 GMT", "description": "This award supports a three-year modeling effort to understand the dynamics surrounding ice-air surface slope reversals on ice streams and ice shelves, with implications for the creation and stability of subglacial lakes. Local reversal of the ice-air surface slope may lead, through a reversal of the hydraulic gradient, to the trapping of basal and surface water, producing subglacial and supraglacial lakes, respectively. In the case of subglacial lakes, once such a sizable reservoir of pressurized water is created the potential exists for drainage, in the form of large outburst floods or as smaller, but sustained, periods of increased subglacial water flow. The research seeks to extend some initial work that has been done to include time-dependence and a wider array of parameters and geometries. The methods will involve the use of a suite of models, all of which will include longitudinal deviatoric and basal-shear stresses, with some also taking account of lateral drag and internal vertical shear. The intellectual merit of the proposed activity includes an improved understanding of the processes and parameters involved in the formation of surface-slope reversals in ice-stream/ice-shelf systems, as well as insight into the stability of subglacial lakes formed as a consequence of slope reversals. The broader impacts resulting from this activity include the provision of tools to study the dynamics of ice-stream/ice-shelf systems, an improved understanding of the physics behind outburst floods, and insights into the coupling of ice streams with their subglacial water systems. The research will support the studies of a beginning postdoctoral researcher. Results of the research will be incorporated into courses and public outreach serving anywhere from hundreds to thousands of people per year.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Dupont, Todd K.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Modeling the Dynamics of Surface-slope Reversals and their Role in the Formation and Stability of Subglacial Lakes", "uid": "p0000665", "west": null}, {"awards": "0940650 Pettit, Erin; 0636996 Waddington, Edwin", "bounds_geometry": "POLYGON((-165 -75,-159 -75,-153 -75,-147 -75,-141 -75,-135 -75,-129 -75,-123 -75,-117 -75,-111 -75,-105 -75,-105 -76,-105 -77,-105 -78,-105 -79,-105 -80,-105 -81,-105 -82,-105 -83,-105 -84,-105 -85,-111 -85,-117 -85,-123 -85,-129 -85,-135 -85,-141 -85,-147 -85,-153 -85,-159 -85,-165 -85,-165 -84,-165 -83,-165 -82,-165 -81,-165 -80,-165 -79,-165 -78,-165 -77,-165 -76,-165 -75))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 16 Mar 2012 00:00:00 GMT", "description": "Pettit/0636795\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to constrain the accumulation rate, thickness, and temperature history for Siple Dome using a vertical velocity profile that includes the effects of an evolving fabric on deformation through time, to invert the depth-profile of fabric determined from sonic velocity measurements and grain size observed in thin sections in Siple Dome for the surface temperature and accumulation rate changes in the past, focusing on the apparent abrupt climate change events at 22ka and 15ka. The intellectual merit of the work is that it will extract past climate information from a number of physical properties of the deep ice using a coupled fabric evolution and ice-sheet flow model. The focus will be on the deep ice-age ice at Siple Dome, where the ice-core record shows puzzling signals and where modeling results imply intriguing deformation patterns. The method will also be applied to the records from Byrd Station and Taylor Dome to ultimately form a basis for future analysis of the West Antarctic Divide core. The broader impacts of the project are that it will ultimately contribute to our understanding of the effects of anisotropy on ice flow dynamics in West Antarctica. It will contribute to our understanding of the connection between ice flow and the paleoclimate record in ice cores, particularly with respect to the relationship between the chemical record and ice deformation. And it will contribute a new ice-flow model that includes the effects of anisotropy and fabric evolution. The project will also contribute to advancing the career of a new, young, female investigator and will support a couple of graduate students. Finally, the work will encouraging diversity in the physical sciences by directly helping to support the Girls on Ice a program that encourages young women to explore science and the natural world.", "east": -105.0, "geometry": "POINT(-135 -80)", "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; FIELD SURVEYS; FIELD INVESTIGATION; Vertical Velocity; COMPUTERS; Ice Core; Firn; Accumulation Rate; Siple Dome; Ice Thickness; Abrupt Climate Change; Ice Temperature; Metamorphism; Anisotropy; Antarctica", "locations": "Siple Dome; Antarctica", "north": -75.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -85.0, "title": "Collaborative Research: Anisotropy, Abrupt Climate Change, and the Deep Ice in West Antarctica", "uid": "p0000741", "west": -165.0}, {"awards": "0838866 Buesseler, Ken", "bounds_geometry": "POLYGON((-75 -62,-74 -62,-73 -62,-72 -62,-71 -62,-70 -62,-69 -62,-68 -62,-67 -62,-66 -62,-65 -62,-65 -62.8,-65 -63.6,-65 -64.4,-65 -65.2,-65 -66,-65 -66.8,-65 -67.6,-65 -68.4,-65 -69.2,-65 -70,-66 -70,-67 -70,-68 -70,-69 -70,-70 -70,-71 -70,-72 -70,-73 -70,-74 -70,-75 -70,-75 -69.2,-75 -68.4,-75 -67.6,-75 -66.8,-75 -66,-75 -65.2,-75 -64.4,-75 -63.6,-75 -62.8,-75 -62))", "dataset_titles": "data deposited with Palmer Long-Term Ecological Research (LTER) repository.", "datasets": [{"dataset_uid": "000215", "doi": "", "keywords": null, "people": null, "repository": "LTER", "science_program": null, "title": "data deposited with Palmer Long-Term Ecological Research (LTER) repository.", "url": "http://pal.lternet.edu/data/"}], "date_created": "Wed, 31 Aug 2011 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eBy using a tool-box of particle flux and characterization techniques appropriate to the study of particulate organic carbon fluxes out of the upper sunlit zone, WHOI researchers will attempt to evaluate the so called \u0027biological pump\u0027 term at the Palmer Long Term Ecological Research (PAL) site in the Western Antarctic Peninsula (WAP). The goal of these measurements is to describe the seasonal dynamics of production, export (sinking) and at-depth remineralization rates of organic matter produced in the Antarctic photic zone. This should lead to a better understanding of the biogeochemical controls on the carbon cycle in this difficult to access region. Additionally, how much of the newly fixed organic carbon is exported off the shelf, effectively driving an influx of atmospheric (including anthropogenic) CO2 to be sequestered into the deep ocean is not presently known. Comparison of prior time series sediment traps in the WAP seem to indicate smaller sinking C fluxes than other, as equally as productive Antarctic coastal regions, e.g. the Ross Sea. New observations and modeling activities will attempt to explain this discrepancy, and to account for the apparently inefficient particle export. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\"", "east": -65.0, "geometry": "POINT(-70 -66)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -62.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Buesseler, Ken; Valdes, James", "platforms": "Not provided", "repo": "LTER", "repositories": "LTER", "science_programs": "LTER", "south": -70.0, "title": "WAPflux - New Tools to Study the Fate of Phytoplankton Production in the West Antarctic Peninsula", "uid": "p0000686", "west": -75.0}, {"awards": "0440847 Raymond, Charles", "bounds_geometry": null, "dataset_titles": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica; Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "datasets": [{"dataset_uid": "609503", "doi": "10.7265/N5222RQ8", "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ross-Amundsen Divide; Strain", "people": "Matsuoka, Kenichi; Power, Donovan; Rasmussen, Al", "repository": "USAP-DC", "science_program": null, "title": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609503"}, {"dataset_uid": "609496", "doi": "10.7265/N5TH8JNG", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Ross-Amundsen Divide", "people": "Power, Donovan; Fujita, Shuji; Raymond, Charles; Matsuoka, Kenichi", "repository": "USAP-DC", "science_program": null, "title": "Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609496"}], "date_created": "Mon, 29 Aug 2011 00:00:00 GMT", "description": "This award supports a project to investigate fabrics with ground-based radar measurements near the Ross/Amundsen Sea ice-flow divide where a deep ice core will be drilled. The alignment of crystals in ice (crystal-orientation fabric) has an important effect on ice deformation. As ice deforms, anisotropic fabrics are produced, which, in turn, influence further deformation. Measurement of ice fabric variations can help reveal the deformation history of the ice and indicate how the ice will deform in the future. Ice cores provide opportunities to determine a vertical fabric profile, but horizontal variations of fabrics remain unknown. Remote sensing with ice-penetrating radar is the only way to do that over large areas. Preliminary results show that well-established polarimetric methods can detect the degree of horizontal anisotropy of fabrics and their orientation, even when they are nearly vertical-symmetric fabrics. In conjunction with ice deformation history, our first mapping of ice fabrics will contribute to modeling ice flow near the future ice core site. The project will train a graduate student and provide research experiences for two under graduate students both in field and laboratory. The project will contribute to ongoing West Antarctic ice sheet program efforts to better understand the impact of the ice sheet on global sea level rise. This project also supports an international collaboration between US and Japanese scientists.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "GPS; FIELD SURVEYS; Antarctic; Radar; Antarctica; FIELD INVESTIGATION; Ice Sheet; Not provided; Ross-Amundsen Divide; West Antarctica; West Antarctic Ice Sheet", "locations": "Antarctica; Ross-Amundsen Divide; West Antarctica; Antarctic; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji; Raymond, Charles; Rasmussen, Al", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods", "uid": "p0000024", "west": null}, {"awards": "0636719 Joughin, Ian; 0636970 Tulaczyk, Slawek", "bounds_geometry": null, "dataset_titles": "Antarctic Active Subglacial Lake Inventory from ICESat Altimetry", "datasets": [{"dataset_uid": "601439", "doi": "10.15784/601439", "keywords": "Altimetry; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Icesat; Laser Altimetry; Subglacial Lake", "people": "Fricker, Helen; Smith, Ben; Joughin, Ian; Tulaczyk, Slawek", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Active Subglacial Lake Inventory from ICESat Altimetry", "url": "https://www.usap-dc.org/view/dataset/601439"}], "date_created": "Wed, 27 Jul 2011 00:00:00 GMT", "description": "Tulaczyk/0636970\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study elevation change anomalies (henceforth ECAs), which are oval-shaped, 5-to-10 km areas observed in remote sensing images in several locations within the Ross Sea sector of the West Antarctic Ice Sheet (WAIS). Within these anomalies, surface elevation changes at rates of up to ~1 to ~2 cm per day, significantly faster than in surrounding regions. These anomalies are thought to result from filling and draining of multi-kilometer-scale subglacial water pockets. The intellectual merit of this project is that these ECA\u0027s represent an unprecedented window into the elusive world of water drainage dynamics beneath the modern Antarctic ice sheet. Although subglacial water fluxes are small compared to normal terrestrial conditions, they play an important role in controlling fast ice streaming and, potentially, stability of the ice sheet. The dearth of observational constraints on sub-ice sheet water dynamics represents one of the most important limitations on progress in quantitative modeling of ice streams and ice sheets. Such models are necessary to assess future ice sheet mass balance and to reconstruct the response of ice sheets to past climate changes. The dynamic sub-ice sheet water transport indicated by the ECAs may have also implications for studies of subglacial lakes and other subglacial environments, which may harbor life adapted to such extreme conditions. The broader impacts of this project are that it will provide advanced training opportunities to one postdoctoral fellow (UW), two female doctoral students (UCSC), who will enhance diversity in polar sciences, and at least three undergraduate students (UCSC). Project output will be relevant to broad scientific and societal interests, such as the future global sea level changes and the response of Polar Regions to climate changes. Douglas Fox, a freelance science journalist, is interested in joining the first field season to write feature articles to popular science magazines and promote the exposure of this project, and Antarctic Science in general, to mass media.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e GLAS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e GLAS", "is_usap_dc": false, "keywords": "ICESAT; Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Smith, Ben; Joughin, Ian; Tulaczyk, Slawek; SMITH, BENJAMIN", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e ICE, CLOUD AND LAND ELEVATION SATELLITE (ICESAT) \u003e ICESAT", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Elevation Change Anomalies in West Antarctica and Dynamics of Subglacial Water Transport Beneath Ice Streams and their Tributaries", "uid": "p0000115", "west": null}, {"awards": "0636929 Bales, Roger", "bounds_geometry": null, "dataset_titles": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "datasets": [{"dataset_uid": "609585", "doi": "10.7265/N5GX48HW", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Bales, Roger", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Measurements of Air and Snow Photochemical Species at WAIS Divide, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609585"}], "date_created": "Thu, 14 Jul 2011 00:00:00 GMT", "description": "This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced\u0027s outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e CHEMILUMINESCENCE", "is_usap_dc": true, "keywords": "Snow; Atmospheric Chemistry; Not provided; LABORATORY; Antarctica; FIELD SURVEYS; Snow Physical Properties; Meteorology; Wais Divide-project; Firn; Atmosphere Exchange; WAIS Divide; FIELD INVESTIGATION", "locations": "Antarctica; WAIS Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bales, Roger", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Atmospheric, Snow and Firn Chemistry Studies for Interpretation of WAIS-Divide Cores", "uid": "p0000041", "west": null}, {"awards": "0424589 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-137 -74,-132.1 -74,-127.2 -74,-122.3 -74,-117.4 -74,-112.5 -74,-107.6 -74,-102.7 -74,-97.8 -74,-92.9 -74,-88 -74,-88 -74.65,-88 -75.3,-88 -75.95,-88 -76.6,-88 -77.25,-88 -77.9,-88 -78.55,-88 -79.2,-88 -79.85,-88 -80.5,-92.9 -80.5,-97.8 -80.5,-102.7 -80.5,-107.6 -80.5,-112.5 -80.5,-117.4 -80.5,-122.3 -80.5,-127.2 -80.5,-132.1 -80.5,-137 -80.5,-137 -79.85,-137 -79.2,-137 -78.55,-137 -77.9,-137 -77.25,-137 -76.6,-137 -75.95,-137 -75.3,-137 -74.65,-137 -74))", "dataset_titles": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams; Archive of data; Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; Ku-band Radar Echograms; Radar Depth Sounder Echograms and Ice Thickness; Snow Radar Echograms", "datasets": [{"dataset_uid": "601048", "doi": "10.15784/601048", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ku-Band; Navigation; Radar", "people": "Leuschen, Carl; Rodriguez, Fernando; Li, Jilu; Allen, Chris; Gogineni, Prasad; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Ku-band Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601048"}, {"dataset_uid": "002497", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Archive of data", "url": "https://www.cresis.ku.edu/data/accumulation"}, {"dataset_uid": "601049", "doi": "10.15784/601049", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Snow", "people": "Paden, John; Leuschen, Carl; Rodriguez, Fernando; Li, Jilu; Allen, Chris; Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Snow Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601049"}, {"dataset_uid": "600384", "doi": "10.15784/600384", "keywords": "Airborne Radar; Antarctica; Basler; Glaciers/ice Sheet; Glaciers/Ice Sheet; Kamb Ice Stream; Radar; Siple Coast; Whillans Ice Stream", "people": "Paden, John; Hale, Richard", "repository": "USAP-DC", "science_program": null, "title": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600384"}, {"dataset_uid": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Tozer, Carly; Ritz, Catherine; Blankenship, Donald D.; Schroeder, Dustin; Mulvaney, Robert; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Ng, Gregory; Greenbaum, Jamin; Cavitte, Marie G. P; Young, Duncan A.", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601047", "doi": "10.15784/601047", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MCoRDS; Navigation; Radar", "people": "Rodriguez, Fernando; Leuschen, Carl; Li, Jilu; Allen, Chris; Gogineni, Prasad; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Radar Depth Sounder Echograms and Ice Thickness", "url": "https://www.usap-dc.org/view/dataset/601047"}], "date_created": "Wed, 01 Jun 2011 00:00:00 GMT", "description": "This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbr\u00e6. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.\u003cbr/\u003e\u003cbr/\u003eThe intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. \u003cbr/\u003e\u003cbr/\u003eAs lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.", "east": -88.0, "geometry": "POINT(-112.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Remote Sensing; Not provided; Pine Island; Ice Sheet; DHC-6; Antarctic; Thwaites Region; Antarctica; Mass Balance; Accumulation; Velocity; Insar", "locations": "Antarctica; Antarctic; Pine Island; Thwaites Region", "north": -74.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Glaciology", "paleo_time": null, "persons": "Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": null, "south": -80.5, "title": "Center for Remote Sensing of Ice Sheets (CReSIS)", "uid": "p0000102", "west": -137.0}, {"awards": "0529087 Ross, Robin; 0529666 Fritsen, Christian; 0528728 Vernet, Maria", "bounds_geometry": "POLYGON((-69.08 -64.8,-68.632 -64.8,-68.184 -64.8,-67.736 -64.8,-67.288 -64.8,-66.84 -64.8,-66.392 -64.8,-65.944 -64.8,-65.496 -64.8,-65.048 -64.8,-64.6 -64.8,-64.6 -65.121,-64.6 -65.442,-64.6 -65.763,-64.6 -66.084,-64.6 -66.405,-64.6 -66.726,-64.6 -67.047,-64.6 -67.368,-64.6 -67.689,-64.6 -68.01,-65.048 -68.01,-65.496 -68.01,-65.944 -68.01,-66.392 -68.01,-66.84 -68.01,-67.288 -68.01,-67.736 -68.01,-68.184 -68.01,-68.632 -68.01,-69.08 -68.01,-69.08 -67.689,-69.08 -67.368,-69.08 -67.047,-69.08 -66.726,-69.08 -66.405,-69.08 -66.084,-69.08 -65.763,-69.08 -65.442,-69.08 -65.121,-69.08 -64.8))", "dataset_titles": "Expedition data of NBP0103; The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "datasets": [{"dataset_uid": "600050", "doi": "10.15784/600050", "keywords": "Bellingshausen Sea; Cryosphere; Oceans; Photosynthetically Active Radiation (par); Sea Ice; Sea Surface; Southern Ocean; Total Integrated Exposure To PAR", "people": "Fritsen, Christian", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600050"}, {"dataset_uid": "600048", "doi": "10.15784/600048", "keywords": "Bellingshausen Sea; Biota; Oceans; Phytoplankton; Southern Ocean", "people": "Vernet, Maria", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600048"}, {"dataset_uid": "002595", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0103", "url": "https://www.rvdata.us/search/cruise/NBP0103"}, {"dataset_uid": "600049", "doi": "10.15784/600049", "keywords": "Bellingshausen Sea; Biota; Oceans; Southern Ocean", "people": "Ross, Robin Macurda; Quetin, Langdon B.", "repository": "USAP-DC", "science_program": null, "title": "The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "url": "https://www.usap-dc.org/view/dataset/600049"}], "date_created": "Sat, 02 Apr 2011 00:00:00 GMT", "description": "This collaborative study between the Desert Research Institute, the University of California, Santa Barbara (0529087; Robin Ross), and the University of California, San Diego (0528728; Maria Vernet) will examine the relationship between sea ice extent along the Antarctic Peninsula and the life history of krill (Euphausia superba), by developing, refining, and linking diagnostic datasets and models of phytoplankton decreases in the fall, phytoplankton biomass incorporation into sea ice, sea ice growth dynamics, sea ice algal production and biomass accumulation, and larval krill energetics, condition, and survival. Krill is a key species in the food web of the Southern Ocean ecosystem, and one that is intricately involved with seasonal sea ice dynamics. Results from the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec) field work as well as historical information on sea ice dynamics and krill recruitment suggest a shift in the paradigm that all pack ice is equally good krill habitat.\u003cbr/\u003e\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the lower trophic levels, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels.", "east": -64.6, "geometry": "POINT(-66.84 -66.405)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -64.8, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences; Antarctic Organisms and Ecosystems; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Fritsen, Christian; Vernet, Maria; Ross, Robin Macurda; Quetin, Langdon B.", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.01, "title": "Collaborative Research: U.S. SO GLOBEC Synthesis and Modeling: Timing is Everything: The Dynamic Coupling among Phytoplankton, Ice, Ice Algae and Krill (PIIAK)", "uid": "p0000522", "west": -69.08}, {"awards": "0839069 Yager, Patricia", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP1005", "datasets": [{"dataset_uid": "002654", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1005", "url": "https://www.rvdata.us/search/cruise/NBP1005"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThe Amundsen Sea Polynya is areally the most productive Antarctic polynya, exhibits higher chlorophyll levels during peak bloom and greater interannual variability than the better-studied Ross Sea Polynya ecosystem. Polynyas may be the key to understanding the future of polar regions as their extent is expected to increase with anthropogenic warming. The project will examine 1) sources of iron to the Amundsen Sea Polynya as a function of climate forcing, 2) phytoplankton community structure in relation to iron supply and mixed-layer depths, 3) the efficiency of the biological pump of carbon to depth and 4) the net flux of carbon as a function of climate and micronutrient forcing. The research also will compare results for the Amundsen Sea to existing data synthesis and modeling efforts for the Palmer LTER and Ross Sea. The project will 1) build close scientific collaborations between US and Swedish researchers; 2) investigate climate change implications with broad societal relevance; 3) train new researchers; 4) encourage participation in research science by underrepresented groups, and 5) involve broad dissemination of results via scientific literature and public outreach, including close interactions with NSF-supported PolarTrec and COSEE K-12 teachers.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Yager, Patricia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative research aboard Icebreaker Oden: ASPIRE (Amundsen Sea Polynya International Research Expedition)", "uid": "p0000844", "west": null}, {"awards": "0337567 Jacobel, Robert", "bounds_geometry": "POLYGON((130 -78,133 -78,136 -78,139 -78,142 -78,145 -78,148 -78,151 -78,154 -78,157 -78,160 -78,160 -79.2,160 -80.4,160 -81.6,160 -82.8,160 -84,160 -85.2,160 -86.4,160 -87.6,160 -88.8,160 -90,157 -90,154 -90,151 -90,148 -90,145 -90,142 -90,139 -90,136 -90,133 -90,130 -90,130 -88.8,130 -87.6,130 -86.4,130 -85.2,130 -84,130 -82.8,130 -81.6,130 -80.4,130 -79.2,130 -78))", "dataset_titles": "Glaciological Investigations of the Bulge and Trunk of Kamb Ice Stream, West Antarctica; Radar Studies of Internal Stratigraphy and Bed Topography along the US ITASE-II Traverse", "datasets": [{"dataset_uid": "609380", "doi": "10.7265/N5ZC80SH", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Kamb Ice Stream", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": null, "title": "Glaciological Investigations of the Bulge and Trunk of Kamb Ice Stream, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609380"}, {"dataset_uid": "609475", "doi": "10.7265/N5G73BMS", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness; ITASE; South Pole; Taylor Dome", "people": "Jacobel, Robert", "repository": "USAP-DC", "science_program": "ITASE", "title": "Radar Studies of Internal Stratigraphy and Bed Topography along the US ITASE-II Traverse", "url": "https://www.usap-dc.org/view/dataset/609475"}], "date_created": "Wed, 20 Oct 2010 00:00:00 GMT", "description": "This award supports a project to test whether Kamb Ice Stream (formerly Ice Stream C (ISC)), an ice stream\u003cbr/\u003ethat is thought to have stopped ~150 years ago, may be already in the process of restarting. If yes, it will help establish what is the rate of ice stream reactivation and what mechanisms are controlling this rate. If there is no evidence for ongoing ice stream reactivation, the physical controls that are preventing it will be examined and alternative scenarios for near-future evolution of this ice stream will be explored. One such scenario is an increase in ice diversion toward the neighboring Whillans Ice Stream. Such diversion may help prevent a complete stoppage of Whillans Ice Stream,which has been slowing down for at least the last 24 years. This project will consist of two components: (1) field observations of bed properties,geometry of internal radar reflectors, as well as surface strain rates and velocity/topography changes using Ice-Penetrating Radar and differential Global Positioning System, (2) numerical modeling study of near future(~100-1000 years) evolution of Kamb Ice Stream. The field component will be focused on the bulge-to-trunk transition, which is located at the present time just downstream of the so-called camp UpC. Reactivation of Kamb Ice Stream should be reflected in a downstream migration of the bulge-trunk transition at possibly high rates (bulge migration rates of ~km/yr occur on surging mountain glaciers). The modeling\u003cbr/\u003ecomponent will be used to generate predictions regarding the near-future behavior of Kamb Ice Stream. This project will provide training opportunities for at least two undergraduate students (per year) at St. Olaf College and for one\u003cbr/\u003eundergraduate student (per year) at UCSC. This collaboration will bring together scientists from three different types of US institutions: (1) a liberal arts college (St.Olaf College), (2) a public research university (UCSC) and (3) a NASA research laboratory (JPL). The project will also help build a new glaciological research program at UCSC. Project results will be incorporated into undergraduate and graduate courses at UCSC and will be made available\u003cbr/\u003eto the general public and educators through downloadable graphics and animations posted on the research website of the UCSC PI. Field data resulting from the project will be posted in the Antarctic Glaciological Data Center for use by other investigators.", "east": 160.0, "geometry": "POINT(145 -84)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "Ice; Antarctic Glaciations; Radar; Antarctic Ice Sheet; Radar Echo Sounder; Ice Sheet Thickness; Ice Stream; Ice Sheet Elevation; Not provided; Radar Echo Sounding; Ice Stratigraphy; Antarctica; West Antarctic Ice Sheet; Continental Ice Sheet; Ice Cap; Antarctic; US ITASE; FIELD SURVEYS; Ice Thickness; FIELD INVESTIGATION", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; West Antarctic Ice Sheet", "north": -78.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobel, Robert", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ITASE", "south": -90.0, "title": "Collaborative Research: Is Ice Stream C Restarting? Glaciological Investigations of the \u0027Bulge\u0027 and the Trunk of Ice Stream C, West Antartica", "uid": "p0000192", "west": 130.0}, {"awards": "0636974 Verosub, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 01 Oct 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eThis project performs a paleomagnetic survey of sediment cores from Antarctica\u0027s continental margin. Its goal is to refine the magnetostratigraphy to improve regional stratigraphic correlations, help date cores that lack biostratigraphic indicators, and understand paleoenvironmental conditions and climate change. As well, these cores record the earth\u0027s magnetic field near the magnetic pole, which may offer important information to scientists modeling the geodynamo.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this work include postdoctoral and undergraduate education. There are also implications for society\u0027s understanding of global climate change, since these techniques offer a different perspective on climate change from Antarctic marine sediment cores, which are critical to understanding the behavior of the ice sheets and their links to the global climate.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Verosub, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "New Paleomagnetic and Environmental Magnetic Studies of Old Cores from the Ross Sea Sector, Antarctica", "uid": "p0000367", "west": null}, {"awards": "0632346 Tulaczyk, Slawek; 0632161 Johnson, Jesse; 0632168 Hulbe, Christina; 0632325 Seals, Cheryl", "bounds_geometry": "POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05))", "dataset_titles": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields; Wiki containing the data and provenance.", "datasets": [{"dataset_uid": "609396", "doi": "10.7265/N5K64G1S", "keywords": "Antarctica; Community Ice Sheet Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Daescu, Dacian N.; Hulbe, Christina", "repository": "USAP-DC", "science_program": null, "title": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields", "url": "https://www.usap-dc.org/view/dataset/609396"}, {"dataset_uid": "001499", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Wiki containing the data and provenance.", "url": "http://websrv.cs.umt.edu/isis/index.php/Present_Day_Antarctica"}], "date_created": "Fri, 02 Jul 2010 00:00:00 GMT", "description": "Johnson/0632161\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a \"Community Ice Sheet Model (CISM)\". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating \"a new generation\" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; International Polar Year; Derived Basal Temperature Evolution; Ice Sheet; Community Ice Sheet Model; Ice Sheet Model; LABORATORY; Amundsen Sea; Eismint; Modeling; Basal Temperature; Numerical Model; Antarctic Ice Sheet; Environmental Modeling; IPY; Antarctica; Model; Not provided; Ice Dynamic", "locations": "Antarctic Ice Sheet; Antarctica; Amundsen Sea", "north": -50.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N.", "platforms": "Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region", "uid": "p0000756", "west": -180.0}, {"awards": "9983751 Veit, Richard", "bounds_geometry": "POLYGON((-70.9063 -52.3528,-67.3465 -52.3528,-63.7867 -52.3528,-60.2269 -52.3528,-56.6671 -52.3528,-53.1073 -52.3528,-49.5475 -52.3528,-45.9877 -52.3528,-42.4279 -52.3528,-38.8681 -52.3528,-35.3083 -52.3528,-35.3083 -52.65918,-35.3083 -52.96556,-35.3083 -53.27194,-35.3083 -53.57832,-35.3083 -53.8847,-35.3083 -54.19108,-35.3083 -54.49746,-35.3083 -54.80384,-35.3083 -55.11022,-35.3083 -55.4166,-38.8681 -55.4166,-42.4279 -55.4166,-45.9877 -55.4166,-49.5475 -55.4166,-53.1073 -55.4166,-56.6671 -55.4166,-60.2269 -55.4166,-63.7867 -55.4166,-67.3465 -55.4166,-70.9063 -55.4166,-70.9063 -55.11022,-70.9063 -54.80384,-70.9063 -54.49746,-70.9063 -54.19108,-70.9063 -53.8847,-70.9063 -53.57832,-70.9063 -53.27194,-70.9063 -52.96556,-70.9063 -52.65918,-70.9063 -52.3528))", "dataset_titles": "Expedition Data; Expedition data of LMG0109", "datasets": [{"dataset_uid": "002699", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0109", "url": "https://www.rvdata.us/search/cruise/LMG0109"}, {"dataset_uid": "002286", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9303"}, {"dataset_uid": "001683", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0309"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The goal of this proposal to bring two groups of undergraduate students to the Antarctic, where they will participate in the collection of data on seabird abundance and behavior. This proposal combines research on the dynamics of seabirds that feed on Antarctic krill, with the teaching of mathematical modeling of foraging behavior and spatial statistics. Students will learn a broad collection of skills through collection of data on physical and biological oceanography as part of the research project that focuses on seabirds. The research goal of this proposal is to learn how foraging seabirds in the Antarctic respond to changes in the abundance and distribution of their prey, primarily Antarctic krill. The approach will be to study bird behavior in the vicinity of krill swarms, and to contrast this behavior to that in areas lacking krill. From these comparisons, foraging models that will make predictions about the dispersion of birds under differing levels of krill abundance will be built. The long-term goal is to be able to make predictions about the impact upon seabirds of future changes in krill stocks. Field work will be conducted in the vicinity of Elephant Island in two field seasons. In each season, the insular shelf north of Elephant Island will be surveyed and the abundance, distribution and behavior of seabirds will be recorded. The primary objective will be to quantify the linkage between prey abundance and bird behavior, with the long-term goal of using information on bird behavior to index long-term changes in the prey base. The teaching goal of this proposal is twofold. First, the project will expose inner city college students to a spectacular and economically important ecosystem. Through their work on an oceanographic research vessel, students will be exposed to a broad diversity of research topics and methods, ranging from behavioral ecology to physical oceanography. Second, back at Staten Island, students will participate in the development of a mathematical biology initiative at the College of Staten Island. Here students will be encouraged to apply basic mathematical reasoning and computer modeling to a real problem - that of determining how foraging choices made by seabirds can ultimately impact their reproductive success.", "east": -35.3083, "geometry": "POINT(-53.1073 -53.8847)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V NBP; R/V LMG", "locations": null, "north": -52.3528, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Veit, Richard; Blake, Daniel", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -55.4166, "title": "CAREER: Dynamics of Predator-Prey Behavior in the Antarctic Ocean", "uid": "p0000589", "west": -70.9063}, {"awards": "0338290 Kremer, Patricia; 0338090 Madin, Laurence", "bounds_geometry": "POLYGON((-69.9083 -52.7624,-68.96368 -52.7624,-68.01906 -52.7624,-67.07444 -52.7624,-66.12982 -52.7624,-65.1852 -52.7624,-64.24058 -52.7624,-63.29596 -52.7624,-62.35134 -52.7624,-61.40672 -52.7624,-60.4621 -52.7624,-60.4621 -54.01423,-60.4621 -55.26606,-60.4621 -56.51789,-60.4621 -57.76972,-60.4621 -59.02155,-60.4621 -60.27338,-60.4621 -61.52521,-60.4621 -62.77704,-60.4621 -64.02887,-60.4621 -65.2807,-61.40672 -65.2807,-62.35134 -65.2807,-63.29596 -65.2807,-64.24058 -65.2807,-65.1852 -65.2807,-66.12982 -65.2807,-67.07444 -65.2807,-68.01906 -65.2807,-68.96368 -65.2807,-69.9083 -65.2807,-69.9083 -64.02887,-69.9083 -62.77704,-69.9083 -61.52521,-69.9083 -60.27338,-69.9083 -59.02155,-69.9083 -57.76972,-69.9083 -56.51789,-69.9083 -55.26606,-69.9083 -54.01423,-69.9083 -52.7624))", "dataset_titles": "Data at U.S. JGOFS Data System; Expedition Data", "datasets": [{"dataset_uid": "000118", "doi": "", "keywords": null, "people": null, "repository": "JGOF", "science_program": null, "title": "Data at U.S. JGOFS Data System", "url": "http://usjgofs.whoi.edu/jg/dir/jgofs/"}, {"dataset_uid": "001573", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0602"}, {"dataset_uid": "001565", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0414"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "Salps are planktonic grazers that have a life history, feeding biology and population dynamic strikingly different from krill, copepods or other crustacean zooplankton. Salps can occur in very dense population blooms that cover large areas and have been shown to have major impacts due to the their grazing and the production of fast-sinking fecal pellets. Although commonly acknowledged as a major component of the Southern Ocean zooplankton community, often comparable in biomass and distribution to krill, salps have received relatively little attention. Although extensive sampling has documented the seasonal abundance of salps in the Southern Ocean, there is a paucity of data on important rates that determine population growth and the role of this species in grazing and vertical flux of particulates. This proposed study will include: measurements of respiration and excretion rates for solitary and aggregate salps of all sizes; measurements of ingestion rates, including experiments to determine the size or concentration of particulates that can reduce ingestion; and determination of growth rates of solitaries and aggregates. In addition to the various rate measurements, this study will include quantitative surveys of salp horizontal and vertical distribution to determine their biomass and spatial distribution, and to allow a regional assessment of their effects. Measurements of the physical characteristics of the water column and the quantity and quality of particulate food available for the salps at each location will also be made. Satellite imagery and information on sea-ice cover will be used to test hypotheses about conditions that result in high densities of salps. Results will be used to construct a model of salp population dynamics, and both experimental and modeling results will be interpreted within the context of the physical and nutritional conditions to which the salps are exposed. This integrated approach will provide a good basis for understanding the growth dynamics of salp blooms in the Southern Ocean. Two graduate students will be trained on this project, and cruise and research experience will be provided for two undergraduate students. A portion of a website allowing students to be a virtual participant in the research will be created to strengthen students\u0027 quantitative skills. Both PI\u0027s will participate in teacher-researcher workshops, and collaboration with a regional aquarium will be developed in support of public education.", "east": -60.4621, "geometry": "POINT(-65.1852 -59.02155)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": true, "keywords": "Not provided; R/V LMG", "locations": null, "north": -52.7624, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Kremer, Patricia; Madin, Larry; Halanych, Kenneth", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "JGOF", "repositories": "JGOF; R2R", "science_programs": null, "south": -65.2807, "title": "Collaborative Research: Salpa Thompsoni in the Southern Ocean: Bioenergetics, Population Dynamics and Biogeochemical Impact", "uid": "p0000227", "west": -69.9083}, {"awards": "8917076 Smith, Raymond", "bounds_geometry": "POLYGON((-49.8233 -60.2167,-48.99564 -60.2167,-48.16798 -60.2167,-47.34032 -60.2167,-46.51266 -60.2167,-45.685 -60.2167,-44.85734 -60.2167,-44.02968 -60.2167,-43.20202 -60.2167,-42.37436 -60.2167,-41.5467 -60.2167,-41.5467 -60.35003,-41.5467 -60.48336,-41.5467 -60.61669,-41.5467 -60.75002,-41.5467 -60.88335,-41.5467 -61.01668,-41.5467 -61.15001,-41.5467 -61.28334,-41.5467 -61.41667,-41.5467 -61.55,-42.37436 -61.55,-43.20202 -61.55,-44.02968 -61.55,-44.85734 -61.55,-45.685 -61.55,-46.51266 -61.55,-47.34032 -61.55,-48.16798 -61.55,-48.99564 -61.55,-49.8233 -61.55,-49.8233 -61.41667,-49.8233 -61.28334,-49.8233 -61.15001,-49.8233 -61.01668,-49.8233 -60.88335,-49.8233 -60.75002,-49.8233 -60.61669,-49.8233 -60.48336,-49.8233 -60.35003,-49.8233 -60.2167))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002326", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9206"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The Antarctic is now experiencing large springtime losses of stratospheric ozone, resulting in an increase in ultraviolet B (UVB, 280-320nm) radiation. The magnitude of ultraviolet radiation reaching the surface now approaches that measured in tropical latitudes. Perhaps more importantly, UVB radiation has increased in the Antarctic while both UVA (320-400nm) and photosynthetically available radiation (PAR, 400-700nm) have remained unchanged. Recent improvements in atmospheric modeling and technology in oceanographic instrumentation will be used in a six week field study during the austral spring 1990. The prime objective will be to document the impact of UV radiation on the phytoplankton community during the ice-edge spring bloom. During this time, oceanographic processes create favorable conditions for increased UVB susceptibility. Biological and bio-optical information will be used to define and quantify linkages between ozone-dependent oscillations in UV to PAR ratios and phytoplankton productivity. Special emphasis will be placed on defining biological restraints imposed by enhanced UVB and altered UVB:UVA:PAR ratios on the balance of UVB photodamage to photorepair, photoprotective and photosynthetic mechanisms operating in the Southern Ocean. The overall aim is to test the hypothesis that phytoplankton in Antarctic waters are adversely influenced by ozone depletion.", "east": -41.5467, "geometry": "POINT(-45.685 -60.88335)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -60.2167, "nsf_funding_programs": null, "paleo_time": null, "persons": "Smith, Raymond", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -61.55, "title": "Ozone Diminution, Ultraviolet Radiation and Photoplankton Biology in Antarctic Waters", "uid": "p0000650", "west": -49.8233}, {"awards": "9909933 Ross, Robin; 9910175 Vernet, Maria", "bounds_geometry": "POLYGON((-71.077 -57.9543,-70.015 -57.9543,-68.953 -57.9543,-67.891 -57.9543,-66.829 -57.9543,-65.767 -57.9543,-64.705 -57.9543,-63.643 -57.9543,-62.581 -57.9543,-61.519 -57.9543,-60.457 -57.9543,-60.457 -58.98629,-60.457 -60.01828,-60.457 -61.05027,-60.457 -62.08226,-60.457 -63.11425,-60.457 -64.14624,-60.457 -65.17823,-60.457 -66.21022,-60.457 -67.24221,-60.457 -68.2742,-61.519 -68.2742,-62.581 -68.2742,-63.643 -68.2742,-64.705 -68.2742,-65.767 -68.2742,-66.829 -68.2742,-67.891 -68.2742,-68.953 -68.2742,-70.015 -68.2742,-71.077 -68.2742,-71.077 -67.24221,-71.077 -66.21022,-71.077 -65.17823,-71.077 -64.14624,-71.077 -63.11425,-71.077 -62.08226,-71.077 -61.05027,-71.077 -60.01828,-71.077 -58.98629,-71.077 -57.9543))", "dataset_titles": "Expedition Data; Expedition data of LMG0205; Expedition data of NBP0104; Expedition data of NBP0202; Expedition data of NBP0204", "datasets": [{"dataset_uid": "001861", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0106"}, {"dataset_uid": "002657", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0104", "url": "https://www.rvdata.us/search/cruise/NBP0104"}, {"dataset_uid": "002704", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0205", "url": "https://www.rvdata.us/search/cruise/LMG0205"}, {"dataset_uid": "002586", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0202", "url": "https://www.rvdata.us/search/cruise/NBP0202"}, {"dataset_uid": "002643", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0204", "url": "https://www.rvdata.us/search/cruise/NBP0204"}, {"dataset_uid": "001856", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0105"}, {"dataset_uid": "001757", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0205"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The U.S. Global Ocean Ecosystems Dynamics (U.S. GLOBEC) program has the goal of understanding and ultimately predicting how populations of marine animal species respond to natural and anthropogenic changes in climate. Research in the Southern Ocean (SO) indicates strong coupling between climatic processes and ecosystem dynamics via the annual formation and destruction of sea ice. The Southern Ocean GLOBEC Program (SO GLOBEC) will investigate the dynamic relationship between physical processes and ecosystem responses through identification of critical parameters that affect the distribution, abundance and population dynamics of target species. The overall goals of the SO GLOBEC program are to elucidate shelf circulation processes and their effect on sea ice formation and krill distribution, and to examine the factors which govern krill survivorship and availability to higher trophic levels, including penguins, seals and whales. The focus of the U.S. contribution to the international SO GLOBEC program will be on winter processes. This component will focus on water-column primary production using direct experimental estimates, modeling restuls from a fast repetition rate fluorometer and modeling of primary production from both optical as well as biophysical models. This research will be coordinated with components focused on sea ice production and sea ice habitat. The result of the integrated SO GLOBEC program will be to improve the predictability of living marine resources, especially with respect to local and global climatic shifts.", "east": -60.457, "geometry": "POINT(-65.767 -63.11425)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V LMG; R/V NBP", "locations": null, "north": -57.9543, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Vernet, Maria; Costa, Daniel; Ross, Robin Macurda; Smith, Raymond", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -68.2742, "title": "GLOBEC: Winter Ecology of Larval Krill: Quantifying their Interaction with the Pack Ice Habitat", "uid": "p0000605", "west": -71.077}, {"awards": "9910122 Martinson, Douglas", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of LMG0106; Expedition data of LMG0205", "datasets": [{"dataset_uid": "002695", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0106", "url": "https://www.rvdata.us/search/cruise/LMG0106"}, {"dataset_uid": "002703", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0205", "url": "https://www.rvdata.us/search/cruise/LMG0205"}, {"dataset_uid": "002697", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG0106", "url": "https://www.rvdata.us/search/cruise/LMG0106"}, {"dataset_uid": "001757", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0205"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a contribution to a coordinated attempt to understand the interactions of biological and physical dynamics by developing mechanistic links between the evolution of the antarctic winter ice and snow cover, and biological habitat variability, through modeling the optical properties of the environment. The work will be carried out in the context of the Southern Ocean Experiment of the Global Ocean Ecosystem Dynamics Study (Globec), a large, multi-investigator study of the winter survival strategy of krill under the antarctic sea ice. The optical properties of snow and sea ice evolve through the winter and vary greatly both spectrally and spatially. These properties are an important element of the physical environment that strongly influences both the distribution of and the resources available to antarctic krill. The intensity of incident radiant energy and its distribution within the snow, ice, and water column environment, and the linked physical, optical, chemical, and biological processes that modulate its distribution are generally known but poorly quantified. The optical properties of snow and ice also influence snow algae, ice algae, and water column productivity, as well as visibility for both predator and prey. Furthermore, optical properties play an essential role in satellite observations as proxy indicators of geophysical sea ice parameters which permit local observations to be more accurately extrapolated in space and time, thus providing regional coverage that would otherwise not be possible. What is proposed is the deployment of an array of instrumented ice beacons, augmented by periodic ship-based and satellite observations, along with theoretical studies to create improved quantitative models with which to follow the temporal and spatial evolution of this snow and ice marine ecosystem. The specific objective is to develop a thermodynamic sea ice/ecosystem model through coupling of existing components in order to test our understanding of the system, determine its sensitivities, and to provide an organizing mechanism for integrating the Southern Ocean Globec observations. ***", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Costa, Daniel", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Optical Environmental of the Western Antarctic Peninsula (WAP) Region", "uid": "p0000865", "west": null}, {"awards": "9117721 Jeffries, Martin", "bounds_geometry": "POLYGON((-110.149 -52.353,-104.86076 -52.353,-99.57252 -52.353,-94.28428 -52.353,-88.99604 -52.353,-83.7078 -52.353,-78.41956 -52.353,-73.13132 -52.353,-67.84308 -52.353,-62.55484 -52.353,-57.2666 -52.353,-57.2666 -54.17539,-57.2666 -55.99778,-57.2666 -57.82017,-57.2666 -59.64256,-57.2666 -61.46495,-57.2666 -63.28734,-57.2666 -65.10973,-57.2666 -66.93212,-57.2666 -68.75451,-57.2666 -70.5769,-62.55484 -70.5769,-67.84308 -70.5769,-73.13132 -70.5769,-78.41956 -70.5769,-83.7078 -70.5769,-88.99604 -70.5769,-94.28428 -70.5769,-99.57252 -70.5769,-104.86076 -70.5769,-110.149 -70.5769,-110.149 -68.75451,-110.149 -66.93212,-110.149 -65.10973,-110.149 -63.28734,-110.149 -61.46495,-110.149 -59.64256,-110.149 -57.82017,-110.149 -55.99778,-110.149 -54.17539,-110.149 -52.353))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002253", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9405"}, {"dataset_uid": "002283", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9305"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is an examination of the physical and structural properties of the antarctic ice pack in the Amundsen, Bellingshausen, and Ross Seas, with the goal of defining the geographical variability of various ice types, the deformation processes that are active in the antarctic ice pack, and the large-scale thermodynamics and heat exchange processes of the ice- covered Southern Ocean. An additional goal is to relate specific characteristics of antarctic sea ice to its synthetic aperture radar (SAR) signature as observed from satellites. Physical properties include the salinity, temperature, and brine volumes, while structural properties include the fraction of frazil, platelet, and congelation ice of the seasonal antarctic pack ice. Differences in ice types are the result of differences in the environment in which the ice forms: frazil ice is formed in supercooled sea water, normally through wind or wave-induced turbulence, while platelet and congelation ice is formed under quiescent conditions. The fraction of frazil ice (which has been observed to be generally in excess of 50% in Weddell Sea ice floes) is an important variable in the energy budget of the upper ocean, and contributes significantly to the stabilization of the surface layers. The integration of sea ice field observations and synthetic aperture radar data analysis and modeling studies will contribute to a better understanding of sea ice parameters and their geophysical controls, and will be useful in defining the kind of air-ice-ocean interactions that can be studied using SAR data, as well as having broader relevance and application to atmospheric, biological, and oceanographic investigations of the Southern Ocean.", "east": -57.2666, "geometry": "POINT(-83.7078 -61.46495)", "instruments": null, "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.353, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jeffries, Martin", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -70.5769, "title": "Sea Ice Physical-Structrual Characteristics: Development and SAR Signature in the Pacific Sector of the Southern Ocean", "uid": "p0000647", "west": -110.149}, {"awards": "9528807 Gordon, Arnold", "bounds_geometry": "POLYGON((-69.58631 -52.35405,-66.572039 -52.35405,-63.557768 -52.35405,-60.543497 -52.35405,-57.529226 -52.35405,-54.514955 -52.35405,-51.500684 -52.35405,-48.486413 -52.35405,-45.472142 -52.35405,-42.457871 -52.35405,-39.4436 -52.35405,-39.4436 -53.54563,-39.4436 -54.73721,-39.4436 -55.92879,-39.4436 -57.12037,-39.4436 -58.31195,-39.4436 -59.50353,-39.4436 -60.69511,-39.4436 -61.88669,-39.4436 -63.07827,-39.4436 -64.26985,-42.457871 -64.26985,-45.472142 -64.26985,-48.486413 -64.26985,-51.500684 -64.26985,-54.514955 -64.26985,-57.529226 -64.26985,-60.543497 -64.26985,-63.557768 -64.26985,-66.572039 -64.26985,-69.58631 -64.26985,-69.58631 -63.07827,-69.58631 -61.88669,-69.58631 -60.69511,-69.58631 -59.50353,-69.58631 -58.31195,-69.58631 -57.12037,-69.58631 -55.92879,-69.58631 -54.73721,-69.58631 -53.54563,-69.58631 -52.35405))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002142", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9705"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9528807 Gordon The proposed project is part of a multi-institutional integrated study of the outflow of newly formed bottom water from the Weddell Sea and its dispersion into the South Atlantic Ocean. It builds upon earlier successful studies of the inflow of intermediate water masses into the Eastern Weddell Sea, their modification within the Weddell Gyre, and their interaction with bottom water formation processes in the western Weddell Sea. The study is called Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL) and includes six components involving hydrographic measurements, natural tracer experiments, and modeling studies. The study will be centered east of the Drake Passage where water masses from the Weddell Sea and the Scotia Sea come together in the Weddell-Scotia Confluence, and will be carried out in cooperation with the national antarctic programs of Germany and Spain. This particular component concerns observations of the temperature and salinity structure, as well as the chemical nature of the water column in the confluence region. The study has four related objectives. The first is to assess the quantity and the physical and chemical characteristics of Weddell Sea source waters for the confluence. The second is to describe the dominant processes associated with spreading and sinking of dense antarctic waters within the Weddell-Scotia Confluence. The third is to estimate the ventilation rate of the world ocean, and the fourth is to estimate seasonal fluctuations in the regional ocean transport and hydrographic structure and to assess the likely influence of seasonal to interannual variability on rates of ventilation by Weddell Sea waters. Ventilation of the deep ocean -- the rising of sub-surface water masses to the surface to be recharged with atmospheric gases and to give up heat to the atmosphere -- is a uniquely antarctic phenomenon that has significant consequences for global change by affecting the g lobal reservoir of carbon dioxide, and by modulating the amount and extent of seasonal sea ice in the southern hemisphere. This component will make systematic observations of the temperature salinity structure of the water and undertake an extensive sampling program for other chemical studies. The purpose is to identify the individual water masses and to relate their temperature and salinity characteristics to the modification processes within the Weddell Sea. ***", "east": -39.4436, "geometry": "POINT(-54.514955 -58.31195)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -52.35405, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Gordon, Arnold", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.26985, "title": "Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL)", "uid": "p0000630", "west": -69.58631}, {"awards": "0440775 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Amundsen Sea Continental Shelf Mooring Data (2006-2007); Expedition data of NBP0702; NBP0702 surface sediment sample information and images", "datasets": [{"dataset_uid": "002645", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0702", "url": "https://www.rvdata.us/search/cruise/NBP0702"}, {"dataset_uid": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Giulivi, Claudia F.; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}, {"dataset_uid": "601473", "doi": "10.15784/601473", "keywords": "Amundsen Sea; Antarctica; Marine Geoscience; Marine Sediments; NBP0702; Photo; R/v Nathaniel B. Palmer; Seafloor Sampling; Sediment Description; Smith-Mcintyre Grab", "people": "Jacobs, Stanley; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP0702 surface sediment sample information and images", "url": "https://www.usap-dc.org/view/dataset/601473"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "AMD; Amd/Us; R/V NBP; NSF/USA; Amundsen Sea; USAP-DC", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "The Amundsen Continental Shelf and the Antarctic Ice Sheet", "uid": "p0000836", "west": null}, {"awards": "0523166 Hofmann, Eileen", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0103", "datasets": [{"dataset_uid": "002601", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0103", "url": "https://www.rvdata.us/search/cruise/NBP0103"}, {"dataset_uid": "002595", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0103", "url": "https://www.rvdata.us/search/cruise/NBP0103"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The objective of the proposed work is to provide for the operation of a Planning Office for the synthesis and modeling phase of the Southern Ocean Global Ocean Ecosystems Dynamics (SO-Globec) program. The office will ensure that synthesis and integration activities that are developed as part of SO-Globec are coordinated with those undertaken by the international and U.S. Globec programs through: 1) organization of special sessions at meetings, 2) preparation of dedicated publications focused on program results, 3) maintenance of a project web site, 4) development of program outreach efforts, and 5) ensuring coordination with International Globec and other national and international programs and organizations. The office will consist of one faculty member and one program specialist.\u003cbr/\u003e\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. Extensive studies describing the ecology and physiology of important species at all trophic levels contributed to the ecosystem approach which is the essence of SO-Globec. The Planning Office will provide a central focal point for ensuring that the results from SO-Globec are made available to the broader scientific community and to the general public, and that the results will be incorporated into the planning of future Southern Ocean programs.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hofmann, Eileen", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "U.S. SO GLOBEC Synthesis and Modeling: Southern Ocean GLOBEC (SO GLOBEC) Planning Office", "uid": "p0000817", "west": null}, {"awards": "9011927 Ross, Robin; 9632763 Smith, Raymond", "bounds_geometry": "POLYGON((-79.68459 -52.36474,-77.851019 -52.36474,-76.017448 -52.36474,-74.183877 -52.36474,-72.350306 -52.36474,-70.516735 -52.36474,-68.683164 -52.36474,-66.849593 -52.36474,-65.016022 -52.36474,-63.182451 -52.36474,-61.34888 -52.36474,-61.34888 -54.071087,-61.34888 -55.777434,-61.34888 -57.483781,-61.34888 -59.190128,-61.34888 -60.896475,-61.34888 -62.602822,-61.34888 -64.309169,-61.34888 -66.015516,-61.34888 -67.721863,-61.34888 -69.42821,-63.182451 -69.42821,-65.016022 -69.42821,-66.849593 -69.42821,-68.683164 -69.42821,-70.516735 -69.42821,-72.350306 -69.42821,-74.183877 -69.42821,-76.017448 -69.42821,-77.851019 -69.42821,-79.68459 -69.42821,-79.68459 -67.721863,-79.68459 -66.015516,-79.68459 -64.309169,-79.68459 -62.602822,-79.68459 -60.896475,-79.68459 -59.190128,-79.68459 -57.483781,-79.68459 -55.777434,-79.68459 -54.071087,-79.68459 -52.36474))", "dataset_titles": "Expedition Data; Expedition data of NBP0105", "datasets": [{"dataset_uid": "002045", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9906"}, {"dataset_uid": "001578", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0601"}, {"dataset_uid": "002605", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0105", "url": "https://www.rvdata.us/search/cruise/NBP0105"}, {"dataset_uid": "002292", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9302"}, {"dataset_uid": "001817", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0201"}, {"dataset_uid": "001613", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0501"}, {"dataset_uid": "001665", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0401"}, {"dataset_uid": "001488", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0901"}, {"dataset_uid": "001998", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0001"}, {"dataset_uid": "001884", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0101"}, {"dataset_uid": "001649", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0301"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The annual advance and retreat of pack ice may be the major physical determinant of spatial and temporal changes in the structure and function of antarctic marine communities. Interannual cycles and/or trends in the annual extent of pack ice may also have significant effects on all levels of the food web, from total annual primary production to breeding success in seabirds. Historical records indicate a six to eight year cycle in the maximum extent of pack ice in the winter. During this decade, winters were colder in 1980 and 1981, and again in 1986 and 1987. Winter-over survival in Adelie penguins varied on the same cycle, higher in winters with heavy pack ice. This Long Term Ecological Research (LTER) project will define ecological processes linking the extent of annual pack ice with the biological dynamics of different trophic levels within antarctic marine communities. The general focus is on interannual variability in representative populations from the antarctic marine food web and on mechanistic linkages that control the observed variability in order to develop broader generalizations applicable to other large marine environments. To achieve these objectives, data from several spatial and temporal scales, including remote sensing, a field approach that includes an annual monitoring program, a series of process-oriented research cruises, and a modeling effort to provide linkages on multiple spatial and temporal scales between biological and environmental components of the ecosystem will be employed.", "east": -61.34888, "geometry": "POINT(-70.516735 -60.896475)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": false, "keywords": "R/V LMG; R/V NBP", "locations": null, "north": -52.36474, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Raymond; Ross, Robin Macurda; Fraser, William; Martinson, Douglas; Ducklow, Hugh", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": "LTER", "south": -69.42821, "title": "Long-Term Ecological Research on the Antarctic Marine Ecosystem: An Ice-Dominated Environment", "uid": "p0000236", "west": -79.68459}, {"awards": "0837988 Steig, Eric", "bounds_geometry": "POLYGON((-180 -65,-144 -65,-108 -65,-72 -65,-36 -65,0 -65,36 -65,72 -65,108 -65,144 -65,180 -65,180 -67.5,180 -70,180 -72.5,180 -75,180 -77.5,180 -80,180 -82.5,180 -85,180 -87.5,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.5,-180 -85,-180 -82.5,-180 -80,-180 -77.5,-180 -75,-180 -72.5,-180 -70,-180 -67.5,-180 -65))", "dataset_titles": "West Antarctica Ice Core and Climate Model Data", "datasets": [{"dataset_uid": "609536", "doi": "10.7265/N5QJ7F8B", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; WAIS Divide", "people": "Steig, Eric J.", "repository": "USAP-DC", "science_program": null, "title": "West Antarctica Ice Core and Climate Model Data", "url": "https://www.usap-dc.org/view/dataset/609536"}], "date_created": "Fri, 30 Apr 2010 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to reconstruct the past physical and chemical climate of Antarctica, with an emphasis on the region surrounding the Ross Sea Embayment, using \u003e60 ice cores collected in this region by US ITASE and by Australian, Brazilian, Chilean, and New Zealand ITASE teams. The ice core records are annually resolved and exceptionally well dated, and will provide, through the analyses of stable isotopes, major soluble ions and for some trace elements, instrumentally calibrated proxies for past temperature, precipitation, atmospheric circulation, chemistry of the atmosphere, sea ice extent, and volcanic activity. These records will be used to understand the role of solar, volcanic, and human forcing on Antarctic climate and to investigate the character of recent abrupt climate change over Antarctica in the context of broader Southern Hemisphere and global climate variability. The intellectual merit of the project is that ITASE has resulted in an array of ice core records, increasing the spatial resolution of observations of recent Antarctic climate variability by more than an order of magnitude and provides the basis for assessment of past and current change and establishes a framework for monitoring of future climate change in the Southern Hemisphere. This comes at a critical time as global record warming and other impacts are noted in the Southern Ocean, the Antarctic Peninsula, and on the Antarctic ice sheet. The broader impacts of the project are that Post-doctoral and graduate students involved in the project will benefit from exposure to observational and modeling approaches to climate change research and working meetings to be held at the two collaborating institutions plus other prominent climate change institutions. The results are of prime interest to the public and the media Websites hosted by the two collaborating institutions contain climate change position papers, scientific exchanges concerning current climate change issues, and scientific contribution series.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "Deuterium Isotopes; Deuterium Excess; Not provided; GROUND-BASED OBSERVATIONS; Wais Divide-project", "locations": null, "north": -65.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Antarctic Climate Reconstruction Utilizing the US ITASE Ice Core Array (2009- 2012)", "uid": "p0000180", "west": -180.0}, {"awards": "0335330 Waddington, Edwin", "bounds_geometry": "POLYGON((-60 83,-55.8 83,-51.6 83,-47.4 83,-43.2 83,-39 83,-34.8 83,-30.6 83,-26.4 83,-22.2 83,-18 83,-18 80.5,-18 78,-18 75.5,-18 73,-18 70.5,-18 68,-18 65.5,-18 63,-18 60.5,-18 58,-22.2 58,-26.4 58,-30.6 58,-34.8 58,-39 58,-43.2 58,-47.4 58,-51.6 58,-55.8 58,-60 58,-60 60.5,-60 63,-60 65.5,-60 68,-60 70.5,-60 73,-60 75.5,-60 78,-60 80.5,-60 83))", "dataset_titles": "Borehole Optical Stratigraphy Modeling, Antarctica", "datasets": [{"dataset_uid": "609468", "doi": "10.7265/N5H70CR5", "keywords": "Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling Code", "people": "Waddington, Edwin D.; Fudge, T. J.; Hawley, Robert L.; Smith, Ben", "repository": "USAP-DC", "science_program": null, "title": "Borehole Optical Stratigraphy Modeling, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609468"}], "date_created": "Thu, 01 Apr 2010 00:00:00 GMT", "description": "This award supports a study of the physical nature and environmental origin of optical features (light and dark zones) observed by video in boreholes in polar ice. These features appear to include an annual signal, as well as longer period signals. Borehole logs exist from a previous project, and in this lab-based project the interpretation of these logs will be improved. The origin of the features is of broad interest to the ice-core community. If some components relate to changes in the depositional environment beyond seasonality, important climatic cycles may be seen. If some components relate to post-depositional reworking, insights will be gained into the physical processes that change snow and firn, and the implications for interpretation of the chemical record in terms of paleoclimate. In order to exploit these features to best advantage in future ice-core and climate-change research, the two principal objectives of this project are to determine what physically causes the optical differences that we see and to determine the environmental processes that give rise to these physical differences. In the laboratory at NICL the conditions of a log of a borehole wall will be re-created as closely as possible by running the borehole video camera along sections of ice core, making an optical log of light reflected from the core. Combinations of physical variables that are correlated with optical features will be identified. A radiative-transfer model will be used to aid in the interpretation of these measurements, and to determine the optimum configuration for an improved future logging tool. An attempt will be made to determine the origin of the features. Two broad possibilities exist: 1) temporal changes in the depositional environment, and 2) post-depositional reworking. This project represents an important step toward a new way of learning about paleoclimate with borehole optical methods. Broader impacts include enhancing the infrastructure for research and education, since this instrument will complement high-resolution continuous-melter chemistry techniques and provide a rapid way to log physical variables using optical features as a proxy for climate signals. Since no core is required for this method, it can be used in rapidly drilled access holes or where core quality is poor. This project will support a graduate student who will carry out this project under the direction of the Principal Investigator. K-12 education will be enhanced through an ongoing collaboration with a science and math teacher from a local middle school. International collaboration will be expanded through work on this project with colleagues at the Norwegian Polar Institute and broad dissemination of results will occur through a project website for the general public.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": true, "keywords": "Ice; Stratigraphy; Optical; Glaciers; Polar Ice; Ice Microphysics; Snow; Firn; Climate Change; LABORATORY; Snow Stratigraphy; Borehole", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Smith, Ben; Waddington, Edwin D.; Hawley, Robert L.; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Borehole Optical Stratigraphy: Ice Microphysics, Climate Change, and the Optical Properties of Firn", "uid": "p0000016", "west": -180.0}, {"awards": "0440666 Waddington, Edwin", "bounds_geometry": null, "dataset_titles": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "datasets": [{"dataset_uid": "609473", "doi": "10.7265/N5QR4V2J", "keywords": "Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; WAIS Divide; WAIS Divide Ice Core", "people": "Koutnik, Michelle; Waddington, Edwin D.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Histories of Accumulation, Thickness, and WAIS Divide Location, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609473"}], "date_created": "Thu, 04 Mar 2010 00:00:00 GMT", "description": "This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women\u0027s Center. It will also provide a research\u003cbr/\u003eexperience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS", "is_usap_dc": true, "keywords": "Ross-Amundsen Divide; FIELD SURVEYS; Internal Layers; Ice Flow Model; West Antarctic Ice Sheet; Accumulation; Glacier; Ice Penetrating Radar; Model; MODELS; Snow Accumulation; GPS; Antarctica; Isochron; Not provided; Snowfall; Radar", "locations": "West Antarctic Ice Sheet; Antarctica; Ross-Amundsen Divide", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Koutnik, Michelle; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e MODELS \u003e MODELS; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": null, "title": "Histories of accumulation, thickness and WAIS Divide location from radar layers using a new inverse approach", "uid": "p0000018", "west": null}, {"awards": "0338008 Wemple, Beverley", "bounds_geometry": null, "dataset_titles": "Laboratory Studies of Isotopic Exchange in Snow; Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "datasets": [{"dataset_uid": "609441", "doi": "10.7265/N54X55R2", "keywords": "Snow/ice; Snow/Ice", "people": "Wemple, Beverley C.", "repository": "USAP-DC", "science_program": null, "title": "Snow Accumulation and Snow Melt in a Mixed Northern Hardwood-Conifer Forest", "url": "https://www.usap-dc.org/view/dataset/609441"}, {"dataset_uid": "609445", "doi": "10.7265/N51834DX", "keywords": "Atmosphere; Chemistry:ice; Chemistry:Ice; Snow/ice; Snow/Ice; Snow Sublimation Rate", "people": "Neumann, Thomas A.", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Studies of Isotopic Exchange in Snow", "url": "https://www.usap-dc.org/view/dataset/609445"}], "date_created": "Fri, 01 Jan 2010 00:00:00 GMT", "description": "This award supports a project to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is of paramount importance to ice core interpretation. Carefully controlled laboratory studies will be conducted at a variety of temperatures to empirically measure the mass transfer coefficient (the rate at which water moves from the solid to the vapor phase) for sublimating snow and to determine the time scale for isotopic equilibration between water vapor and ice. In addition the isotopic fractionation coefficient for vapor derived from sublimating ice will be determined and the results will be used to update existing models of mass transfer and isotopic evolution in firn. It is well known that water vapor moves through firn due to diffusion, free convection and forced convection. Although vapor movement through variably-saturated firn due to these processes has been modeled, because of a lack of laboratory data the mass transfer coefficient had to be estimated. Field studies have documented the magnitudes of post-depositional changes, but field studies do not permit rigorous analysis of the relative importance of the many processes which are likely to act in natural snow packs. The results of these laboratory investigations will be broadly applicable to a number of studies and will allow for improvement of existing physically-based models of post-depositional isotopic change, isotopic diffusion in firn, and vapor motion in firn. A major component of this project will be the design and fabrication of the necessary, novel experimental apparatus, which will be facilitated by existing technical expertise, cold room facilities, and laboratory equipment at CRREL. This project is a necessary step toward a quantitative understanding of the isotopic effects of water vapor movement in firn. The proposed work has broader impacts in several different areas. The modeling results will be applicable to a wide range of studies of water in the polar environment, including studies of wind-blown or drifting snow. The proposed collaborative study will partially support a Dartmouth graduate student for three years. This project will also provide support for a young first-time NSF investigator at the University of Vermont. Undergraduate students from Dartmouth will be involved in the research through the Women in Science Project and undergraduate students at the University of Vermont will be supported through the Research Experiences for Undergraduates program. The principal investigators and graduate student will continue their tradition of k-12 school outreach by giving science lessons and talks in local schools each year. Research results will be disseminated through scientific conferences, journal publications, and institutional seminars.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e SNOW TUBE; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e HYGROMETERS \u003e HYGROMETERS", "is_usap_dc": true, "keywords": "Snow Accumulation; Snow Chemistry; Snow Melt; Snowfall; Snow Water Equivalent; LABORATORY; Seasonal Snow Cover; Not provided; Snow; Sublimation Rate; FIELD SURVEYS; FIELD INVESTIGATION", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Neumann, Thomas A.; Wemple, Beverley C.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Laboratory Studies of Isotopic Exchange in Snow and Firn", "uid": "p0000132", "west": null}, {"awards": "0230285 Wilson, Terry", "bounds_geometry": "POLYGON((152.833 -75.317,154.4897 -75.317,156.1464 -75.317,157.8031 -75.317,159.4598 -75.317,161.1165 -75.317,162.7732 -75.317,164.4299 -75.317,166.0866 -75.317,167.7433 -75.317,169.4 -75.317,169.4 -75.9186,169.4 -76.5202,169.4 -77.1218,169.4 -77.7234,169.4 -78.325,169.4 -78.9266,169.4 -79.5282,169.4 -80.1298,169.4 -80.7314,169.4 -81.333,167.7433 -81.333,166.0866 -81.333,164.4299 -81.333,162.7732 -81.333,161.1165 -81.333,159.4598 -81.333,157.8031 -81.333,156.1464 -81.333,154.4897 -81.333,152.833 -81.333,152.833 -80.7314,152.833 -80.1298,152.833 -79.5282,152.833 -78.9266,152.833 -78.325,152.833 -77.7234,152.833 -77.1218,152.833 -76.5202,152.833 -75.9186,152.833 -75.317))", "dataset_titles": null, "datasets": null, "date_created": "Sat, 12 Dec 2009 00:00:00 GMT", "description": "OPP-0230285/OPP-0230356\u003cbr/\u003ePIs: Wilson, Terry J./Hothem, Larry D.\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.\u003cbr/\u003e\u003cbr/\u003eStrategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.\u003cbr/\u003e\u003cbr/\u003eAn education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.", "east": 169.4, "geometry": "POINT(161.1165 -78.325)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "GPS", "locations": null, "north": -75.317, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Wilson, Terry", "platforms": "SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repositories": null, "science_programs": null, "south": -81.333, "title": "Collaborative Research: Transantarctic Mountains Deformation Network: GPS Measurements of Neotectonic Motion in the Antarctic Interior", "uid": "p0000574", "west": 152.833}, {"awards": "0122520 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-110 -62,-105 -62,-100 -62,-95 -62,-90 -62,-85 -62,-80 -62,-75 -62,-70 -62,-65 -62,-60 -62,-60 -63.5,-60 -65,-60 -66.5,-60 -68,-60 -69.5,-60 -71,-60 -72.5,-60 -74,-60 -75.5,-60 -77,-65 -77,-70 -77,-75 -77,-80 -77,-85 -77,-90 -77,-95 -77,-100 -77,-105 -77,-110 -77,-110 -75.5,-110 -74,-110 -72.5,-110 -71,-110 -69.5,-110 -68,-110 -66.5,-110 -65,-110 -63.5,-110 -62))", "dataset_titles": "Antarctic Radar Echograms and Derived Ice Thickness Data from CReSIS", "datasets": [{"dataset_uid": "609414", "doi": "", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar", "people": "Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Radar Echograms and Derived Ice Thickness Data from CReSIS", "url": "https://www.usap-dc.org/view/dataset/609414"}], "date_created": "Wed, 01 Jul 2009 00:00:00 GMT", "description": "0122520\u003cbr/\u003eGogineni\u003cbr/\u003e\u003cbr/\u003eSea level has been rising over the last century. Although the immediate impact of sea level rise may be less severe than other effects of global climate change, the long-term consequences can be much more devastating since nearly 60% of the world population lives in coastal regions. Scientists have postulated that excess water is being released from polar ice sheets due to long-term, global climate change, but there are insufficient data to confirm these theories. Understanding the interactions between the ice sheets, oceans and atmosphere is essential to quantifying the role of ice sheets in sea level rise. Toward that end, this research project involves the innovative application of information technology in the development and deployment of intelligent radar sensors for measuring key glaciological parameters. \u003cbr/\u003e\u003cbr/\u003eRadar instrumentation will consist of a synthetic aperture radar (SAR) that can operate in bistatic or monostatic mode. One important application of the SAR will be in the determination of basal conditions, particularly the presence and distribution of basal water. Basal water lubricates the ice/bed interface, enhancing flow, and increasing the amount of ice discharged into the ocean. Another application of the SAR will be to measure ice thickness and map internal layers in both shallow and deep ice. Information on near-surface internal layers will be used to estimate the average, recent accumulation rate, while the deeper layers provide a history of past accumulation and flow rates. A tracked vehicle and an automated snowmobile will be used to test and demonstrate the utility of an intelligent radar in glaciological investigations.\u003cbr/\u003e\u003cbr/\u003eThe system will be developed to collect, process and analyze data in real time and in conjunction with a priori information derived from archived sources. The combined real time and archived information will be used onboard the vehicles to select and generate an optimum sensor configuration. This project thus involves innovative research in intelligent systems, sounding radars and ice sheet modeling. In addition it has a very strong public outreach and education program, which include near-real-time image broadcasts via the world wide web", "east": -60.0, "geometry": "POINT(-85 -69.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e AIRSAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": true, "keywords": "Radar Echo Sounding; Not provided; FIELD SURVEYS; Airborne Radar Sounding; Radar Echo Sounder; Antarctic Ice Sheet; LABORATORY; Antarctica; Ice Sheet Thickness; Antarctic; Ice Sheet; Synthetic Aperture Radar Imagery; Radar Altimetry; Ice Sheet Elevation; FIELD INVESTIGATION; Radar", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": -62.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Gogineni, Prasad", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "ITR/SI+AP: A Mobile Sensor Web for Polar Ice Sheet Measurements", "uid": "p0000583", "west": -110.0}, {"awards": "0523183 Padman, Laurence", "bounds_geometry": "POLYGON((-75 -65,-74 -65,-73 -65,-72 -65,-71 -65,-70 -65,-69 -65,-68 -65,-67 -65,-66 -65,-65 -65,-65 -65.6,-65 -66.2,-65 -66.8,-65 -67.4,-65 -68,-65 -68.6,-65 -69.2,-65 -69.8,-65 -70.4,-65 -71,-66 -71,-67 -71,-68 -71,-69 -71,-70 -71,-71 -71,-72 -71,-73 -71,-74 -71,-75 -71,-75 -70.4,-75 -69.8,-75 -69.2,-75 -68.6,-75 -68,-75 -67.4,-75 -66.8,-75 -66.2,-75 -65.6,-75 -65))", "dataset_titles": "U.S. GLOBEC Southern Ocean data", "datasets": [{"dataset_uid": "002739", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "U.S. GLOBEC Southern Ocean data", "url": "https://www.bco-dmo.org/project/2039"}], "date_created": "Mon, 22 Jun 2009 00:00:00 GMT", "description": "This collaborative study between Old Dominion University, the College of William and Mary, Earth and Space Research, and the Woods Hole Oceanographic Institution will examine the interactions among the ocean circulation, vertical mixing, sea ice, and marine biological processes on the western Antarctic Peninsula continental shelf. The study will result in analytical and numerical modeling tools that are based on, and will have been tested against the extensive data set obtained in the course of the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec). These models will provide insight into circulation and biological dynamics that will be applicable to the development and refinement of physical and biological models for other high latitude systems. \u003cbr/\u003e\u003cbr/\u003eSO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the environmental setting and dynamics that constrain ecological processes, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels", "east": -65.0, "geometry": "POINT(-70 -68)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "OCEAN CURRENTS; NOT APPLICABLE; Antarctica; Southern Ocean", "locations": "Antarctica; Southern Ocean", "north": -65.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Padman, Laurence", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -71.0, "title": "Collaborative Proposal: U.S. SO GLOBEC Synthesis and Modeling: Circulation and Hydrographic Data Analyses and Modeling Studies", "uid": "p0000216", "west": -75.0}, {"awards": "9220373 Neale, Patrick", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP9306", "datasets": [{"dataset_uid": "002282", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9306"}, {"dataset_uid": "002589", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP9306", "url": "https://www.rvdata.us/search/cruise/NBP9306"}], "date_created": "Fri, 19 Jun 2009 00:00:00 GMT", "description": "Increases in middle ultraviolet radiation associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, and results have been extrapolated to estimate the effect of ozone depletion on primary productivity in the marginal ice zone. This research will refine the assessment by specifying detailed wavelength-dependent biological weighting functions for the inhibition of photosynthesis by ultraviolet radiation, and by considering the mitigating effects of vertical mixing. Biological weighting functions of phytoplankton in the marginal ice zone will be measured under controlled conditions and applied in a new model of photosynthesis to predict primary productivity in situ, as well as under altered ultraviolet irradiance. These predictions will be compared with observations on samples from the water column and with measurements during incubations of several hours under different irradiance regimes. Results of these comparisons will be used to test the model and to quantify the potential artifact of long incubations. Assumptions about the kinetics of photoinhibition and recovery, critical to modeling the effects of vertical mixing, will be examined with time-course experiments. Results will be incorporated into a model of photosynthesis and photoinhibition in the water column that will be used to predict the influence of ozone depletion on marine primary production, particularly in the marginal zone.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Effects of Ultraviolet Radiation on the Photosynthesis of Phytoplankton in the Antarctic Marginal Ice Zone", "uid": "p0000808", "west": null}, {"awards": "0538195 Marone, Chris", "bounds_geometry": "POLYGON((-147.75896 -61.77943,-147.758362 -61.77943,-147.757764 -61.77943,-147.757166 -61.77943,-147.756568 -61.77943,-147.75597 -61.77943,-147.755372 -61.77943,-147.754774 -61.77943,-147.754176 -61.77943,-147.753578 -61.77943,-147.75298 -61.77943,-147.75298 -61.779665,-147.75298 -61.7799,-147.75298 -61.780135,-147.75298 -61.78037,-147.75298 -61.780605,-147.75298 -61.78084,-147.75298 -61.781075,-147.75298 -61.78131,-147.75298 -61.781545,-147.75298 -61.78178,-147.753578 -61.78178,-147.754176 -61.78178,-147.754774 -61.78178,-147.755372 -61.78178,-147.75597 -61.78178,-147.756568 -61.78178,-147.757166 -61.78178,-147.757764 -61.78178,-147.758362 -61.78178,-147.75896 -61.78178,-147.75896 -61.781545,-147.75896 -61.78131,-147.75896 -61.781075,-147.75896 -61.78084,-147.75896 -61.780605,-147.75896 -61.78037,-147.75896 -61.780135,-147.75896 -61.7799,-147.75896 -61.779665,-147.75896 -61.77943))", "dataset_titles": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "datasets": [{"dataset_uid": "609460", "doi": "10.7265/N5WH2MX7", "keywords": "Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Shear Stress; Solid Earth; Strain", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/609460"}, {"dataset_uid": "600054", "doi": "10.15784/600054", "keywords": "Antarctica; Glacial Till; Glaciers/ice Sheet; Glaciers/Ice Sheet; Lab Experiment; Marine Sediments; Physical Properties; Solid Earth", "people": "Marone, Chris; Anandakrishnan, Sridhar", "repository": "USAP-DC", "science_program": null, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "url": "https://www.usap-dc.org/view/dataset/600054"}], "date_created": "Thu, 18 Jun 2009 00:00:00 GMT", "description": "0538195\u003cbr/\u003eMarone\u003cbr/\u003eThis award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.", "east": -147.75298, "geometry": "POINT(-147.75597 -61.780605)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE TRANSDUCERS", "is_usap_dc": true, "keywords": "Subglacial Observations; Laboratory Investigation; LABORATORY; Subglacial", "locations": null, "north": -61.77943, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Marone, Chris; Anandakrishnan, Sridhar", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -61.78178, "title": "Laboratory Study of Stick-Slip Behavior and Deformation Mechanics of Subglacial Till", "uid": "p0000554", "west": -147.75896}, {"awards": "0636629 Kurz, Mark", "bounds_geometry": "POLYGON((160.7 -77.8,161.06 -77.8,161.42 -77.8,161.78 -77.8,162.14 -77.8,162.5 -77.8,162.86 -77.8,163.22 -77.8,163.58 -77.8,163.94 -77.8,164.3 -77.8,164.3 -77.86,164.3 -77.92,164.3 -77.98,164.3 -78.04,164.3 -78.1,164.3 -78.16,164.3 -78.22,164.3 -78.28,164.3 -78.34,164.3 -78.4,163.94 -78.4,163.58 -78.4,163.22 -78.4,162.86 -78.4,162.5 -78.4,162.14 -78.4,161.78 -78.4,161.42 -78.4,161.06 -78.4,160.7 -78.4,160.7 -78.34,160.7 -78.28,160.7 -78.22,160.7 -78.16,160.7 -78.1,160.7 -78.04,160.7 -77.98,160.7 -77.92,160.7 -77.86,160.7 -77.8))", "dataset_titles": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "datasets": [{"dataset_uid": "600066", "doi": "10.15784/600066", "keywords": "Antarctica; Cosmogenic Radionuclides; Dry Valleys; Geology/Geophysics - Other; Glaciology; LIDAR; Navigation; Sample/collection Description; Sample/Collection Description", "people": "Soule, S. Adam; Kurz, Mark D.", "repository": "USAP-DC", "science_program": null, "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "url": "https://www.usap-dc.org/view/dataset/600066"}], "date_created": "Sun, 01 Feb 2009 00:00:00 GMT", "description": "This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change.", "east": 164.3, "geometry": "POINT(162.5 -78.1)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD INVESTIGATION", "locations": null, "north": -77.8, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Soule, Samuel; Kurz, Mark D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.4, "title": "Periglacial Landscape Evolution in Antarctic Lava Flows and Glacial Tills", "uid": "p0000559", "west": 160.7}, {"awards": "0341050 LaBelle, James", "bounds_geometry": null, "dataset_titles": "Data Project A-128-S.", "datasets": [{"dataset_uid": "000115", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Data Project A-128-S.", "url": "http://www.dartmouth.edu/~spacephy/labelle_group/"}], "date_created": "Mon, 12 Jan 2009 00:00:00 GMT", "description": "This project will continue the operation of surface-based magnetometers, imaging and broadbeam riometers (relative ionospheric opacity instruments), and two-wavelength zenith photometers at South Pole and McMurdo stations in Antarctica, and imaging riometers at Iqaluit (nominally conjugate to South Pole) and Sondrestrom in the Arctic. Additionally, the data acquisition systems at South Pole and McMurdo for the common recording of other geophysical data, and the provision of these data to collaborating investigators will be continued. The Antarctic data sets are web-based, and can be accessed in near-real time. \u003cbr/\u003eThe continuation of the activities in the 2004-2006 time frame will contribute to several major science initiatives, including the GEM (Geospace Environment Modeling), CEDAR (Coupling, Energetics and Dynamics of Atmospheric Regions), ISTP/GGS (International Solar-Terrestrial Project/Global Geospace Science), and National Space Weather programs. The overall objective of the project is to understand the relevant physical processes that produce the observed phenomena, and how they relate to driving forces, either internal, such as magnetospheric/ionospheric instabilities, or external, such as solar wind/interplanetary magnetic field variations. It is expected that this project will lead to an enhanced capability to predict sufficiently in advance the possible occurrence of events that might have negative technological or societal impacts, and thus provide time to lessen their effects.", "east": null, "geometry": null, "instruments": "SOLAR/SPACE OBSERVING INSTRUMENTS \u003e RADIO WAVE DETECTORS \u003e RIOMETER", "is_usap_dc": true, "keywords": "Not provided; Lf/Mf/Hf Receiver", "locations": null, "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": "Labelle, James; Lessard, Marc", "platforms": "Not provided", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": null, "title": "Collaborative Research: Polar Experiment Network for Geospace Upper-atmosphere Investigations (PENGUIn) - A New Vision for Global Studies", "uid": "p0000565", "west": null}, {"awards": "0338295 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((-139 -82,-138.2 -82,-137.4 -82,-136.6 -82,-135.8 -82,-135 -82,-134.2 -82,-133.4 -82,-132.6 -82,-131.8 -82,-131 -82,-131 -82.08,-131 -82.16,-131 -82.24,-131 -82.32,-131 -82.4,-131 -82.48,-131 -82.56,-131 -82.64,-131 -82.72,-131 -82.8,-131.8 -82.8,-132.6 -82.8,-133.4 -82.8,-134.2 -82.8,-135 -82.8,-135.8 -82.8,-136.6 -82.8,-137.4 -82.8,-138.2 -82.8,-139 -82.8,-139 -82.72,-139 -82.64,-139 -82.56,-139 -82.48,-139 -82.4,-139 -82.32,-139 -82.24,-139 -82.16,-139 -82.08,-139 -82))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 04 Aug 2008 00:00:00 GMT", "description": "This award supports a project to test whether Kamb Ice Stream (formerly Ice Stream C (ISC)), an ice stream\u003cbr/\u003ethat is thought to have stopped ~150 years ago, may be already in the process of restarting. If yes, it will help establish what is the rate of ice stream reactivation and what mechanisms are controlling this rate. If there is no evidence for ongoing ice stream reactivation, the physical controls that are preventing it will be examined and alternative scenarios for near-future evolution of this ice stream will be explored. One such scenario is an increase in ice diversion toward the neighboring Whillans Ice Stream. Such diversion may help prevent a complete stoppage of Whillans Ice Stream,which has been slowing down for at least the last 24 years. This project will consist of two components: (1) field observations of bed properties,geometry of internal radar reflectors, as well as surface strain rates and velocity/topography changes using Ice-Penetrating Radar and differential Global Positioning System, (2) numerical modeling study of near future(~100-1000 years) evolution of Kamb Ice Stream. The field component will be focused on the bulge-to-trunk transition, which is located at the present time just downstream of the so-called camp UpC. Reactivation of Kamb Ice Stream should be reflected in a downstream migration of the bulge-trunk transition at possibly high rates (bulge migration rates of ~km/yr occur on surging mountain glaciers). The modeling\u003cbr/\u003ecomponent will be used to generate predictions regarding the near-future behavior of Kamb Ice Stream. This project will provide training opportunities for at least two undergraduate students (per year) at St. Olaf College and for one\u003cbr/\u003eundergraduate student (per year) at UCSC. This collaboration will bring together scientists from three different types of US institutions: (1) a liberal arts college (St.Olaf College), (2) a public research university (UCSC) and (3) a NASA research laboratory (JPL). The project will also help build a new glaciological research program at UCSC. Project results will be incorporated into undergraduate and graduate courses at UCSC and will be made available\u003cbr/\u003eto the general public and educators through downloadable graphics and animations posted on the research website of the UCSC PI. Field data resulting from the project will be posted in the Antarctic Glaciological Data Center for use by other investigators.", "east": -131.0, "geometry": "POINT(-135 -82.4)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Topography; GPS; Kamb Ice Stream; Ice Stream; FIELD SURVEYS; FIELD INVESTIGATION; Not provided; Ice Penetrating Radar; Ice Stream C; Velocity; Surface Strain Rates; Antarctic", "locations": "Antarctic; Kamb Ice Stream; Ice Stream C", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Tulaczyk, Slawek; Joughin, Ian", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repositories": null, "science_programs": null, "south": -82.8, "title": "Collaborative Research: Is Kamb Ice Stream Restarting? Glaciological Investigations of the Bulge-Trunk Transition on Kamb Ice Stream, West Antarctica", "uid": "p0000238", "west": -139.0}, {"awards": "0233823 Fountain, Andrew; 0230338 Hallet, Bernard", "bounds_geometry": "POLYGON((162.132 -77.73,162.1495 -77.73,162.167 -77.73,162.1845 -77.73,162.202 -77.73,162.2195 -77.73,162.237 -77.73,162.2545 -77.73,162.272 -77.73,162.2895 -77.73,162.307 -77.73,162.307 -77.7303,162.307 -77.7306,162.307 -77.7309,162.307 -77.7312,162.307 -77.7315,162.307 -77.7318,162.307 -77.7321,162.307 -77.7324,162.307 -77.7327,162.307 -77.733,162.2895 -77.733,162.272 -77.733,162.2545 -77.733,162.237 -77.733,162.2195 -77.733,162.202 -77.733,162.1845 -77.733,162.167 -77.733,162.1495 -77.733,162.132 -77.733,162.132 -77.7327,162.132 -77.7324,162.132 -77.7321,162.132 -77.7318,162.132 -77.7315,162.132 -77.7312,162.132 -77.7309,162.132 -77.7306,162.132 -77.7303,162.132 -77.73))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 02 Jul 2008 00:00:00 GMT", "description": "This award supports a comprehensive study of land-based polar ice cliffs. Through field measurements, modeling, and remote sensing, the physics underlying the formation of ice cliffs at the margin of Taylor Glacier in the McMurdo Dry Valleys will be investigated. At three sites, measurements of ice deformation and temperature fields near the cliff face will be combined with existing energy balance data to quantify ice-cliff evolution over one full seasonal cycle. In addition, a small seismic network will monitor local \"ice quakes\" associated with calving events. Numerical modeling, validated by the field data, will enable determination of the sensitivity of ice cliff evolution to environmental variables. There are both local and global motivations for studying the ice cliffs of Taylor Glacier. On a global scale, this work will provide insight into the fundamental processes of calving and glacier terminus A better grasp of ice cliff processes will also improve boundary conditions required for predicting glaciers\u0027 response to climate change. Locally, the Taylor Glacier is an important component of the McMurdo Dry Valleys landscape and the results of this study will aid in defining ecologically-important sources of glacial meltwater and will lead to a better understanding of moraine formation at polar ice cliffs. This study will help launch the career of a female scientist, will support one graduate student, and provide experiential learning experiences for two undergraduates. The post-doctoral researcher will also use this research in the curriculum of a wilderness science experiential education program for high school girls.", "east": 162.307, "geometry": "POINT(162.2195 -77.7315)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOCOUPLES \u003e THERMOCOUPLES; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e SURVEYING TOOLS", "is_usap_dc": false, "keywords": "SEISMOLOGICAL STATIONS; Ice Quakes; Ice Cliffs; Not provided; Taylor Glacier; FIELD SURVEYS; Remote Sensing; GROUND-BASED OBSERVATIONS; Modeling; Ice Deformation; Glacial Meltwater; FIELD INVESTIGATION; McMurdo Dry Valleys", "locations": "McMurdo Dry Valleys; Taylor Glacier", "north": -77.73, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Hallet, Bernard; Fountain, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided", "repositories": null, "science_programs": null, "south": -77.733, "title": "Collaborative Research: Mechanics of Dry-Land Calving of Ice Cliffs", "uid": "p0000721", "west": 162.132}, {"awards": "0233303 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.\u003cbr/\u003eThis award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.\u003cbr/\u003eA better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Ice Sheet; Basal Melting; Ice Shelf Meltwater; Not provided; Oceanography; Ice Velocity; Glaciology; Sea Level Rise; Ice Sheet Stability; Mass; Ross Ice Sheet; Numerical Model; Basal Freezing; Ice Cavity Circulations; George VI Ice Shelf; Outflow", "locations": "Ross Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Melting and Calving of Antarctic Ice Shelves", "uid": "p0000730", "west": null}, {"awards": "0229629 Anandakrishnan, Sridhar", "bounds_geometry": "POLYGON((-165 -82,-161.5 -82,-158 -82,-154.5 -82,-151 -82,-147.5 -82,-144 -82,-140.5 -82,-137 -82,-133.5 -82,-130 -82,-130 -82.2,-130 -82.4,-130 -82.6,-130 -82.8,-130 -83,-130 -83.2,-130 -83.4,-130 -83.6,-130 -83.8,-130 -84,-133.5 -84,-137 -84,-140.5 -84,-144 -84,-147.5 -84,-151 -84,-154.5 -84,-158 -84,-161.5 -84,-165 -84,-165 -83.8,-165 -83.6,-165 -83.4,-165 -83.2,-165 -83,-165 -82.8,-165 -82.6,-165 -82.4,-165 -82.2,-165 -82))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 14 Jun 2007 00:00:00 GMT", "description": "This award supports a project to investigate the new-found, startling sensitivity of two major West Antarctic ice streams to tidal oscillations to learn the extent and character of the effect and its ramifications for future ice-stream behavior. Ice streams D, C and Whillans (B) all show strong but distinct tidal signals. The ice plain of Whillans is usually stopped outright, forward motion being limited to two brief periods each day, at high tide and on the falling tide. Motion events propagate across the ice plain at seismic wave velocities. Near the mouth of D, tides cause a diurnal variation of about 50% in ice-stream speed that propagates upglacier more slowly than on Whillans, and seismic data show that C experiences even slower upglacier propagation of tidal signals. Tidal influences are observed more than 100 km upglacier on C, more than 40 km upglacier on D, and may be responsible for fluctuations in basal water pressure reported 400 km upstream on Whillans, nearly the full length of the ice stream. During the first year, the spatial extent of this behavior will be measured on Whillans Ice Stream and ice stream D by five coordinated seismic and GPS instrument packages at 100-km spacing on each ice stream. These packages will be deployed by Twin Otter at sites selected by review of satellite imagery and will operate autonomously through a combination of solar and battery power for two lunar cycles to study the sensitivity of the ice stream motion to spring and neap tides. Additionally, existing data sets will be examined further for clues to the mechanisms involved, and preliminary models will be developed to reconcile the seemingly contrasting behaviors observed on the ice streams. The second and third field seasons will examine in greater detail the tidal behavior of Whillans (year 2) and D (year 3). Work will especially focus on detailed study of at least one source area for events on Whillans, assuming that source areas inferred from preliminary data remain active. Vertical motions have not yet been detected, but differential GPS will increase our detection sensitivity. Seismic instrumentation will greatly increase temporal resolution and the ability to measure the propagation speed and any spatial heterogeneity. Modeling will be refined as more is learned from the field experiments. The project should yield numerous broader impacts. The improved knowledge of ice-stream behavior from this study will contribute to assessment of the potential for rapid ice-sheet change affecting global sea level with societal consequences. Results will be disseminated through scientific publication and talks at professional meetings, as well as contacts with the press, university classes taught by the PIs, visits to schools and community groups, and other activities. Two graduate students will be educated through the project.", "east": -130.0, "geometry": "POINT(-147.5 -83)", "instruments": null, "is_usap_dc": false, "keywords": "Ice Stream; Tidal Motion; Vertical Motions; Seismic; West Antarctic; Ice Stream Motion; Global Sea Level; Modeling; Not provided", "locations": "West Antarctic", "north": -82.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar; Alley, Richard; Voigt, Donald E.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -84.0, "title": "Collaborative Research: Tidal Modulation of Ice Stream Flow", "uid": "p0000075", "west": -165.0}, {"awards": "0337838 Fricker, Helen", "bounds_geometry": "POINT(71 -69.75)", "dataset_titles": "Access to data", "datasets": [{"dataset_uid": "001537", "doi": "", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "Access to data", "url": "http://www.iris.edu/data/data.htm"}], "date_created": "Fri, 27 Apr 2007 00:00:00 GMT", "description": "This award supports a comprehensive study of rift growth on the Amery Ice Shelf (AIS), East Antarctica, using a combination of in situ and remote sensing data with numerical modeling. On the AIS there is an opportunity to examine an active rift system, which is a combination of two longitudinal-to-flow rifts, which originated at the ice shelf front in the suture zones between merging flowbands, and two transverse-to-flow rifts, which formed at the tip of the western longitudinal rift around 1996. Work in progress indicates that these two transverse rifts do not propagate independently of each other, but somehow grow more or less synchronously. The longest of these rifts-the eastern one-grows at an average rate of about 8m per day. When it meets the eastern longitudinal rift, an event that is expected to occur during the funding period (mid-2006), an iceberg (~30 x 30 km) will calve. Based on observations collected over the past half century, there is reason to believe that such a calving event may be a part of a repetitive sequence. In the proposed project, the expansion and propagation of both transverse rifts will be studied using a network of GPS and seismometers deployed around the tip of each transverse rift. Once the iceberg has calved, the effects its calving has on the dynamics of the ice shelf and the activation of previously inactive rifts will also be studied. Insofar as the rate of calving activity is a proxy for local and regional climate conditions, a broader impact of the proposed work is directly related to the socio-environmental topics of climate and sea-level change. The subject of iceberg calving has a history of sparking a great deal of interest from the media and the public alike, especially since the recent large calving events from the Ross and Ronne ice shelves and the remarkably sudden break-up of the Larsen Ice Shelf. The work will involve at least one graduate student, and will involve a partnership with a local charter high school. Field work, instrument deployments, and data collection and analysis will be conducted in close collaboration with the Australian Antarctic Division and the University of Tasmania, which has been a crucial component of research conducted to date. This project will also make use of the Scripps Institution of Oceanography Visualization Center as a means to display results to faculty and researchers of the University of California, San Diego, undergraduate and graduate students, to school children and their teachers, and ultimately to the visiting public.", "east": 71.0, "geometry": "POINT(71 -69.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS", "is_usap_dc": false, "keywords": "Not provided; Geodesy; Seismic", "locations": null, "north": -69.75, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fricker, Helen; Minster, Jean-Bernard", "platforms": "Not provided", "repo": "IRIS", "repositories": "IRIS", "science_programs": null, "south": -69.75, "title": "Monitoring an Active Rift System at the Front of Amery Ice Shelf, East Antarctica", "uid": "p0000668", "west": 71.0}, {"awards": "0538475 Bart, Philip", "bounds_geometry": "POLYGON((-180 -75,-178 -75,-176 -75,-174 -75,-172 -75,-170 -75,-168 -75,-166 -75,-164 -75,-162 -75,-160 -75,-160 -75.3,-160 -75.6,-160 -75.9,-160 -76.2,-160 -76.5,-160 -76.8,-160 -77.1,-160 -77.4,-160 -77.7,-160 -78,-162 -78,-164 -78,-166 -78,-168 -78,-170 -78,-172 -78,-174 -78,-176 -78,-178 -78,-180 -78,-180 -77.7,-180 -77.4,-180 -77.1,-180 -76.8,-180 -76.5,-180 -76.2,-180 -75.9,-180 -75.6,-180 -75.3,-180 -75))", "dataset_titles": "NBP0802 and NBP0803 Sediment samples (full data link not provided); NBP0802 data; NBP0803 data", "datasets": [{"dataset_uid": "000138", "doi": "", "keywords": null, "people": null, "repository": "AMGRF", "science_program": null, "title": "NBP0802 and NBP0803 Sediment samples (full data link not provided)", "url": "http://www.arf.fsu.edu/"}, {"dataset_uid": "000123", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0803 data", "url": "https://www.rvdata.us/search/cruise/NBP0803"}, {"dataset_uid": "000122", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP0802 data", "url": "https://www.rvdata.us/search/cruise/NBP0802"}], "date_created": "Thu, 29 Mar 2007 00:00:00 GMT", "description": "This project determines the recent history of the West Antarctic Ice Sheet (WAIS) through a multidisciplinary study of the seabed in the Ross Sea of Antarctica. WAIS is perhaps the world\u0027s most critical ice sheet to sea level rise dut to near-future global warming. its history has been a key focus for the past decade, but there are significant questions as to whether WAIS was stable during the last glacial maximum--about 20,000 years ago--or undergoing advance and retreat. This project studies grounding zone translantions in Eastern Basin to constrain WAIS movements using a multidisciplinary approach that integrates multibeam bathymetry, seismic stratigraphy, sedimentology, diatom biostratigraphy, radiocarbon dating, 10Be concentration analyses, and numerical modeling.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts include improving society\u0027s understanding of sea level rise linked to global warming; postdoctoral, graduate, and undergraduate education; and expanding the participation of groups underrepresented in Earth sciences through links with LSU\u0027s Geoscience Alliance to Encourage Minority Participation.", "east": -160.0, "geometry": "POINT(-170 -76.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e WATERGUNS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "Ross Sea; R/V NBP; Ice Sheet; Last Glacial Maximum; Seismic Stratigraphy", "locations": "Ross Sea", "north": -75.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Bart, Philip; Tomkin, Jonathan", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "AMGRF", "repositories": "AMGRF; R2R", "science_programs": null, "south": -78.0, "title": "WAIS grounding-zone migrations in Eastern Basin, Ross Sea and the LGM dilemma: New strategies to resolve the style and timing of outer continental shelf grounding events", "uid": "p0000539", "west": -180.0}, {"awards": "0408475 Harry, Dennis", "bounds_geometry": "POINT(-175 -85)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Mar 2007 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research to apply numerical modeling to constrain the uplift and exhumation history of the Transantarctic Mountains. The Transantarctic Mountains (TAM) are an anomalously high (\u003e4500 m) and relatively broad (up to 200 km) rift-flank uplift demarcating the boundary between East and West Antarctica. Dynamics of the East Antarctic ice-sheet and the climate are affected by the mountain range, and an understanding of the uplift history of the mountain range is critical to understanding these processes. This project will constrain the uplift and denudation history of the Transantarctic Mountains based on thermo-mechanical modeling held faithful to thermochronological, geological, and geophysical data. The research will be the primary responsibility of post-doctoral researcher Audrey Huerta, working in collaboration with Dennis Harry, 1 undergraduate student, and 1 graduate student.\u003cbr/\u003e\u003cbr/\u003eThermochronologic evidence of episodic Cretaceous through Cenozoic rapid cooling within the TAM indicates distinct periods of uplift and exhumation. However, a more detailed interpretation of the uplift history is difficult without an understanding of the evolving thermal structure and topography of the TAM prior to and during uplift. These aspects of the mountain range can best be constrained by an understanding of the evolving regional tectonic setting. Proximity of the TAM to the West Antarctic Rift System (WARS) suggests a link between uplift of the TAM and extension within the WARS.\u003cbr/\u003e\u003cbr/\u003eThe project will integrate two techniques: lithospheric-scale geodynamic modeling and crustal-scale thermal modeling. The lithospheric-scale deformational and thermal evolution of TAM will be modeled by a finite element model designed to track the thermal and deformational response of the Antarctic lithosphere to a protracted extensional environment. Previous investigators have linked the high elevation and broad width of the TAM to a deep level of necking in which mantle thinning is offset from the location of crustal extension. In this study, a three-dimensional dynamic model will be used to track the uplift and thermal evolution of the TAM in a setting in which necking is at a deep level, and in which extension within the crust and extension within the mantle are offset. Velocity boundary conditions applied to the edges of the model will vary through time to simulate the extensional and transtensional evolution of the WARS. Because the model is dynamic, the thermal structure, strength, and strain field, evolve naturally in response to these initial and boundary conditions.\u003cbr/\u003e\u003cbr/\u003eDynamic models are uniquely suited to understanding lithospheric deformational and thermal evolution, however kinematic models are best suited for addressing the detailed thermal and exhumation history of crustal uplifts. Thus, a 2-dimensional kinematic-thermal model will be designed to simulate the uplift history of the TAM and the resulting erosional, topographic, and thermal evolution. Uplift will be modeled as normal-fault movement on a set of discrete fault planes with uplift rate varying through time. Erosion will be modeled as a diffusive process in which erosion rates can be varied through time (simulating climate changes), and vary spatially as a linear function of gradient and distance from the drainage divide. Synthetic time-temperature (t-T) histories will be calculated to compare model results to thermochronologic data.", "east": -175.0, "geometry": "POINT(-175 -85)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -85.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC; PHANEROZOIC \u003e MESOZOIC \u003e CRETACEOUS; PHANEROZOIC \u003e CENOZOIC \u003e PALEOGENE", "persons": "Huerta, Audrey D.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -85.0, "title": "Uplift and Exhumation of the Transantarctic Mountains and Relation to Rifting in West Antarctica", "uid": "p0000728", "west": -175.0}, {"awards": "0229292 Cressie, Noel", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 28 Feb 2007 00:00:00 GMT", "description": "Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice\u003cbr/\u003esheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Surface Elevation; Stress Field; Basal Elevation; DHC-6", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cressie, Noel; Jezek, Kenneth; Berliner, L.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repositories": null, "science_programs": null, "south": null, "title": "Dynamics of Ice Streams: A Physical Statistical Approach", "uid": "p0000711", "west": null}, {"awards": "9814816 Blankenship, Donald", "bounds_geometry": "POLYGON((-129 -80.5,-128.4 -80.5,-127.8 -80.5,-127.2 -80.5,-126.6 -80.5,-126 -80.5,-125.4 -80.5,-124.8 -80.5,-124.2 -80.5,-123.6 -80.5,-123 -80.5,-123 -80.55,-123 -80.6,-123 -80.65,-123 -80.7,-123 -80.75,-123 -80.8,-123 -80.85,-123 -80.9,-123 -80.95,-123 -81,-123.6 -81,-124.2 -81,-124.8 -81,-125.4 -81,-126 -81,-126.6 -81,-127.2 -81,-127.8 -81,-128.4 -81,-129 -81,-129 -80.95,-129 -80.9,-129 -80.85,-129 -80.8,-129 -80.75,-129 -80.7,-129 -80.65,-129 -80.6,-129 -80.55,-129 -80.5))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 13 Feb 2007 00:00:00 GMT", "description": "9814816 Blankenship This award supports a four year project to develop of better understanding the ice streams of the Ross Sea Embayment (A--F) which drain the interior West Antarctic Ice Sheet (WAIS) by rapidly moving vast quantities of ice to the calving front of the Ross Ice Shelf. The project will examine the role of these ice streams as buffers between the interior ice and the floating ice shelves. The reasons for their fast flow, the factors controlling their current grounding-line-, margin-, and head-positions are crucial to any attempt at modeling the WAIS system and predicting the future of the ice sheet. For the Antarctic ice streams of the Siple Coast, the transition from no-sliding (or all internal deformation) to motion dominated by sliding is defined as the \"onset-region\". To fully understand (and adequately model) the WAIS, this onset region must be better understood. The lateral margins of the ice streams are also a transition that need better explanation. Hypotheses on controls of the location of the onset region range from the \"purely-glaciologic\" to the \"purely-geologic. Thus, to model the ice sheet accurately, the basal boundary conditions (roughness, wetness, till properties) and a good subglacial geologic map, showing the distribution, thickness, and properties of the sedimentary basins, are required. These parameters can be estimated from seismic, radar, and other geophysical methods. The transition region of ice stream D will be studied in detail with this coupled geophysical experiment. In addition, selected other locations on ice streams C \u0026 D will be made, to compare and contrast conditions with the main site on ice stream D. Site-selection for the main camp will be based on existing radar, GPS, and satellite data as well as input from the modeling community.", "east": -123.0, "geometry": "POINT(-126 -80.75)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -80.5, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Blankenship, Donald D.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -81.0, "title": "Collaborative Research: Characterizing the Onset of Ice Stream Flow: A Ground Geophysical Field Program", "uid": "p0000603", "west": -129.0}, {"awards": "0230197 Holt, John", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; Amundsen Sea Sector Data Set; Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "datasets": [{"dataset_uid": "609292", "doi": "10.7265/N59W0CDC", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Solid Earth", "people": "Corr, Hugh F. J.; Holt, John W.; Blankenship, Donald D.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609292"}, {"dataset_uid": "609312", "doi": "10.7265/N5J9649Q", "keywords": "Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Fastook, James L.", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Sector Data Set", "url": "https://www.usap-dc.org/view/dataset/609312"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Muldoon, Gail R.; Blankenship, Donald D.; Jackson, Charles; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}], "date_created": "Mon, 01 Jan 2007 00:00:00 GMT", "description": "This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical\u003cbr/\u003edata will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.\u003cbr/\u003eThe West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea\u003cbr/\u003elevel rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical\u003cbr/\u003ecenters. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.\u003cbr/\u003eThe results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.\u003cbr/\u003eThrough its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": true, "keywords": "Thwaites Glacier; Ice Velocity; Ablation; Amundsen Sea; Pine Island Glacier; Elevation; Antarctica (agasea); Ice Sheet Elevation; West Antarctic Ice Sheet; Ice Temperature; Amundsen Basin; Subglacial Topography; Ice Melt; West Antarctica; Velocity Measurements; Snow Accumulation; Antarctica; Bedrock Elevation; Modeling", "locations": "Antarctica; West Antarctica; Amundsen Basin; Pine Island Glacier; Thwaites Glacier; West Antarctic Ice Sheet; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "uid": "p0000243", "west": -180.0}, {"awards": "9526566 Bindschadler, Robert", "bounds_geometry": null, "dataset_titles": "Decadal-Length Composite West Antarctic Air Temperature Records", "datasets": [{"dataset_uid": "609097", "doi": "10.7265/N55D8PS0", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Meteorology; Temperature; West Antarctica", "people": "Stearns, Charles R.; Shuman, Christopher A.", "repository": "USAP-DC", "science_program": null, "title": "Decadal-Length Composite West Antarctic Air Temperature Records", "url": "https://www.usap-dc.org/view/dataset/609097"}], "date_created": "Tue, 28 Nov 2006 00:00:00 GMT", "description": "This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SMMR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SSM/I", "is_usap_dc": true, "keywords": "West Antarctica; Near-Surface Air Temperatures; Surface Temperatures; Special Sensor Microwave/imager; Passive Microwave Brightness Temperatures; Scanning Multichannel Microwave Radiometer; SSM/I; SSMR; AWS Byrd Station; NIMBUS-7; Emissivity Modeling; Antarctica; West Antarctic Ice Sheet; Not provided; DMSP; AWS Siple; Automated Weather Station; AWS Lynn; AWS Lettau; AWS", "locations": "Antarctica; West Antarctica; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bindschadler, Robert; Shuman, Christopher A.; Stearns, Charles R.", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e DEFENSE METEOROLOGICAL SATELLITE PROGRAM (DMSP) \u003e DMSP; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NIMBUS \u003e NIMBUS-7", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Passive Microwave Remote Sensing for Paleoclimate Indicators at Siple Dome, Antarctica", "uid": "p0000191", "west": null}, {"awards": "0230452 Severinghaus, Jeffrey", "bounds_geometry": "POINT(124.5 -80.78)", "dataset_titles": "Antarctic megadunes", "datasets": [{"dataset_uid": "000191", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Antarctic megadunes", "url": "http://nsidc.org/antarctica/megadunes/"}], "date_created": "Wed, 27 Sep 2006 00:00:00 GMT", "description": "This award supports a study of the chemical composition of air in the snow layer (firn) in a region of \"megadunes\" near Vostok station, Antarctica. It will test the hypothesis that a deep \"convective zone\" of vigorous wind-driven mixing can prevent gas fractionation in the upper one-third of the polar firn layer. In the megadunes, ultralow snow accumulation rates lead to structural changes (large grains, pipes, and cracks) that make the permeability of firn to air movement orders of magnitude higher than normal. The unknown thickness of the convective zone has hampered the interpretation of ice core 15N/14N and 40Ar/36Ar ratios as indicators of past firn thickness, which is a key constraint on the climatically important variables of temperature, accumulation rate, and gas age-ice age difference. Studying this \"extreme end-member\" example will better define the role of the convective zone in gas reconstructions. This study will pump air from a profile of ~20 depths in the firn, to definitively test for the presence of a convective zone based on the fit of observed 15 N/14N and 40Ar/36Ar to a molecular- and eddy-diffusion model. Permeability measurements on the core and 2-D air flow modeling (in collaboration with M. Albert) will permit a more physically realistic interpretation of the isotope data and will relate mixing vigor to air velocities. A new proxy indicator of convective zone thickness will be tested on firn and ice core bubble air, based on the principle that isotopes of slow-diffusing heavy noble gases (Kr, Xe) should be more affected by convection than isotopes of fast-diffusing N2 . These tools will be applied to a test of the hypothesis that the megadunes and a deep convective zone existed at the Vostok site during glacial periods, which would explain the anomalously low 15N/14N and 40Ar/36Ar in the Vostok ice core glacial periods. The broader impacts of this work include 1) clarification of phase relationships of greenhouse gases and temperature in ice core records, with implications for understanding of past and future climates, 2) education of one graduate student, and 3) building of collaborative relationships with five investigators.", "east": 124.5, "geometry": "POINT(124.5 -80.78)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS", "is_usap_dc": false, "keywords": "Antarctica; Methane; Carbon-14; Permeability; CO2; Firn Core; FIELD SURVEYS; Deuterium Excess; GROUND-BASED OBSERVATIONS; LABORATORY; Isotope; Ice Core Density; Firn Air; Megadunes; Ice Core; Not provided; FIELD INVESTIGATION", "locations": "Antarctica", "north": -80.78, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bauer, Rob; Albert, Mary R.; Severinghaus, Jeffrey P.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NSIDC", "repositories": "NSIDC", "science_programs": null, "south": -80.78, "title": "How Thick Is the Convective Zone: A Study of Firn Air in the Megadunes Near Vostok, Antarctica", "uid": "p0000097", "west": 124.5}, {"awards": "0126149 Liu, Hongxing", "bounds_geometry": null, "dataset_titles": "Access to Antarctic coastline coverage and reference documents; Access to Antarctic snow zone coverage and reference documents; Access to boundary file and reference documents; Access to ice velocity data and reference documents; Access to snow melt extent image files and reference documents", "datasets": [{"dataset_uid": "001640", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to snow melt extent image files and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001779", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to ice velocity data and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001352", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to Antarctic snow zone coverage and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001351", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to Antarctic coastline coverage and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}, {"dataset_uid": "001350", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Access to boundary file and reference documents", "url": "http://geog.tamu.edu/~liu/research/download.htm"}], "date_created": "Tue, 15 Aug 2006 00:00:00 GMT", "description": "This award supports a project to characterize the morphology, ice motion velocity and mass balance of Lambert Glacier, Antarctica using state-of-the-art remote sensing and GIS techniques. Lambert Glacier is the largest ice stream in the world. Because of its size, it plays a fundamental role in the study of glacial dynamics and mass budget in response to present and future climate changes. Along with the bedrock topography and ice thickness data derived from airborne radio echo soundings and snow accumulation data compiled from ground-based measurements, the dynamic behavior and mass balance of the Lambert glacial basin in a Geographic Information Systems (GIS) environment will be examined. Specific objectives are to: (1) Extract two-dimensional ice velocity field over the entire Lambert glacial basin using speckle matching and differential interferometric SAR (InSAR) techniques, and produce a full coverage of radar coherence map over the drainage basin. With the ice velocity data, calculate the strain rate field from the initiation areas of the ice stream onto the Amery Ice Shelf; (2) Derive high-resolution digital elevation model (DEM) over the Lambert glacial drainage basin using SAR stereo, differential interferometric SAR, and GLAS laser altimetry techniques. Based on the DEM, extract ice divides and ice flow directions, delineate the snow catchment basin, and calculate the balance deformation velocity and the basal shear stress; (3) Interpolate traverse ice thickness data collected by Australian and Russian airborne radio echo sounding surveys into a regular grid, and derive a regular grid of bedrock topography in combination with the DEM; (4) Integrate newly derived ice velocity and ice thickness data as well as snow accumulation rate data compiled from previous ground-based measurements into a geographic information system (GIS), and calculate the mass flux through the ice stream at the grounding lines and net mass balance throughout the drainage basin. With these new measurements and calculations derived from advanced remote sensing techniques, we will be able to improve our understanding of dynamic behavior and current mass balance status of the Lambert glacial basin, gain an insight on the relationship between ice mass change and the variation in regional and global climate at decadal scale, and provide an evaluation on the issue of whether the Lambert glacier basin is subject to surging in the context of future climate change.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SMMR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e SSM/I; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IFSAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": false, "keywords": "DEM; Not provided; RADARSAT-1", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Liu, Hongxing; Jezek, Kenneth", "platforms": "Not provided; OTHER \u003e MODELS \u003e DEM; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-1", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": null, "title": "High-Resolution Modeling of Surface Topography, Ice Motion, and Mass Balance in the Lambert Glacial Basin using Radar Remote Sensing and GIS Techniques", "uid": "p0000204", "west": null}, {"awards": "0126187 Alley, Richard", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 11 Apr 2006 00:00:00 GMT", "description": "0126187\u003cbr/\u003eAlley\u003cbr/\u003e\u003cbr/\u003eThis award provides support for a 2 year modeling effort to study the dynamics of Pine Island Glacier (PIG). The discharge from the PIG constitutes the largest mass loss from any single West Antarctic ice stream. Satellite observations indicate that this outlet glacier is experiencing ongoing thinning and acceleration. The emphasis of this work will be on understanding the cause and the near-term projection of the observed thinning of PIG. Model experiments will address the hypothesis that the observed changes were caused by the loss of a buttressing ice shelf, and that the changes will continue in the form of an upglacier propagating wave of thinning and acceleration. To perform this work a numerical model of the coupled mass, energy, and momentum balance of Pine Island Glacier basin will be developed. The model will comprise four modular components, which will be coupled and then benchmarked against the European Ice Sheet Modeling Inititative (EISMINT) model intercomparison. The model will then be applied to the thinning of Pine Island Glacier using likely ice-shelf histories and possible basal boundary conditions to learn which may be accurate and to assess possible future behavior. The primary expected result will be an improved understanding of the importance of ice-shelf buttressing and the potential for inland thinning due to the reduction of ice-shelf drag.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alley, Richard; Dupont, Todd K.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "The Thinning of Pine Island Glacier: Model Development and Study of the Importance of Ice-Shelf Drag on Inland Ice", "uid": "p0000715", "west": null}, {"awards": "0088047 Bell, Robin", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Tue, 03 Jan 2006 00:00:00 GMT", "description": "0088047\u003cbr/\u003eBell\u003cbr/\u003e\u003cbr/\u003eThis award supports a two year project to address fundamental questions about the mass and energy flux through Lake Vostok, a subglacial lake in East Antarctica, sealed beneath almost 4 kilometers of ice. The project will involve developing lake circulation models, complemented by the analysis of new ice penetrating radar data over the lake and surrounding regions. This project will help to accurately define the regions of melting and freezing within the lake and help to provide an improved estimate of the form of the lake. The combined data analysis and modeling effort will provide a critical framework for developing international plans to sample the waters of Lake Vostok for biota and to recover sediments from Lake Vostok for paleoclimate studies.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Paleoclimate; Circulation Models; Lake Vostok; Data Analysis; Subglacial; Modeling; Not provided", "locations": "Lake Vostok", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bell, Robin; Tremblay, Bruno; Hohmann, Roland; Clarke, Garry; Studinger, Michael S.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Mass and Energy Fluxes Through Lake Vostok: Observations and Models", "uid": "p0000093", "west": null}, {"awards": "9909518 Raymond, Charles", "bounds_geometry": "POLYGON((-154 -80,-152 -80,-150 -80,-148 -80,-146 -80,-144 -80,-142 -80,-140 -80,-138 -80,-136 -80,-134 -80,-134 -80.5,-134 -81,-134 -81.5,-134 -82,-134 -82.5,-134 -83,-134 -83.5,-134 -84,-134 -84.5,-134 -85,-136 -85,-138 -85,-140 -85,-142 -85,-144 -85,-146 -85,-148 -85,-150 -85,-152 -85,-154 -85,-154 -84.5,-154 -84,-154 -83.5,-154 -83,-154 -82.5,-154 -82,-154 -81.5,-154 -81,-154 -80.5,-154 -80))", "dataset_titles": "Compilation of Antarctic Radar Data, Siple Coast, 2000-2002", "datasets": [{"dataset_uid": "609274", "doi": "10.7265/N5736NTS", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Siple Coast", "people": "Raymond, Charles; Conway, Howard; Catania, Ginny", "repository": "USAP-DC", "science_program": null, "title": "Compilation of Antarctic Radar Data, Siple Coast, 2000-2002", "url": "https://www.usap-dc.org/view/dataset/609274"}], "date_created": "Fri, 03 Jun 2005 00:00:00 GMT", "description": "9909518 Raymond This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide \"shutdown\" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.", "east": -134.0, "geometry": "POINT(-144 -82.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e AVHRR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "Ice Stream; West Antarctic Ice Sheet; Radarsat; Siple Dome; Radar; Ice Floe; Not provided; AVHRR; Siple Coast; Ice Stratigraphy; Margin Scars; NOAA POES; RAMP; GROUND-BASED OBSERVATIONS; Ice Flow; Accumulation Rate; Antarctic Ice Sheet; RADARSAT-1", "locations": "Siple Coast; Antarctic Ice Sheet; Siple Dome; West Antarctic Ice Sheet", "north": -80.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Raymond, Charles; Conway, Howard; Catania, Ginny", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e POLAR ORBITING ENVIRONMENTAL SATELLITES (POES) \u003e NOAA POES; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e RADARSAT \u003e RADARSAT-1", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research:History and Evolution of the Siple Coast Ice Stream Systems as Recorded by Former Shear-Margin Scars", "uid": "p0000275", "west": -154.0}, {"awards": "0135989 Wilen, Larry", "bounds_geometry": null, "dataset_titles": "Ice Fabric Characteristics: Siple Dome, A Core", "datasets": [{"dataset_uid": "609255", "doi": "10.7265/N54B2Z7V", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Siple Dome Ice Core", "people": "Wilen, Larry", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Ice Fabric Characteristics: Siple Dome, A Core", "url": "https://www.usap-dc.org/view/dataset/609255"}], "date_created": "Wed, 02 Mar 2005 00:00:00 GMT", "description": "0135989\u003cbr/\u003eWilen\u003cbr/\u003e\u003cbr/\u003eThis is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "GROUND-BASED OBSERVATIONS; Ice Core Data; Siple Dome; Ice Fabric; Ice Core; USAP-DC", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Arctic Natural Sciences", "paleo_time": null, "persons": "Wilen, Larry", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Collaborative Research: Fabric and Texture Characteristics of Micro-Physical Processes in Ice", "uid": "p0000134", "west": null}, {"awards": "9909469 Scambos, Ted", "bounds_geometry": null, "dataset_titles": "Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica", "datasets": [{"dataset_uid": "609141", "doi": "10.7265/N5WS8R52", "keywords": "Antarctica; Geodesy; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Kamb Ice Stream", "people": "Scambos, Ted; Raymond, Charles; Gades, Anthony; Conway, Howard; Catania, Ginny", "repository": "USAP-DC", "science_program": null, "title": "Ice Motion and Topography Near Margin Areas of Kamb Ice Stream, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609141"}], "date_created": "Fri, 01 Aug 2003 00:00:00 GMT", "description": "9909469 Scambos This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide \"shutdown\" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS RECEIVERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Ice Velocity; Ice Acceleration; Ice Sheet Elevation; GROUND-BASED OBSERVATIONS; Ice Stream; Antarctic Ice Sheet; Ice Sheet; Ice Surface Elevation; Ice Position; Ice Surface; Ice Stream C Velocities; Ice Movement; Ice; Cryosphere", "locations": "Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Catania, Ginny; Conway, Howard; Gades, Anthony; Raymond, Charles", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: History and Evolution of the Siple Coast Ice Stream System as Recorded by Former Shear-Margin Scars", "uid": "p0000165", "west": null}, {"awards": "9526572 Bales, Roger", "bounds_geometry": null, "dataset_titles": "Snow-atmosphere Transfer Function for Reversibly Deposited Chemical Species in West Antarctica", "datasets": [{"dataset_uid": "609122", "doi": "10.7265/N5ZP441W", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Siple Dome; Snow/ice; Snow/Ice; WAISCORES", "people": "Bales, Roger; McConnell, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Snow-atmosphere Transfer Function for Reversibly Deposited Chemical Species in West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609122"}], "date_created": "Thu, 11 Jul 2002 00:00:00 GMT", "description": "This award is for support for a program of measurements to improve our understanding of the relationship between formaldehyde (HCHO) and hydrogen peroxide (H2O2) in the atmosphere and the concentrations of the same species in Antarctic snow, firn and ice. This work aims to relate changes in concentrations in the snow, firn and ice to corresponding changes in tropospheric chemistry. Atmospheric and firn sampling for formaldehyde and hydrogen peroxide at one or more of the WAIS ice core drilling sites will be undertaken and controlled laboratory studies to estimate thermodynamic and rate parameters will be performed. In addition, this work will involve modeling of atmosphere-snow exchange processes to infer the \"transfer function\" for reactive species at the sites and atmospheric photochemical modeling to relate changes in concentrations of formaldehyde and hydrogen peroxide in snow, firn and ice to atmospheric oxidation capacity. This work will contribute to a better understanding of the relationship between atmospheric concentrations of various species and those same species measured in snow and ice samples.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Siple Dome; Antarctica; Isotope; WAISCORES; GROUND-BASED OBSERVATIONS; GROUND STATIONS; Snow; Glaciology; LABORATORY; Siple; Siple Coast; Thermometry; Hydrogen Peroxide; Ice Sheet", "locations": "Antarctica; Siple; Siple Coast; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bales, Roger; McConnell, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Snow-Atmosphere Transfer Function for Reversibly Deposited Chemical Species in West Antarctica", "uid": "p0000060", "west": null}, {"awards": "9530379 Anderson, Robert", "bounds_geometry": "POLYGON((-180 -54,-179 -54,-178 -54,-177 -54,-176 -54,-175 -54,-174 -54,-173 -54,-172 -54,-171 -54,-170 -54,-170 -55.2,-170 -56.4,-170 -57.6,-170 -58.8,-170 -60,-170 -61.2,-170 -62.4,-170 -63.6,-170 -64.8,-170 -66,-171 -66,-172 -66,-173 -66,-174 -66,-175 -66,-176 -66,-177 -66,-178 -66,-179 -66,180 -66,145 -66,110 -66,75 -66,40 -66,5 -66,-30 -66,-65 -66,-100 -66,-135 -66,-170 -66,-170 -64.8,-170 -63.6,-170 -62.4,-170 -61.2,-170 -60,-170 -58.8,-170 -57.6,-170 -56.4,-170 -55.2,-170 -54,-135 -54,-100 -54,-65 -54,-30 -54,5 -54,40 -54,75 -54,110 -54,145 -54,-180 -54))", "dataset_titles": "Data sets for RVIB Nathaniel B Palmer February-April, 1998, cruise; U.S. JGOFS Southern Ocean (AESOPS) Data", "datasets": [{"dataset_uid": "002116", "doi": "", "keywords": null, "people": null, "repository": "JGOF", "science_program": null, "title": "Data sets for RVIB Nathaniel B Palmer February-April, 1998, cruise", "url": "http://usjgofs.whoi.edu/jg/dir/jgofs/southern/nbp98_2/"}, {"dataset_uid": "002115", "doi": "", "keywords": null, "people": null, "repository": "JGOF", "science_program": null, "title": "U.S. JGOFS Southern Ocean (AESOPS) Data", "url": "http://usjgofs.whoi.edu/southernobjects.html"}, {"dataset_uid": "000249", "doi": "", "keywords": null, "people": null, "repository": "JGOF", "science_program": null, "title": "U.S. JGOFS Southern Ocean (AESOPS) Data", "url": "http://usjgofs.whoi.edu/southernobjects.html"}], "date_created": "Thu, 01 Jan 1970 00:00:00 GMT", "description": "9530379 Anderson This research project is part of the US Joint Global Ocean Flux Study (JGOFS) Southern Ocean Program aimed at (1) a better understanding of the fluxes of carbon, both organic and inorganic, in the Southern Ocean, (2) identifying the physical, ecological and biogeochemical factors and processes which regulate the magnitude and variability of these fluxes, and (3) placing these fluxes into the context of the contemporary global carbon cycle. This work is one of forty-four projects that are collaborating in the Southern Ocean Experiment, a three- year effort south of the Antarctic Polar Frontal Zone to track the flow of carbon through its organic and inorganic pathways from the air-ocean interface through the entire water column into the bottom sediment. The experiment will make use of the RVIB Nathaniel B. Palmer and the R/V Thompson. This component is a study of how naturally radioactive material in the ocean sediment may be used to reconstruct the flux of biogenic material through the water column to the sediment, and by inference, the productivity of the surface layers. There is evidence that the current surface conditions of high nutrient levels, but low chlorophyll levels do not extend back into colder climatic epochs, and that an examination of radionuclides may allow the reconstruction of rates of paleoproductivity. Two aspects of the biogeochemical cycling and physical transport of radionuclide tracers in the modern ocean will be investigated. In the first part, the concentration of a series of natural radionuclide tracers (thorium-230, protactinium-231, and Beryllium-10) in the Southern Ocean will be measured for their scavenging behavior both in the water column and in particulate material collected by sediment traps. The goal is to test the proposed use of radionuclide ratios as proxy variables for the export flux. In the second part, the concentration values will be introduced into an ocean general circulat ion model to evaluate the transport of radionuclides by the ocean circulation on scales that are larger than the spatial gradients in particle flux. These combined efforts will better define our ability to use radionuclide ratios to evaluate past changes in ocean productivity, and improve our understanding of the response of ocean productivity to climate variability. ***", "east": -170.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "Beryllium; Calcium Carbonate; Thorium; Radionulides; Radiocarbon; Organic Carbon; Pa; Protactinium; Uranium; Opal; Th; Be; NBP9802; U; Not provided", "locations": null, "north": -54.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Anderson, Robert", "platforms": "Not provided", "repo": "JGOF", "repositories": "JGOF", "science_programs": null, "south": -66.0, "title": "Proxies of Past Changes in Southern Ocean Productivity: Modeling and Experimental Development", "uid": "p0000713", "west": -170.0}]
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Since 1990, Palmer LTER (PAL) research has been guided by the hypothesis that variability in the polar marine ecosystem is mechanistically coupled to changes in the annual advance, retreat and spatial extent of sea ice. Since that time, the hypothesis has been modified to incorporate climate migration, i.e. the displacement of a cold, dry polar climate by a warm, moist climate regime in the northern component of the PAL region, producing fundamental changes in food web structure and elemental cycling. The observed northern changes are affecting all trophic levels and elemental cycling, and the primary mechanism of change involves match-mismatch dynamics. The proposed research builds on previous findings, with a new emphasis on process studies and modeling to elucidate the mechanistic links between teleconnections, climate change, physical oceanographic forcing and ecosystem dynamics. The proposed research will examine the hypothesis that regional warming and sea ice decline associated with historical and on-going climate migration in the northern part of the study area have altered key phenological relationships, leading to changes in species distributions, increasing trophic mismatches and changes in habitat, food availability, ecosystem dynamics and biogeochemical cycling. Through targeted process studies linked to numerical model simulations, the research also will test the hypothesis that deep cross-shelf canyons characterizing the core study region are focal areas for ecosystem processes that result in predictable, elevated food resources for top-predators. The effort includes the addition of 3 new PIs: a zooplankton ecologist with expertise in biogeochemical fluxes, a phytoplankton ecologist focusing on bio-optics and autonomous observations using gliders, and a numerical simulation modeler specializing in coupled global models of ocean circulation, plankton ecology and biogeochemical cycles. The program will add trace metal sampling and analysis, moored physical oceanographic sensors, a moored sediment trap in the south, drifting sediment traps and stable carbon (del 13C) and nitrogen (del 15N) isotope analyses. Missions lasting up to 45 days using gliders deployed before, during and after summer cruises will, along with moorings and satellite remote sensing of sea ice, ocean color, sea surface temperatures and wind fields, greatly extend the observational program in space and time. Since its inception, PAL has been a leader in Information Management to enable knowledge-building within and beyond the Antarctic, oceanographic and LTER communities. PAL has designed and deployed a new information infrastructure with a relational database architecture to facilitate data distribution and sharing. The Education and Outreach program capitalizes on the public's fascination with Antarctica to promote scientific literacy from kindergarten students to adult citizens concerned with climate change and environmental sustainability. Through communicating results to the public and working with scientific assessment bodies (e.g., IPCC) and Antarctic Treaty parties to protect Earth's last frontier, PAL researchers contribute to the national scientific agenda and the greater public benefit.
Marine protected areas (MPAs) are protected areas of seas, oceans, and estuaries. They need coordinated research and monitoring for informed management to fulfill their conservation potential. Coordination is challenging, however, often due to knowledge gaps caused by inadequate access to data and resources, compounded by insufficient communication between scientists and managers. This Research Coordinating Network (RCN) uses the world’s largest MPA in the Ross Sea, Antarctica, as a model system to create an international interdisciplinary network supporting policy-relevant research and monitoring that could be implemented in other remote, large-scale international MPAs. The first 10-year review of the Ross Sea MPA in 2027 will present a critical opportunity to coordinate across science, policy, and other partner communities to ensure the 2027 review (and subsequent reviews) are well grounded in robust scientific data, analyses, and streamlined inputs into policy. Many Antarctic research, policy, and conservation groups exist, some are even already focused on the Ross Sea, but there is not yet a formalized framework for coordination. Hence, the need for an RCN which can formalize connections among policy, research, and other communities focused specifically on research and monitoring of the Ross Sea region MPA. The RCN also provides an example of how to bring together diverse interdisciplinary participants towards an effective, integrated science-policy collaboration. To fulfill their conservation potential and provide safeguards for biodiversity, Marine Protected Areas (MPAs) need coordinated research and monitoring for informed management through effective evaluation of ecosystem dynamics. The Ross Sea MPA in Antarctica is the world’s largest MPA and the only one on the high seas. The Research Coordination Network (RCN) will connect three key components: (i) policy engagement, (ii) community partner engagement, and (iii) integrated science. The science component comprises three themes: data science and cyberinfrastructure; biophysical modeling; and observations that include monitoring and process studies. Guided by clear research questions across the three components, the RCN will lead to new knowledge about the barriers to science-policy engagement and strategies to overcome them; strategies for effectively engaging diverse community partners; and science needed to better understand the Ross Sea ecosystem structure and function, including strategies for international coordination. The three science themes inform understanding of the ecosystem, and thus, the potential efficacy of the Ross Sea region MPA. Data science and cyberinfrastructure provide essential structures for coordinated research. Biophysical modeling is critical for evaluating ecosystem metrics and can be illustrative for understanding changes in ecosystem structure and function. Observations and process studies are needed for addressing knowledge gaps and informing cyberinfrastructure tools and biophysical modeling efforts. The science integration component will advance knowledge while also advancing transformative interdisciplinary collaboration across data science, modeling, and observations. The RCN will build new connections and collaborations among scientists, policymakers and community partners, internationally and across disciplines, while integrating science and policy in novel ways. The RCN will operate through regular engagement across the network communities, including meetings and targeted activities with specific products and outcomes. The RCN increases diversity, science diplomacy, knowledge exchange, and conservation and five early- to mid-career researchers have leading roles. The contributions from this RCN will facilitate significant advances in the ability to understand high latitude marine ecosystems and how these systems respond to competing stressors, including climate change and fishing. Further, lessons learned through the RCN could offer guidance on how other large-scale international MPAs are monitored and assessed. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Glaciers move in response to gravity pulling them downhill and much of the resistance to this motion is supplied by the bedrock that they sit on. For fast moving glaciers this motion is largely the result of basal ice sliding over and around bedrock bumps, and the specific processes at the ice-bed interface that facilitate this sliding play a dominant role in setting the glacier speed. Sliding atop the ice-bed interface is known to create cavities (pockets of water) downstream of bedrock bumps. These cavities facilitate water flow, control areas of ice-bed contact, regulate basal drag, dictate subglacial erosion, and affect ice mechanics in general. Thus, the length and shape of cavities (geometry) as they separate from the bed is of fundamental importance in glaciology. This project will determine the fundamental processes that set the shapes of those cavities. This work will benefit the scientific community by producing improved estimates to basal sliding and subglacial hydrology which are two of the main uncertainties in glacier-flow modeling. It will also lead to a better understanding of subglacial erosion which effectively controls the basal bump geometries. This in turn will lead to improved understanding of the fundamentals of glacier and ice-sheet dynamics. Therefore, the outcome of the project could ultimately improve future projections of sea-level rise, benefitting society at large. In addition, this project will train a postdoctoral researcher and undergraduate students from tribal institutions. This project will: 1) Use a novel experimental device to generate a cavity geometry data set for a range of independent controls; and 2) Use the results from part one to constrain numerical models that will allow for the exploration of a greater range of parameter space than is possible in the physical experiments alone. Using a novel cryogenic ring-shear device, this project will systematically assess three likely controls on cavity geometry: effective stress, sliding speed, and bump geometry, while simultaneously tracking strain indicators within the ice and the geometry of the cavity through the transparent walls of the device. These experiments will be conducted with the University of Wisconsin-Madison, state-of-the-art ring-shear device and represent the first instance where all three parameters’ effects on the resultant cavity geometry can be measured simultaneously. The lab experiment findings of cavity geometry and strain rates within the ice will be used to help constrain the process-based numerical modeling of cavity formation. The numerical simulations of ice flow around obstacles will provide information about the stress and strain distribution within the ice, and from this data we can explore the ability of existing theories to predict cavity geometry for fast-flowing ice. The physics within the numerical model will be updated as needed to incorporate processes such as a stress dependent ice rheology or changes in the ice-bed contact physics that are currently unaccounted for. Outcomes will be 1) a detailed understanding of the physics that govern cavity geometry and 2) a simple parameterization of the lab and modeling results that can be easily incorporated into glaciological models for improved estimates of subglacial sliding, hydrology, and erosion. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
MacAyeal, Douglas; Banwell, Alison; Campbell, Seth; Schild, Kristin; Cassoto, Ryan
No dataset link provided
Non-Technical Abstract: This project explores the areas or crash-zones where floating ice shelves in Antarctica compressively flow against obstructions such as islands and plugs of stagnant ice frozen to the sea bed. The significance of these crash-zones is that they are responsible for generating the resistive forces that allow ice shelves to slow down the flow of ice farther inland into the ocean. Ice conditions within these boundaries thus determine how Antarctica’s ice sheets contribute to sea-level rise. The research will feature on-the-ice glaciological and geophysical field measurements near pressure ridges near Scott Base and the transition to the ice road where large wave-like pressure ridges form on the ice-shelf surface. This field area is along the coast of Ross Island adjacent to major logistical stations of the US and New Zealand Antarctic programs. Thus the research will help station managers better preserve one of the key roadways that connects the stations to the major runway used to fly to virtually all other parts of Antarctica. The research will also interact with educational programs such as featured in the long-standing Juneau Icefield Research Project as well as potential involvement of an artist from the US Antarctic Program’s Polar STEAM in the second field season. Technical Abstract: This project explores the dynamics of boundaries where ice shelves compressively flow against obstructions such as islands and areas of grounded ice. The significance of these boundaries is that they are responsible for generating the resistive forces that allow ice shelves to impede or slow down the flow of grounded inland ice into the ocean. Ice conditions within these boundaries thus determine how Antarctica’s ice sheets contribute to sea-level rise. The research will feature glaciological and geophysical field surveys in a compressive boundary area near pressure ridges adjacent to Scott Base and the transition to the ice road along the coast of Ross Island, an area affecting access to major logistical hubs of the US and New Zealand Antarctic programs. Field data will be combined with remote sensing, numerical modeling and theory development to answer key questions about the dynamics of compressive boundaries such as: is there a limit to compressive stress due to ice fracture and the bending of the ice shelf into sinusoidal pressure ridges? Over what time scales does this compressive stress build, fluctuate and decay, and how is it related to the processes that form rumples? Are there ways in which the ridges actually protect the compressive boundary from damage such as by setting up a means to scatter ocean swell impinging from the open ocean? How should compressive ice-shelf boundaries be represented in large scale ice-sheet/shelf models for the prediction of future sea-level rise? A variety of broader impact work will be done both specifically targeting the research field area and more broadly addressing scientific and societal concerns. The field area contains a critical logistics roadway that connects McMurdo Station, Scott Base and a runway essential for continent-wide air logistics. The project will inform how to stabilize the roadway against excessive damage from summer ablation and other factors. Other broader impacts include: (a) Open-Science evaluation of climate systems engineering strategies for glacial geoengineering mitigation of sea-level rise, (b) cooperation with the Juneau Icefield Research Program (JIRP) education component, (c) support and facilitation of an online FieldSafe workshop and associated panel discussion to support early-career Antarctic field teams to mitigate environmental and interpersonal risks in remote field sites, and (d) potential involvement of an artist from the US Antarctic Program’s Polar STEAM in the second field season. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Ice sheets lose ice mass through gravity-driven flow to the ocean where ice breaks into icebergs and melts, contributing to global sea level rise. Water commonly found at the base of ice sheets facilitates this process by lubricating the ice-rock interface. The recent discovery of vast, kilometer-thick groundwater reservoirs beneath the Antarctic Ice Sheet thus raises important questions about the potential impact of groundwater on ice flow. It has been hypothesized that groundwater flow to the ice-sheet bed may accelerate ice flow as the ice sheet shrinks in response to global warming. Evaluating this hypothesis is challenging due to poorly understood interactions between water, ice, and rock, but is crucial for anticipating the response of ice sheets and sea level to climate change. Understanding how groundwater responds to a changing ice sheet also has important implications for the heat, chemical elements, and microorganisms it stores and transports. To assess the impact of groundwater processes on ice dynamics, a new idealized modeling framework will be developed, incorporating several novel hydromechanical couplings between ice sheets, subglacial drainage systems, and groundwater aquifers. This framework will enable testing the hypotheses that (1) aquifers decelerate ice mass loss in the absence of a well-developed subglacial drainage system, but that (2) an efficient, channelized drainage system can reduce and even reverse this decelerating effect, and that (3) the impact of these phenomena is most pronounced for steep ice flowing rapidly over thick sedimentary basins and depends in a complex way on aquifer permeability. Existing geodetic, seismic, and other geophysical datasets at well-studied Thwaites Glacier and Whillans Ice Stream will be used to constrain model parameters and investigate the impact of groundwater processes in contrasting glaciologic settings. This work will help rule out or highlight subglacial groundwater as one of the next major challenges for efforts to predict the future of the Antarctic Ice Sheet and sea-level rise on decadal to millennial timescales. The project will contribute to educating the next generation of scientists by supporting an early-career PI and a graduate student, as well as participation in a field and research educational program in Alaska and the production of chapters for an online, open-source, free interactive textbook. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The West Antarctic Peninsula (WAP) is experiencing significant environmental changes, including warming temperatures, reduced sea ice, and glacier retreat. These changes could impact marine ecosystems and biological and chemical processes, particularly the biological pump, which is the process by which carbon is transported from the ocean surface to the deep sea, playing a crucial role in regulating atmospheric carbon dioxide levels. This project aims to understand how climate change affects the biological pump in the WAP region. Using a combination of advanced modeling techniques and data from long-term research programs, the project will investigate the processes governing the biological pump and its climate feedback. The findings will provide insights into the future dynamics of the WAP region and contribute to our understanding of climate change impacts on polar marine ecosystems. This research is important as it will enhance knowledge of how polar regions respond to climate change, which is vital for predicting global climate patterns and informing conservation efforts. Furthermore, the project supports the development of early-career researchers and promotes diversity in science through collaborations with educational programs and outreach to underrepresented communities. This project focuses on the WAP, a region undergoing rapid environmental changes. The goal is to investigate and quantify the factors controlling the biological pump and its feedback to climate change and variability. A novel hybrid modeling framework will be developed, integrating observational data from the Palmer Long-Term Ecological Research program and the Rothera Oceanographic and Biological Time-Series into a sophisticated one-dimensional mechanistic biogeochemical model. This framework will utilize Artificial Intelligence and Machine Learning techniques for data assimilation and parameter optimization. By incorporating complementary datasets and optimizing model parameters, the project aims to reduce uncertainties in modeling biological pump processes. The study will also use climate scenarios from the Coupled Model Intercomparison Project Phase 6 to assess the impacts of future climate conditions on the biological pump. Additionally, the project will examine the role of vertical mixing of dissolved organic matter in total export production, providing a comprehensive understanding of the WAP carbon cycle. The outcomes will improve temporal resolution and data assimilation, advancing the mechanistic understanding of the interplay between ocean dynamics and biogeochemical processes in the changing polar environment. The project will also leverage unique datasets and make the model framework and source codes publicly available, facilitating collaboration and benefiting the broader scientific community. Outreach efforts include engaging with educational programs and promoting diversity in Polar Science through collaborations with institutions serving underrepresented groups. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Perennially ice-covered lakes in the McMurdo Dry Valleys of Antarctica contain abundant microbial mats, and the export of this mat material can fertilize the surrounding polar desert ecosystems. These desert soils are one of the most organic-poor on earth yet host a community of microorganisms. Microbial mat material is exported from the shallow, gas-supersaturated regions of the lakes when gas bubbles form in the mats, lifting them to the ice cover; the perennial ice cover maintains gas supersaturation. These mats freeze in and are exported to the surrounding soils through ice ablation. The largest seasonal decrease and thinnest ice cover in the history of Lake Fryxell was recorded during the 2022-2023 Austral summer. In this thin ice year, the water column dissolved oxygen increased over prior observations, and the lake bottom surface area with bubble-disrupted mat was more than double that observed in 1980-1981 and 2006-2007. This work will constrain mat mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning to understand how future changing regional climate and predicted seasonal loss of lake ice cover will affect nutrient transport in the McMurdo Dry Valleys. Exceptional years of mat export are hypothesized to have the most significant impact on nutrient export to soil communities; variability in mat liftoff may thus play a role in the McMurdo Dry Valleys ecosystem response to changing climate. The perennial ice cover of lakes in the McMurdo Dry Valleys of Antarctica modulates the transfer of gasses, organic and inorganic material, between the lakes and surrounding soils. The export of biomass in these lakes is driven by the supersaturation of atmospheric gasses in the shallow regions under perennial ice cover. Gas bubbles nucleate in the mats, producing buoyancy that lifts them to the bottom of the ice, where they freeze in and are exported to the surrounding soils through ice ablation. These mats represent a significant source of biomass and nutrients to the McMurdo Dry Valleys soils, which are among the most organic-poor on earth. Nevertheless, this biomass remains unaccounted for in organic carbon cycling models for the McMurdo Dry Valleys. Ice cover data from the McMurdo Dry Valleys Long Term Ecological Research Project shows that the ice thickness has undergone cyclical variation over the last 40 years, reaching the largest seasonal decrease and thinnest ice-cover in the recorded history of Lake Fryxell during the 2022-2023 austral summer. Preliminary work shows that the surface area with mat liftoff at Lake Fryxell is more than double that observed in 1980-1981 and 2006-2007, coinciding with this unprecedented thinning of the ice-cover and an increase in the water column dissolved O2. This research will constrain biomass mobilization within and out of Lake Fryxell in the McMurdo Dry Valleys during a period of unprecedented ice thinning. The researchers hypothesize that a thinner ice cover promotes more biomass mobilization by 1) stimulating additional production of gas bubbles from the existing gas-supersaturated waters during summertime photosynthesis to create microbial mat liftoff and 2) promoting mat liftoff in deeper, thicker microbial mats, and 3) that this biomass can be traced into the soils by characterizing its chemistry and modeling the most likely depositional settings. This work will use microbial mat samples, lake dissolved oxygen and photosynthetically active radiation data and underwater drone footage documenting the depth distribution of liftoff mats in January 2023, and long-term ice cover thickness, photosynthetically active radiation, and lake level change data collected by the McMurdo Dry Valleys Long Term Ecological Research Project to test hypotheses 1-3. The dispersal of the liftoff mat exposed at Lake Fryxell surface will be modeled using a Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. Exceptional liftoff years like the present are hypothesized to have the most significant impact on the soil communities as the rates of soil respiration increase with the addition of carbon. However, continued warming in the next 10 - 40 years may result in seasonal loss of the ice cover and cessation of liftoff mat export. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Ross Sea Region Marine Protected Area (RSRMPA), one of the world’s largest MPAs, encompasses one of the healthiest marine ecosystems remaining on this planet; however, it is exposed to increasing stress from ongoing climate change and fishing pressure. Numerous gaps in our understanding of the highly coupled nature of the Ross Sea marine ecosystem need to be addressed to support conservation efforts in the Ross Sea region, including informing the efficacy and management of the RSRMPA into the coming decades. The overarching goal of this research is to formulate an innovative and sustainable world-class research program aimed at better understanding, conserving, and managing the RSRMPA through the coordination of multi-faceted system-level approaches. There will be a coordinated effort to facilitate international collaboration; create education, outreach, and Diverse Equitable and Inclusive (DEI) opportunities; and increase conservation awareness. Coordinating Ross Sea marine ecosystem research will contribute to enhancing system-level global research, sustainable data networks, DEI, and climate equity. This program will also provide opportunity to develop similar frameworks for other large-scale, globally important systems. The trans-disciplinary aspiration can also serve to guide the NSF in sustaining or initiating new funding opportunities while addressing several of the 10 NSF BIG IDEAS and engaging multiple NSF Directorates. The project will help maintain NSF’s mission of scientific leadership by networking the Antarctic community by providing science-based conservation plans to help mitigate environmental changes in this pristine region of the Southern Ocean. The researchers will convene a workshop to strategize the implementation of an internationally networked, world class program that is based on inter- and trans-disciplinary approaches (including bridging science, cyberinfrastructure, policy, management, and conservation), while also providing opportunities for STEM education, early career development, and core DEI principles. To effectively facilitate the prioritization of research related to the regional and global interconnectedness of the Ross Sea marine ecosystem, the workshop will involve leading experts in Ross Sea marine research and other researchers, stakeholders, and policy experts involved in the greater oceanographic, climate and ecosystem/food web modeling communities. The workshop will determine a long-term decadal plan comprising the following phases: (1) initial data synthesis and ecosystem/food web model development; (2) field observations and modeling, networked through an internationally coordinated Ross Sea Observing System; and (3) data synthesis and modeling, including a “sunset” plan to support ongoing RSRMPA management and preservation of the Ross Sea marine ecosystem. Outcomes will include a workshop report detailing the long-term research plan, a peer-reviewed article, educational and outreach materials, and a list of proposed research topics for implementing a world class research program and Principal Investigators who will help coordinate the multiple efforts aimed at addressing major gaps in our knowledge of the Ross Sea system. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function.<br/> <br/> <br/>To understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Satellite observations of Earth’s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth’s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth’s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Non-technical Abstract The McMurdo Dry Valleys LTER seeks to understand how changes in the temporal variability of ecological connectivity interact with existing landscape legacies to alter the structure and functioning of this extreme polar desert ecosystem. This research has broad implications, as it will help us to understand how natural ecosystems respond to ongoing anthropogenic global change. At the same time, this project also serves an important educational and outreach function, providing immersive research and educational experiences to students and artists from diverse backgrounds, and helping to ensure a diverse and well-trained next generation of leaders in polar ecosystem science and stewardship. Ultimately, the results of this project will help us to better understand and prepare for the effects of climate change and develop scientific insights that are relevant far beyond Antarctic ecosystems. The McMurdo Dry Valleys (MDVs) make up an extreme polar desert ecosystem in the largest ice-free region of Antarctica. The organisms in this ecosystem are generally small. Bacteria, microinvertebrates, cyanobacterial mats, and phytoplankton can be found across the streams, soils, glaciers, and ice-covered lakes. These organisms have adapted to the cold and arid conditions that prevail outside of lakes for all but a brief period in the austral summer when the ecosystem is connected by liquid water. In the summer when air temperatures rise barely above freezing, soils warm and glacial meltwater flows through streams into the open moats of lakes. Most biological activity across the landscape occurs in summer. Through the winter, or polar night (6 months of darkness), glaciers, streams, and soil biota are inactive until sufficient light, heat, and liquid water return, while lake communities remain active all year. Over the past 30 years, the MDVs have been disturbed by cooling, heatwaves, floods, rising lake levels, as well as permafrost and lake ice thaw. Considering the clear ecological responses to this variation in physical drivers, and climate models predicting further warming and more precipitation, the MDV ecosystem sits at a threshold between the current extreme cold and dry conditions and an uncertain future. This project seeks to determine how important the legacy of past events and conditions versus current physical and biological interactions shape the current ecosystem. Four hypotheses will be tested, related to 1) whether the status of specific organisms are indicative ecosystem stability, 2) the relationship between legacies of past events to current ecosystem resilience (resistance to big changes), 3) carryover of materials between times of high ecosystem connectivity and activity help to maintain ecosystem stability, and 4) changes in disturbances affect how this ecosystem persists through the annual polar night (i.e., extended period of dark and cold). Technical Abstract In this iteration of the McMurdo LTER project (MCM6), the project team will test ecological connectivity and stability theory in a system subject to strong physical drivers (geological legacies, extreme seasonality, and contemporary climate change) and driven by microbial organisms. Since microorganisms regulate most of the world’s critical biogeochemical functions, these insights will be relevant far beyond polar ecosystems and will inform understanding and expectations of how natural and managed ecosystems respond to ongoing anthropogenic global change. MCM6 builds on previous foundational research, both in Antarctica and within the LTER network, to consider the temporal aspects of connectivity and how it relates to ecosystem stability. The project will examine how changes in the temporal variability of ecological connectivity interact with the legacies of the existing landscape that have defined habitats and biogeochemical cycling for millennia. The project team hypothesizes that the structure and functioning of the MDV ecosystem is dependent upon legacies and the contemporary frequency, duration, and magnitude of ecological connectivity. This hypothesis will be tested with new and continuing monitoring, experiments, and analyses of long-term datasets to examine: 1) the stability of these ecosystems as reflected by sentinel taxa, 2) the relationship between ecological legacies and ecosystem resilience, 3) the importance of material carryover during periods of low connectivity to maintaining biological activity and community stability, and 4) how changes in disturbance dynamics disrupt ecological cycles through the polar night. Tests of these hypotheses will occur in field and modeling activities using new and long-term datasets already collected. New datasets resulting from field activities will be made freely available via widely-known online databases (MCM LTER and EDI). The project team has also developed six Antarctic Core Ideas that encompass themes from data literacy to polar food webs and form a consistent thread across the education and outreach activities. Building on past success, collaborations will be established with teachers and artists embedded within the science teams, who will work to develop educational modules with science content informed by direct experience and artistic expression. Undergraduate mentoring efforts will incorporate computational methods through a new data-intensive scientific training program for MCM REU students. The project will also establish an Antarctic Research Experience for Community College Students at CU Boulder, to provide an immersive educational and research experience for students from diverse backgrounds in community colleges. MCM LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science and stewardship. Historically underrepresented participation will be expanded at each level of the project. To aid in these efforts, the project has established Education & Outreach and Diversity, Equity, and Inclusion committees to lead, coordinate, support, and integrate these activities through all aspects of MCM6. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Bassis/1149085 This CAREER award supports a project to develop physically based bounds on the amount ice sheets can contribute to sea level rise in the coming centuries. To simulate these limits, a three-dimensional discrete element model will be developed and applied to simulate regions of interest in the Greenland and Antarctic ice sheets. These regions will include Helheim Glacier, Jakobshavn Isbräe, Pine Island Glacier and sections of the Larsen Ice Shelf. In the discrete element model the ice will be discretized into distinct blocks or boulders of ice that interact through inelastic collisions, frictional forces and bonds. The spectrum of best to worst case scenarios will be examined by varying the strength and number of bonds between neighboring blocks of ice. The worst case scenario corresponds to completely disarticulated ice that behaves in a manner akin to a granular material while the best case scenario corresponds to completely intact ice with no preexisting flaws or fractures. Results from the discrete element model will be compared with those from analogous continuum models that incorporate a plastic yield stress into the more traditional viscous flow approximations used to simulate ice sheets. This will be done to assess if a fracture permitting plastic rheology can be efficiently incorporated into large-scale ice sheet models to simulate the evolution of ice sheets over the coming centuries. This award will also support to forge a partnership with two science teachers in the Ypsilanti school district in southeastern Michigan. The Ypsilanti school district is a low income, resource- poor region with a population that consists of ~70% underrepresented minorities and ~69% of students qualify for a free or reduced cost lunch. The cornerstone of the proposed partnership is the development of lesson plans and content associated with a hands-on ice sheet dynamics activity for 6th and 7th grade science students. The activity will be designed so that it integrates into existing classroom lesson plans and is aligned with State of Michigan Science Technology, Engineering and Math (STEM) curriculum goals. The aim of this program is to not only influence the elementary school students, but also to educate the teachers to extend the impact of the partnership beyond the duration of this study. Graduate students will be mentored and engaged in outreach activities and assist in supervising undergraduate students. Undergraduates will play a key role in developing an experimental, analogue ice dynamics lab designed to illustrate how ice sheets and glaciers flow and allow experimental validation of the proposed research activities. The research program advances ice sheet modeling infrastructure by distributing results through the community based Community Ice Sheet Model.
1. A non-technical explanation of the project's broader significance and importance, that serves as a public justification for NSF funding. This part should be understandable to an educated reader who is not a scientist or engineer. Katabatic or drainage winds, carry high-density air from a higher elevation down a slope under the force of gravity. Although katabatic flows are ubiquitous in alpine and polar regions, a surface-layer similarity theory is currently lacking for these flows, undermining the accuracy of numerical weather and climate prediction models. This project is interdisciplinary, and will give graduate and undergraduate students valuable experience interacting with researchers outside their core discipline. Furthermore, this project will broaden participating in science through recruitment of students from under-represented groups at OU and CU through established programs. The Antarctic Ice Sheet drives many processes in the Earth system through its modulation of regional and global atmospheric and oceanic circulations, storage of fresh water, and effects on global albedo and climate. An understanding of the surface mass balance of the ice sheets is critical for predicting future sea level rise and for interpreting ice core records. Yet, the evolution of the ice sheets through snow deposition, erosion, and transport in katabatic winds (which are persistent across much of the Antarctic) remains poorly understood due to the lack of an overarching theoretical framework, scarcity of in situ observational datasets, and a lack of accurate numerical modeling tools. Advances in the fundamental understanding and modeling capabilities of katabatic transport processes are urgently needed in view of the future climatic and snowfall changes that are projected to occur within the Antarctic continent. This project will leverage the expertise of a multidisciplinary team of investigators (with backgrounds spanning cryospheric science, environmental fluid mechanics, and atmospheric science) to address these knowledge gaps. 2. A technical description of the project that states the problem to be studied, the goals and scope of the research, and the methods and approaches to be used. In many cases, the technical project description may be a modified version of the project summary submitted with the proposal. Using field observations and direct numerical simulations of katabatic flow, this project is expected--- for the first time---to lead to a surface-layer similarity theory for katabatic flows relating turbulent fluxes to mean vertical gradients. The similarity theory will be used to develop surface boundary conditions for large eddy simulations (LES), enabling the first accurate LES of katabatic flow. The numerical tools that the PIs will develop will allow them to investigate how the partitioning between snow redistribution, transport, and sublimation depends on the environmental parameters typically encountered in Antarctica (e.g. atmospheric stratification, surface sloping angles, and humidity profiles), and to develop simple models to infer snow transport based on satellite remote sensing and regional climate models This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The unique Antarctic environment offers insight into processes and records not seen anywhere else on Earth, and is critical to understanding our planet’s history and future. The remoteness and logistics of Antarctic science brings together researchers from diverse disciplines who otherwise wouldn’t be presented with opportunities for collaboration, and often rarely attend the same academic conferences. The Interdisciplinary Antarctic Earth Science (IAES) conference is a biennial gathering that supports the collaboration of U.S. bio-, cryo-, geo-, and atmospheric science researchers working in the Antarctic. This proposal will support the next two IAES conferences to be held in 2022 and 2024, as well as a paired deep-field camp planning workshop. The IAES conference is important to the mission of the NSF in supporting interdisciplinary collaboration in the Antarctic Earth sciences, but also fulfills recommendations by the National Academy for improving cross-disciplinary awareness, data sharing, and early career researcher mentoring and development. The size and scope of the IAES conference allow it to serve as a hub for novel, interdisciplinary collaboration, as well as help develop the next generation of Antarctic Earth scientists. The goals of the IAES conference are to develop and deepen scientific collaborations across the Antarctic Earth science community, and create a framework for future deep-field, as well as non-field-based research. Across a 2.5 day hybrid conference, the IAES themes will include 1) connecting surficial processes, geology, and the deep earth; 2) landscape, ice sheet, ocean and atmospheric interactions; 3) exploring the hidden continent; and 4) evolution and ecology of ancient and modern organisms, ecosystems, and environments. The conference will share science through presentations of current research and keynote talks, broaden participation through welcoming new researchers from under-represented communities and disciplines, and deepen collaboration through interdisciplinary networking highlighting potential research connections, novel mentorship activities, and promoting data re-use, and application of remote sensing and modeling. Discussions resulting from the IAES conference will be used to develop white papers on future Antarctic collaborative research and deep-field camps based on community-driven research priorities. Community surveys and feedback will be solicited throughout the project to guide the future development of the IAES conference. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
A class of small molecules, very short-lived substances (VSLS; e.g. CHBr3,CH2Br2, and CH3I) are important components in the climate system where they act as tropospheric ozone destroyers as described in the multilateral environmental Montreal Protocol on Substances that Deplete the Ozone Layer. The Southern Ocean represents a key component in the climate system and has a critical role in other global biogeochemical cycles. This project will use the NSF/NCAR Community Earth System Model (CESM) with a newly developed online air-sea exchange framework, to evaluate biogeochemical controls on the marine sources of VSLS in the Southern Ocean as well as the Southern Hemisphere. A machine-learning approach will be used to couple ocean biogeochemistry with air-sea exchange for these compounds. A variety of oceanic and atmospheric observations of VSLS will be used to evaluate a unique oceanic VSLS inventory. In particular, the recent ORCAS field campaign provides a unique opportunity to examine Southern Ocean VSLS emissions, and their impacts from ocean biogeochemistry, meteorology and sea ice cycles. The project will also support a postdoctoral early-career researcher, and a specific effort of this project is STEM education and public outreach activities. The research team will extend opportunities to high school and undergraduate students so they may gain experience in the coupled ocean and atmospheric sciences, including exposure to and experience in programming and modeling. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part 1: Non-technical description The goal of all LTER sites is to conduct policy-relevant ecosystem research for questions that require tens of years of data and cover large geographical areas. The Palmer Antarctica Long Term Ecological Research (PAL-LTER) site has been in operation since 1990 and has been studying how the marine ecosystem west of the Antarctica Peninsula (WAP) is responding to a climate that is changing as rapidly as any place on the Earth. The study is evaluating how warming conditions and decreased ice cover leading to extended periods of open water are affecting many aspects of ecosystem function. The team is using combined cutting-edge approaches including yearly ship-based research cruises, small-boat weekly sampling, autonomous vehicles, animal biologging, oceanographic floats and seafloor moorings, manipulative lab-based process studies and modeling to evaluate both seasonal and annual ecosystem responses. These combined approaches are allowing for the study the ecosystem changes at scales needed to assess both short-term and long-term drivers. The study region also includes submarine canyons that are special regions of enhanced biological activity within the WAP. This research program is paired with a comprehensive education and outreach program promoting the global significance of Antarctic science and research. In addition to training for graduate and undergraduate students, they are using newly-developed Polar Literacy Principles as a foundation in a virtual schoolyard program that shares polar instructional materials and provides learning opportunities for K-12 educators. The PAL-LTER team is also leveraging the development of Out of School Time materials for afterschool and summer camp programs, sharing Palmer LTER-specific teaching materials with University, Museum, and 4-H Special Interest Club partners. Part 2: Technical description Polar ecosystems are among the most rapidly changing on Earth. The Palmer LTER (PAL-LTER) program builds on three decades of coordinated research along the western side of the Antarctic Peninsula (WAP) to gain new mechanistic and predictive understanding of ecosystem changes in response to disturbances spanning long-term decadal (‘press’) drivers and changes due to higher-frequency (‘pulse’) drivers, such as large storms and extreme seasonal anomaly in sea ice cover. The influence of major natural climate modes that modulate variations in sea ice, weather, and oceanographic conditions to drive changes in ecosystem structure and function (e.g., El Niño Southern Oscillation and Southern Annular Mode) are being studied at multiple time scales –from diel, seasonal, interannual, to decadal intervals, and space scales–from hemispheric to global scale investigated by remote sensing, the regional scales. Specifically, the team is evaluating how variability of physical properties (such as vertical and alongshore connectivity processes) interact to modulate biogeochemical cycling and community ecology in the WAP region. The study is providing an evaluation of ecosystem resilience and ecological responses to long-term “press-pulse” drivers and a decadal-level reversal in sea ice coverage. This program is providing fundamental understanding of population and biogeochemical responses for a marine ecosystem experiencing profound change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Iceberg calving is a complex natural fracture process and a dominant cause of mass loss from the floating ice shelves on the margins of the Antarctic ice sheet. There is concern that rapid changes at these ice shelves can destabilize parts of the ice sheet and accelerate their contribution to sea-level rise. The goal of this project is to understand and simulate the fracture mechanics of calving and to develop physically-consistent calving schemes for ice-sheet models. This would enable more reliable estimation of Antarctic mass loss by reducing the uncertainty in projections. The research plan is integrated with an education and outreach plan that aims to (1) enhance computational modeling skills of engineering and Earth science students through a cross-college course and a high-performance computing workshop and (2) increase participation and diversity in engineering and sciences by providing interdisciplinary research opportunities to undergraduates and by deploying new cyberlearning tools to engage local K-12 students in the Metro Nashville Public Schools in computational science and engineering, and glaciology. This project aims to provide fundamental understanding of iceberg calving by advancing the frontiers in computational fracture mechanics and nonlinear continuum mechanics and translating it to glaciology. The project investigates crevasse propagation using poro-damage mechanics models for hydrofracture that are consistent with nonlinear viscous ice rheology, along with the thermodynamics of refreezing in narrow crevasses at meter length scales. It will develop a fracture-physics based scheme to better represent calving in ice-sheet models using a multiscale method. The effort will also address research questions related to calving behavior of floating ice shelves and glaciers, with the goal of enabling more reliable prediction of calving fronts in whole-Antarctic ice-sheet simulations over decadal-to-millennial time scales. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctic notothenioid fishes, also known as cryonotothenioids, inhabit the icy and highly oxygenated waters surrounding the Antarctic continent after diverging from notothenioids inhabiting more temperate waters. Notothenioid hemoglobin and blood parameters are known to have evolved along with the establishment of stable polar conditions, and among Antarctic notothenioids, icefishes are evolutionary oddities living without hemoglobin following the deletion of all functional hemoglobin genes from their genomes. In this project, we investigate the evolution of hemoglobin genes and gene clusters across the notothenioid radiation until their loss in the icefish ancestor after its divergence from the dragonfish lineage to understand the forces, mechanisms, and potential causes for hemoglobin gene loss in the icefish ancestor.
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections. The project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Our knowledge of Antarctic weather and climate relies on only a handful of direct observing stations located on this harsh and remote continent. This observing system reports meteorological measurements from an existing network of automatic weather stations (AWS) spread across a vast area. This MRI project will enable the development, testing and eventual deployment of a next generation of polar automatic climate and weather observing stations for unattended use in the Antarctic. The proposed new Automatic Weather Station (AWS) system will enhance the capabilities and accuracy of the meteorological observations, enabling climate quality measurements. This project will involve development of a more capable instrumentation core, with two major goals. The first goal is to lower the cost for an AWS electronic core to 3 times less than currently employed systems. The second is to enable an onboard temperature calibration capability, an innovative development for the Antarctic AWS. The capability for onboard calibration will add confidence in the critical climate measure of ambient temperature, along with other standard meteorological parameters. Observations made by a modernized AWS network will inform and extend future numerical climate modeling efforts, improve operational weather forecasts, capture weather phenomena, and support environmental science research in other disciplines. A theme of the project is the inclusion of community college students in all aspects of the effort. With an eye on training the next generation of research instrumentation expertise, while involving other science, technology, engineering and mathematics (STEM) fields, undergraduate students will be involved in the development, testing and deployment of new AWS systems. As well as reporting, data analysis and publication of scientific knowledge, students intending to transfer to a 4-year university, as well as those pursuing electronics or electrical engineering associate degrees will be introduced to weather and climate topics. This MRI award was supported with funds from the Division of Polar Programs and the Division of Atmospheric and Geospace Sciences, both of the Directorate of Geosciences.
Reconstructions of past changes in thickness and extent of the Antarctic ice sheet are important for evaluating past and present sea-level change, and for validating numerical models necessary to make realistic predictions of changes under future climate and ocean conditions. Models estimate that the Ross Sea sector was one of the largest contributors to sea-level rise from Antarctica as the ice sheet adjusted during the past ten thousand years from the glacial period to the Holocene. In this sector, ice flow into the embayment comes through West Antarctic ice streams and through East Antarctic outlet glaciers that flow through the Transantarctic Mountains. Observational data constrain the last glacial maximum and the Holocene retreat, but models are necessary to understand the environmental conditions needed for outlet glaciers to reach observed high stands, to fit the observed patterns of retreat, and to understand how the contribution of ice from West Antarctica and from East Antarctica changed over time. The investigators will use available geological and geophysical data in combination with forward ice-flow models and inverse models to investigate the evolution of the four Transantarctic outlet glaciers where sufficient data exist. The objectives of this new modeling are to constrain the glaciological conditions necessary for these glaciers to thicken during the last glacial, thin during the Holocene, and reach their present-day state. By testing specific hypotheses this work contributes to an interdisciplinary effort to understand Holocene deglaciation of the Ross Sea Embayment. In addition, the modeling will address the resolving power of the available data to answer key questions for each target glacier. Broader impacts include mentoring a graduate student, public outreach, incorporation of research into high-school and university classes, and support of an early-career investigator.
Siddoway, Christine; Thomson, Stuart; Teyssier, Christian
No project link provided
in progress
No project link provided
in progress
Sediment records off the coast of Marie Byrd Land (MBL), Antarctica suggest frequent and dramatic changes in the size of the West Antarctic Ice Sheet (WAIS) over short (tens of thousands of years) and long (millions of years) time frames in the past. WAIS currently overrides much of MBL and covers the rugged and scoured bedrock landscape. The ice sheet carved narrow linear troughs that reach depths of two to three thousand meters below sea level as outlet glaciers flowed from the interior of the continent to the oceans. As a result, large volumes of fragmented continental bedrock were carried out to the seabed. The glaciers cut downward into a region of crystalline rocks (i.e. granite) whose temperature change as a function of rock depth happens to be significant. This strong geothermal gradient in the bedrock is favorable for determining when the bedrock experienced rapid exhumation or "uncovering". Analyzing the chemistry of minerals (zircon and apatite) within the eroded rocks will provide information about the rate and timing of the glacier removal of bedrock from the Antarctic continent. The research addresses the following questions: When did the land become high enough for a large ice sheet to form? What was the regional pre-glacial topography? Under what climate conditions, and at what point in the growth of an ice sheet, did glaciers begin to cut sharply into bedrock to form the narrow troughs that flow seaward? The research will lead to greater understanding of past Antarctic ice sheet fluctuations and identify precise timing of glacial incision. These results will refine ice sheet history and aid the international societal response to contemporary ice sheet change and its global consequences. The project will contribute to the training of two graduate and two undergraduate students in STEM. The objective is to clarify the onset of WAIS glacier incision and assess the evolution of Cenozoic paleo-topography. Low-temperature (T) thermochronology and Pecube 3-D thermo-kinematic modeling will be applied to date and characterize episodes of glacial erosional incision. Single-grain double- and triple-dating of zircon and apatite will reveal the detailed crustal thermal evolution of the region enabling the research team to determine the comparative topographic influences on glaciation versus bedrock uplift induced by Eocene to present tectonism/magmatism. High-T mineral thermochronometers across Marie Byrd Land (MBL) record rapid extension-related cooling at ~100 Ma from temperatures of >800 degrees C to ≤ 300 degrees C. This signature forms a reference horizon, or paleogeotherm, through which the Cenozoic landscape history using low-T thermochronometers can be explored. MBL's elevated geothermal gradient, sustained during the Cenozoic, created favorable conditions for sensitive apatite and zircon low-T thermochronometers to record bedrock cooling related to glacial incision. Students will be trained to use state-of-the-art analytical facilities in Arizona and Minnesota, expanding the geo- and thermochronologic history of MBL from bedrock samples and offshore sedimentary deposits. The temperature and time data they acquire will provide constraints on paleotopography, isostasy, and the thermal evolution of MBL that will be modeled in 3D using Pecube model simulations. Within hot crust, less incision is required to expose bedrock containing the distinct thermochronometric profile; a prediction that will be tested with inverse Pecube 3-D models of the thermal field through which bedrock and detrital samples cooled. Using results from Pecube, the ICI-Hot team will examine time-varying topography formed in response to changes in erosion rates, topographic relief, geothermal gradient and/or flexural isostatic rigidity. These effects are manifestations of dynamic processes in the WAIS, including ice sheet loading, ice volume fluctuations, relative motion upon crustal faults, and magmatism-related elevation increase across the MBL dome. The project makes use of pre-existing sample collections housed at the US Polar Rock Repository, IODP's Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
van der Veen, Cornelis; Stearns, Leigh; Paden, John
No dataset link provided
Van der Veen/1543530 The objective of this research is to gain better understanding of the West Antarctic ice flow in the transition region from grounded ice to floating ice shelves and investigate the conditions that can initiate and sustain major retreat of these glaciers. Several major Antarctic outlet glaciers and ice streams will be investigated using a suite of observational techniques and modeling tools. Glaciers include Thwaites Glacier, which has become a focal point in the discussion of West Antarctic retreat, Whillans Ice Stream as an example of the archetype ice stream, and Byrd Glacier, a major outlet glacier draining East Antarctica through the Transantarctic Mountains into the Ross Ice Shelf. This study will investigate whether the ongoing changes in these glaciers will lead to long-term mass loss (the onset of ice sheet collapse), or whether these glaciers will quickly stabilize with a new geometry. To adequately incorporate the dynamic behavior of outlet glaciers and ice streams requires inclusion of the relevant physical processes, and the development of regional models that employ a numerical grid with a horizontal grid spacing sufficiently refined to capture smaller-scale bed topographic features that may control the flow of these glaciers. This award revisits the issue of stability of marine-terminating glaciers whose grounding line is located on a retrograded bed slope. In particular, an attempt will be made to resolve the question whether observed rapid changes are the result of perturbations at the terminus or grounding line, or whether these changes reflect ice-dynamical forcing over the grounded reaches. High-resolution satellite imagery will be used to investigate ice-flow perturbations on smaller spatial scales than has been done before, to evaluate the importance of localized sites of high basal resistance on grounding-line stability. This collaborative project involves a range of modeling strategies including force-budget analysis, flow-band modeling, Full Stokes modeling for local studies, and using the Ice Sheet System Model developed at JPL for regional modeling. Broader Impacts include training two graduate students in computer simulations and ice sheet modeling algorithms. The work will also expand on a web-based interactive flowline model, so that it includes more realistic grounding line dynamics.
Arrigo, Kevin; Thomas, Leif N; Baumberger, Tamara; Resing, Joseph
No dataset link provided
Phytoplankton blooms throughout the world’s oceans support critical marine ecosystems and help remove carbon dioxide (CO2) from the atmosphere. Traditionally, it has been assumed that phytoplankton blooms in the Southern Ocean are stimulated by iron from either nearby land or sea-ice. However, recent work demonstrates that hydrothermal vents may be an additional iron source for phytoplankton blooms. This enhancement of phytoplankton productivity by different iron sources supports rich marine ecosystems and leads to the sequestration of carbon in the deep ocean. Our proposed work will uncover the importance of hydrothermal activity in stimulating a large phytoplankton bloom along the southern boundary of the Antarctic Circumpolar Current just north of the Ross Sea. It will also lead towards a better understanding of the overall impact of hydrothermal activity on the carbon cycle in the Southern Ocean, which appears to trigger local hotspots of biological activity which are a potential sink for atmospheric CO2. This project will encourage the participation of underrepresented groups in ocean sciences, as well as providing educational opportunities for high school and undergraduate students, through three different programs. Stanford University’s Summer Undergraduate Research in Geoscience and Engineering (SURGE) program provides undergraduates from different US universities and diverse cultural backgrounds the opportunity to spend a summer doing a research project at Stanford. The Stanford Earth Summer Undergraduate Research Program (SESUR) is for Stanford undergraduates who want to learn more about environmental science by performing original research. Finally, Stanford’s School of Earth, Energy, and Environmental Sciences High School Internship Program enables young scientists to serve as mentors, prepares high school students for college, and serves to strengthen the partnership between Stanford and local schools. Students present their results at the Fall AGU meeting as part of the AGU Bright STaRS program. This project will form the basis of at least two PhD dissertations. The Stanford student will participate in Stanford’s Woods Institute Rising Environmental Leaders Program (RELP), a year-round program that helps graduate students hone their leadership and communication skills to maximize the impact of their research. The graduate student will also participate in Stanford’s Grant Writing Academy where they will receive training in developing and articulating research strategies to tackle important scientific questions. This interdisciplinary program combines satellite and ship-based measurements of a large poorly understood phytoplankton bloom (the AAR bloom) in the northwestern Ross Sea sector of the Southern Ocean with a detailed modeling study of the physical processes linking deep dissolved iron (DFe) reservoirs to the surface phytoplankton bloom. Prior to the cruise, we will implement a numerical model (CROCO) for our study region so that we can better understand the circulation, plumes, turbulence, fronts, and eddy field around the AAR bloom and how they transport and mix hydrothermally produced DFe vertically. Post cruise, observations of the vertical distribution of 3He (combined with DMn and DFe), will be used as initial conditions for a passive tracer in the model, and tracer dispersal will be assessed to better quantify the role of the various turbulent processes in upwelling DFe-rich waters to the upper ocean. The satellite-based component of the program will characterize the broader sampling region before, during, and after our cruise. During the cruise, our automated software system at Stanford University will download and process images of sea ice concentration, Chl-a concentration, sea surface temperature (SST), and sea surface height (SSH) and send them electronically to the ship. Operationally, our goal is to use all available satellite data and preliminary model results to target shipboard sampling both geographically and temporally to optimize sampling of the AAR bloom. We will use available BGC-Argo float data to help characterize the AAR bloom. In collaboration with SOCCOM, we will deploy additional BGC-Argo floats (if available) during our transit through the study area to allow us to better characterize the bloom. The centerpiece of our program will be a 40-day process study cruise in austral summer. The cruise will consist of an initial “radiator” pattern of hydrographic surveys/sections along the AAR followed by CTDs to selected submarine volcanoes. When/if eddies are identified, they will be sampled either during or after the initial surveys. The radiator pattern, or parts thereof, will be repeated 2-3 times. Hydrographic survey stations will include vertical profiles of temperature, salinity, oxygen, oxidation-reduction potential, light scatter, and PAR (400-700 nm). Samples will be collected for trace metals, ligands, 3He, and total suspended matter. Where intense hydrothermal activity is identified, samples for pH and total CO2 will also be collected to characterize the hydrothermal system. Water samples will be collected for characterization of macronutrients, and phytoplankton physiology, abundance, species composition, and size. During transits, we will continuously measure atmospheric conditions, current speed and direction, and surface SST, salinity, pCO2, and fluorescence from the ship’s systems to provide detailed maps of these parameters. The ship will be used as a platform for conducting phytoplankton DFe bioassay experiments at key stations throughout the study region both inside and outside the bloom. We will also perform detailed comparisons of algal taxonomic composition, physiology, and size structure inside and outside the bloom to determine the potential importance of each community on local biogeochemistry. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt. This research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.
The Antarctic Automatic Weather Station network is the most extensive surficial meteorological network in the Antarctic, approaching its 30th year at several of its data stations. Its prime focus is also as a long term observational record, to measure the near surface weather and climatology of the Antarctic atmosphere. Antarctic Automatic Weather Stations measure air-temperature, pressure, wind speed and direction at a nominal surface height of ~ 2-3m. Other parameters such as relative humidity and snow accumulation may also be taken. The surface observations from the Antarctic Automatic Weather Station network are also used operationally, for forecast purposes, and in the planning of field work. Surface observations made from the network have also been used to check the validity of satellite and remote sensing observations. The proposed effort informs our understanding of the Antarctic environment and its weather and climate trends over the past few decades. The research has implications for potential future operations and logistics for the US Antarctic Program during the winter season. As a part of this endeavor, all project participants will engage in a coordinated outreach effort to bring the famous Antarctic "cold" to public seminars, K-12, undergraduate, and graduate classrooms, and senior citizen centers. This project proposes to use the surface conditions observed by the Antarctic Automatic Weather Station (AWS) network to determine how large-scale modes of climate variability impact Antarctic weather and climate, how the surface observations from the AWS network are linked to surface layer and boundary layer processes. Consideration will also be given to low temperature physical environments such as may be encountered during Antarctic winter, and the best ways to characterize these, and other ?cold pool? phenomena. Observational data from the AWS are collected via Iridium network, or DCS Argos aboard either NOAA or MetOp polar orbiting satellites and thus made available in near real time to operational and synoptic weather forecasters over the GTS (WMO Global Telecommunication System). Being able to support improvements in numerical weather prediction and climate modeling will have lasting impacts on Antarctic science and logistical support. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Antarctic Automatic Weather Station network is the most extensive surficial meteorological network in the Antarctic, approaching its 30th year at several of its data stations. Its prime focus is also as a long term observational record, to measure the near surface weather and climatology of the Antarctic atmosphere. Antarctic Automatic Weather Stations measure air-temperature, pressure, wind speed and direction at a nominal surface height of ~ 2-3m. Other parameters such as relative humidity and snow accumulation may also be taken. The surface observations from the Antarctic Automatic Weather Station network are also used operationally, for forecast purposes, and in the planning of field work. Surface observations made from the network have also been used to check the validity of satellite and remote sensing observations. The proposed effort informs our understanding of the Antarctic environment and its weather and climate trends over the past few decades. The research has implications for potential future operations and logistics for the US Antarctic Program during the winter season. As a part of this endeavor, all project participants will engage in a coordinated outreach effort to bring the famous Antarctic "cold" to public seminars, K-12, undergraduate, and graduate classrooms, and senior citizen centers.<br/><br/>This project proposes to use the surface conditions observed by the Antarctic Automatic Weather Station (AWS) network to determine how large-scale modes of climate variability impact Antarctic weather and climate, how the surface observations from the AWS network are linked to surface layer and boundary layer processes. Consideration will also be given to low temperature physical environments such as may be encountered during Antarctic winter, and the best ways to characterize these, and other ?cold pool? phenomena. Observational data from the AWS are collected via Iridium network, or DCS Argos aboard either NOAA or MetOp polar orbiting satellites and thus made available in near real time to operational and synoptic weather forecasters over the GTS (WMO Global Telecommunication System). Being able to support improvements in numerical weather prediction and climate modeling will have lasting impacts on Antarctic science and logistical support.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The world ocean is continuously in motion, and a large fraction of this motion takes the form of "eddies", nearly-horizontal swirls of water spanning tens to hundreds of kilometers. These eddies affect the ocean by mediating large-scale currents, redistributing heat, and supplying nutrients to oceanic ecosystems. Consequently, the ocean science community has historically invested substantial effort in characterizing the properties and impact of these eddies. In polar regions, the sea ice cover inhibits observations of eddies, and the relatively small horizontal size of the eddies hampers computer simulations of their behavior. Nonetheless, previous studies have identified an active population of eddies beneath the Arctic sea ice and shown that these eddies play a crucial role in maintaining the large-scale circulation in the Arctic seas. However, there has been no systematic attempt to study such eddies under Antarctic sea ice, leaving a significant gap in our understanding of eddies and their contribution to the large-scale ocean circulation around Antarctica. The proposed research combines multiple approaches to improve our understanding of the eddy dynamics. Statistical characterizations of the sub-sea ice eddy field will be derived using hydrographic observations under Antarctic sea ice from Argo floats and instrumented seals. High-resolution global ocean and sea ice models will be used to track the simulated eddies back to their formation sites to identify the eddy formation mechanisms. Theoretical calculations will be conducted to test the hypothesis that the eddies primarily originate from hydrodynamic instabilities associated with subsurface density gradients. These theoretical, modeling, and data analysis approaches will be combined to estimate the eddies' contribution to lateral tracer transports and their impact on mean circulations of the near-Antarctic ocean. The proposed work will facilitate future scientific endeavors by providing publicly-available databases of detected eddy properties. This project will support the research of several junior scientists: an undergraduate student, two graduate students, and an early-career faculty member. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Walker, Catherine; Zhang, Weifeng; Seroussi, Helene
No dataset link provided
Most of the mass loss from the Antarctic Ice Sheet, a major contributor to sea level rise, occurs at its margins, where ice meets the ocean. Glaciers and ice streams flow towards the coast and can go afloat over the water, forming ice shelves. Ice shelves make up almost half of the entire Antarctic coastline, and hold back the flow of inland ice in Antarctica continent; thus they are integral to the overall stability of the Antarctic Ice Sheet. Ice shelves lose mass by two main processes: iceberg calving and basal melting. Temporal and spatial fluctuations in both are driven by various processes; a major driver of ice shelf melt is the heat provided by the neighboring Southern Ocean. Ocean heat, in turn, is driven by various aspects of the ice shelf environment. One of the most significant contributors to changes in the ocean’s heat content is the presence of sea ice. This research will focus on the effects of coastal polynyas (areas of open water amidst sea ice), how they modulate the local ocean environment, and how that environment drives ice shelf basal melting. To date, the relationship between polynyas and ice shelf melt has not been characterized on an Antarctic-wide scale. Understanding the feedbacks between polynya size and duration, ocean stratification, and ice shelf melt, and the strength of those feedbacks, will improve the ability to characterize influences on the long-term stability of ice shelves, and in turn, the Antarctic Ice Sheet as a whole. A critical aspect of this study is that it will provide a framework for understanding ice shelf-ocean interaction across a diverse range of geographic settings. This, together with improvements of various models, will help interpret the impacts of future climate change on these systems, as their responses are likely quite variable and, overall, different from the large-scale response of the ice sheet. This project will also provide a broader context to better design future observational studies of specific coastal polynya and ice shelf processes. This study focuses on four main hypotheses: 1) Variations of coastal polynya extent are correlated with those of the ice shelf melt rates, and this correlation varies around Antarctica; 2) Polynya extent modulates a feedback between ice shelf melt and accretion regimes through stratification of local waters; 3) Polynya extent together with seafloor bathymetry regulate the volume of warm offshore waters that reach ice margins; and 4) The strength of the feedback between polynya and glacier ice varies with geographic setting and influences the long-term stability of the glacial system. Observational data, including ice-penetrating radar, radar and laser altimetry, and in situ hydrographic data, and derived data sets from the Southern Ocean State Estimate (SOSE) project and BedMachine Antarctica, will be used in conjunction with ocean (MIT global circulation model, MITgcm) and ice sheet (Ice sheet and Sea-level System Model, ISSM) models to reveal underlying dynamics. The joint analysis of the observational data enables an investigation of polynya, ocean, and ice shelf signals and their interplay over time across a range of settings. The results of this data analysis also provide inputs and validation data for the modeling tasks, which will allow for characterization of the feedbacks in our observations. The coupled modeling will enable us to examine the interaction between polynya circulation and ice shelves in different dynamical regimes and to understand ice and ocean feedback over time. Diagnosing and interpreting the pan-Antarctic spatial variability of the polynya-ice shelf interaction are the main objectives of this research and separates this study from other projects targeted at the interactive processes in specific regions. As such, this research focuses on seven preliminary target sites around the Antarctic coast to establish a framework for interpreting coupled ice shelf-ocean variability across a diverse range of geographic settings. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part 1: Non-technical description This is a continuation of a long-term population dynamics study (1978-present) using an intensive mark-recapture tagging of Weddell seals in Erebus Bay, Antarctica. Past work has become a global model for population studies of large animals. Results have documented strong annual variation in reproduction, abundance, and population composition. This program will add components to evaluate the demographic role of immigrant mothers, evaluate possible drivers of annual variation in overall population dynamics, assess genetic differences between immigrant and locally born mothers, and document patterns of gene flow among seal colonies in the Ross Sea region. These new aspects will focus on understanding of population structure, function, and genetics and provide key information for predicting how the seal population will respond to environmental change. The addition of genetic approaches will advance available data for multiple groups in multiple countries working on Weddell Seals. This work includes an early career scientists training program for faculty university graduate and undergraduate students and well as a defined program for data sharing. The research is paired with active education and outreach programs, social media, websites, educational resources, videos and high-profile public lecture activities. The informal science education program will expand on the project’s successful efforts at producing and delivering short-form videos that have been viewed over 1.6 million times to date. In addition, the education program will add new topics such as learning about seals using genomics and how seals respond to a changing world to a multimedia-enhanced electronic book about the project’s long-term research on Weddell seals, which will be freely available to the public early in the project. Part 2: Technical description Reliable predictions are needed for how populations of wild species, especially those at high latitudes, will respond to future environmental conditions. This study will use a strategic extension of the long-term demographic research program that has been conducted annually on the Erebus Bay population of Weddell seals since 1978 to help meet that need. Recent analyses of the study population indicate strong annual variation in reproduction, abundance, and population composition. The number of new immigrant mothers that join the population each year has recently grown such that most new mothers are now immigrants. Despite the growing number of immigrants, the demographic importance and geographic origins of immigrants are unknown. The research will (1) add new information on drivers of annual variation in immigrant numbers, (2) compare and combine information on the vital rates and demographic role of immigrant females and their offspring with that of locally born females, and (3) add genomic analyses that will quantify levels of genetic variation in and gene flow among the study population and other populations in the Ross Sea. The project will continue the long-term monitoring of the population at Erebus Bay and characterize population dynamics and the role of immigration using a combination of mark-recapture analyses, stochastic population modeling, and genomic analyses. The study will continue to provide detailed data on individual seals to other science teams, educate and mentor individuals in the next generation of ecologists, introduce two early-career, female scientists to Antarctic research, and add genomics approaches to the long-term population study of Erebus Bay Weddell seals. The research will be complemented with a robust program of training and an informal science education program. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The response of the Antarctic ice sheet to climate change is a central issue in projecting global sea-level rise. While much attention is focused on the ongoing rapid changes at the coastal margin of the West Antarctic Ice Sheet, obtaining records of past ice-sheet and climate change is the only way to constrain how an ice sheet changes over millennial timescales. Whether the West Antarctic Ice Sheet collapsed during the last interglacial period (~130,000 to 116,000 years ago), when temperatures were slightly warmer than today, remains a major unsolved problem in Antarctic glaciology. Hercules Dome is an ice divide located at the intersection of the East Antarctic and West Antarctic ice sheets. It is ideally situated to record the glaciological and climatic effects of changes in the West Antarctic Ice Sheet. This project will establish whether Hercules Dome experienced major changes in flow due to changes in the elevation of the two ice sheets. The project will also ascertain whether Hercules Domes is a suitable site from which to recover climate records from the last interglacial period. These records could be used to determine whether the West Antarctic Ice Sheet collapsed during that period. The project will support two early-career researchers and train students at the University of Washington. Results will be communicated through outreach programs in coordination the Ice Drilling Project Office, the University of Washington's annual Polar Science Weekend in Seattle, and art-science collaboration. This project will develop a history of ice dynamics at the intersection of the East and West Antarctic ice sheets, and ascertain whether the site is suitable for a deep ice-coring operation. Ice divides provide a unique opportunity to assess the stability of past ice flow. The low deviatoric stresses and non-linearity of ice flow causes an arch (a "Raymond Bump") in the internal layers beneath a stable ice divide. This information can be used to determine the duration of steady ice flow. Due to the slow horizontal ice-flow velocities, ice divides also preserve old ice with internal layering that reflects past flow conditions caused by divide migration. Hercules Dome is an ice divide that is well positioned to retain information of past variations in the geometry of both the East and West Antarctic Ice Sheets. This dome is also the most promising location at which to recover an ice core that can be used to determine whether the West Antarctic Ice Sheet collapsed during the last interglacial period. Limited ice-penetrating radar data collected along a previous scientific surface traverse indicate well-preserved englacial stratigraphy and evidence suggestive of a Raymond Bump, but the previous survey was not sufficiently extensive to allow thorough characterization or determination of past changes in ice dynamics. This project will conduct a dedicated survey to map the englacial stratigraphy and subglacial topography as well as basal properties at Hercules Dome. The project will use ground-based ice-penetrating radar to 1) image internal layers and the ice-sheet basal interface, 2) accurately measure englacial attenuation, and 3) determine englacial vertical strain rates. The radar data will be combined with GPS observations for detailed topography and surface velocities and ice-flow modeling to constrain the basal characteristics and the history of past ice flow. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or part under the American Rescue Plan Act of 2021 (Public Law 117-2). Part I: Non-technical description: Adélie penguin colonies are declining and disappearing from the western Antarctic Peninsula. However, not all colonies in a certain area decline or disappear at the same rate. This research project will evaluate the influence of terrestrial surface properties on Adélie penguin colonies, leveraging five decades of research on seabirds near Palmer Station where an Adélie colony on Litchfield Island became extinct in 2007 while other colonies nearby are still present. The researchers will combine information obtained from remote sensing, UAS (Unoccupied Aircraft System, or drones) high-resolution maps, reconstruction of past moss banks and modeling with machine learning tools to define suitable penguin and peatbank moss habitats and explore the influence of microclimate on their distributions. In particular, the researchers are asking if guano from penguin colonies could act as fertilizers of moss banks in the presence of localized wind patters that can carry airborne nitrogen to the mosses. Modeling will relate penguin and peatbank moss spatial patterns to environmental variables and provide a greater understanding of how continued environmental change could impact these communities. The project allows for documentation of terrestrial Antarctic ecosystems in support of seabirds and provisioning of such information to the broader science community that seeks to study penguins, educating graduate and undergraduate students and a post-doctoral researcher. The research team includes two young women as Principal Investigators, one of them from an under-represented ethnic minority, first time Antarctic Principal Investigator, from an EPSCoR state (Wyoming), broadening participation in Antarctic research. Researchers will serve as student mentors through the Duke Bass Connections program entitled Biogeographic Assessment of Antarctic Coastal Habitats. This program supports an interdisciplinary team of graduate and undergraduate students collaborating with project faculty and experts on cutting-edge research bridging the classroom and the real world. Part II: Technical description: This research aims to understand the changes at the microclimate scale (meters) by analyzing present and past Adélie penguin colonies and moss peatbanks in islands around Palmer Station in the western Antarctic Peninsula – interlinked systems that are typically considered in isolation. By integrating in situ and remote data, this project will synthesize the drivers of biogeomorphology on small islands of the Antarctic Peninsula, a region of rapid change where plants and animals often co-occur and animal presence often determines the habitation of plants. A multi-disciplinary approach combine field measurements, remote sensing, UAS (Unoccupied Aircraft Systems) maps, paleoecology and modeling with machine learning to define suitable habitats and the influence of microclimates on penguin and peatbank distributions. The link between the two aspects of this study, peatbanks and penguins, is the potential source of nutrients for peat mosses from penguin guano. Peatbank and penguin distribution will be modeled and all models will be validated using in situ information from moss samples that will identify mechanistic processes. This project leverages 5 decades of seabird research in the area and high-definition remote sensing provided by the Polar Geospatial center to study the microclimate of Litchfield Island where an Adélie colony became extinct in 2007 when other colonies nearby are still present. The research team includes two early career women as Principal Investigators, one of them from an under-represented ethnic minority, first time Antarctic Principal Investigator, from an EPSCoR state (Wyoming). Researchers will serve as mentors for students through the Duke Bass Connections program entitled Biogeogrpahic Assessment of Antarctic Coastal Habitats which bridges the classroom and the real world. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Pygoscelis penguins are central place foragers during the summer while they raise their chicks. They leave and return to the same colony location after hunting for food and rely on the availability of Antarctic krill, their primary food source. This research focuses on whether penguin diets and colony location reflect the retention of prey around and near colonies on the West Antarctic Peninsula. Eddies and other oceanographic processes may facilitate prey retention at certain locations, driving penguin colony establishment and success. This project hypothesizes that Pygoscelis penguin diets will be composed of more Antarctic krill (Euphausia superba) when local prey retention is high, possibly due to subsurface eddies. This hypothesis will be tested using satellite-based estimates of Pygoscelis penguin diet composition using multispectral sensor data to estimate nitrogen values and infer trophic level. Prey retention will be calculated along the peninsula using the Regional Ocean Modeling System (ROMS). Simulated particles and diel vertical migration will be used to mimic krill behavior. These particles can be experimentally seeded across multiple depths in multiple years to assess residence times in the system. Using penguin colony data from the Mapping Application for Penguin Populations and Projected Dynamics (MAPPPD), the PI will correlate diet and retention metrics to local penguin colony growth and persistence and build a predictive model of where colonies may form in the future. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Sea-ice coverage surrounding Antarctica has expanded during the era of satellite observations, in contrast to rapidly shrinking Arctic sea ice. Most climate models predict Antarctic sea ice loss, rather than growth, indicating that there is much to learn about Antarctic sea ice in terms of its natural variability, processes and interactions affecting annual growth and retreat, and the impact of atmospheric factors such increasing greenhouse gases and stratospheric ozone depletion. This project is designed to improve model simulations of sea ice and examine the role of wind and wave forcing on changes in sea ice around Antarctica. This project seeks to explain basic interactions of the coupled atmosphere, ocean, and ice dynamics in the Antarctic climate system, especially in the region near the sea ice edge. The summer evolution of sea ice cover and the near surface heat exchange of atmosphere and ocean depend on the geometric distribution of floes and the open water surrounding them. The distribution of floes has the greatest impact on the sea ice state in the marginal seas, where the distribution itself can vary rapidly. This project would develop and implement a model of sea ice floes in the Los Alamos sea ice model, known as CICE5. This sea ice component would be coupled to the third generation WaveWatch model within the Community Climate System Model Version 2. The coupled model would be used to study sea ice-wave interactions and the role of modeling sea ice floes in the Antarctic. The broader impacts of this project include outreach, support of female scientists, and improvement of the sea-ice codes in widely used climate models.
Undersea canyons play disproportionately important roles as oceanic biological hotspots and are critical for our understanding of many coastal ecosystems. Canyon-associated biological hotspots have persisted for thousands of years Along the Western Antarctic Peninsula, despite significant climate variability. Observations of currents over Palmer Deep canyon, a representative hotspot along the Western Antarctic Peninsula, indicate that surface phytoplankton blooms enter and exit the local hotspot on scales of ~1-2 days. This time of residence is in conflict with the prevailing idea that canyon associated hotspots are primarily maintained by phytoplankton that are locally grown in association with these features by the upwelling of deep waters rich with nutrients that fuel the phytoplankton growth. Instead, the implication is that horizontal ocean circulation is likely more important to maintaining these biological hotspots than local upwelling through its physical concentrating effects. This project seeks to better resolve the factors that create and maintain focused areas of biological activity at canyons along the Western Antarctic Peninsula and create local foraging areas for marine mammals and birds. The project focus is in the analysis of the ocean transport and concentration mechanisms that sustain these biological hotspots, connecting oceanography to phytoplankton and krill, up through the food web to one of the resident predators, penguins. In addition, the research will engage with teachers from school districts serving underrepresented and underserved students by integrating the instructors and their students completely with the science team. Students will conduct their own research with the same data over the same time as researchers on the project. Revealing the fundamental mechanisms that sustain these known hotspots will significantly advance our understanding of the observed connection between submarine canyons and persistent penguin population hotspots over ecological time, and provide a new model for how Antarctic hotspots function. To understand the physical mechanisms that support persistent hotspots along the Western Antarctic Peninsula (WAP), this project will integrate a modeling and field program that will target the processes responsible for transporting and concentrating phytoplankton and krill biomass to known penguin foraging locations. Within the Palmer Deep canyon, a representative hotspot, the team will deploy a High Frequency Radar (HFR) coastal surface current mapping network, uniquely equipped to identify the eddies and frontal regions that concentrate phytoplankton and krill. The field program, centered on surface features identified by the HFR, will include (i) a coordinated fleet of gliders to survey hydrography, chlorophyll fluorescence, optical backscatter, and active acoustics at the scale of the targeted convergent features; (ii) precise penguin tracking with GPS-linked satellite telemetry and time-depth recorders (TDRs); (iii) and weekly small boat surveys that adaptively target and track convergent features to measure phytoplankton, krill, and hydrography. A high resolution physical model will generalize our field measurements to other known hotspots along the WAP through simulation and determine which physical mechanisms lead to the maintenance of these hotspots. The project will also engage educators, students, and members of the general public in Antarctic research and data analysis with an education program that will advance teaching and learning as well as broadening participation of under-represented groups. This engagement includes professional development workshops, live connections to the public and classrooms, student research symposia, and program evaluation. Together the integrated research and engagement will advance our understanding of the role regional transport pathways and local depth dependent concentrating physical mechanisms play in sustaining these biological hotspots. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This collaborative study between the University of California, Santa Cruz, Duke University, the University of South Florida, the University of Alaska-Anchorage, and the University of California, San Diego will examine the identification of biological and physical features associated with the abundance and distribution of individual Antarctic predators; the identification and characterization of biological 'hot spots' within the Western Antarctic Peninsula; and the development of temporally and spatially explicit models of krill consumption within the WAP by vertebrate predators. It is one of several data synthesis and modeling components that use the data obtained in the course of the field work of the Southern Ocean Global Ocean Ecosystems Dynamics (SO GLOBEC) experiment.<br/>SO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with understanding how predators utilize 'hot spots', i.e. locally intense areas of biological productivity, and how 'hot spots' might temporally and spatially structure krill predation rates, and will be integrated with other synthesis and modeling studies that deal with the hydrography primary production, and krill dynamics.
The purpose of this project is to use geological data that record past changes in the Antarctic ice sheets to test computer models for ice sheet change. The geologic data mainly consist of dated glacial deposits that are preserved above the level of the present ice sheet, and range in age from thousands to millions of years old. These provide information about the size, thickness, and rate of change of the ice sheets during past times when the ice sheets were larger than present. In addition, some of these data are from below the present ice surface and therefore also provide some information about past warm periods when ice sheets were most likely smaller than present. The primary purpose of the computer model is to predict future ice sheet changes, but because significant changes in the size of ice sheets are slow and likely occur over hundreds of years or longer, the only way to determine whether these models are accurate is to test their ability to reproduce past ice sheet changes. The primary purpose of this project is to carry out such a test. The research team will compile relevant geologic data, in some cases generate new data by dating additional deposits, and develop methods and software to compare data to model simulations. In addition, this project will (i) contribute to building and sustaining U.S. science capacity through postdoctoral training in geochronology, ice sheet modeling, and data science, and (ii) improve public access to geologic data and model simulations relevant to ice sheet change through online database and website development. Technical aspects of this project are primarily focused on the field of cosmogenic-nuclide exposure-dating, which is a method that relies on the production of rare stable and radio-nuclides by cosmic-ray interactions with rocks and minerals exposed at the Earth's surface. Because the advance and retreat of ice sheets results in alternating cosmic-ray exposure and shielding of underlying bedrock and surficial deposits, this technique is commonly used to date and reconstruct past ice sheet changes. First, this project will contribute to compiling and systematizing a large amount of cosmogenic-nuclide exposure age data collected in Antarctica during the past three decades. Second, it will generate additional geochemical data needed to improve the extent and usefulness of measurements of stable cosmogenic nuclides, cosmogenic neon-21 in particular, that are useful for constraining ice-sheet behavior on million-year timescales. Third, it will develop a computational framework for comparison of the geologic data set with existing numerical model simulations of Antarctic ice sheet change during the past several million years, with particular emphasis on model simulations of past warm periods, for example the middle Pliocene ca. 3-3.3 million years ago, during which the Antarctic ice sheets are hypothesized to have been substantially smaller than present. Fourth, guided by the results of this comparison, it will generate new model simulations aimed at improving agreement between model simulations and geologic data, as well as diagnosing which processes or parameterizations in the models are or are not well constrained by the data. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The western portion of the Antarctic continent is very active in terms of plate tectonic processes that can produce significant variations in the Earths mantle temperature as well as partial melting of the mantle. In addition to these internal processes, the ice sheet in western Antarctica is melting due to Earths warming climate and adding water to the ocean. These changes in ice mass cause adjustments in rocks within the Earth's crust, allowing the surface to rebound in some locations and fall in others, altering the geographical pattern of sea-level change. However, the solid Earth response depends strongly on the strength of the rocks at a wide range of timescales which is not well-known and varies with temperature and other rock properties. This project has three primary goals. (1) It will assess how processes such as rifting, mantle upwelling and lithospheric instability have altered the lithosphere and underlying asthenosphere of western Antarctica, contributing to a planet-wide understanding of these processes. (2) It will use new measurements of mantle and crust properties to estimate the rate at which heat from the solid Earth flows into the base of the ice, which is important for modeling the rates at which the ice melts and flows. (3) It will places bounds on mantle viscosity, which is key for modeling the interaction of the solid Earth with changing ice and water masses and their implications for sea-level rise. To accomplish these goals, new resolution of crust and mantle structure will be obtained by analyzing seismic waves from distant earthquakes that have been recorded at numerous seismic stations in Antarctica. These analyses will include new combinations of seismic wave data that provide complementary information about mantle temperature, heat flow and viscosity. This project will provide educational and career opportunities to a Brown University graduate student, undergraduates from groups underrepresented in science who will come to Brown University for a summer research program, and other undergraduates. The project will bring together faculty and students for a seminar at Brown that explores the connections between the solid Earth and ice processes in Antarctica. Project research will be incorporated in outreach to local public elementary schools and high schools. This research addresses key questions about mantle processes and properties in western Antarctica. What are the relative impacts of rifting, mantle plumes, and lithospheric delamination in the evolution of the lithosphere and asthenosphere? Where is topography isostatically compensated, and where are dynamic processes such as plate flexure or tractions from 3-D mantle flow required? What are the bounds on heat flow and mantle viscosity, which represent important inputs to models of ice sheet evolution and its feedback from the solid Earth? To address these questions, this project will measure mantle and crust properties using seismic tools that have not yet been applied in Antarctica: regional-scale measurement of mantle attenuation from surface waves; Sp body wave phases to image mantle velocity gradients such as the lithosphere-asthenosphere boundary; and surface wave amplification and ellipticity. The resulting models of seismic attenuation and velocity will be jointly interpreted to shed new light on temperature, bulk composition, volatile content, and partial melt, using a range of laboratory-derived constitutive laws, while considering data from mantle xenoliths. To test the relative roles of rifting, mantle plumes, and delamination, and to assess isostatic support for Antarctic topography, the predictions of these processes will be compared to the new models of crust and mantle properties. To improve bounds on western Antarctic heat flow, seismic attenuation and velocity will be used in empirical comparisons and in direct modeling of vertical temperature gradients. To better measure mantle viscosity at the timescales of glacial isostatic adjustment, frequency-dependent viscosity will be estimated from the inferred mantle conditions. This project will contribute to the education and career development of the following: a Brown University Ph.D. student, Brown undergraduates, and undergraduates from outside the university will be involved through the Department of Earth, Environmental and Planetary Sciences (DEEPS) Leadership Alliance NSF Research Experience for Undergraduates (REU) Site which focuses on geoscience summer research experiences for underrepresented students. The project will be the basis for a seminar at Brown that explores the connections between the solid Earth and cryosphere in Antarctica and will contribute to outreach in local public elementary and high schools. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Warming on the western Antarctic Peninsula in the later 20th century has caused widespread changes in the cryosphere (ice and snow) and terrestrial ecosystems. These recent changes along with longer-term climate and ecosystem histories will be deciphered using peat deposits. Peat accumulation can be used to assess the rate of glacial retreat and provide insight into ecological processes on newly deglaciated landscapes in the Antarctic Peninsula. This project builds on data suggesting recent ecosystem transformations that are linked to past climate of the western Antarctic Peninsula and provide a timeline to assess the extent and rate of recent glacial change. The study will produce a climate record for the coastal low-elevation terrestrial region, which will refine the major climate shifts of up to 6 degrees C in the recent past (last 12,000 years). A novel terrestrial record of the recent glacial history will provide insight into observed changes in climate and sea-ice dynamics in the western Antarctic Peninsula and allow for comparison with off-shore climate records captured in sediments. Observations and discoveries from this project will be disseminated to local schools and science centers. The project provides training and career development for a postdoctoral scientist as well as graduate and undergraduate students. The research presents a new systematic survey to reconstruct ecosystem and climate change for the coastal low-elevation areas on the western Antarctic Peninsula (AP) using proxy records preserved in late Holocene peat deposits. Moss and peat samples will be collected and analyzed to generate a comprehensive data set of late-Holocene climate change and ecosystem dynamics. The goal is to document and understand the transformations of landscape and terrestrial ecosystems on the western AP during the late Holocene. The testable hypothesis is that coastal regions have experienced greater climate variability than evidenced in ice-core records and that past warmth has facilitated dramatic ecosystem and cryosphere response. A primary product of the project is a robust reconstruction of late Holocene climate changes for coastal low-elevation terrestrial areas using multiple lines of evidence from peat-based biological and geochemical proxies, which will be used to compare with climate records derived from marine sediments and ice cores from the AP region. These data will be used to test several ideas related to novel peat-forming ecosystems (such as Antarctic hairgrass bogs) in past warmer climates and climate controls over ecosystem establishment and migration to help assess the nature of the Little Ice Age cooling and cryosphere response. The chronology of peat cores will be established by radiocarbon dating of macrofossils and Bayesian modeling. The high-resolution time series of ecosystem and climate changes will help put the observed recent changes into a long-term context to bridge climate dynamics over different time scales. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Algae in the surface ocean convert carbon dioxide into organic carbon through photosynthesis. The biological carbon pump transports this organic carbon from the atmosphere to the deep ocean where it can be stored for tens to hundreds of years. Annually, the amount transported is similar to that humans are currently emitting by burning fossil fuels. However, at present we cannot predict how this important process will change with a warming ocean. These investigators plan to develop a 15+ year time-series of vertical carbon transfer for the Western Antarctic Peninsula; a highly productive Antarctic ecosystem. This region is also rapid transition to warmer temperatures leading to reduced sea ice coverage. This work will help researchers better understand how the carbon cycle in the Western Antarctic Peninsula will respond to climate change. The researchers will develop the first large-scale time-series of carbon flux anywhere in the ocean. This research will also support the education and training of a graduate student and support the integration of concepts in Antarctic research into two undergraduate courses designed for non-science majors and advanced earth science students. The researchers will also develop educational modules for introducing elementary and middle-school age students to important concepts such as gross and net primary productivity, feedbacks in the marine and atmospheric systems, and the differences between correlation and causation. Results from this proposal will also be incorporated into a children’s book, “Plankton do the Strangest Things”, that is targeted at 5-7 year olds and is designed to introduce them to the incredible diversity and fascinating adaptations of microscopic marine organisms. This research seeks to leverage 6 years (2015-2020) of 234Th samples collected on Palmer LTER program, 5 years of prior measurements (2009-2010, 2012-2014), and upcoming cruises (2021-2023) to develop a time-series of summertime particle flux in the WAP that stretches for 15 years. The 238U-234Th disequilibrium approach utilizes changes in the activity of the particle-active radio-isotope 234Th relative to its parent nuclide 238U to quantify the flux of sinking carbon out of the surface ocean (over a time-scale of ~one month). This proposal will fund 234Th analyses from nine years’ worth of cruises (2015-2023) and extensive analyses designed to investigate the processes driving inter-annual variability in the BCP. These include: 1) physical modeling to quantify the importance of advection and diffusion in the 234Th budget, 2) time-series analyses of particle flux, and 3) statistical modeling of the relationships between particle flux and multiple presumed drivers (biological, chemical, physical, and climate indices) measured by collaborators in the Palmer LTER program. This multi-faceted approach is critical for linking the measurements to models and for predicting responses to climate change. It will also test the hypothesis that export flux is decreasing in the northern WAP, increasing in the southern WAP, and increasing when integrated over the entire region as a result of earlier sea ice retreat and a larger ice-free zone. The project will also investigate relationships between carbon export and multiple potentially controlling factors including: primary productivity, algal biomass and taxonomic composition, biological oxygen saturation, zooplankton biomass and taxonomic composition, bacterial production, temperature, wintertime sea ice extent, date of sea ice retreat, and climate modes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part 1: Non-technical description: It is well known that the Southern Ocean plays an important role in global carbon cycling and also receives a disproportionately large influence of climate change. The role of marine viruses on ocean productivity is largely understudied, especially in this global region. This team proposes to use combination of genomics, flow cytometry, and network modeling to test the hypothesis that viral biogeography, infection networks, and viral impacts on microbial metabolism can explain variations in net community production (NCP) and carbon cycling in the Southern Ocean. The project includes the training of a postdoctoral scholar, graduate students and undergraduate students. It also includes the development of a new Polar Sci ReachOut program in partnership with the University of Michigan Museum of Natural History especially targeted to middle-school students and teachers and the general public. The team will also produce a Science for Tomorrow (SFT) program for use in middle schools in metro-Detroit communities and lead a summer Research Experience for Teachers (RET) fellows. Part 2: Technical description: The study will leverage hundreds of existing samples collected for microbes and viruses from the Antarctic Circumpolar Expedition (ACE). These samples provide the first contiguous survey of viral diversity and microbial communities around Antarctica. Viral networks are being studied in the context of biogeochemical data to model community networks and predict net community production (NCP), which will provide a way to evaluate the role of viruses in Southern Ocean carbon cycling. Using cutting edge molecular and flow cytometry approaches, this project addresses the following questions: 1) How/why are Southern Ocean viral populations distributed across environmental gradients? 2a) Do viruses interfere with "keystone" metabolic pathways and biogeochemical processes of microbial communities in the Southern Ocean? 2b) Does nutrient availability or other environmental variables drive changes in virus-microbe infection networks in the Southern Ocean? Results will be used to develop and evaluate generative models of NCP predictions that incorporate the importance of viral traits and virus-host interactions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences. This project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The West Antarctic Ice Sheet contains enough ice to raise global sea levels by 3-4 meters. Ice-sheet volume falls, and sea level increases, when more ice is lost to the ocean by glacier flow than is replaced by snowfall. Glacier speed is reduced when ice shelves, which are the floating extensions of the ice sheets, are present. Processes that affect ice shelf thickness and extent therefore influence the rates of grounded ice loss and sea-level rise. West Antarctica is currently losing ice, at an accelerating rate, with most loss occurring in the Amundsen Sea region via discharge from Pine Island and Thwaites glaciers. This loss was initiated by increased circulation of relatively warm ocean water beneath these glacier's ice shelves, causing them to thin by melting. However, this melting also depends on how the changing shape of the ice shelves affects the ocean circulation beneath them and the speeds of the grounded glaciers upstream. Limited understanding of these processes leads to uncertainties in estimates of future ice loss. This interdisciplinary project brings together glaciologists and oceanographers from three US institutions to study the interactions between changing glacier flow, ice shelf shape and extent, and ocean circulation. Data and numerical models will be used to identify the key processes that determine how rapidly this region can shed ice. The project team will train postdocs and graduate students in cutting-edge modeling techniques, and educate the public about Antarctic ice loss through talks, school science fairs, and Seattle Science Center's annual Polar Science Weekend. The project team will conduct simulations, using a combination of ice-sheet and ocean models, to reduce uncertainties in projected ice loss from Pine Island and Thwaites glaciers by: (i) assessing how ice-shelf melt rates will change as the ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of sub-shelf melt rates to changes in ocean state on the nearby continental shelf. These studies will reduce uncertainty on ice loss and sea-level rise estimates, and lay the groundwork for development of future fully-coupled ice-sheet/ocean models. The project will first develop high-resolution ice-shelf-cavity circulation models driven by modern observed regional ocean state and validated with estimates of melt derived from satellite observations. Next, an ice-flow model will be used to estimate the future grounding retreat. An iterative process with the ocean-circulation and ice-flow models will then simulate melt rates at each stage of retreat. These results will help assess the validity of the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway, which was based on simplified models of melt rate. These models will also provide a better understanding of the sensitivity of melt to regional forcing such as changes in Circumpolar Deep Water temperature and wind-driven changes in thermocline height. Finally, several semi-coupled ice-ocean simulations will help determine the influence of the ocean-circulation driven melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.
Salvatore, Mark; Gooseff, Michael N.; Sokol, Eric; Barrett, John
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Part I: Non-technical description: Water is life and nowhere is it more notable than in deserts. Within the drylands on Earth, the Antarctic deserts, represented in this study by the McMurdo Dry Valleys, exemplify life in extreme environments with scarce water, low temperatures and long periods of darkness during the polar winter. There is a scarcity of methods to determine water availability, data necessary to predict which species are successful in the drylands, unless measurements are done manually or with field instruments. This project aims to develop a new method of determining soil moisture and use the new data to identify locations suitable for life. Combining these habitats with known species distributions in the McMurdo Dry Valleys, results from this project will predict which species should be present, and also what is the expected species distribution in a changing environment. In this way the project takes advantage of a combination of methods, from recent remote sensing products, ecological models and 30 years of field collections to bring a prediction of how life might change in the McMurdo Dry Valleys in a warmer, and possibly, moister future climate. This project benefits the National Science Foundation goals of expanding fundamental knowledge of Antarctic biota and the processes that sustain life in extreme environments. The knowledge acquired in this project will be disseminated to other drylands through training of high-school curricular programming in Native American communities of the SouthWest. Part II: Technical description: Terrestrial environments in Antarctica are characterized by low liquid water supply, sub-zero temperatures and the polar night in winter months. During summer, melting of snow patches, seasonal steams from glacial melt and vicinity to lakes provide a variety of environments that maintain life, not yet studied at landscape-scale level for habitat suitability and the processes that drive them. This project proposes to integrate remote sensing, hydrological models and ecological models to establish habitat suitability for species in the McMurdo Dry Valleys based on water availability. The approach is at a landscape level in order to establish present-day and future scenarios of species distribution. There are four main objectives: remote sensing development of moisture levels in soils, combining biological and soil data, building and calibrating models of habitat suitability by combining species distribution and environmental variability and applying statistical species distribution model. The field data to develop habitat suitability and calibration of models will leverage a the 30-year dataset collected by the McMurdo Long-Term Ecological Research program. Mechanistic models developed will be essential to predict species distribution in future climate scenarios. Training of post-doctoral researchers and a graduate student will prepare for the next generation of Antarctic scientists. Results from this project will train high-school students from native American communities in the SouthWest where similar desert conditions exist. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Antarctic Peninsula is experiencing rapid environmental changes, which will influence the community of organisms that live there. However, we know very little about the microscopic organisms living in the soil in this region. Soil biology (including bacteria, fungi, and invertebrates) are responsible for many important processes that sustain ecosystems, such as nutrient recycling. Without understanding the environmental conditions that influence soil biodiversity along the Antarctic Peninsula, our ability to predict the consequences of global change is strongly limited. This project will identify the soil community at many sites along the Antarctic Peninsula to discover how the community changes with environmental conditions from north to south. The project will also identify how the soil community at each site differs under different types of plants. Understanding more about the ways in which plant cover and climate conditions influence soil biodiversity will allow predictions of how communities will respond to future changes such as climate warming and invasive plant species. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The investigators will engage with outreach to K-12 students and the general public both directly and through a blog and will participate in workshops for K-12 teachers. Additionally, the project will provide the opportunity for many undergraduate and graduate students of diverse backgrounds to be trained in interdisciplinary research. The investigators will determine the nature and strength of plant-soil linkages in influencing soil community composition and diversity over a latitudinal gradient of environmental and climatic conditions. The goals are to (1) increase our understanding of current biogeography and diversity by providing in-depth knowledge of soil community composition and complexity as it relates to environmental and climatic characteristics; and (2) determine the nature of aboveground-belowground community linkages over varying spatial scales. The team will identify the composition and diversity of soil communities under key habitat types (grass, moss, algae, etc.). Microbial communities (bacteria, fungi, archaea) will be investigated using pyrosequencing for community composition analysis and metagenomic sequencing to identify functional capabilities. Invertebrates (nematodes, tardigrades, rotifers, microarthropods) will be extracted and identified to the lowest possible taxonomic level. Soil chemistry (pH, nutrient content, soil moisture, etc.) and climate conditions will be measured to determine the relationship between soil communities and physical and chemical properties. Structural equation modeling will be used to identify aboveground-belowground linkage pathways and quantify link strengths under varying environmental conditions.
Warming at the northern Antarctic Peninsula is causing fundamental changes in the marine ecosystem. Antarctic krill are small shrimp-like animals that are most abundant in that area. They are also an essential part of the marine food web of the waters surrounding Antarctica. Meanwhile, a rapidly growing international fishery has developed for krill. Understanding changes in krill populations is therefore critical both to the management of the fishery and the ability of scientists to predict changes in the Antarctic marine ecosystem. This project will have two broader societal impacts. First, the project will support the training of students for careers in oceanography. The students will be recruited from underrepresented groups in an effort to increase diversity, equity and inclusion in STEM. Second, results from this project will develop improved population models, which are essential for the effective management of the Antarctic krill fishery. In collaboration with US delegates on the Commission for the Conservation of Antarctic Marine Living Resources, the researchers will produce a report outlining the key findings from the study. Effective population modeling relies on empirical and theoretical understanding of how environment drives krill reproduction. There are two critical egg development stages in Antarctic krill that impact population growth. They are early egg development, and advanced egg development/spawning. The timing and duration of early egg development determines the number of eggs produced and the number of seasonal spawning events a female can undergo. The research team will use samples of Antarctic krill collected over the last 30 years in late winter/early spring, summer and early fall. The reproductive development stages of individual females in these samples will be assessed. These data will be modeled against climatological and oceanographic data to test three hypotheses. First, they will test if colder winter conditions correspond to early preparation for spawning. Second, they will test if favorable winter-summer conditions increase early spawning. Finally, they will test if favorable winter-summer conditions lengthen the spawning season. The study will advance current understanding of the environmental conditions that promote population increases in Antarctic krill and will fill an important gap in current knowledge of the reproductive development and output of Antarctic krill. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Weddell Gyre is one of the major components of the Southern Ocean circulation system, linking heat and carbon fluxes in the Antarctic Circumpolar Current to the continental margins. Water masses entering the Weddell Gyre are modified as they move in a great circular route around the gyre margin and change through processes involving air-sea-cryosphere interactions as well as through ocean eddies that mix properties across the gyre boundaries. Some of the denser water masses exit the gyre through pathways along the northern boundary, and ultimately ventilate the global deep ocean as Antarctic Bottom Water. While in-situ and satellite observations, as well as computer modeling efforts, provide estimates of the large-scale average flow within the gyre, details of the smaller-scale, or "mesoscale" eddy flow remain elusive. The proposed research will quantify mixing due to mesoscale eddies within the Weddell Gyre, as well as the transport of incoming deep water from the northeast, thought to be a result of transient eddies. Since the Weddell Gyre produces source water for about 40% of Antarctic Bottom Water formation, understanding the dynamics in this region helps to identify causes of documented changes in global bottom waters. This in turn, will give insight into how climate change is affecting global oceans, through modification of dense polar waters and Antarctic Bottom Water characteristics. This project aims to track 153 RAFOS-enabled Argo floats in the ice-covered regions of the Weddell Gyre. The resultant tracks along with all available Argo and earlier float data will be used to calculate Eulerian and Lagrangian means and eddy statistics for the Weddell Gyre. The study will link RAFOS tracks with Argo profiles under ice, allowing one to characterize the importance of eddies in water column modification at critical ice-edge boundaries and leads. With RAFOS tracks near the northeastern limit of the gyre, the project will investigate the eddy-driven processes of incoming Circumpolar Deep Water, to understand better the mechanisms and volume fluxes involved. Previous work shows that a large fraction of the mean circulation in the southern and western limits of the gyre, where it contacts the Antarctic continent, occurs in a narrow boundary layer above the slope. The research here will integrate this flow structure into a complete interior and boundary layer mean circulation synthesis. The findings and products from the proposed work will improve the positioning of Argo profiles in the polar regions, which would allow for more accurate climatological maps and derived quantities. Estimates of meso-scale mixing may serve as a foundation for the development of new parameterization schemes employed in climate models, as well as local and global ocean circulation models in polar regions. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Southern Ocean accounts for ~40% of the total ocean uptake of anthropogenic carbon dioxide despite covering only 20% of the global ocean surface, and is particularly rich in long-lived eddies. These eddies, or large ocean whirlpools which can be observed from space, can alter air-sea fluxes of carbon dioxide in ways that are not yet fully understood. New observations from autonomous platforms measuring ocean carbon content suggest that there is significant heterogeneity in ocean carbon fluxes which can be linked to these dynamic eddy features. Due to computational and time limitations, ocean eddies are not explicitly represented in most global climate simulations, limiting our ability to understand the role eddies play in the ocean carbon cycle. This study will explore the impact of eddies on ocean carbon content and air-sea carbon dioxide fluxes in the Southern Ocean using both simulated- and observation-based strategies and the findings will improve our understanding of the ocean’s role in the carbon cycle and in global climate. While this work will primarily be focused on the Southern Ocean, the results will be globally applicable. The researchers will also broaden interest in physical and chemical oceanography among middle school-age girls in the University of South Florida’s Oceanography Camp for Girls by augmenting existing lessons with computational methods in oceanography. This project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite sea surface height data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls, recognized by NSF as a “Model STEM Program for Women and Girls” focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This research will take advantage of the greater number of Antarctic weather observations collected as part of the World Meteorological Organization's "Year of Polar Prediction". Researchers will use these additional observations to study new ways of incorporating data into existing weather prediction models. The primary goal of this research is to improve the accuracy of weather forecasts in Antarctica. This work is important, as the harsh weather in Antarctica greatly impacts scientific research and the support of this research. Being able to accurately predict changing weather increases the safety and efficiency of Antarctic field science and operations. The proposed effort seeks to advance goals of the World Meteorological Organization's Polar Prediction Project and its Year of Polar Prediction-Southern Hemisphere (YOPP-SH) effort. Researchers will investigate and demonstrate the forecast impact of enhanced atmospheric observations obtained from YOPP-SH's Special Observing Period on polar numerical weather prediction. This will be done by using the Antarctic Mesoscale Prediction System (AMPS). AMPS is the primary numerical weather prediction capability for the United States Antarctic Program (USAP). Modeling experimentation will assess the impact of Special Observing Period data on Antarctic forecasts and will serve as a vehicle for testing new data assimilation approaches for AMPS. The primary goal for this work is improved forecasting and numerical weather prediction tools. Outcomes will include quantification of the value of enhanced southern hemisphere atmospheric observations. This work will also help improve AMPS and its ability to support the USAP. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Southern Ocean accounts for ~40% of the total ocean uptake of anthropogenic carbon dioxide despite covering only 20% of the global ocean surface, and is particularly rich in long-lived eddies. These eddies, or large ocean whirlpools which can be observed from space, can alter air-sea fluxes of carbon dioxide in ways that are not yet fully understood. New observations from autonomous platforms measuring ocean carbon content suggest that there is significant heterogeneity in ocean carbon fluxes which can be linked to these dynamic eddy features. Due to computational and time limitations, ocean eddies are not explicitly represented in most global climate simulations, limiting our ability to understand the role eddies play in the ocean carbon cycle. This study will explore the impact of eddies on ocean carbon content and air-sea carbon dioxide fluxes in the Southern Ocean using both simulated- and observation-based strategies and the findings will improve our understanding of the ocean’s role in the carbon cycle and in global climate. While this work will primarily be focused on the Southern Ocean, the results will be globally applicable. The researchers will also broaden interest in physical and chemical oceanography among middle school-age girls in the University of South Florida’s Oceanography Camp for Girls by augmenting existing lessons with computational methods in oceanography. This project aims to quantify the impacts of mesoscale eddy processes on ocean carbon content and air-sea carbon dioxide (CO2) fluxes in the Southern Ocean. For the modeling component, the investigators will explore relationships between eddies, ocean carbon content, and air-sea CO2 fluxes within the 1/6-degree resolution Biogeochemical Southern Ocean State Estimate (B-SOSE). They investigators will produce high-resolution composites of the carbon content and physical structure within both cyclonic and anticyclonic eddies by region, quantify the influence of these eddies on the overall simulated air-sea CO2 flux, and diagnose the physical mechanisms driving this influence. For the observational component, the investigators will match eddies observed via satellite altimetry to ocean carbon observations and characterize observed relationships between eddies and ocean carbon content with a focus on Southern Ocean winter observations where light limits biological processes, allowing isolation of the contribution of physical processes. This work will also provide motivation for higher resolution and better eddy parameterizations in climate models, more mesoscale biogeochemical observations, and integration of satellite sea surface height data into efforts to map air-sea fluxes of CO2. Each summer, the PI delivers a lab lesson at the University of South Florida Oceanography Camp for Girls, recognized by NSF as a “Model STEM Program for Women and Girls” focused on broadening participation by placing emphasis on recruiting a diverse group of young women. As part of this project, the existing interactive Jupyter Notebook-based Python coding Lab lesson will be augmented with a B-SOSE-themed modeling component, which will broaden interest in physical and chemical oceanography and data science, and expose campers to computational methods in oceanography. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The Antarctic ice sheet is underlain by a dynamic water system that lubricates the flow of ice streams and outlet glaciers, provides a habitat for a diverse microbial ecosystem, and delivers freshwater and nutrients to the Southern Ocean. However, imaging this subglacial environment is difficult: Antarctica is a vast continent with ice up to four kilometers (2.5 miles) thick. To detect water at the ice-bed interface and in deeper groundwater reservoirs, this project will adapt a technique called electromagnetic sounding that is well-established on land and in the ocean for imaging fluids beneath the surface. Groundwater is estimated to be a significant part of the subglacial water budget in Antarctica, yet previous observational approaches have been unable to characterize its volume and distribution. This project will thus yield critical information about how ice-rock-water-ocean systems interact and inform our understanding of ice-sheet processes, global nutrient cycles, and freshwater flux to the ocean. The project will provide cross-disciplinary training for a graduate student and postdoctoral scientist, and develop an educational outreach program through the Birch Aquarium. Standard geophysical surveying techniques used in glaciology to image subglacial water (radio-echo sounding and active-source seismology) are not directly sensitive to water content. In contrast, ground-based electromagnetic (EM) methods are sensitive to water content through its impact on bulk conductivity. Although EM methods are well-established for high-precision mapping of hydrology in other geological environments, their application on ice sheets is in its infancy. The proposed work will adapt both passive- and active-source EM techniques to glaciological questions to quantify the three-dimensional structure of subglacial water beneath an ice stream and in a grounding zone. The project will perform a suite of synthetic inversion studies to determine the range of applications of EM techniques in glaciology and execute a field experiment on the Whillans Ice Plain to investigate two hypotheses about the subglacial water system based on previous observational and modeling results: (1) Subglacial Lake Whillans is underlain by a deep, saline groundwater reservoir; and (2) there is an estuary-like zone of mixing between fresh subglacial water and seawater near, and possibly landward, of the grounding line.
ANDRILL is a scientific drilling program to investigate Antarctica's role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica's climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth's ocean-climate system. <br/><br/>This award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica's major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.<br/><br/>The South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area's complex tectonic history.<br/><br/>The broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society's understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. <br/><br/>As key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica's ice sheets are important to society's understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth's climatic future.
Correlating ecosystem responses to past climate forcing is highly dependent on the use of reliable techniques for establishing the age of events (dating techniques). In Antarctic dry regions (land areas without glaciers), carbon-14 dating has been used to assess the ages of organic deposits left behind by ancient lakes. However, the reliability of the ages is debatable because of possible contamination with "old carbon" from the surrounding landscape. The proposed research will attempt to establish two alternate dating techniques, in situ carbon-14 cosmogenic radionuclide exposure dating and optically stimulated luminescence (OSL), as reliable alternate dating methods for lake history in Antarctic dry areas that are not contaminated by the old carbon. The end goal will be to increase scientific understanding of lake level fluctuation in the lakes of Taylor Valley, Antarctica so that inference about past climate, glacier, and ecosystem response can be inferred. The results of this study will provide a coarse-scale absolute chronology for lake level history in Taylor Valley, demonstrate that exposure dating and OSL are effective means to understand the physical dynamics of ancient water bodies, and increase the current understanding of polar lacustrine and ice sheet responses to past and present climatic changes. These chronologies will allow polar lake level fluctuations to be correlated with past changes in global and regional climate, providing information critical for understanding and modeling the physical responses of these environments to modern change. This research supports a PhD student; the student will highlight this work with grade school classes in the United States. This research aims to establish in situ carbon-14 exposure dating and OSL as reliable alternate (to carbon-14 of organic lake deposits) geochronometers that can be used to settle the long-disputed lacustrine history and chronology of Taylor Valley, Antarctica and elsewhere. Improved lake level history will have significant impacts for the McMurdo Dry Valleys Long Term Ecological Research (MCM LTER) site as the legacy of fluctuating lake levels of the past affects the distribution of organic matter and nutrients, and impacts biological connectivity valley-wide. This work will provide insight into the carbon reservoir of large glacial lakes in the late Holocene and have implications for previously reported radiocarbon chronologies. OSL samples will be analyzed in the Desert Research Institute Luminescence Laboratory in Reno, NV. For the in situ carbon-14 work, rock samples extracted from boulders and bedrock surfaces will be prepared at Tulane University. The prepared in situ carbon-14 samples will be analyzed at the National Ocean Sciences Accelerator Mass Spectrometry laboratory in Woods Hole, MA. The two datasets will be combined to produce a reliable, coarse scale chronology for late Quaternary lake level fluctuations in Taylor Valley. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Icebergs are a component of the Antarctic climate system, yet a comprehensive representation of their dynamics in climate models has remained elusive. Representing the role of icebergs in global climate models (GCMs) poses a formidable challenge to the scientific community. The most striking shortcoming of current iceberg models is arguably that they do not represent giant tabular icebergs, even though giant icebergs carry most of the freshwater stored in icebergs in the Southern Ocean. This lack of large icebergs in models is mostly due to the difficulties associated with adequately modeling iceberg decay. In particular, fracturing and breakup are not typically considered in iceberg models, despite being dominant iceberg decay processes. Investigators are to address these issues using a hierarchy of iceberg models, ranging from an idealized analytical model to a comprehensive GCM, in concert with recent observational data. The main objective of this study is to develop a new iceberg model that: (i) accounts for iceberg breakup and fracturing processes that have been neglected to date, (ii) improves on the representation of iceberg decay processes that were considered in previous models, (iii) explicitly represents large tabular icebergs. The primary broader impact of the proposed work will be through a K-12 teacher workshop series showcasing this project as an example of how scientists develop physical models. Ongoing changes in the California K-12 science standards will enable the teachers to creatively use this material in their classrooms. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or part under the American Rescue Plan Act of 2021 (Public Law 117-2). The Geospace environment comprises a complex system of the incoming solar wind plasma flow interacting with the Earth's magnetic field and transferring its energy and momentum into the magnetosphere. This interaction takes place mainly on the Earth's dayside, where reconnecting geomagnetic field line might be "open" and directly connected to the interplanetary magnetic field lines, thus providing direct pathways for the solar wind energy to be transferred down to the ionosphere and upper atmosphere. The spatial extent of the polar cap areas controlled by the ionospheric plasma convection demarcate the so-called "Open-Closed Boundary" where solar wind particles reach down polar ionospheres. Observations of that boundary serve the important role in validating geomagnetic field modeling and help studying space weather. Motivated by the compelling Geospace research in the polar regions, this award will allow scientists to investigate magnetosphere-ionosphere coupling processes and ionospheric irregularities inside the polar caps and their space weather impacts by establishing a new ground-based network that will be deployed in the Antarctic polar cap region. This will be achieved using three new instrumented platforms (next generation of Automatic Geophysical Observatories) along the snow traverse route from the Korean Antarctic Station Jang Bogo toward to the Concordia Station at Dome C by the Korea Polar Research Institute's (KOPRI) team. Geospace data collected by these three platforms will be shared by the U.S. and Korean researchers, as well as will be made available to other scientists. The research involves early-career researchers, as well as train students who will build and operate remote Antarctic platforms, as well as analyze collected data to investigate space weather events and validate models. This project expands the U.S. institutions partnership with the KOPRI scientists and logistical support personnel. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The McMurdo Dry Valleys are the largest ice-free region in Antarctica and home to a seasonally active hydrologic system, with streams and saline lakes. Streams are fed by summer meltwater from local glaciers and snowbanks. Therefore, streamflow is tied to summer climate conditions such as air temperatures, ground temperatures, winds, and incoming solar radiation. Based on 50 years of monitoring, summer stream activity has been observed to change, and it likely varied during the geologic past in response to regional climate change and fluctuating glaciers. Thus, deposits from these streams can address questions about past climate, meltwater, and lake level changes in this region. How did meltwater streamflow respond to past climate change? How did streamflow vary during periods of glacial advance and retreat? At what times did large lakes fill many of the valleys and what was their extent? The researchers plan to acquire a record of stream activity for the Dry Valleys that will span the three largest valleys and a time period of about 100,000 years. This record will come from a series of active and ancient alluvial fans that were deposited by streams as they flowed from valley sidewalls onto valley floors. The study will provide a long-term context with which to assess recent observed changes to stream activity and lake levels. The research will be led by two female mid-career investigators and contribute significantly to student research opportunities and education. The research will contribute to graduate and undergraduate education by including students in both field and laboratory research, as well as incorporating data and results into the classroom. The research will be disseminated to K-12 and non-scientific communities through outreach that includes professional development training for K-12 teachers in eastern Massachusetts, development of hands-on activities, visits to K-12 classrooms, and STEM education and literacy activities in North Carolina. The PIs propose to constrain rates of fluvial deposition and periods of increased fluvial activity in the McMurdo Dry Valleys during the Holocene and late Pleistocene. During 50 years of hydrologic monitoring in the Dry Valleys, scientists have observed that streams exhibit significant response to summer conditions. Previous studies of glacial and lacustrine deposits indicate regional glacier advance in the Dry Valleys during recent interglacial periods and high lake levels during and after the Last Glacial Maximum (LGM), with potentially significant low and high stands during the Holocene. However, the geologic record of meltwater activity is poorly constrained. The PIs seek to develop the first spatially-extensive record of stream deposition in the Dry Valleys by analyzing and dating alluvial fans. Given that alluvial fans are deposited by summer meltwater streams in a relatively stable tectonic setting, this record will serve as a proxy of regional summer climate conditions. Meltwater streams are an important component of the regional hydrologic system, connecting glaciers to lakes and affecting ecosystems and soils. A record of fluvial deposition is key to understanding the relationship between past climate change and regional hydrology. The proposed research will include remote- and field-based mapping of alluvial fans, stream channels, and meltwater sources as well as modeling potential incoming solar radiation to the fans and moisture sources during the austral summer. In the field, the PIs will document stratigraphy, collect near-surface sediments from 25 fans across four valleys (Taylor, Pearse, Wright, and Victoria), and collect 2- to 3-m vertical cores of ice-cemented sediments from three alluvial fan complexes. The PIs will then conduct depositional dating of fluvial sands via optically stimulated luminescence, and analyze mineralogy and bulk major element chemistry with X-ray powder diffraction and X-ray fluorescence. From these analyses, the PIs propose to (1) determine the timing of local- to regional-scale periods of high fluvial deposition, (2) calculate depositional rates, and (3) constrain depositional environments and sediment provenance. Given that many of the alluvial fans occur below the hypothesized maximum extents of glacially-dammed lakes in Wright and Victoria valleys, detailed stratigraphy, sediment provenance, and OSL dating of these fans could shed light on ongoing debates regarding the timing and extent of LGM and post-LGM lakes. The work will support a postdoctoral researcher, a PhD student, and many undergraduate and master’s students in cross-disciplinary research that spans stratigraphy, geochemistry, paleoclimatology and physics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.
Geologic data provide crucial insights into Antarctic Ice Sheet dynamics; for example, progressive exposure of mountain peaks emerging from the ice sheet reveal ice elevation changes, and the past ‘footprint’ of marine-based ice sheets is imprinted on the seafloor. Numerical ice sheet simulations can link these geologic records in space and time to make larger-scale inferences about continent-wide ice sheet evolution. This work integrates both marine and terrestrial geologic datasets with numerical simulations to investigate Antarctic Ice Sheet behavior (and contribution to global sea level) throughout the last deglaciation, ~20,000 years ago until present. Specifically, this research addresses two issues regarding the relationship between simulations and data and their use in reconstructing past ice-sheet behavior: (1) Geologic records from the modern seafloor suggest significantly earlier retreat of marine-based ice compared to terrestrial records of mountain peak exposure (ice thinning). Computer experiments investigate several hypotheses for this mismatch in timing. (2) Exposure age data (terrestrial measurements recording ice elevation changes) are often interpreted to reflect ice dynamics hundreds of kilometers away from the study site. This work uses simulations to explore the linkage between ice elevation changes ‘upstream’ as glaciers flow through mountainous regions and ice dynamics further ‘downstream’ where ice contacts the ocean. This work will produce a publicly available, customizable, and easily accessible toolkit for comparing simulations and data, including a database of geologic records to use as constraints. The project is interdisciplinary, bridging a communication gap between the ice-sheet simulations and geologic data-collecting communities. This project combines numerical simulations and geologic data to explore fundamental knowledge gaps regarding the interpretation and use of marine and terrestrial datasets. This work will produce an ensemble of continent-wide coupled ice sheet and glacial isostatic adjustment simulations, constrained with comprehensive existing geologic data, to reproduce a history of deglacial Antarctic Ice Sheet evolution that is compatible with the geologic record as well as glaciologically and gravitationally self-consistent. Comparison between simulations and data is improved through high-resolution nested ice sheet modeling techniques, which provide unprecedented context for exposure age data generally located in regions of complex topography. Numerical simulations will be performed with systematically varied parameters and boundary conditions, and can thus support an investigation of (1) chronological mismatches between terrestrial thinning and marine ice sheet retreat during the mid-Holocene, and (2) how marine grounding-line dynamics are propagated upstream to coastal outlet glaciers and further interior under a variety of different scenarios. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). Climate change is promoting increased melting in Greenland and Antarctica, contributing to the global sea level rise. Understanding what drives the increase and the amount of meltwater from the ice sheets is paramount to improve our skills to project future sea level rise and associated consequences. Melting in Antarctica mostly occurs along ice shelves (tongues of ice floating in the water). They do not contribute directly to sea level when they melt but their disappearance allows the glaciers at the top to flow faster towards the ocean, increasing the contribution of Antarctica to sea level rise. Satellite data can only offer a partial view of what is happening, either because of limited coverage or because of the presence of clouds, which often obstruct the view in this part of the world. Models, on the other hand, can provide estimates but the spatial detail they can provide is still limited by many factors. This project will use artificial intelligence to overcome these problems and to merge satellite data and model outputs to generate daily maps of surface melting with unprecedented detail. These techniques are similar to those used in cell phones to sharpen images or to create landscapes that look “real” but are only existing in the “computer world,” but they have never been applied to melting in Antarctica for improving estimates of sea level rise. Meltwater in Antarctica has been shown to impact ice shelf stability through the fracturing and flexural processes. Image scarcity has often forced the community to use general climate and regional climate models to explore hydrological features. Notwithstanding models having been considerably refined over the past years, they still require improvements in capturing the processes driving the energy balance and, most importantly, the feedback among the drivers and the energy balance terms that drive the hydrological processes. Moreover, spatial resolution is still too coarse to properly capture hydrological processes, especially over ice shelves. Machine learning (ML) tools can help in this regard, especially when it is computationally infeasible to run physics-based models at desired resolutions in space and time, like in the case of ice shelf surface hydrology. This project will train Generative Adversarial Networks (GANs) with the outputs of a regional climate model and remote sensing data to generate unprecedented, high-resolution (100 m) maps of surface melting. Beside improving the spatial resolution, and hence providing a long-needed and crucial dataset to the polar community, the tool here proposed will be able to provide satellite-like maps on a daily basis, hence addressing also those issues related to the lack of spatial coverage. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Icebergs influence climate by controlling how freshwater from ice sheets is distributed into the ocean, where roughly half of ice sheet mass loss is attributed to iceberg calving in the current climate. The freshwater deposited by icebergs as they drift and melt can affect ocean circulation, sea-ice formation, and biological primary productivity. Furthermore, calving of icebergs from ice shelves, the floating extensions of ice sheets, can influence ice sheet evolution and sea-level rise by reducing the resistive stresses provided by ice shelves on the seaward flow of upstream grounded ice. The majority of mass calved from ice shelves occurs in the form of tabular icebergs, which are typically hundreds of meters thick and on the order of tens to hundreds of kilometers in length and width. Tabular calving occurs when full-thickness ice shelf fractures known as rifts propagate to the edges of the ice shelf. These calving events are infrequent, often with decades between events on an individual ice shelf. Changes in tabular calving behavior, i.e., the size and frequency of calving events, can strongly influence climate and ice sheet evolution. However, tabular calving behavior, and how it responds to changes in climate, is neither well understood nor accurately represented in climate models. In this project, a tabular calving parameterization for climate models will be developed. The parameterization will be derived according to data generated from a series of realistic and idealized century-scale tabular calving simulations, which will be performed with a novel ice flow and damage framework that can be applied at the scale of individual ice sheet-ice shelf systems: the CD-MPM-SSA (Continuum Damage Material Point Method for Shelfy-Stream Approximation). During these simulations, the geometry of the ice shelf, mechanical/rheological properties of the ice, and climate forcings such as ocean temperature will be varied to determine the rifting and calving response. The calving parameterization derived from these experiments will be implemented in a Geophysical Fluid Dynamics Laboratory (GFDL) climate model, where it will be coupled with a bonded-particle iceberg model. Then, experiments will be run to study the feedback between changes in iceberg calving behavior and climate. Success of this project will improve our understanding and representation of the ice mass budget, ice sheet evolution, and ocean freshwater fluxes, and will improve projections of climate change and sea-level rise. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This study will collect a novel dataset to determine how the West Antarctic Ice Sheet (WAIS) responded to a warmer climate during the last interglacial period (~125,000 years ago) by reconstructing the glacial history at the Mt. Waesche volcano. Reconstructing WAIS geometry when the ice sheet was smaller than present is difficult and data are lacking because the evidence lies beneath the present ice sheet. This study will drill through the ice sheet and recover bedrock that can be analyzed for its surface exposure history to help determine when the surface became overridden by the ice sheet. This study will provide constraints on the past maximum and minimum spatial extent of WAIS during the last glacial-interglacial cycle. Understanding the geometry of a reduced WAIS during intervals when the planet was warmer than present may provide a possible analogue for future environmental conditions given predicted temperature trends. A reduction of WAIS results in rising sea levels which threatens coastal communities across the globe. The data will help improve numerical ice sheet models to better predict WAIS response to current and future climate trends. The project supports a teacher educational workshop and the training of graduate and undergraduate students. The goal of this project is to obtain rock samples from beneath the WAIS through shallow (<80 m) drilling at Mt. Waesche, a volcano in Marie Byrd Land, near an ice dome of WAIS (2000 m elevation). The lithologies of lava flows exposed on the flank of the volcano are well-suited for cosmogenic 3He and 36Cl as well as 40Ar/39Ar measurements which will establish eruption and exposure age. Existing 40Ar/39Ar data indicate basaltic lava flows on the volcano flank as young as 350 ka. Thus, measured cosmogenic nuclides measured in rock cores from beneath the ice surface will be indicative of relatively recent exposure during periods of reduced ice elevation, most likely, during the last interglacial. The first field season is focused on identifying appropriate locations for drilling and a ground penetrating radar (GPR) survey of the subglacial topography <100m under the blue ice area. Mapping and dating the adjacent exposed lava flows will allow tracing of lava flows of known age and composition below the ice margin that will be targeted for drilling the following year. The second field season activities include drilling 8 boreholes (two transects) through blue ice with the Winkie drill near the ice margin to 80 m depth to obtain rock cores from the sub-ice lava flows. 3He exposure ages will constrain the duration and minimum extent of past surface lowering of the WAIS in Marie Byrd Land. Deeper GPR imaging (up to 700 m) will hope to reveal additional evidence of lava/ice interactions that would independently place constraints on lower ice levels during past eruptions. Results from this study will be compared with the modeled ice elevation histories at Mt. Waesche to validate ice sheet modeling efforts. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The spatial extent of the West Antarctic Ice Sheet during the last interglacial period (129,000 to 116,000 years ago) is currently unknown, yet this information is fundamental to projections of the future stability of the ice sheet in a warming climate. Paleoclimate records and proxy evidence such as dust can inform on past environmental conditions and ice-sheet coverage. This project will combine new, high-sensitivity geochemical measurements of dust from Antarctic ice collected at Allan Hills with existing water isotope records to document climate and environmental changes through the last interglacial period. These changes will then be compared with Earth-system model simulations of dust and water isotopes to determine past conditions and constrain the sensitivity of the West Antarctic Ice Sheet to warming. The project will test the hypothesis that the uncharacteristically volcanic dust composition observed at another peripheral ice core site at Taylor Glacier during the last interglacial period is related to changes in the spatial extent of the West Antarctic Ice Sheet. This project aims to characterize mineral dust transport during the penultimate glacial-interglacial transition. The team will apply high-precision geochemical techniques to the high-volume, high-resolution ice core drilled at the Allan Hills site in combination with Earth system model simulations to: (1) determine if the volcanic dust signature found in interglacial ice from Taylor Glacier is also found at Allan Hills, (2) determine the likely dust source(s) to this site during the last interglacial, and (3) probe the atmospheric and environmental changes during the last interglacial with a diminished West Antarctic Ice Sheet. The team will develop a suite of measurements on previously drilled ice from Allan Hills, including isotopic compositions of Strontium and Neodymium, trace element concentrations, dust-size distribution, and imaging of ice-core dust to confirm the original signal observed and provide a broader spatial reconstruction of dust transport. In tandem, the team will conduct Earth system modeling with prognostic dust and water-isotope capability to test the sensitivity of dust transport under several plausible ice-sheet and freshwater-flux configurations. By comparing dust reconstruction and model simulations, the team aims to elucidate the driving mechanisms behind dust transport during the last interglacial period. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctica is among the most rapidly warming places on the planet, and some reports suggest the Antarctic environment is approaching, or possibly beyond, the tipping point for ice shelf collapse. The loss of ice around Antarctica is dramatically changing habitat availability for marine fauna, particularly benthic marine invertebrate species. Building on past studies, this research will provide insights into how changing climate impacts species distribution and community structure. Geological data suggests that during periods when ice extent was much reduced relative to modern levels, marine seaways connected the Ross and Weddell Seas on either side of Antarctica. However, most theories about the origins of current marine invertebrate distribution patterns fail to consider this transantarctic connection. This research will use molecular genomic tools to probe the DNA of Antarctic marine invertebrates and explore alternative hypotheses about factors that may have shaped current patterns of animal biodiversity in the Southern Ocean. Research will inform predictions about how species distributions may change as Antarctic ice sheets continue to deteriorate and provide critical information on how organisms adjust their ranges in response to environmental change. This work includes several specific outreach activities including presentations in K-8 classrooms, several short-format videos on Antarctic genomics and field work, and two 3-day workshops on bioinformatics approaches. A minimum of 4 graduate students, a postdoc and several undergraduates will also be trained during this project. The overarching goal of this research is to understand environmental factors that have shaped patterns of present-day diversity in Antarctic benthic marine invertebrates. Evidence from sediment cores and modeling suggests ice shelf collapses have occurred multiple times in the last few million years. During these periods, transantarctic seaways connected the Ross and Weddell Seas. This research will assess whether the presence of transantarctic waterways helps explain observed similarities between the Ross and Weddell Seas benthic marine invertebrate fauna better than other current hypotheses (e.g., dispersal by the Antarctic Circumpolar Current, or expansion from common glacial refugia). Seven Antarctic benthic invertebrate taxa will be targeted to test alternative hypothesis about the origins of population genetic structure in the Southern Ocean using Single Nucleotide Polymorphism (SNP) markers that sample thousands of loci across the genome. Additionally, research will test the current paradigm that divergence between closely related, often cryptic, species is the result of population bottlenecks caused by glaciation. Specifically, SNP data will be mapped on to draft genomes of three of our target taxa to assess the degree of genetic divergence and look for signs of selection. Research findings may be applicable to other marine ecosystems around the planet. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Nontechnical Abstract Mount Erebus volcano on Ross Island, Antarctica, is the southernmost active volcano on the planet. It provides a natural laboratory to study a volcanic system that has been in a continuous state of activity with a persistent lava lake over at least the last 40 years. Worldwide only four other volcanoes with such long-lived lava lakes exist: Erta Ale, Ethiopia; Kilauea, Hawaii; Nyiragongo, Congo; and Ambrym, Vanuatu. These volcanoes are a rare anomaly that provide a window into the underlying magmatic system and behavior. Erebus is of particular interest as it cycles through phases of very explosive activity every 20 thousand years. This project will investigate interactions between the magmatic system, the rift it is located in, and the impact of the gravitational load the volcano imposes on the underlying crust and its own magmatic system. Possible interactions between these factors may explain the changes in activity. The project will analyze geophysical data that have been collected at Erebus over at least the last two decades. The results of this work will be available to the public and scientific community and inform geodynamic models in this region. The project funds an early-career scientist and a graduate student at New Mexico Tech and contributes to the development of the next generation of scientists. Technical Abstract The proposed work targets scientific questions recently formulated by the community during the 2016 NSF-sponsored Scientific Drivers and Future of Mount Erebus Volcano Observatory workshop. The location and geometry of the magmatic plumbing from vent to lower crust system remain poorly constrained, particularly below 1 km depth. The style and causes for changes in volcanic and magmatic activity over the short term (minutes to hours) and on the decadal scale remains enigmatic. Two decades of campaign and continuous GPS data on Ross Island will inform about the longer term dynamics of both, Ross Island growing within the Terror Rift, and Erebus? deeper magmatic system. This project will organize and analyze all existing GPS data for Ross Island, and interpret any anomalies in the resulting time series. These activities require organization, consistent processing and interpretation/modeling of the existing ~20 years of GPS data, which include campaign, continuous, and high-rate GPS observations. We will generate these position time series in a consistent local reference frame and make the results, including models of transient deformation available to the community. Volcanic, tectonic and isostatic adjustment related deformation will be modeled to place Erebus in a broad volcano-tectonic framework of West Antarctica. During the data analysis phase, the utility of existing GPS data for reflection studies of snow and sea-level dynamics will also be evaluated.
The West Antarctic Ice Sheet is the most vulnerable polar ice mass to warming and already a major contributor to global mean sea level rise. Its fate in the light of prolonged warming is a topic of major uncertainty. Accelerated sea level rise from ice mass loss in the polar regions is a major concern as a cause of increased coastal flooding affecting millions of people. This project will disclose a unique geological archive buried beneath the seafloor off the Amundsen Sea, Antarctica, which will reveal how the West Antarctic Ice Sheet behaved in a warmer climate in the past. The data and insights can be used to inform ice-sheet and ocean modeling used in coastal policy development. The project will also support the development of a competitive U.S. STEM workforce. Online class exercises for introductory geology classes will provide a gateway for qualified students into undergraduate research programs and this project will enhance the participation of women in science by funding the education of current female Ph.D. students. The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of > 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current “icehouse” period ~3.3 Ma. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part I: Non-technical description: Earth’s terrestrial ecosystems have the potential to either slow down or hasten the pace of climate change. The direction depends in part on both plant and microbial responses to warming. This study uses Antarctica as a model ecosystem to study the carbon balance of a simplified ecosystem (simplified compared to terrestrial ecosystems elsewhere) in response to a warming treatment. Carbon balance is dictated by sequestered carbon (through photosynthesis) and released carbon (plant and microbial respiration). Hence, to best assess plant and microbial responses to warming, this study uses a plant gradient that starts at the glacier (no plants, only soil microbes) to an old site entirely covered by plants. Experimental warming in the field is achieved by open-top chambers that warm the air and soil inside. The net ecosystem carbon exchange, the net result of sequestered and released carbon, will be measured in warmed and control plots with a state-of-the art gas exchange machine. Laboratory temperature incubation studies will supplement field work to attribute changes in carbon fluxes to individual plant species and soil microbial taxa (i.e., “species”). Data from this study will feed into earth system climate change models. The importance of this study will be shared with the broader community through the production of a video series created by an award-winning science media production company, an Antarctic blog, and through interactions with schools in the United States (on-site through Skype and in-person visits). Part II: Technical description: Responses of the carbon balance of terrestrial ecosystems to warming will feed back to the pace of climate change, but the size and direction of this feedback are poorly constrained. Least known are the effects of warming on carbon losses from soil, and clarifying the major microbial controls is an important research frontier. This study uses a series of experiments and observations to investigate microbial, including autotrophic taxa, and plant controls of net ecosystem productivity in response to warming in intact ecosystems. Field warming is achieved using open-top chambers paired with control plots, arrayed along a productivity gradient. Along this gradient, incoming and outgoing carbon fluxes will be measured at the ecosystem-level. The goal is to tie warming-induced shifts in net ecosystem carbon balance to warming effects on soil microbes and plants. The field study will be supplemented with lab temperature incubations. Because soil microbes dominate biogeochemical cycles in Antarctica, a major focus of this study is to determine warming responses of bacteria, fungi and archaea. This is achieved using a cutting-edge stable isotope technique, quantitative stable isotope probing (qSIP) developed by the proposing research team, that can identify the taxa that are active and involved in processing new carbon. This technique can identify individual microbial taxa that are actively participating in biogeochemical cycling of nutrients (through combined use of 18O-water and 13C-bicarbonate) and thus can be distinguished from those that are simply present (cold-preserved). The study further assesses photosynthetic uptake of carbon by the vegetation and their sensitivity to warming. Results will advance research in climate change, plant and soil microbial ecology, and ecosystem modeling. Science communication will be achieved through an informative video series, a daily Antarctic blog, and online- and in-person visits to schools in the United States. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2). The geologic record reveals that volcanic activity increases when glaciers retreat and major ice sheets thin. This relationship produces a positive feedback mechanism where the uptick in volcanism increases greenhouse gasses concentrations, leading to climate warming and further deglaciation. Although the pattern between volcanism and deglaciation is observed in the geologic record, the exact mechanism(s) by which glaciers impact a volcanic plumbing system is unknown. This project focuses on Mount Waesche, a volcano in West Antarctica, that frequently erupts during warm, interglacial periods and undergoes a period of less activity during cold, glacial periods. This project will examine compositions of the rocks and minerals from Mount Waesche to determine magma storage depths, allowing the investigators to understand how magma plumbing systems change in response to glacial cycles. These results will be compared with geodynamic simulations to understand the physics behind the effects of deglaciation on the magmatic plumbing systems within Earth’s crust. The investigators will additionally partner with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. Isotopic and sedimentary datasets reveal that volcanic activity typically increases during interglacial periods. However, the physical mechanisms through which changes in the surface loading affect volcanic magmatic plumbing systems remain unconstrained. Recently generated 40Ar/39Ar eruption ages indicate that 86% of the dated samples from Mt. Waesche, a late Quaternary volcano in Marie Byrd land, correlate with interglacial periods, suggesting this volcano uniquely responds to changes in the West Antarctic Ice Sheet. We propose to combine the petrology of Mount Waesche’s volcanic record, constraints on changing ice loads through time, and geodynamic modelling to: (1) Determine how pre-eruptive storage conditions change during glacial and interglacial periods using whole rock and mineral compositions of volcanic rocks; (2) Conduct geodynamic modeling to elucidate the relationship between lithospheric structure, temporal variations in ice sheet thickness, and subsequent changes in crustal stresses and magmatic transport and, therefore, the mechanism(s) by which deglaciation impacts magmatic plumbing systems; (3) Use the outcomes of objectives (1) and (2) to provide new constraints on the changes in ice sheet thickness through time that could plausibly trigger future volcanic and magmatic activity in West Antarctica. This collaborative approach will provide a novel methodology to determine prior magnitudes and rates of ice load changes within the Marie Byrd Land region of Antarctica. Lastly, estimates of WAIS elevation changes from this study will be compared to ongoing studies at Mount Waesche focused on constraining last interglacial ice sheet draw down using cosmogenic exposure ages obtained from shallow drilling. The scope of work also includes a partnership with Mentoring Kids Works to develop several Polar and Earth Science Educational Modules aimed at improving reading skills in third grade students in New Mexico. The proposed Polar and Earth Science program consists of modules that include readings of books introducing students to Earth and Polar science themes, paired with Earth and Polar Science activities, followed by simple experiments, where students make predictions and collect data. Information required to implement our Polar and Earth Science curriculum will be made available online. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part 1: Non-technical description: Global climate warming is increasing the frequency and severity of low oxygen events in marine and freshwater environments worldwide, and these events threaten the health of aquatic ecosystems and the viability of fish populations. The Southern Ocean surrounding Antarctica has historically been a stable, icy-cold, and oxygen-rich environment, but is now warming at an unprecedented rate and faster than all other regions in the Southern hemisphere. Antarctic fishes have evolved in sub-zero temperatures that have been stable over long periods of time with traits allowing them to thrive in frigid waters, but with diminished resilience to warming temperatures. Presently little is known about the ability of Antarctic fishes to withstand hypoxic, or low-oxygen, conditions that often accompany warming. This research will investigate the hypoxia tolerance of four species of Antarctic fishes, including two species of icefishes that lack the oxygen-carrying protein, hemoglobin, which may compromise their ability to oxygenate tissues under hypoxic conditions. The hypoxia tolerance of four Antarctic fish species will be compared to that of a related fish species inhabiting warmer coastal regions of South America. Physiological and biochemical responses to hypoxia will be evaluated and compared amongst the five species to bolster our predictions of the capacity of Antarctic fishes to cope with a changing environment. This research will provide training opportunities for undergraduate and graduate students, and a postdoctoral research fellow. A year-long seminar series hosted by the Aquarium of the Pacific will feature female scientists who work in Antarctica to inspire youth in the greater Los Angeles area to pursue careers in science. Part 2: Technical description: The overarching hypothesis to be tested in this project is that the long evolution of Antarctic notothenioid fishes in a cold, oxygen-rich environment has reduced their capacity to mount a robust physiological, biochemical, and molecular response to hypoxia compared to related, cold-temperate fish species. Hypoxia tolerance will be compared among the red-blooded Antarctic notothenioids, Notothenia coriiceps and Notothenia rossii; the hemoglobinless Antarctic icefishes, Chaenocephalus aceratus and Chionodraco rastrospinosus; and the basal, cold-temperate notothenioid, Eleginops maclovinus, a species that has never inhabited waters south of the Polar Front. The minimum level of oxygen required to sustain maintenance metabolic requirements (O2crit) will be quantified. Animals will then be exposed to 65% of O2crit for 48 hours, and responses to hypoxia will be evaluated by measuring hematocrit and hemoglobin levels, as well as metabolites in brain, liver, glycolytic and cardiac muscles. Maximal activities of key enzymes of aerobic and anaerobic metabolism will be quantified to assess capacities for synthesizing ATP in hypoxic conditions. Gill remodeling will be analyzed using light and scanning electron microscopy. The molecular response to hypoxia will be characterized in liver and brains by quantifying levels of the master transcriptional regulator of oxygen homeostasis, hypoxia-inducible factor-1 (HIF-1), and hypoxic gene expression will be quantified using RNA-Seq. Cell cultures will be used to determine if a previously identified insertion mutation in notothenioid HIF-1 affects the ability of HIF-1 to drive gene expression and thus, hypoxia tolerance. The results of this project will provide the most comprehensive assessment of the hypoxia tolerance of Antarctic fishes to date. Broader impacts include research training opportunities for undergraduate and graduate students and a postdoctoral research associate, with a focus on involving Native Alaskan students in research. In partnership with the Aquarium of the Pacific, a year-long public seminar series will be held, showcasing the research and careers of 9 women who conduct research in Antarctica. The goal of the series is to cultivate and empower a community of middle and high school students in the greater Los Angeles area to pursue their interests in science and related fields, and to enhance the public engagement capacities of research scientists so that they may better inspire youth and early career scientists in STEM fields. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
A nontechnical description of the project The primary scientific goal of the project is to test whether Taylor Valley, Antarctica has been eroded significantly by glaciers in the last ~2 million years (Ma). Taylor Valley is one of the Dry Valleys of the Transantarctic Mountains, which are characterized by low mean annual temperatures, low precipitation, and limited erosion. These conditions have allowed fragile glacial landforms to be preserved for up to 15 Ma. Sediment eroded and deposited by glaciers is found on the valley walls and floors, with progressively younger deposits preserved at lower elevations. Scientists can date glacial deposits to understand the process and timing of past glacial erosion. Previous work in the Dry Valleys region suggested that extremely cold glaciers like Taylor Glacier, a major outlet glacier entering the valleys, were not erosive during the last several million years. This research will test a new hypothesis that glacial erosion and sediment production beneath Taylor Glacier have been active in the last few million years. This hypothesis will be tested using a new isotopic dating method called "comminution dating' which determines when fine-grained sediment particles called silt were formed. If the sediment age is young, then the results will suggest that glacial processes have been more dynamic than previously thought. Overall, this study will increase our understanding of the nature and extent of past glaciations in Antarctica. Because the silt produced by erosion sediment is a nutrient for local ecosystems, the results will also shed light on delivery of nutrients to soils, streams, and coastal zones in high polar regions. This project will be led by an early career scientist and includes training of a Ph.D. student. A technical description of the project There is a long-standing scientific controversy about the stability of the East Antarctic Ice Sheet with much evidence centered in the Dry Valleys region of South Victoria Land. A prevailing view of geomorphologists is that the landscape has been very stable and that the effects of glaciation have been minimal for the past ~15 Ma. This project will distinguish between two end-member scenarios of glacial erosion and deposition by Taylor Glacier, an outlet glacier of the East Antarctic Ice Sheet that terminates in Taylor Valley in the Dry Valleys region of Antarctica. In the first scenario, all valley relief is generated prior to 15 Ma when non-polar climates enabled warm-based glaciers to incise and widen ancient river channels. In this case, younger glacial deposits record advances of cold-based glaciers of decreasing ice volume and limited glacial erosion, and sediment generation resulted in glacial deposits composed primarily of older recycled sediments. In the second scenario, selective erosion of the valley floor has continued to deepen Taylor Valley but has not affected the adjacent peaks over the last 2 Ma. In this scenario, the "bathtub rings" of Quaternary glacial deposits situated at progressively lower elevations through time could be due to the lowering of the valley floor by subglacial erosion and with it, production of new sediment which is now incorporated into these deposits. While either scenario would result in the present-day topography, they differ in the implied evolution of regional glacial ice volume over time and the timing of both valley relief production and generation of fine-grained particles. The two scenarios will be tested by placing time constraints on fine particle production using U-series comminution dating. This new geochronologic tool exploits the loss of 234U due to alpha-recoil. The deficiency in 234U only becomes detectable in fine-grained particles with a sufficiently high surface-area-to-volume ratio which can incur appreciable 234U loss. The timing of comminution and particle size controls the magnitude of 234U loss. While this geochronologic tool is in its infancy, the scientific goal of this proposal can be achieved by resolving between ancient and recently comminuted fine particles, a binary question that the preliminary modeling and measured data show is readily resolved.
Part I: Non-technical description: Predicting how polar ice sheets will respond to future global warming is difficult because all the processes that contribute to their melting are not well understood. This is important because the more ice on land that melts, the higher sea levels will rise. The most significant uncertainty in current estimates of sea-level rise in the coming decades is the potential contribution from the Antarctic Ice Sheet. One way to increase our knowledge about how large ice sheets respond to climate change in response to natural factors is to examine the geologic past. Natural global warming (and cooling) events in Earth’s history provide examples that we can use to better understand processes, interactions, and responses we can’t directly observe today. One such time period, approximately three million years ago (known as the Pliocene), was the last time atmospheric carbon dioxide levels were as high as they are today and, therefore, represents a time period to study to better understand the ice sheet response to a warming climate. Specifically, this project is interested in understanding how ocean currents near Antarctica, which transport heat and store carbon, behaved during these past climate events. The history of past ice sheet-ocean interactions are recorded in sediments that were deposited, layer upon layer, in the deep sea offshore Antarctica. In January-February 2018, a team of scientists and crew set sail to the Ross Sea, offshore west Antarctica, on the scientific ocean drilling vessel JOIDES Resolution to recover such sediment archives. This project focuses on a sediment core from that expedition, which captures the relatively warm Pliocene time interval, as well as the subsequent transition into cooler climates typical of the past two million years. The researchers will analyze the sediment with multiple complementary measurements, including: grain size, composition, chemistry of organic matter, physical structures, microfossil type and abundance, and more. These analyses will be done by the research team, including several students, at their respective laboratories and will then integrated into a unified record of ice sheet-ocean interactions. Ultimately, the results will be used to improve modeled projections of how the Antarctic Ice Sheet could respond to future climate change. Part II: Technical description: Geological records from the Antarctic Ice Sheet (AIS) margin demonstrate that the ice sheet oscillated in response to orbital variations in insolation (i.e., ~400, 100, 41, and 20 kyr), and it appears to be more sensitive to specific frequencies that regulate mean annual insolation (i.e., 41-kyr obliquity), particularly when the ice sheet extends into marine environments and is impacted by ocean circulation. However, the relationship between orbital forcing and the production of Antarctic Bottom Water (AABW) is unconstrained. Thus, a knowledge gap exists in understanding how changing insolation impacts ice marginal and Southern Ocean conditions that directly influence ventilation of the global ocean. The researchers hypothesize that insolation-driven changes directly affected the production and export of AABW to the Southern Ocean from the Pliocene through the Pleistocene. For example, obliquity amplification during the warmer Pliocene may have led to enhanced production and export of dense waters from the shelf due to reduced AIS extent, which, in turn, led to greater AABW outflow. To determine the relationship of AABW production to orbital regime, they plan to reconstruct both from a single, continuous record from the levee of Hillary Canyon, a major conduit of AABW outflow, on the Ross Sea continental rise. To test their hypothesis, they will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) They will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. They will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) They will use grain-size data, physical properties, XRF core scanning, CT imaging, and hyperspectral imaging to guide lithofacies analysis to infer processes occurring during glacial, deglacial, and interglacial periods. Statistical techniques and optimization methods will be applied to test for astronomical forcing of sedimentary packages in order to provide a cyclostratigraphic framework and interpret the orbital-forcing regime. (3) They will use bulk sedimentary carbon and nitrogen abundance and isotope data to determine how relative contributions of terrigenous and marine organic matter change in response to orbital forcing. All of these data will be integrated with sedimentological records to deconvolve organic matter production from its deposition or remobilization due to AABW outflow as a function of the oscillating extent of the AIS. These data sets will be integrated into a unified chronostratigraphy to determine the relationship between AABW outflow and orbital-forcing scenarios under the varying climate regimes of the Plio-Pleistocene. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Part 1: Because of the manner in which it is formed at high latitudes in the Antarctic ice, Antarctic Bottom Water (AABW) is the coldest, saltiest and densest water on the planet. The global circulation of is often quantified via the transport in a two-dimensional, latitude/depth coordinate space. However, AABW formation, northward flow and distribution between the Atlantic, Indian and Pacific basins are fundamentally three-dimensional processes. AABW is formed in a handful of distinct sites around the Antarctic coast, notably the southern Weddell Sea, the western Ross Sea, along the Ad´elie coast, and in Prydz Bay. AABW is one of the key components of the global ocean overturning circulation, and plays a critical role in regulating Earth's climate, on multi-decadal-to-millennial time scales. Part 2: Mapping of AABW transport to northern basins is not well constrained, with conflicting conclusions drawn in previous studies. At one extreme the ACC has been suggested to be a “conduit" that simply allows each variety of AABW to transit directly northward. At the other extreme, it has been suggested that the ACC “blends" all shelf AABW sources together before they reach the northern basins. To close the gap in understanding, this collaborative project draws on three complementary analytical tools: process-oriented modeling of AABW export across the ACC, a high-resolution global ocean model, and an observationally-constrained estimate of the global circulation. The proposed identification and mechanistic understanding of AABW pathways. This project will also advance the careers of three postdoctoral researchers and two early-career faculty members, and will continue collaborative links between the PI and a foreign investigator. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Uncertainty in projections of future sea level rise comes, in part, from ice-sheet melting under the influence of unpredictable variations in ocean and atmospheric temperature near ice sheets. Using state-of-the-art modeling techniques, the Antarctic Ice Sheet Large Ensemble (AISLENS) Project will estimate the range of possible Antarctic Ice Sheet melt during the recent past and over the next several centuries that could result from such climate variations. The AISLENS Project will also facilitate research by providing modeling output as an open product to the broader climate and glaciology communities. The project will support an early career faculty member, and interdisciplinary training for a graduate student, postdoctoral fellow and undergraduate student. As a part of this project, an undergraduate course on "Sea Level Rise and Coastal Engineering" will be also developed, bringing together Earth Science and Civil Engineering students in an interdisciplinary setting and contributing to their education in sea level science and coastal adaptation. This will be done in the geographic context of the Southeastern US, the region of most concentrated vulnerability to sea-level rise in the US. The primary goal of the proposed research is to understand and quantify the role of internal climate variability in driving ice loss from the Antarctic Ice Sheet over the recent past and into the future. The AISLENS Project will encompass hundreds of simulations of Antarctic ice sheet evolution from 1950 to 2300 forced by realistic variations in climate, including snowfall and melt from fluctuating oceanic and atmospheric temperatures. Plausible realizations of Antarctic climate forcing will be generated from stochastic emulation of output from the Energy Exascale Earth System Model (E3SM) under past and future emissions scenarios. These realizations of variable climate will be used to force the MPAS Albany Land Ice (MALI) model, a state-of-the-art model of ice flow in the Antarctic Ice Sheet. In this project, AISLENS will be used to conduct uncertainty and attribution analyses. In the uncertainty analysis, the evolution of ensemble spread in simulations of the future evolution of the Antarctic Ice Sheet will be systematically decomposed to determine which temporal and spatial scales of climate variability contribute the most to future ice-sheet projection uncertainty. In the attribution analysis, a range of satellite-based observations of recent Antarctic ice loss will be compared to the envelope of internal variability of Antarctic ice loss simulated in AISLENS simulations encompassing the recent past. This analysis will provide context to recent observations indicating significant variability of Antarctic climate forcing and provide a possible path forward for conducting robust statistical inference studies for observed ice-sheet changes. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
The ice of the polar ice sheets is among the purest substances on Earth, yet the small amount of impurities --such as acids-- are important to how the ice flows and what can be learned from ice cores about past climate. The goal of this project is to understand the role of such acids on the deformation of polycrystalline ice by comparing the deformation behavior of pure and sulfuric acid-doped samples. Sulfuric acid was chosen both because of its importance for interpreting past climate and because it can lead to water veins in ice at low temperatures. This work will focus on the location, movement, and impact of acids in polycrystalline ice that are more complex than in single crystals of ice. By deforming samples and performing microstructural characterization, the role of acids on deformation rate, grain evolution, and the movement of the acids themselves, will be assessed. The work will lead to the education of a Ph.D. student at Dartmouth College, introduce undergraduate students to research at both the University of Washington and Dartmouth College. Despite the ubiquitous use of the constitutive relation for ice commonly referred to as "Glen's Flow Law", significant uncertainty exists particularly with regard to the role of impurities and the development of oriented fabrics. The aim of this project is to improve the constitutive relationship for ice by performing deformation tests and microstructural characterization of pure and sulfuric acid-doped ice. The project will focus on sulfuric acid's impact on ice viscosity, fabric evolution, and diffusivity. Sulfuric acid can have both direct and indirect effects on the mechanical properties of polycrystalline ice. The direct effects change the dislocation velocity and/or density, and the indirect effects change the grain size and fabric. The complexity and interaction of these effects means that it is not possible to understand the effects of sulfuric acid by simply examining ice core specimens. In this project, the team will deform four types of ice: lab-grown ice samples doped with similar-to-natural concentrations of sulfuric acid, lab-grown high-purity ice, layered doped and pure ice, and natural ice from Antarctic ice cores. Deformation will be performed in both uniaxial compression and simple shear. The addition of simple shear tests is critical for relating the laboratory-observed deformation behavior to the behavior of polar ice sheets where the shear strain dominates ice motion in basal ice. After deformation to strains from 5 percent up to 25 percent, the microstructural development will be assessed with methods including a variety of scanning electron microscope techniques, Raman microscopy, synchrotron-based Nano-X-ray fluorescence, and ion chromatography. These analysis techniques will allow the determination of 1) the segregation and movement of impurities, 2) the rate of grain-boundary migration, 3) the number of recrystallized grains; and 4) the full orientation of the ice crystals. The results will enable both microstructural modeling of the effects of sulfuric acid and numerical modeling of diffusion in ice cores. The net result will be a better understanding of ice deformation that improves ice-core interpretation and ice-sheet modeling. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Enderlin/1643455 This award supports a project that will use a novel remote sensing method, which was initially developed to investigate melting of icebergs around Greenland, to examine spatial and temporal variations in ocean forcing around the Antarctic ice sheet periphery. Nearly three-quarters of the Antarctic ice sheet is fringed by regions of floating glacier ice called ice shelves. These ice shelves play an important role in modulating the flow of ice from the ice sheet interior towards the coast, similar to how dams regulate the downstream flow of water from reservoirs. Therefore, a reduction in ice shelf size due to changing air and ocean temperatures can have serious implications for the flux of glacier ice reaching the Antarctic coast, and thus, sea level change. Observations of recent ocean warming in the Amundsen Sea, thinning of the ice shelves, and increased ice flux from the West Antarctic ice sheet interior suggests that ice shelf destabilization triggered by ocean warming may already be underway in some regions. Although detailed observations are available in the Amundsen Sea region, our understanding of spatial and temporal variations in ocean conditions and their influence on ice shelf stability is limited by the scarceness of observations spanning the ice sheet periphery. The project will yield insights into variability in the submarine melting of ice shelves and will help advance the career of a female early-career scientist in a male-dominated field. The project will use repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images will be used to construct maps of iceberg surface elevation, which will be differenced in time to derive time series of iceberg volume change and area-averaged melt rates. Where ocean data are available, the melt rates will be compared to these data to assess whether variations in ocean temperature can explain observed iceberg melt variability. Large spatial gradients in melt rates will be compared to estimates of iceberg drift rates, which will be inferred from the repeat satellite images as well as numerically modeled drift rates produced by (unfunded) collaborators, to quantify the effects of water shear on iceberg melt rates. Spatial and temporal patterns in iceberg melting will also be compared to independently derived ice shelf thickness datasets. Overall, the analysis should yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica.
Part I: Nontechnical Earths warming climate has the potential to drive widespread collapse of glaciers and ice sheets across the planet, driving global sea-level rise. Understanding both the rate and magnitude of such changes is essential for predicting future sea-level and how it will impact infrastructure and property. Collapse of the ice sheets of Antarctica has the potential to raise global sea-level by up to 60 meters. However, not all regions of Antarctica are equally suspectable to collapse. One area with potential for collapse is the Wilkes Subglacial Basin in East Antarctica, a region twice the size of California's Central Valley. Geologic evidence indicates that the ice-sheet in this region has retreated significantly in response to past global warming events. While the geologic record clearly indicates ice-sheets in this area are vulnerable, the rate and magnitude of any future retreat will be influenced significantly by geology of the region. In particular, ice-sheets sitting above warm Earth will collapse more quickly during warming climate. Constraining the geologic controls on the stability of the ice-sheets of the Wilkes Subglacial Basin remains challenging since the ice-sheet hides the geology beneath kilometers of ice. As a step in understanding the potential for future ice loss in the Wilkes Subglacial Basin this project will conduct geophysical analysis of existing data to better constrain the geology of the region. These results will constrain new models designed to understand the tectonics that control the behavior of the ice-sheets in the region. These new models will highlight the geological properties that exert the most significant control on the future of the ice-sheets of the Wilkes Subglacial Basin. Such insights are critical to guide future efforts aimed at collecting in-situ observations needed to more fully constrain Antarctica's potential for future sea-level. Part II: Technical Description In polar environments, inward-sloping marine basins are susceptible to an effect known as the marine ice-sheet instability (MISI): run-away ice stream drainage caused by warm ocean water eroding the ice shelf from below. The magnitude and time-scale of the ice-sheet response strongly depend on the physical conditions along the ice-bed interface, which are, to a first order, controlled by the tectonic evolution of the basin. Topography, sedimentology, geothermal heat flux, and mantle viscosity all play critical roles in ice-sheet stability. However, in most cases, these solid-Earth parameters for regions susceptible to the MISI are largely unknown. One region with potential susceptibility to MISI is the Wilkes Subglacial Basin of East Antarctica. The project will provide an integrated investigation of the Wilkes Subglacial Basin, combining geophysical analyses with both mantle flow and ice-sheet modeling to understand the stability of the ice sheet in this region, and the associated potential sea level rise. The work will be focused on four primary objectives: (1) to develop an improved tectonic model for the region based on existing seismic observations as well as existing geophysical and geological data; (2) to use the new tectonic model and seismic data to estimate the thermal, density, and viscosity structure of the upper mantle and to develop a heat flow map for the WSB; (3) to simulate mantle flow and to assess paleotopography based on our density and viscosity constraints; and (4) to assess ice-sheet behavior by modeling (a) past ice-sheet stability using our paleotopography estimates and (b) future ice-sheet stability using our heat flow and mantle viscosity estimates. Ultimately, the project will generate improved images of the geophysical structure beneath the WSB that will allow us to assess the geodynamic origin for this region and to assess the influence of geologic parameters on past, current, and future ice-sheet behavior. These efforts will then highlight areas and geophysical properties that should be the focus of future geophysical deployments. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Iverson/1643120 This award supports a project to study temperate ice, using both experimental methods and modeling, in order to determine the effect of water on its flow resistance and structure and to study the mobility of water within the ice. A new mathematical model of ice stream flow and temperature is developed in conjunction with these experiments. The model includes water production, storage, and movement in deforming ice and their effects on flow resistance at ice stream margins and on water availability for lubrication of ice stream beds. Results will improve estimates of the evolution of ice stream speed and geometry in a warming climate, and so improve the accuracy of assessments of the contribution of the Antarctic ice sheet to sea level rise over the next century. Ice streams are zones of rapid flow within the Antarctic ice sheet and are primarily responsible for its discharge of ice to the ocean and major effect on sea-level rise. Water plays a central role in the flow of ice streams. It lubricates their bases and softens their margins, where flow speeds abruptly transition from rapid to slow. Within ice stream margins some ice is "temperate", meaning that it is at its melting temperature and thus contains intercrystalline water that significantly softens the ice. Two postdoctoral researchers will be supported, trained, and mentored for academic careers, and three undergraduates will be introduced to research in the geosciences. This award is part the NSF/GEO-UK NERC lead agency opportunity (NSF 14-118) and is a collaboration between Iowa State University in the United States and Oxford University in the United Kingdom. The two-phase deformation of temperate ice will be studied, with the objective of determining its effect on the flow of Antarctic ice streams. The project has two components that reinforce each other. First there will be laboratory experiments in which a rotary device at Iowa State University will be used to determine relationships between the water content of temperate ice and its rheology and permeability. The second component will involve the development at Oxford University of a two-phase, fluid-dynamical theory of temperate ice and application of this theory in models of ice-stream dynamics. Results of the experiments will guide the constitutive rules and parameter ranges considered in the theory, and application of elements of the theory will improve interpretations of the experimental results. The theory and resultant models will predict the coupled distributions of temperate ice, water, stress, deformation, and basal slip that control the evolution of ice-stream speed and geometry. The modeling will result in parameterizations that allow ice streaming to be included in continental-scale models of ice sheets in a simplified but physically defensible way.
Glacial retreat in West Antarctica is correlated with ocean warming; however, less is known about the ocean's effect on East Antarctica's glaciers including Totten Glacier located on the Sabrina Coast. The retreat of Totten Glacier has global significance as the glacier drains a sector of the East Antarctic Ice Sheet that contains enough ice to raise global sea levels by as much as 3.5 meters. This study looks to determine the influence of ocean temperatures on East Antarctic glaciers, including Totten Glacier, over the last ~18,000 years by studying seafloor sediment around Antarctica. These sediments, or muds, include the remains of microscopic marine organisms as well as tiny particles originating from eroded Antarctic bedrock. These muds provide a record of past environmental changes including ocean temperatures and the advance and retreat of glaciers. Scientists use a variety of physical and chemical analyses to determine how long ago this mud was deposited, the temperature of the ocean at that location through time, and the relative location of glacial ice. In this project, researchers will refine and test new methods for measuring ocean temperature from the sediments to better understand the influence of ocean temperatures on East Antarctic glacier response. Results will be integrated into ice sheet and climate models to improve the accuracy of ice sheet modeling efforts and subsequent sea level predictions. Results from this project will be disseminated at scientific conferences, in the scientific literature, and more broadly to the general public via the St. Petersburg Science Festival and at the Oceanography Camp for Girls. The influence of ocean temperatures on East Antarctic glaciers is largely unknown. This research focuses on ice-proximal Antarctic margin paleoceanographic proxy calibration and validation, which will improve understanding of past ocean-ice sheet interactions on a variety of timescales. In this project, researchers from the University of South Florida will (1) further develop and refine two ocean temperature proxies, foraminifer Mg/Ca and TEX86, for use in ice-proximal Antarctic continental margin sediments and (2) investigate deglacial to present (~18-0 ka) ocean-ice interactions at the outlet of the climatically sensitive Aurora Subglacial Basin. The proposed research utilizes sediment trap, sediment core, and physical oceanographic data previously collected from the Sabrina Coast continental shelf during NSF-funded cruise NBP14-02. Studies of existing sediment cores will integrate multiple paleotemperature, meltwater/salinity, nutrient, bottom water oxygen, and sea ice proxies with geophysical and lithologic data to understand past regional ocean-ice interactions. While the recent international Antarctic research focus has been on understanding the drivers of West Antarctic Ice Sheet retreat, models suggest it would be imprudent to ignore the East Antarctic Ice Sheet, which is proving more sensitive to climate perturbations than previously realized. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Antarctica is almost entirely covered by ice, in places over two miles thick. This ice hides a landscape that is less well known than the surface of Mars and represents one of Earth's last unexplored frontiers. Ice-penetrating radar images provide a remote glimpse of this landscape including ice-buried mountains larger than the European Alps and huge fjords twice as deep as the Grand Canyon. The goal of this project is to collect sediment samples derived from these landscapes to determine when and under what conditions these features formed. Specifically, the project seeks to understand the landscape in the context of the history and dynamics of the overlying ice sheet and past mountain-building episodes. This project accomplishes this goal by analyzing sand collected during previous sea-floor drilling expeditions off the coast of Antarctica. This sand was supplied from the continent interior by ancient rivers when it was ice-free over 34 million year ago, and later by glaciers. The project will also study bedrock samples from rare ice-free parts of the Transantarctic Mountains. The primary activity is to apply multiple advanced dating techniques to single mineral grains contained within this sand and rock. Different methods and minerals yield different dates that provide insight into how Antarctica?s landscape has eroded over the many tens of millions of years during which sand was deposited offshore. The dating techniques that are being developed and enhanced for this study have broad application in many branches of geoscience research and industry. The project makes cost-effective use of pre-existing sample collections housed at NSF facilities including the US Polar Rock Repository, the Gulf Coast Core Repository, and the Antarctic Marine Geology Research Facility. The project will contribute to the STEM training of two graduate and two undergraduate students, and includes collaboration among four US universities as well as international collaboration between the US and France. The project also supports outreach in the form of a two-week open workshop giving ten students the opportunity to visit the University of Arizona to conduct STEM-based analytical work and training on Antarctic-based projects. Results from both the project and workshop will be disseminated through presentations at professional meetings, peer-reviewed publications, and through public outreach and media. The main objective of this project is to reconstruct a chronology of East Antarctic subglacial landscape evolution to understand the tectonic and climatic forcing behind landscape modification, and how it has influenced past ice sheet inception and dynamics. Our approach focuses on acquiring a record of the cooling and erosion history contained in East Antarctic-derived detrital mineral grains and clasts in offshore sediments deposited both before and after the onset of Antarctic glaciation. Samples will be taken from existing drill core and marine sediment core material from offshore Wilkes Land (100°E-160°E) and the Ross Sea. Multiple geo- and thermo-chronometers will be employed to reconstruct source region cooling history including U-Pb, fission-track, and (U-Th)/He dating of zircon and apatite, and 40Ar/39Ar dating of hornblende, mica, and feldspar. This offshore record will be augmented and tested by applying the same methods to onshore bedrock samples in the Transantarctic Mountains obtained from the US Polar Rock Repository and through fieldwork. The onshore work will additionally address the debated incision history of the large glacial troughs that cut the range, now occupied by glaciers draining the East Antarctic Ice Sheet. This includes collection of samples from several age-elevation transects, apatite 4He/3He thermochronometry, and Pecube thermo-kinematic modeling. Acquiring an extensive geo- and thermo-chronologic database will also provide valuable new information on the poorly known ice-hidden geology and tectonics of subglacial East Antarctica that has implications for improving supercontinent reconstructions and understanding continental break-up.
The ice sheets of Antarctica and Greenland are losing mass and contributing to accelerating global sea-level rise. Satellite altimetry provides precise measurement of ice-sheet volume change, but computing ice-sheet mass change—the quantity relevant for estimating the ice sheet’s sea-level contribution—requires knowing the density of the ice sheet. The density near the ice-sheet surface also affects age estimates of air bubbles recovered in ice cores, which are a key source of information on past climate changes. Ice-sheet density is primarily controlled by the rate at which firn (snow that has persisted for a year or more on ice sheets) compacts into ice, but there is currently no widely accepted theory of how this compaction occurs. The goal of this project is thus to advance understanding of how firn densifies. The team will conduct laboratory experiments and analyze ice-penetrating radar and ice-core data from Antarctica. A key desired outcome of the project is a new model of firn densification that can be used to improve satellite-based altimetry measurements of present-day ice-sheet change and reconstructions of past climate changes from ice cores. This project will combine laboratory experiments, numerical modeling, and geophysical techniques to determine the rheology of firn as it compacts to form ice. The team will use two methods to measure firn compaction: (1) lab-based experiments and (2) analysis of ice-core and radar data. For the lab-based work, the team will conduct a suite of compaction experiments on synthetic firn samples under uni-axial strain and constant temperature and axial stress. They will also measure the grain-size evolution. By running a large number of experiments (> 25), the team will constrain key parameters that determine how firn compaction rate depends on density, temperature, grain size, and axial stress. The experiments will be conducted in a table-top apparatus at temperatures as low as -40 degrees C and axial stresses up to 4 MPa. For the field-data-based component, the team will analyze ice-core and ice-penetrating radar data to produce the first coincident set of radar-derived firn compaction rates, borehole temperatures, firn densities, and firn grain sizes. Results from lab and field data will be tied together using a numerical firn compaction model. This model is formulated using conservation of mass, momentum, and energy, along with an explicit description of firn rheology and grain-size evolution. Constraints on firn rheology will be incorporated into this model and the team will use it to examine fundamental questions about how changes in the climate affect firn density. This is a crucial unknown that contributes significant measurement uncertainty in estimates of past and present climate change. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
Buizert/1643394 This award supports a project to use ice cores to study teleconnections between the northern hemisphere, tropics, and Antarctica during very abrupt climate events that occurred during the last ice age (from 70,000 to 11,000 years ago). The observations can be used to test scientific theories about the role of the westerly winds on atmospheric carbon dioxide. In a warming world, snow fall in Antarctica is expected to increase, which can reduce the Antarctic contribution to sea level rise, all else being equal. The study will investigate how snow fall changed in the past in response to changes in temperature and atmospheric circulation, which can help improve projections of future sea level rise. Antarctica is important for the future evolution of our planet in several ways; it has the largest inventory of land-based ice, equivalent to about 58 m of global sea level and currently contributes about 0.3 mm per year to global sea level rise, which is expected to increase in the future due to global warming. The oceans surrounding Antarctica help regulate the uptake of human-produced carbon dioxide. Shifts in the position and strength of the southern hemisphere westerly winds could change the amount of carbon dioxide that is absorbed by the ocean, which will influence the rate of global warming. The climate and winds near and over Antarctica are linked to the rest of our planet via so-called climatic teleconnections. This means that climate changes in remote places can influence the climate of Antarctica. Understanding how these climatic teleconnections work in both the ocean and atmosphere is an important goal of climate research. The funds will further contribute towards training of a postdoctoral researcher and an early-career researcher; outreach to public schools; and the communication of research findings to the general public via the media, local events, and a series of Wikipedia articles. The project will help to fully characterize the timing and spatial pattern of millennial-scale Antarctic climate change during the deglaciation and Dansgaard-Oeschger (DO) cycles using multiple synchronized Antarctic ice cores. The phasing of Antarctic climate change relative to Greenland DO events can distinguish between fast atmospheric teleconnections on sub-decadal timescales, and slow oceanic ones on centennial time scales. Preliminary work suggests that the spatial pattern of Antarctic change can fingerprint specific changes to the atmospheric circulation; in particular, the proposed work will clarify past movements of the Southern Hemisphere westerly winds during the DO cycle, which have been hypothesized. The project will help resolve a discrepancy between two previous seminal studies on the precise timing of interhemispheric coupling between ice cores in both hemispheres. The study will further provide state-of-the-art, internally-consistent ice core chronologies for all US Antarctic ice cores, as well as stratigraphic ties that can be used to integrate them into a next-generation Antarctic-wide ice core chronological framework. Combined with ice-flow modeling, these chronologies will be used for a continent-wide study of the relationship between ice sheet accumulation and temperature during the last deglaciation.
Coastal waters surrounding Antarctica represent some of the most biologically rich and most untouched ecosystems on Earth. In large part, this biological richness is concentrated within the numerous openings that riddle the expansive sea ice (these openings are known as polynyas) near the Antarctic continent. These polynyas represent regions of enhanced production known as hot-spots and support the highest animal densities in the Southern Ocean. Many of them are also located adjacent to floating extensions of the vast Antarctic Ice Sheet and receive a substantial amount of meltwater runoff each year during the summer. However, little is known about the specific processes that make these ecosystems so biologically productive. Of the 46 Antarctic coastal polynyas that are presently known, only a handful have been investigated in detail. This project will develop ecosystem models for the Ross Sea polynya, Amundsen polynya, and Pine Island polynya; three of the most productive Antarctic coastal polynyas. The primary goal is to use these models to better understand the fundamental physical, chemical, and biological interacting processes and differences in these processes that make these systems so biologically productive yet different in some respects (e.g. size and productivity) during the present day settings. Modeling efforts will also be extended to potentially assess how these ecosystems may have functioned in the past and how they might change in the future under different physical and chemical and climatic settings. The project will advance the education of underrepresented minorities through Stanford?s Summer Undergraduate Research in Geoscience and Engineering (SURGE) Program. SURGE will provide undergraduates the opportunity to gain mentored research experiences at Stanford University in engineering and the geosciences. Old Dominion University also will utilize an outreach programs for local public and private schools as well as an ongoing program supporting the Boy Scout Oceanography merit badge program to create outreach and education impacts. Polynyas (areas of open water surrounded by sea ice) are disproportionately productive regions of polar ecosystems, yet controls on their high rates of production are not well understood. This project will provide quantitative assessments of the physical and chemical processes that control phytoplankton abundance and productivity within polynyas, how these differ for different polynyas, and how polynyas may change in the future. Of particular interest are the interactions among processes within the polynyas and the summertime melting of nearby ice sheets, including the Thwaites and Pine Island glaciers. In this proposed study, we will develop a set of comprehensive, high resolution coupled physical-biological models and implement these for three major, but diverse, Antarctic polynyas. These polynyas, the Ross Sea polynya, the Amundsen polynya, and Pine Island polynya, account for >50% of the total Antarctic polynya production. The research questions to be addressed are: 1) What environmental factors exert the greatest control of primary production in polynyas around Antarctica? 2) What are the controlling physics that leads to the heterogeneity of dissolved iron (dFe) supply to the euphotic zone in polynyas around the Antarctic continental shelf? What effect does this have on local rates of primary production? 3) What are the likely changes in the supply of dFe to the euphotic zone in the next several decades due to climate-induced changes in the physics (winds, sea-ice, ice shelf basal melt, cross-shelf exchange, stratification and vertical mixing) and how will this affect primary productivity around the continent? The Ross Sea, Amundsen, and Pine Island polynyas are some of the best-sampled polynyas in Antarctica, facilitating model parameterization and validation. Furthermore, these polynyas differ widely in their size, location, sea ice dynamics, relationship to melting ice shelves, and distance from the continental shelf break, making them ideal case studies. For comparison, the western Antarctic Peninsula (wAP), a productive continental shelf where polynyas are a relatively minor contributor to biological production, will also be modeled. Investigating specific processes within different types Antarctic coastal waters will provide a better understand of how these important biological oases function and how they might change under different environmental conditions.
Bromirski/1246151 This award supports a project intended to discover, through field observations and numerical simulations, how ocean wave-induced vibrations on ice shelves in general, and the Ross Ice Shelf (RIS), in particular, can be used (1) to infer spatial and temporal variability of ice shelf mechanical properties, (2) to infer bulk elastic properties from signal propagation characteristics, and (3) to determine whether the RIS response to infragravity (IG) wave forcing observed distant from the front propagates as stress waves from the front or is "locally" generated by IG wave energy penetrating the RIS cavity. The intellectual merit of the work is that ocean gravity waves are dynamic elements of the global ocean environment, affected by ocean warming and changes in ocean and atmospheric circulation patterns. Their evolution may thus drive changes in ice-shelf stability by both mechanical interactions, and potentially increased basal melting, which in turn feed back on sea level rise. Gravity wave-induced signal propagation across ice shelves depends on ice shelf and sub-shelf water cavity geometry (e.g. structure, thickness, crevasse density and orientation), as well as ice shelf physical properties. Emphasis will be placed on observation and modeling of the RIS response to IG wave forcing at periods from 75 to 300 s. Because IG waves are not appreciably damped by sea ice, seasonal monitoring will give insights into the year-round RIS response to this oceanographic forcing. The 3-year project will involve a 24-month period of continuous data collection spanning two annual cycles on the RIS. RIS ice-front array coverage overlaps with a synergistic Ross Sea Mantle Structure (RSMS) study, giving an expanded array beneficial for IG wave localization. The ice-shelf deployment will consist of sixteen stations equipped with broadband seismometers and barometers. Three seismic stations near the RIS front will provide reference response/forcing functions, and measure the variability of the response across the front. A linear seismic array orthogonal to the front will consist of three stations in-line with three RSMS stations. Passive seismic array monitoring will be used to determine the spatial and temporal distribution of ocean wave-induced signal sources along the front of the RIS and estimate ice shelf structure, with the high-density array used to monitor and localize fracture (icequake) activity. The broader impacts include providing baseline measurements to enable detection of ice-shelf changes over coming decades which will help scientists and policy-makers respond to the socio-environmental challenges of climate change and sea-level rise. A postdoctoral scholar in interdisciplinary Earth science will be involved throughout the course of the research. Students at Cuyamaca Community College, San Diego County, will develop and manage a web site for the project to be used as a teaching tool for earth science and oceanography classes, with development of an associated web site on waves for middle school students.
Gerbi/1643301 This award supports a project to develop software that will allow researchers considering seismic or radar field surveys to test, ahead of time, whether the data they plan to collect will have sufficient resolution to measure the natural variations in the mechanical properties of ice, which determine the response of flowing ice to changing climatic conditions. The mechanical properties of ice depend largely on the temperature and the orientation of the crystals that make up the ice. The most accurate method for measuring ice crystal orientation and temperature is through drilling and direct analysis of an ice core. However, this method is very costly, time-consuming, and limited in spatial coverage. Geophysical techniques, such as seismic and radar, can cover much more area, but we have little knowledge about the practical limitations of these techniques as they relate to calculating mechanical properties. This project addresses that knowledge gap through construction of a computational toolbox that will allow accurate assessment of the ability of geophysical surveys to image crystal orientation and ice temperature. Researchers can then use these tools to adjust the field survey plans to maximize the return on investment. By working to improve the efficiency and effectiveness of future geophysical work related to glacial flow, this proposal will improve scientists? ability to quantify sea-level variations within the larger context of climate change. The project includes building new user-friendly, publicly accessible software and instructional modules. The work will provide training for graduate and undergraduate students, who will play a role in research and develop instructional materials. Ice viscosity, the resistance of ice to flow, exerts significant control over ice velocity. Therefore, mapping ice viscosity is important for understanding the current and future behavior of glaciers and ice sheets. To do so, scientists must determine the temperature and crystal orientation fabric throughout the ice. Seismic and radar techniques can survey large areas quickly, and thus are promising, yet not fully tested, methods to efficiently measure the thermal and mechanical structure of flowing ice. As part of this project, scientists will develop and use a computational framework to quantify the degree to which seismic and radar techniques can resolve the crystal orientation fabric and temperature of streaming ice, and then test how sensitive ice flow is to the attendant uncertainty. To meet these goals, a numerical toolbox will be built which will allow the glacier/ice stream geometry and physical properties (temperature, crystal orientation fabric, density and acidity) to be varied. The toolbox will be capable of both creating synthetic radar and seismic profiles through forward modeling and inverting synthetic profiles to allow evaluation of how well geophysical techniques can image the original thermal and mechanical structure. These simulated radar and seismic data will allow scientists to better quantify the influence of the variability in mechanical properties of the ice on flow velocities and patterns. The results of this work will guide planning for future field campaigns, making them more effective and efficient. This project does not require fieldwork in the Antarctic.
This project will acquire measurements of the concentration of beryllium-10 (10Be) from an ice core from the South Pole, Antarctica. An isotope of the element beryllium, 10Be, is produced in the atmosphere by high-energy protons (cosmic rays) that enter Earth's atmosphere from space. It is removed from the atmosphere by settling or by scavenging by rain or snowfall. Hence, concentrations of 10Be in snow at the South Pole reflect the production rate of 10Be in the atmosphere. Because the rate of production of 10Be over Antarctica depends primarily on the strength of the Sun's magnetic field, measurements of 10Be in the South Pole ice core will provide a record of changes in solar activity. The South Pole ice core will reach an age of 40,000 years at the bottom. The project will result in measurements of 10Be at annual resolution for the last 100 years and selected periods in the more distant past, such as the Maunder Minimum, a period during the late 17th century during which no sunspots were observed, or the last glacial cold period, about 20,000 years ago. A climate model that can simulate the production of 10Be in the atmosphere, it's transport through the atmosphere, and its deposition at the snow surface in Antarctica will be used to aid in using the 10Be data to determine past changes in solar activity from decadal to millennial scale, and in turn to evaluate the role of the Sun in Earth?s climate from a new perspective. The production of 10Be in Earth's atmosphere results from the spallation of oxygen and nitrogen in the atmosphere by cosmic rays. Cosmic ray variations in the high latitudes are primarily modulated by solar variability. Time-series records of 10Be from ice cores are therefore important for deriving variations in solar activity through time, which is fundamental to understanding climate variability. Deposition of 10Be to the ice surface is also influenced by variability in atmospheric circulation and deposition processes, and South Pole is the best available location for minimizing the influence of variable atmospheric circulation on 10Be deposition. To date, only one record of 10Be exists from South Pole; that record is widely used in solar forcing estimates used in climate models, but covers only the last millennium and ends in CE 1982. We will obtain 10Be concentration measurements in a 1500-m, 40000-year long ice core from the South Pole. This will extend the existing record both further back in time and forward to the present, providing overlap with the modern instrumental record of solar and climate variability. High resolution (annual to biannual) measurements will be made in targeted areas of interest, including the last 100 years, the Maunder Minimum (CE 1650-1715), and the last glacial maximum. The novel data will be used in conjunction with climate model experiments that incorporate 10Be production, transport, and deposition physics. Together, data and modeling will create an updated record of atmospheric 10Be production and hence of solar activity.
The Earth's climate has changed through time and during the Eocene Epoch (56 to 34 million years ago) there was a transition from 'greenhouse' to 'icehouse' conditions. During the Eocene, a shift to cooler temperatures at high latitudes resulted in the inception of polar glaciation. This in turn affected the environment for living organisms. This project looks to uncover the interaction between biological, oceanographic, and climate systems for the Eocene in Antarctica using chemical analysis of fossil shark teeth collected during past expeditions. The combination of paleontological and geochemical analyses will provide insight to the past ecology and ocean conditions; climate models will be applied to test the role of tectonics, greenhouse gas concentration and ocean circulation on environmental change during this time period. The study contributes to understanding the interaction of increased atmospheric carbon dioxide and ocean circulation. This project also seeks to improve diversity, equity, and inclusion within the geosciences workforce with efforts targeted to undergraduate, graduate, postdoctoral, and early career faculty. The research goal is to elucidate the processes leading from the Eocene greenhouse to Oligocene icehouse conditions. Previous explanations for this climate shift centers on Antarctica, where tectonic configurations influenced oceanic gateways, ocean circulation reduced heat transport, and/or greenhouse gas declines prompted glaciation. The team will reconstruct watermass, current, and climate fluctuations proximal to the Antarctic Peninsula using geochemical indicators (oxygen and neodymium isotope composition) from fossil shark teeth collected from Seymour Island. The approach builds on previous shark paleontological studies, incorporates geochemical analyses for environmental reconstruction (i.e., temperature gradients and ocean circulation), and tests hypotheses on Earth System dynamics using novel global climate model simulations with geochemical tracers. This project will advance global climate modeling capabilities with experiments that consider Eocene tectonic configuration within isotope-enabled climate model simulations. A comparison of geochemical results from Eocene climate simulations and empirical records of shark teeth will reveal processes and mechanisms central to the Eocene Antarctic climatic shift. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
This project investigates a rapidly moving section of the West Antarctic Ice Sheet known as the Whillans Ice Stream. Ice streams and outlet glaciers are the major pathways for ice discharge from ice sheets into the ocean. Consequently, understanding ice stream dynamics, specifically the processes controlling the frictional resistance of ice sliding on sediments at its base, is essential for predictive modeling of how Earth's ice sheets will respond to a changing climate. Rather than flowing smoothly, Whillans Ice Stream advances in stick-slip cycles: brief periods of rapid sliding, equivalent to magnitude 7 earthquakes, alternating with much longer periods of repose. The PIs will perform simulations of these stick-slip cycles using computer codes originally developed for modeling tectonic earthquakes. By matching observed ice motions, the PIs will constrain the range of frictional processes acting at the base of the ice stream. An additional focus of the project is on brittle fracture processes in ice, expressed through seismic waves radiated by faulting and/or crevassing episodes that accompany the large-scale sliding events. An understanding of ice fracture provides a basis for assessing the susceptibility of ice shelves to rifting and catastrophic disintegration. Project results will be incorporated into outreach activities (from elementary school to community college events) as well as a polar science class for the California State Summer School for Mathematics and Science (COSMOS) program for high school students. Simulations of the stick-slip cycle will employ 3D dynamic rupture models that simultaneously solve for the seismic wavefield and rupture process, consistent with elastodynamic material response and friction laws on the ice stream bed. Stresses and frictional properties will be varied to achieve consistency with surface GPS and broadband seismic data as well as borehole seismograms from the WISSARD project. The results will be interpreted using laboratory till friction experiments, which link velocity-weakening/strengthening behavior to temperature and water content, and to related experiments quantifying basal drag from ice flow over rough beds. The source mechanism of seismicity accompanying the slip events (shear faulting versus crevassing) will be determined using 3D waveform modeling in conjunction with mechanical models of the seismic source processes. This proposal does not require fieldwork in the Antarctic.
Licht/1443433 Sediments deposited by the Antarctic ice sheet are an archive of its history with time and help geologists to determine how the remote interior of the ice sheet has changed over the past several hundred thousand years. This project will focus on the formation and dynamics of moraines (accumulations of dirt and rocks that are incorporated in the glacier surface or have been pushed along by the glacier as it moves) near the blue ice area of Mt. Achernar in the central Transantarctic Mountains in Antarctica.. The study will improve basic understanding of the formation of these moraines. Fieldwork at the site will focus on imaging the internal structure of the moraine to determine the processes by which it, and others like it, form over time. Additional analyses will include measurements of ice flow and collection of rock samples to determine the timing of debris deposition and the changes in the sources of sediments from deep within the Antarctic continent. The project will provide both graduate and undergraduate students training in paleoclimate studies, geology, and numerical modeling approaches. The broader impacts of the proposed work include hands on training in the Earth Sciences for graduate and undergraduate students, collaboration with colleagues in New Zealand and Sweden to provide an international research experience for students from the US, and three educational modules to be delivered by student researchers regarding Antarctica's role in global environments. The research is societally relevant and multidisciplinary and the topics are ideal for sharing with the public. All research findings will be made publicly available to others via timely publication in high-impact, peer-reviewed journals and all data will be submitted to the National Snow and Ice Data Center, and excess samples will be provided to the U.S. Polar Rock Repository. Direct observations of ice sheet history from the margins of Antarctica's polar plateau are essential for testing numerical ice sheet models, and the laterally extensive, blue-ice moraines of the Mt. Achernar Moraine complex in the central Transantarctic Mountains contain a unique and nearly untapped direct, quasi-continuous record of ice sheet change over multiple glacial cycles. The project objectives include improved understanding of processes and rates of blue ice moraine formation, as well as identifying the topographic, glaciological, and climatic controls on their evolution. Data to be collected with fieldwork in Antarctica include: imaging of internal ice structure with ground-penetrating radar, measurement of ice flow velocity and direction with a global positioning system (GPS) array, analysis of debris concentration and composition in glacier ice, state-of-the-art cosmogenic multi-nuclide analyses to determine exposure ages of moraine debris, mapping of trimlines and provenance analysis. Numerical model simulations, constrained by field data, will be used to evaluate the factors influencing changes in glacier flow that potentially impact the accumulation of the moraine debris. All together, the new data and modeling efforts will improve conceptual models of blue ice moraine formation, and thereby make them a more valuable proxy for developing a better understanding of the history of the ice sheet.
The ocean tide is a large component of total variability of ocean surface height and currents in the seas surrounding Antarctica, including under the floating ice shelves. Maximum tidal height range exceeds 7 m (near the grounding line of Rutford Ice Stream) and maximum tidal currents exceed 1 m/s (near the shelf break in the northwest Ross Sea). Tides contribute to several important climate and ecosystems processes including: ocean mixing, production of dense bottom water, flow of warm Circumpolar Deep Water onto the continental shelves, melting at the bases of ice shelves, fracturing of the ice sheet near a glacier or ice stream’s grounding line, production and decay of sea ice, and sediment resuspension. Tide heights and, in particular, currents can change as the ocean background state changes, and as the geometry of the coastal margins of the Antarctic Ice Sheet varies through ice shelf thickness changes and ice-front and grounding-line advances or retreats. For satellite-based studies of ocean surface height and ice shelf thickness changes, tide heights are a source of substantial noise that must be removed. Similarly, tidal currents can also be a substantial noise signal when trying to estimate mean ocean currents from short-term measurements such as from acoustic Doppler current profilers mounted on ships and CTD rosettes. Therefore, tide models play critical roles in understanding current and future ocean and ice states, and as a method for removing tides in various measurements. A paper in Reviews of Geophysics (Padman, Siegfried and Fricker, 2018, see list of project-related publications below) provides a detailed review of tides and tidal processes around Antarctica.
This project provides a gateway to tide models and a database of tide height coefficients at the Antarctic Data Center, and links to toolboxes to work with these models and data.
Modeling fluctuations in the extent of the West Antarctic Ice Sheet (WAIS) over time is a principal goal of the glaciological community. These models will provide a critical basis for predictions of future sea level change, and therefore this work great societal relevance. The mid-Pliocene time interval is of particular interest, as it is the most recent period in which global temperatures were warmer and atmospheric CO2 concentrations may have been higher than current levels. However, observational constraints on fluctuations in the WAIS older than the last glacial maximum are rare. The investigators propose to collect geochemical data from the Ohio Range and Scott Glacier to quantify past variability in the height of the WAIS. Limited available cosmogenic nuclide data are broadly consistent with a model indicating that Pliocene WAIS elevations and volumes were smaller than at present, and that WAIS collapse was common. The PIs will use geologic observations and cosmogenic nuclide concentrations from bedrock samples at multiple locations and at multiple elevations, including sub-ice samples, to constrain WAIS ice volume changes in a "dipstick" like fashion. Data obtained from the proposed research will provide targets for data-ice sheet model comparisons to accurately characterize Plio-Pleistocene and future WAIS behavior. As part of this project, the investigators will work with the Natural History Museum and the Earth & Planetary Science department at Harvard to develop an exhibit that will become part of the Museum's recently opened Earth and Planetary Science Gallery. The project involves mentoring of a female graduate student as well as an undergraduate student.
General Statement: The continental shelf region west of the Antarctic Peninsula has recently undergone dramatic changes and ecosystem shifts, and the community of organisms that live in, or feed off, the sea floor sediments is being impacted by species invasions from the north. Previous studies of these sediments indicate that this community may consume much more of the regional productivity than previously estimated, suggesting that sediments are a rich and important component of this ecosystem and one that may be ripe for dramatic change. Furthermore, under richer sediment conditions, iron is mobilized and released back to the water column. Since productivity in this ecosystem is thought to be limited by the availability of iron, increased rates of iron release from these sediments could stimulate productivity and promote greater overall ecosystem change. In this research, a variety of sites across the shelf region will be sampled to accurately evaluate the role of sediments in consuming ecosystem productivity and to estimate the current level of iron release from the sediments. This project will provide a baseline set of sediment results that will present a more complete picture of the west Antarctic shelf ecosystem, will allow for comparison with water column measurements and for evaluation of the fundamental workings of this important ecosystem. This is particularly important since high latitude systems may be vulnerable to the effects of climate fluctuations. Both graduate and undergraduate students will be trained. Presentations will be made at scientific meetings, at other universities, and at outreach events. A project web site will present key results to the public and explain how this new information improves understanding of Antarctic ecosystems. Technical Description of Project: In order to determine the role of sediments within the west Antarctic shelf ecosystem, this project will determine the rates of sediment organic matter oxidation at a variety of sites across the Palmer Long Term Ecosystem Research (LTER) study region. To estimate the rates of release of iron and manganese from the sediments, these same sites will be sampled for detailed vertical distributions of the concentrations of these metals both in the porewaters and in important mineral phases. Since sediment sampling will be done at LTER sites, the sediment data can be correlated with the rich productivity data set from the LTER. In detail, the project: a) will determine the rates of oxygen consumption, organic carbon oxidation, nutrient release, and iron mobilization by shelf sediments west of the Antarctic Peninsula; b) will investigate the vertical distribution of diagenetic reactions within the sediments; and c) will assess the regional importance of these sediment rates. Sediment cores will be used to determine sediment-water fluxes of dissolved oxygen, total carbon dioxide, nutrients, and the vertical distributions of these dissolved compounds, as well as iron and manganese in the pore waters. Bulk sediment properties of porosity, organic carbon and nitrogen content, carbonate content, biogenic silica content, and multiple species of solid-phase iron, manganese, and sulfur species will also be determined. These measurements will allow determination of total organic carbon oxidation and denitrification rates, and the proportion of aerobic versus anaerobic respiration at each site. Sediment diagenetic modeling will link the processes of organic matter oxidation to metal mobilization. Pore water and solid phase iron and manganese distributions will be used to model iron diagenesis in these sediments and to estimate the iron flux from the sediments to the overlying waters. Finally, the overall regional average and distribution of the sediment processes will be compared with the distributions of seasonally averaged chlorophyll biomass and productivity.
Predictions of future sea level rise require better understanding of the changing dynamics of the Greenland and Antarctic ice sheets. One way to better understand the past history of the ice sheets is to obtain records from inland ice for past geological periods, particularly in Antarctica, the world?s largest remaining ice sheet. Such records are exceedingly rare, and can be acquired at volcanic outcrops in the La Gorce Mountains of the central Transantarctic Mountains. Volcanoes now exposed within the La Gorce Mountains erupted beneath the East Antarctic ice sheet and the data collected will record how thick the ice sheet was in the past. In addition, information will be used to determine the thermal conditions at the base of the ice sheet, which impacts ice sheet stability. The project will also investigate the origin of volcanic activity in Antarctica and links to the West Antarctic Rift System (WARS). The WARS is a broad area of extended (i.e. stretched) continental crust, similar to that found in East Africa, and volcanism is wide spread and long-lived (65 million years to currently active) and despite more than 50 years of research, the fundamental cause of volcanism and rifting in Antarctica is still vigorously debated. The results of this award therefore also potentially impact the study of oceanic volcanism in the entire southwestern Pacific region (e.g., New Zealand and Australia), where volcanic fields of similar composition and age have been linked by common magma sources and processes. The field program includes a graduate student who will work on the collection, analysis, and interpretation of petrological data as part of his/her Masters project. The experience and specialized analytical training being offered will improve the quality of the student?s research and optimize their opportunities for their future. The proposed work fosters faculty and student national and international collaboration, including working with multi-user facilities that provide advanced technological mentoring of science students. Results will be broadly disseminated in peer-reviewed journals, public presentations at science meetings, and in outreach activities. Petrologic and geochemical data will be disseminated to be the community through the Polar Rock Repository. The study of subglacially erupted volcanic rocks has been developed to the extent that it is now the most powerful proxy methodology for establishing precise ?snapshots? of ice sheets, including multiple critical ice parameters. Such data should include measurements of ice thickness, surface elevation and stability, which will be used to verify, or reject, published semi-empirical models relating ice dynamics to sea level changes. In addition to establishing whether East Antarctic ice was present during the formation of the volcanoes, data will be used to derive the coeval ice thicknesses, surface elevations and basal thermal regime(s) in concert with a precise new geochronology using the 40Ar/39Ar dating method. Inferences from measurement of standard geochemical characteristics (major, trace elements and Sr, Nd, Pb, O isotopes) will be used to investigate a possible relationship between the volcanoes and the recently discovered subglacial ridge under the East Antarctic ice, which may be a rift flank uplift. The ridge has never been sampled, is undated and its significance is uncertain. The data will provide important new information about the deep Earth and geodynamic processes beneath this mostly ice covered and poorly understood sector of the Antarctic continent.
Blankenship: 9319369 Bell: 9319854 Behrendt: 9319877 This award supports a project to conduct an integrated geophysical survey over a large portion of the West Antarctic Ice Sheet (WAIS) toward an understanding of the dynamic behavior of the ice sheet and the nature of the lithosphere beneath the ice sheet. West Antarctica is characterized by two kinds of the Earth s most dynamic systems, a continental rift (the West Antarctic Rift System) and a marine based ice sheet (the WAIS). Active continental rift systems, caused by divergent plate motions, result in thinned continental crust. Associated with the thin crust are fault-bounded sedimentary basins, active volcanism, and elevated heat flow. Marine ice sheets are characterized by rapidly moving streams of ice, penetrating and draining a slowly moving ice reservoir. Evidence left by past marine ice sheets indicates that they may have a strongly non- linear response to long-term climate change which results in massive and rapid discharges of ice. Understanding the evolution of the ice stream system and its interaction with the interior ice is the key to understanding this non-linear response. Subglacial geology and ice dynamics are generally studied in isolation, but evidence is mounting that the behavior of the West Antarctic ice streams may be closely linked to the nature of the underlying West Antarctic rift system. The fast moving ice streams appear to glide on a lubricating layer of water-saturated till. This till requires easily eroded sediment and a source of water, both of which may be controlled by the geology of the rift system; the sediments from the fault-bounded basins and the water from the elevated heat flux associated with active lithospheric extension. This project represents an interdisciplinary aerogeophysical study to characterize the lithosphere of the West Antarctic rift system beneath critical regions of the WAIS. The objective is to determine the effects of the rift architect ure, as manifested by the distribution of sedimentary basins and volcanic constructs, on the ice stream system. The research tool is a unique geophysical aircraft with laser altimetry, ice penetrating radar, aerogravity, and aeromagnetic systems integrated with a high precision kinematic GPS navigation system. It is capable of imaging both the surface and bed of the ice sheet while simultaneously measuring the gravity and magnetic signature of the subglacial lithosphere. Work to be done under this award will build on work already completed in the southern sector of central West Antarctica and it will focus on the region of the Byrd Subglacial Basin and Ice Stream D. The ice sheet in these regions is completely covered by satellite imagery and so this project will be integrated with remote sensing studies of the ice stream. The changing dynamics of Ice Stream D, as with other West Antarctic ice streams, seem to be correlated with changes in the morphological provinces of the underlying rift system. The experimental targets proceed from the divide of the interior ice, downstream through the onset of streaming to the trunk of Ice Stream D. This study will be coordinated with surface glaciological investigations of Ice Stream D and will be used to guide cooperative over-snow seismic investigations of the central West Antarctic rift system. The data will also be used to select a site for future deep ice coring along the crest of the WAIS. These data represent baseline data for long term global change monitoring work and represent crucial boundary conditions for ice sheet modeling efforts.
This study aims to better understand salt accumulation in cold deserts and develop a model of salt transport by groundwater. Cold deserts, like the Antarctic McMurdo Dry Valleys (MDV), are similar to hot deserts in that they accumulate high concentrations of salts because there is not enough water to flush the salts out of the soils into the ocean. The accumulation of salt allows for the creation of brine-rich groundwater that freezes at much lower temperatures. Field work will focus on several groundwater features in the MDV including Don Juan Pond, a shallow lake that accumulates extremely high levels of salts and does not freeze until the temperature reaches -51 degrees C (-60 degrees F). The setting offers the potential to better understand this unique water environment including life at its extremes. It also serves as an analog environment for Mars, a planet that is entirely underlain by permafrost, similar to the MDV. This project will support a doctoral student at the University of Washington Department of Earth and Space Sciences, who will be trained in chemical analysis, chemical and physical modeling, and remote field work in a polar desert environment. Past research suggests that the movement of soluble ions in sediment and soil is controlled by the water activity, permeability, and the thermal regime; however, processes controlling the ionic redistribution in Antarctic environments are poorly constrained. This project aims to better understand the formation, salt redistribution, and water activity of pervasive brine-rich groundwater that is enriched in calcium chloride. A primary goal is to develop a brine thermal;reactive;transport model for the MDV region using data collected from the field to constrain model inputs and ground-truth model outputs. The model will develop a Pitzer-type thermodynamic, reactive transport model and couple it to a ground temperature model. The model will test mechanisms of groundwater formation in the MDV and the properties (e.g. composition, temperature, and water activity) of widespread shallow brine-rich waters. Water is an essential ingredient for life and defining processes that control the availability of water is critical for understanding the habitability of extreme environments, including Mars.
Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region. We will test an ice-sheet model against existing observations, improve treatment of key processes in the model, and make projections with uncertainty assessments. This is a three-year modeling study using the open-source Ice Sheet System Model in coordination with other models to improve projections of future sea-level change. Project goals are to: 1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance; 2. improve the model by utilizing sensitivity studies with regional process-oriented models to create numerically efficient parameterizations for key sub-grid-scale processes; 3. project a range of likely evolutions of the Amundsen Sea Embayment sector and their respective contributions to sea level in the next several centuries; 4. attribute sources of errors in the hindcast and provide an assessment of the uncertainties in the projections, including a range of likely outcomes given various forcings and inclusion or omission of physical processes in the model. At present, the long-term stability of the Amundsen Sea Embayment is unknown, with both theory (the "marine ice sheet instability hypothesis") and observations (rapid thinning and grounding-line retreat approaching regions where the bed deepens inland) suggesting that collapse is possible. But incompletely understood physical processes (e.g., basal hydrology, rheology, and sliding; tidal effects; ice-ocean interaction along the shelf and within the grounding zone) and lack of resolution in basal topography datasets making the ultimate outcome uncertain. Thus, there is a pressing need for high-resolution simulations of this region that include numerical representations of controlling physical processes (many of which are applicable elsewhere) within a higher-order ice-sheet model capable of assimilating recent observations and providing uncertainty analyses associated with model and data limitations. By focusing on the Amundsen Sea Embayment as a connected region across the 10-10,000-meter scales using a hierarchy of one, two, and three-dimensional models along with the sensitivity analysis tools built into the Ice Sheet System Model, this project aims to produce (1) the most reliable results to date when compared with studies that consider only one ice stream or the entire ice sheet and (2) estimates of differing dynamic responses arising from errors in data, model parameterizations, and forcings. Given the uncertainties, the project will produce a range of predictions with characteristic trends that can be recognized within future observational data sets. As new data become available, some predicted rates of change could be culled from the predictive paths generated by this study.
During winter, sea-ice coverage along the Antarctic coast is punctuated by numerous polynyas--isolated openings of tens to hundreds of kilometer wide. These coastal polynyas are hotspots of sea ice production and the primary source regions of the bottom water in the global ocean. They also host high levels of biological activities and are the feeding grounds of Emperor penguins and marine mammals. The polynyas are a key component of the Antarctic coastal system and crucial for the survival of penguins and many other species. These features also differ dramatically from each other in timing of formation, duration, phytoplankton growth season, and overall biological productivity. Yet, the underlying reasons for differences among them are largely unknown. This project studies the fundamental biophysical processes at a variety of polynyas, examines the connection between the physical environment and the phytoplankton and penguin ecology, and investigates the mechanisms behind polynya variability. The results of this interdisciplinary study will provide a context for interpretation of field measurements in Antarctic coastal polynyas, set a baseline for future polynya studies, and examine how polynya ecosystems may respond to local and large-scale environmental changes. The project will include educational and outreach activities that convey scientific messages to a broad audience. It aims to increase public awareness of the interconnection between large-scale environmental change and Antarctic coastal systems. The main objectives of this study are to form a comprehensive understanding of the temporal and spatial variability of Antarctic coastal polynyas and the physical controls of polynya ecosystems. The project takes an interdisciplinary approach and seeks to establish a modeling system centered on the Regional Ocean Modeling System. This system links the ice and ocean conditions to the plankton ecology and penguin population. Applications of the modeling system in representative polynyas, in conjunction with analysis of existing observations, will determine the biophysical influences of individual forcing factors. In particular, this study will test a set of hypothesized effects of winds, offshore water intrusion, ice-shelf melting, sea-ice formation, glacier tongues, and ocean stratification on the timing of polynya phytoplankton bloom and the overall polynya biological productivity. The project will also examine how changing polynya state affects penguin breeding success, adult survival, and population growth. The team will conduct idealized sensitivity analysis to explore implications of forcing variability, including local and large-scale environmental change, on Antarctic coastal ecosystems.
The Ross Ice Shelf is the largest existing ice shelf in Antarctica, and is currently stabilizing significant portions of the land ice atop the Antarctic continent. An ice shelf begins where the land ice goes afloat on the ocean, and as such, the Ross Ice Shelf interacts with the ocean and seafloor below, and the land ice behind. Currently, the Ross Ice Shelf slows down, or buttresses, the fast flowing ice streams of the West Antarctic Ice Sheet (WAIS), a marine-based ice sheet, which if melted, would raise global sea level by 3-4 meters. The Ross Ice Shelf average ice thickness is approximately 350 meters, and it covers approximately 487,000 square kilometers, an area slightly larger than the state of California. The Ross Ice Shelf has disappeared during prior interglacial periods, suggesting in the future it may disappear again. Understanding the dynamics, stability and future of the West Antarctic Ice Sheet therefore requires in-depth knowledge of the Ross Ice Shelf. The ROSETTA-ICE project brings together scientists from 4 US institutions and from the Institute of Geological and Nuclear Sciences Limited, known as GNS Science, New Zealand. The ROSETTA-ICE data on the ice shelf, the water beneath the ice shelf, and the underlying rocks, will allow better predictions of how the Ross Ice Shelf will respond to changing climate, and therefore how the WAIS will behave in the future. The interdisciplinary ROSETTA-ICE team will train undergraduate and high school students in cutting edge research techniques, and will also work to educate the public via a series of vignettes integrating ROSETTA-ICE science with the scientific and human history of Antarctic research. The ROSETTA-ICE survey will acquire gravity and magnetics data to determine the water depth beneath the ice shelf. Radar, LIDAR and imagery systems will be used to map the Ross Ice Shelf thickness and fine structure, crevasses, channels, debris, surface accumulation and distribution of marine ice. The high resolution aerogeophysical data over the Ross Ice Shelf region in Antarctica will be acquired using the IcePod sensor suite mounted externally on an LC-130 aircraft operating from McMurdo Station, Antarctica. Field activities will include ~36 flights on LC-130 aircraft over two field seasons in Antarctica. The IcePod instrument suite leverages the unique experience of the New York Air National Guard operating in Antarctica for NSF scientific research as well as infrastructure and logistics. The project will answer questions about the stability of the Ross Ice Shelf in future climate, and the geotectonic evolution of the Ross Ice Shelf Region, a key component of the West Antarctic Rift system. The comprehensive benchmark data sets acquired will enable broad, interdisciplinary analyses and modeling, which will also be performed as part of the project. ROSETTA-ICE will illuminate Ross ice sheet-ice shelf-ocean dynamics as the system nears a critical juncture but still is intact. Through interacting with an online data visualization tool, and comparing the ROSETTA-ICE data and results from earlier studies, we will engage students and young investigators, equipping them with new capabilities for the study of critical earth systems that influence global climate.
The McMurdo Dry Valleys, Antarctica, are a mosaic of terrestrial and aquatic ecosystems in a cold desert. The McMurdo Long Term Ecological Research (LTER) project has been observing these ecosystems since 1993 and this award will support key long-term measurements, manipulation experiments, synthesis, and modeling to test current theories on ecosystem structure and function. Data collection is focused on meteorology and physical and biological dimensions of soils, streams, lakes, glaciers, and permafrost. The long-term measurements show that biological communities have adapted to the seasonally cold, dark, and arid conditions that prevail for all but a short period in the austral summer. Physical (climate and geological) drivers impart a dynamic connectivity among portions of the Dry Valley landscape over seasonal to millennial time scales. For instance, lakes and soils have been connected through cycles of lake-level rise and fall over the past 20,000 years while streams connect glaciers to lakes over seasonal time scales. Overlaid upon this physical system are biotic communities that are structured by the environment and by the movement of individual organisms within and between the glaciers, streams, lakes, and soils. The new work to be conducted at the McMurdo LTER site will explore how the layers of connectivity in the McMurdo Dry Valleys influence ecosystem structure and function. This project will test the hypothesis that increased ecological connectivity following enhanced melt conditions within the McMurdo Dry Valleys ecosystem will amplify exchange of biota, energy, and matter, homogenizing ecosystem structure and functioning. This hypothesis will be tested with new and continuing experiments that examine: 1) how climate variation alters connectivity among landscape units, and 2) how biota are connected across a heterogeneous landscape using state-of-the-science tools and methods including automated sensor networks, analysis of seasonal satellite imagery, biogeochemical analyses, and next-generation sequencing. McMurdo LTER education programs and outreach activities will be continued, and expanded with new programs associated with the 200th anniversary of the first recorded sightings of Antarctica. These activities will advance societal understanding of how polar ecosystems respond to change. McMurdo LTER will continue its mission of training and mentoring students, postdocs, and early career scientists as the next generation of leaders in polar ecosystem science, and lead the development of international environmental stewardship protocols for human activities in the region.
In order to understand what environmental conditions might look like for future generations, we need to turn to archives of past times when the world was indeed warmer, before anyone was around to commit them to collective memory. The geologic record of Earth's past offers a glimpse of what could be in store for the future. Research by Ivany and her team looks to Antarctica during a time of past global warmth to see how seasonality of temperature and rainfall in coastal settings are likely to change in the future. They will use the chemistry of fossils (a natural archive of these variables) to test a provocative hypothesis about near-monsoonal conditions in the high latitudes when the oceans are warm. If true, we can expect high-latitude shipping lanes to become more hazardous and fragile marine ecosystems adapted to constant cold temperatures to suffer. With growing information about how human activities are likely to affect the planet in the future, we will be able to make more informed decisions about policies today. This research involves an international team of scholars, including several women scientists, training of graduate students, and a public museum exhibit to educate children about how we study Earth's ancient climate and what we can learn from it. Antarctica is key to an understanding how Earth?s climate system works under conditions of elevated CO2. The poles are the most sensitive regions on the planet to climate change, and the equator-to-pole temperature gradient and the degree to which high-latitude warming is amplified are important components for climate models to capture. Accurate proxy data with good age control are therefore critical for testing numerical models and establishing global patterns. The La Meseta Formation on Seymour Island is the only documented marine section from the globally warm Eocene Epoch exposed in outcrop on the continent; hence its climate record is integral to studies of warming. Early data suggest the potential for strongly seasonal precipitation and runoff in coastal settings. This collaboration among paleontologists, geochemists, and climate modelers will test this using seasonally resolved del-18O data from fossil shallow marine bivalves to track the evolution of seasonality through the section, in combination with independent proxies for the composition of summer precipitation (leaf wax del-D) and local seawater (clumped isotopes). The impact of the anticipated salinity stratification on regional climate will be evaluated in the context of numerical climate model simulations. In addition to providing greater clarity on high-latitude conditions during this time of high CO2, the combination of proxy and model results will provide insights about how Eocene warmth may have been maintained and how subsequent cooling came about. As well, a new approach to the analysis of shell carbonates for 87Sr/86Sr will allow refinements in age control so as to allow correlation of this important section with other regions to clarify global climate gradients. The project outlined here will develop new and detailed paleoclimate records from existing samples using well-tuned as well as newer proxies applied here in novel ways. Seasonal extremes are climate parameters generally inaccessible to most studies but critical to an understanding of climate change; these are possible to resolve in this well-preserved, accretionary-macrofossil-bearing section. This is an integrated study that links marine and terrestrial climate records for a key region of the planet across the most significant climate transition in the Cenozoic.
Marine communities along the western Antarctic Peninsula are highly productive ecosystems which support a diverse assemblage of charismatic animals such as penguins, seals, and whales as well as commercial fisheries such as that on Antarctic krill. Fjords (long, narrow, deep inlets of the sea between high cliffs) along the central coast of the Peninsula appear to be intense, potentially climate sensitive, hotspots of biological production and biodiversity, yet the structure and dynamics of these fjord ecosystems are very poorly understood. Because of this intense biological activity and the charismatic fauna it supports, these fjords are also major destinations for a large Antarctic tourism industry. This project is an integrated field and modeling program to evaluate physical oceanographic processes, glacial inputs, water column community dynamics, and seafloor bottom community structure and function in these important yet little understood fjord systems. These Antarctic fjords have characteristics that are substantially different from well-studied Arctic fjords, likely yielding much different responses to climate warming. This project will provide major new insights into the dynamics and climate sensitivity of Antarctic fjord ecosystems, highlighting contrasts with Arctic sub-polar fjords, and potentially transforming our understanding of the ecological role of fjords in the rapidly warming west Antarctic coastal marine landscape. The project will also further the NSF goal of training new generations of scientists, providing scientific training for undergraduate, graduate, and postdoctoral students. This includes the unique educational opportunity for undergraduates to participate in research cruises in Antarctica and the development of a novel summer graduate course on fjord ecosystems. Internet based outreach activities will be enhanced and extended by the participation of a professional photographer who will produce magazine articles, websites, radio broadcasts, and other forms of public outreach on the fascinating Antarctic ecosystem. This project will involve a 15-month field program to test mechanistic hypotheses concerning oceanographic and glaciological forcing, and phytoplankton and benthic community response in the Antarctic fjords. Those efforts will be followed by a coupled physical/biological modeling effort to evaluate the drivers of biogeochemical cycles in the fjords and to explore their potential sensitivity to enhanced meltwater and sediment inputs. Fieldwork over two oceanographic cruises will utilize moorings, weather stations, and glacial, sea-ice and seafloor time-lapse cameras to obtain an integrated view of fjord ecosystem processes. The field team will also make multiple shipboard measurements and will use towed and autonomous underwater vehicles to intensively evaluate fjord ecosystem structure and function during spring/summer and autumn seasons. These integrated field and modeling studies are expected to elucidate fundamental properties of water column and sea bottom ecosystem structure and function in the fjords, and to identify key physical-chemical-glaciological forcing in these rapidly warming ecosystems.
There is compelling historical evidence that the West Antarctic Ice Sheet (WAIS) is vulnerable to rapid retreat and collapse. Recent observations, compared to observations made 20-30 years before, indicate that both ice shelves (thick ice with ocean below) and land ice (thick ice with land below), are now melting at a much faster rate. Some numerical models suggest that significant ice retreat may begin within many of our lifetimes, starting with the abrupt collapse of Pine Island and Thwaites Glaciers in the next 50 years. This may be followed by retreat of much of the WAIS and then the collapse of parts of the East Antarctic ice sheet (EAIS). This research project will assess the extent to which global ocean circulation and climate will be impacted if enormous volumes of fresh water and ice flow into the Southern Ocean. It will establish whether a rapid collapse of WAIS in the near-future poses any significant threat to the stability of modern-day climate and human society. This is a topic that has so far received little attention as most prior research has focused on the response of climate to melting the Greenland ice sheet. Yet model simulations predict that the volumes of fresh water and ice released from Antarctica in the next few centuries could be up at least ten-times larger than from Greenland. The Intellectual Merit of this project stems from its ability to establish a link between the physical Antarctic system (ice sheet dynamics, fresh water discharge and iceberg calving) and global climate. The PIs (Principal Investigators) will assess the sensitivity of ocean circulation and climate to increased ice sheet melt using a combination of ocean, iceberg, ice sheet and climate models. Results from this study will help identify areas of the ice sheet that are vulnerable to collapse and also regions of the ocean where a significant freshening will have a considerable impact on climate, and serve to guide the deployment of an observational monitoring system capable of warning us when ice and fresh water discharge start to approach levels capable of disrupting ocean circulation and global climate. This project will support and train two graduate students, and each PI will be involved with local primary and secondary schools, making presentations, mentoring science fair projects, and contributing to curriculum development. A novel, web-based, interactive, cryosphere learning tool will be developed to help make school children more aware of the importance of the Polar Regions in global climate, and this software will be introduced to science teachers at a half day workshop organized by the UMass STEM Education Institute. Recent numerical simulations using a continental ice sheet/shelf model show the potential for more rapid and greater Antarctic ice sheet retreat in the next 50-300 years (under the full range of IPCC RCP (Intergovernmental Panel on Climate Change, Representative Concentration Pathways) future warming scenarios) than previously projected. Exactly how the release of enormous volumes of ice and fresh water to the Southern Ocean will impact global ocean circulation and climate has yet to be accurately assessed. This is in part because previous model simulations were too coarse to accurately resolve narrow coastal boundary currents, shelf breaks, fronts, and mesoscale eddies that are all very important for realistically simulating fresh water transport in the ocean. In this award, future projections of fresh water discharge and iceberg calving from Antarctic will be used to force a high resolution eddy-resolving ocean model (MITgcm) coupled to a new iceberg module and a fully-coupled global climate model (CCSM4). High resolution ocean/iceberg simulations will determine the role of mesoscale eddies in freshwater transport and give new insight into how fresh water is advected to far-field locations, including deep water formation sites in the North Atlantic. These simulations will provide detailed information about subsurface temperatures and changes in ocean circulation close to the ice front and grounding line. An accompanying set of fully coupled climate model simulations (NCAR CCSM4) will identify multidecadal-to-centennial changes in the climate system triggered by increased high-latitude Southern Ocean freshwater forcing. Particular attention will be given to changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC), wind stress, sea ice formation, and global temperatures. In doing so, this project will more accurately determine whether abrupt and potentially catastrophic changes in global climate are likely to be triggered by changes in the Antarctic system in the near-future.
Gases trapped in ice cores have revealed astonishing things about the greenhouse gas composition of the past atmosphere, including the fact that carbon dioxide concentrations never rose above 300 parts per million during the last 800,000 years. This places today's concentration of 400 parts per million in stark contrast. Furthermore, these gas records show that natural sources of greenhouse gas such as oceans and ecosystems act as amplifiers of climate change by increasing emissions of gases during warmer periods. Such amplification is expected to occur in the future, adding to the human-produced gas burden. The South Pole ice core will build upon these prior findings by expanding the suite of gases to include, for the first time, those potent trace gases that both trapped heat and depleted ozone during the past 40,000 years. The present project on inert gases and methane in the South Pole ice core will improve the dating of this crucial record, to unprecedented precision, so that the relative timing of events can be used to learn about the mechanism of trace gas production and destruction, and consequent climate change amplification. Ultimately, this information will inform predictions of future atmospheric chemical cleansing mechanisms and climate in the context of our rapidly changing atmosphere. This award also engages young people in the excitement of discovery and polar research, helping to entrain the next generations of scientists and educators. Education of graduate students, a young researcher (Buizert), and training of technicians, will add to the nation?s human resource base. This award funds the construction of the gas chronology for the South Pole 1500m ice core, using measured inert gases (d15N and d40Ar--Nitrogen and Argon isotope ratios, respectively) and methane in combination with a next-generation firn densification model that treats the stochastic nature of air trapping and the role of impurities on densification. The project addresses fundamental gaps in scientific understanding that limit the accuracy of gas chronologies, specifically a poor knowledge of the controls on ice-core d15N and the possible role of layering and impurities in firn densification. These gaps will be addressed by studying the gas enclosure process in modern firn at the deep core site. The work will comprise the first-ever firn air pumping experiment that has tightly co-located measurements of firn structural properties on the core taken from the same borehole. The project will test the hypothesis that the lock-in horizon as defined by firn air d15N, CO2, and methane is structurally controlled by impermeable layers, which are in turn created by high-impurity content horizons in which densification is enhanced. Thermal signals will be sought using the inert gas measurements, which improve the temperature record with benefits to the firn densification modeling. Neon, argon, and oxygen will be measured in firn air and a limited number of deep core samples to test whether glacial period layering was enhanced, which could explain low observed d15N in the last glacial period. Drawing on separate volcanic and methane synchronization to well-dated ice cores to create independent ice and gas tie points, independent empirical estimates of the gas age-ice age difference will be made to check the validity of the firn densification model-inert gas approach to calculating the gas age-ice age difference. These points will also be used to test whether the anomalously low d15N seen during the last glacial period in east Antarctic ice cores is due to deep air convection in the firn, or a missing impurity dependence in the firn densification models. The increased physical understanding gained from these studies, combined with new high-precision measurements, will lead to improved accuracy of the gas chronology of the South Pole ice core, which will enhance the overall science return from this gas-oriented core. This will lead to clarification of timing of atmospheric gas variations and temperature, and aid in efforts to understand the biogeochemical feedbacks among trace gases. These feedbacks bear on the future response of the Earth System to anthropogenic forcing. Ozone-depleting substances will be measured in the South Pole ice core record, and a precise gas chronology will add value. Lastly, by seeking a better understanding of the physics of gas entrapment, the project aims to have an impact on ice-core science in general.
The aim of study is to understand how climate-related changes in snow and ice affect predator populations in the Antarctic, using the Adélie penguin as a focal species due to its long history as a Southern Ocean 'sentinel' species and the number of long-term research programs monitoring its abundance, distribution, and breeding biology. Understanding the environmental factors that control predator population dynamics is critically important for projecting the state of populations under future climate change scenarios, and for designing better conservation strategies for the Antarctic ecosystem. For the first time, datasets from a network of observational sites for the Adélie penguin across the entire Antarctic will be combined and analyzed, with a focus on linkages among the ice environment, primary production, and the population responses of Adélie penguins. The project will also further the NSF goals of making scientific discoveries available to the general public and of training new generations of scientists. The results of this project can be used to illustrate intuitively to the general public the complex interactions between ice, ocean, pelagic food web and top predators. This project also offers an excellent platform to demonstrate the process of climate-change science - how scientists simulate climate change scenarios and interpret model results. This project supports the training of undergraduate and graduate students in the fields of polar oceanography, plankton and seabird ecology, coupled physical-biological modeling and mathematical ecology. The results will be broadly disseminated to the general oceanographic research community through scientific workshops, conferences and peer-reviewed journal articles, and to undergraduate and graduate education communities, K-12 schools and organizations, and the interested public through web-based servers using existing infrastructure at the investigators' institutions. The key question to be addressed in this project is how climate impacts the timing of periodic biological events (phenology) and how interannual variation in this periodic forcing influences the abundance of penguins in the Antarctic. The focus will be on the timing of ice algae and phytoplankton blooms because the high seasonality of sea ice and associated pulsed primary productivity are major drivers of the Antarctic food web. This study will also examine the responses of Adélie penguins to changes in sea ice dynamics and ice algae-phytoplankton phenology. Adélie penguins, like many other Antarctic seabirds, are long-lived, upper trophic-level predators that integrate the effects of sea ice on the food web at regional scales, and thus serve as a reliable biological indicator of environmental changes. The proposed approach is designed to accommodate the limits of measuring and modeling the intermediate trophic levels between phytoplankton and penguins (e.g., zooplankton and fish) at the pan-Antarctic scale, which are important but latent variables in the Southern Ocean food web. Through the use of remotely sensed and in situ data, along with state of the art statistical approaches (e.g. wavelet analysis) and numerical modeling, this highly interdisciplinary study will advance our understanding of polar ecosystems and improve the projection of future climate change scenarios.
Hamilton/1246400 This award supports an integrated field observation, remote sensing and numerical modeling study of the McMurdo Shear Zone (SZ). The SZ is a 5-10 km wide strip of heavily crevassed ice that separates the McMurdo and Ross ice shelves, and is an important region of lateral support for the Ross Ice Shelf. Previous radar and remote sensing studies reveal an enigmatic picture of the SZ in which crevasses detected at depth have no apparent surface expression, and have orientations which are possibly inconsistent with the observed flow field. In the proposed work, we seek to test the hypothesis that the SZ is a zone of chaotic Lagrangian mixing with (intersecting) buried crevasses which leads to rheological instability, potentially allowing large scale velocity discontinuities. The work will involve detailed field-based observations of crevasse distributions and structure using ground-penetrating radar, and GPS and remote sensing observations of the flow and stress field in the SZ. Because of the hazardous nature of the SZ, the radar surveys will be conducted largely with the aid of a lightweight robotic vehicle. Observations will be used to develop a finite element model of ice shelf shear margin behavior. The intellectual merit of this project is an increased understanding of ice shelf shear margin dynamics. Shear margins play a key role in ice shelf stability, and ice shelves in turn modulate the flux of ice from the ice sheet across the grounding line to the ocean. Insights from this project will improve large-scale models being developed to predict ice sheet evolution and future rates of sea level rise, which are topics of enormous societal concern. The broader impacts of the project include an improved basis for US Antarctic Program logistics planning as well as numerous opportunities to engage K-12 students in scientific discovery. Intensified crevassing in the shear zone between the Ross and McMurdo ice shelves would preclude surface crossing by heavy traverse vehicles which would lead to increased costs of delivering fuel to South Pole and a concomitant loss of flight time provided by heavy-lift aircraft for science missions on the continent. Our multidisciplinary research combining glaciology, numerical modeling, and robotics engineering is an engaging way to show how robotics can assist scientists in collecting hazardous field measurements. Our outreach activities will leverage Dartmouth's current NSF GK-12 program, build on faculty-educator relationships established during University of Maine's recent GK-12 program, and incorporate project results into University of Maine's IDEAS initiative, which integrates computational modeling with the existing science curriculum at the middle school level. This award has field work in Antarctica.
Timmerman/1341311 This award supports a project to study the physical processes that synchronize glacial-scale variability between the Northern Hemisphere ice sheets and the Antarctic ice-sheet. Using a coupled numerical ice-sheet earth-system model, the research team will explore the cryospheric responses to past changes in greenhouse gas concentrations and variations in earth's orbit and tilt. First capturing the sensitivity of each individual ice-sheet to these forcings and then determining their joint variability induced by changes in sea level, ocean temperatures and atmospheric circulation, the researchers will quantify the relative roles of local versus remote effects on long-term ice volume variability. The numerical experiments will provide deeper physical insights into the underlying dynamics of past Antarctic ice-volume changes and their contribution to global sea level. Output from the transient earth system model simulations will be directly compared with ice-core data from previous and ongoing drilling efforts, such as West Antarctic Ice Sheet (WAIS) Divide. Specific questions that will be addressed include: 1) Did the high-latitude Southern Hemispheric atmospheric and oceanic climate, relevant to Antarctic ice sheet forcing, respond to local insolation variations, CO2, Northern Hemispheric changes, or a combination thereof?; 2) How did WAIS and East Antarctic Ice Sheet (EAIS) vary through the Last Glacial Termination and into the Holocene (21 ka- present)?; 3) Did the WAIS (or EAIS) contribute to rapid sea-level fluctuations during this period, such as Meltwater Pulse 1A? 4) Did WAIS collapse fully at Stage 5e (~ 125 ka), and what was its timing relative to the maximum Greenland retreat?; and 5) How did the synchronized behavior of Northern Hemisphere and Southern Hemisphere ice-sheet variations affect the strength of North Atlantic Deep Water and Antarctic Bottom Water formation and the respective overturning cells? The transient earth-system model simulations conducted as part of this project will be closely compared with paleo-climate reconstructions from ice cores, sediment cores and terrestrial data. This will generate an integrated understanding of the hemispheric contributions of deglacial climate change, the origin of meltwater pulses, and potential thresholds in the coupled ice-sheet climate system in response to different types of forcings. A well-informed long-term societal response to sea level rise requires a detailed understanding of ice-sheet sensitivities to external forcing. The proposed research will strongly contribute to this task through numerical modeling and paleo-data analysis. The research team will make the resulting model simulations available on the web-based data server at the Asia Pacific Data Research Center (APDRC) to enable further analysis by the scientific community. As part of this project a female graduate student and a postdoctoral researcher will receive training in earth-system and ice-sheet modeling and paleo-climate dynamics. This award has no field work in Antarctica.
Intellectual Merit: This project will produce a new compilation of Ross Sea seismic stratigraphy, including new interpretations, that can be used to provide boundary conditions on the tectonic and glacial evolution of West Antarctica and the Ross Sea. The principal goals include compilation of, and interpretation of, all available existing seismic reflection data for the Western Ross Sea, coupled with geophysical modeling to produce paleo-bathymetric reconstructions for the entire 800 km-wide Ross Sea. Specific tasks will include: extending existing work on mapping travel time to reflectors, identifying relations in the seismic data that indicate subsidence through sea level, constructing velocity models for converting travel time to thickness, and using the velocity models to estimate density and porosity of sediments for backstripping analysis. Modeling/backstripping efforts will be used to constrain past bathymetry. Digital interpretations and stratigraphic grids will be provided as supplements to publications. In that way the results of this study can be used in thermal subsidence modeling and restoration of eroded rock to other parts of Ross Embayment and Marie Byrd Land by others. Digital products may be provided in advance of publication to modelers in a way that will not hurt publication chances. Broader impacts: The results of this work will be important for paleo-geographic reconstructions of Antarctica and will therefore be of use to a broad range of researchers, particularly those working in the Ross Sea region. The digital products can be used to test models for the past fluctuations of West Antarctic ice sheets, and in planning for future sediment drilling projects. Two undergraduates to be chosen from applicants will be involved in summer internships held at the University of Rhode Island. Outreach will also include a new website and one or more Wikipedia entries related to Ross Sea sub-sea floor characteristics. The project includes an international collaboration with Dr. Chiara Sauli and others at Instituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS) in Italy.
The Palmer Antarctica LTER (Long Term Ecological Research) site has been in operation since 1990. The goal of all the LTER sites is to conduct policy-relevant research on ecological questions that require tens of years of data, and cover large geographical areas. For the Palmer Antarctica LTER, the questions are centered around how the marine ecosystem west of the Antarctica peninsula is responding to a climate that is changing as rapidly as any place on the Earth. For example, satellite observations over the past 35 years indicate the average duration of sea ice cover is now ~90 days (3 months!) shorter than it was. The extended period of open water has implications for many aspects of ecosystem research, with the concurrent decrease of Adèlie penguins within this region regularly cited as an exemplar of climate change impacts in Antarctica. Cutting edge technologies such as autonomous underwater (and possibly airborne) vehicles, seafloor moorings, and numerical modeling, coupled with annual oceanographic cruises, and weekly environmental sampling, enables the Palmer Antarctica LTER to expand and bridge the time and space scales needed to assess climatic impacts. This award includes for the first time study of the roles of whales as major predators in the seasonal sea ice zone ecosystem. The team will also focus on submarine canyons, special regions of enhanced biological activity, along the Western Antarctic Peninsula (WAP). The current award's overarching research question is: How do seasonality, interannual variability, and long term trends in sea ice extent and duration influence the structure and dynamics of marine ecosystems and biogeochemical cycling? Specific foci within the broad question include: 1. Long-term change and ecosystem transitions. What is the sensitivity or resilience of the ecosystem to external perturbations as a function of the ecosystem state? 2. Lateral connectivity and vertical stratification. What are the effects of lateral transports of freshwater, heat and nutrients on local ocean stratification and productivity and how do they drive changes in the ecosystem? 3. Top-down controls and shifting baselines. How is the ecosystem responding to the cessation of whaling and subsequent long-term recovery of whale stocks? 4. Foodweb structure and biogeochemical processes. How do temporal and spatial variations in foodweb structure influence carbon and nutrient cycling, export, and storage? The broader impacts of the award leverage local educational partnerships including the Sandwich, MA STEM Academy, the New England Aquarium, and the NSF funded Polar Learning and Responding (PoLAR) Climate Change Education Partnership at Columbia's Earth Institute to build new synergies between Arctic and Antarctic, marine and terrestrial scientists and students, governments and NGOs. The Palmer Antarctic LTER will also conduct appropriate cross LTER site comparisons, and serve as a leader in information management to enable knowledge-building within and beyond the Antarctic, oceanographic, and LTER communities.
Waddington/1246045 This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.
Intellectual Merit: The PIs propose to complement the ANDRILL marine record with a terrestrial project that will provide chronological control for past fluctuations of the West Antarctic Ice Sheet (WAIS) and alpine glaciers in McMurdo Sound. The project will develop high-resolution maps of drifts deposited from grounded marine-based ice and alpine glaciers on islands and peninsulas in McMurdo Sound. In addition, the PIs will acquire multi-clast/multi-nuclide cosmogenic analyses of these mapped drift sheets and alpine moraines and use regional climate modeling to shed light on the range of possible environmental conditions in the McMurdo region during periods of grounded ice expansion and recession. The PIs will make use of geological records for ice sheet and alpine glacier fluctuations preserved on the flanks of Mount Discovery, Black Island, and Brown Peninsula. Drifts deposited from grounded, marine-based ice will yield spatial constraints for former advances and retreats of the WAIS. Moraines from alpine glaciers, hypothesized to be of interglacial origin, could yield a first-order record of hydrologic change in the region. Synthesizing the field data, the team proposes to improve the resolution of existing regional-scale climate models for the Ross Embayment. The overall approach and anticipated results will provide the first steps towards linking the marine and terrestrial records in this critical sector of Antarctica. Broader impacts: Results from the proposed work will be integrated with outreach programs at Boston University, Columbia University, and Worcester State University. The team will actively collaborate with the American Museum of Natural History to feature this project prominently in museum outreach. The team will also include a PolarTREC teacher as a member of the research team. The geomorphological results will be presented in 3D at Boston University?s Antarctic Digital Image Analyses Lab. The research will form the basis of a PhD dissertation at Boston University.
Southern Ocean Carbon and Climate Observations and Modeling (SOCCOM) project seeks to drive a transformative shift in our understanding of the crucial role of the Southern Ocean in taking up anthropogenic carbon and heat, and resupplying nutrients from the abyss to the surface. An observational program will generate vast amounts of new biogeochemical data that will provide a greatly improved view of the dynamics and ecosystem responses of the Southern Ocean. A modeling component will apply these observations to enhancing understanding of the current ocean, reducing uncertainty in projections of future carbon and nutrient cycles and climate. Because it serves as the primary gateway through which the intermediate, deep, and bottom waters of the ocean interact with the surface layers and thus the atmosphere, the Southern Ocean has a profound influence on the oceanic uptake of anthropogenic carbon and heat as well as nutrient resupply from the abyss to the surface. Yet it is the least observed and understood region of the world ocean. The oceanographic community is on the cusp of two major advances that have the potential to transform understanding of the Southern Ocean. The first is the development of new biogeochemical sensors mounted on autonomous profiling floats that allow sampling of ocean biogeochemistry and acidification in 3-dimensional space with a temporal resolution of five to ten days. The SOCCOM float program proposed will increase the average number of biogeochemical profiles measured per month in the Southern Ocean by ~10-30x. The second is that the climate modeling community now has the computational resources and physical understanding to develop fully coupled climate models that can represent crucial mesoscale processes in the Southern Ocean, as well as corresponding models that assimilate observations to produce a state estimate. Together with the observations, this new generation of models provides the tools to vastly improve understanding of Southern Ocean processes and the ability to quantitatively assess uptake of anthropogenic carbon and heat, as well as nutrient resupply, both today and into the future. In order to take advantage of the above technological and modeling breakthroughs, SOCCOM will implement the following research programs: * Theme 1: Observations. Scripps Institution of Oceanography will lead a field program to expand the number of Southern Ocean autonomous profiling floats and equip them with sensors to measure pH, nitrate, and oxygen. The University of Washington and Monterey Bay Aquarium Research Institute will design, build, and oversee deployment of the floats. Scripps will also develop a mesoscale eddying Southern Ocean state estimate that assimilates physical and biogeochemical data into the MIT ocean general circulation model. * Theme 2: Modeling. University of Arizona and Princeton University, together with NOAA's Geophysical Fluid Dynamics Laboratory (GFDL), will use SOCCOM observations to develop data/model assessment metrics and next-generation model analysis and evaluation, with the goal of improving process level understanding and reducing the uncertainty in projections of our future climate. Led by Climate Central, an independent, non-profit journalism and research organization that promotes understanding of climate science, SOCCOM will collaborate with educators and media professionals to inform policymakers and the public about the challenges of climate change and its impacts on marine life in the context of the Southern Ocean. In addition, the integrated team of SOCCOM scientists and educators will: * communicate data and results of the SOCCOM efforts quickly to the public through established data networks, publications, broadcast media, and a public portal; * train a new generation of diverse ocean scientists, including undergraduate students, graduate students, and postdoctoral fellows versed in field techniques, data calibration, modeling, and communication of research to non-scientists; * transfer new sensor technology and related software to autonomous instrument providers and manufacturers to ensure that they become widely useable.
The research will examine how diatoms (an important group of plankton in the Southern Ocean) adapt to environmental change. Diatoms will be sampled from different regions of the Southern Ocean, including the Drake Passage, the Pacific Sector of the Southern Ocean and the Ross Sea and examined to determine the range of genetic variation among diatoms in these regions. Experiments on a range of diatoms will be conducted in home laboratories and will be aimed at measuring shifts in physiological capacities over many generations in response to directional changes in the environment (temperature and pH). The information on the genetic diversity of field populations combined with information on potential rates of adaptability and genome changes will provide insight into ways in which polar marine diatoms populations may respond to environmental changes that may occur in surface oceans in the future or may have occurred during past climate conditions. Such information allows better modeling of biogeochemical cycles in the ocean as well as improves our abilities to interpret records of past ocean conditions. The project will support a doctoral student and a postdoctoral researcher as well as several undergraduate students. These scientists will learn the fundamentals of experimental evolution, a skill set that is being sought in the fields of biology and oceanography. The project also includes a collaboration with the Metcalf Institute for Marine and Environmental Reporting that will design and facilitate a session focused on current research related to evolution and climate change to be held at the annual conference of the National Association of Science Writers (NASW). Both physiological and genetic variation are key parameters for understanding evolutionary processes in phytoplankton but they are essentially unknown for Southern Ocean diatoms. The extent to which these two factors determine plasticity and adaptability in field populations and the interaction between them will influence how and whether cold-adapted diatoms can respond to changing environments. This project includes a combination of field work to identify genetic diversity within diatoms using molecular approaches and experiments in the lab to assess the range of physiological variation in contemporary populations of diatoms and evolution experiments in the lab to assess how the combination of genetic diversity and physiological variation influence the evolutionary potential of diatoms under a changing environment. This research will uncover general relationships between physiological variation, genetic diversity, and evolutionary potential that may apply across microbial taxa and geographical regions, substantially improving efforts to predict shifts in marine ecosystems. Results from this study can be integrated into developing models that incorporate evolution to predict ecosystem changes under future climate change scenarios.
Antarctic Bottom Water (AABW) formation is a key component in setting the global thermohaline (overturning) circulation. Recent studies infer a reduction of the AABW component from reduced volume of AABW entering global deep ocean basins around the Antarctic continent. It is important to obtain better estimates of AABW production rate in its source areas, and to investigate whether the global overturning circulation is slowing down. The project will continue fieldwork with CTD/LADCP surveys including 2 yearly repeat sections, mooring recoveries and deployments. Seasonal-interannual variability of CDW intrusion, dense shelf water accumulation and export as well as overflow from the Prydz Bay shelf will also be observed. The Prydz Bay- Amery Ice Shelf region has been suggested as a key AABW production site. USAP access to this remote region of the Antarctic continent is challenging. The project will involve fieldwork to be carried out with Danish and Chinese collaboration aboard the Chinese research vessel, Xue Long. A high-resolution regional ocean-sea ice coupled model will be developed to allow time and space continuous three-dimensional ocean state estimation. Both in-situ and remote sensing observations along with the modeling simulation results will be used to investigate (i) the local atmosphere-ocean-sea ice interaction and shelf processes that produce dense shelf water and (ii) the dynamic processes that control the shelf water export.
Intellectual Merit: To understand Antarctica's geodynamic development, origin of the Transantarctic Mountains (TAMs) and the Wilkes Subglacial Basin (WSB) must be determined. Current constraints on the crustal thickness and seismic velocity structure beneath the TAMs and the WSB are limited, leading to uncertainties over competing geologic models that have been suggested to explain their formation. The PI proposes to broaden the investigation of this region with a new seismic deployment, the Transantarctic Mountains Northern Network (TAMNNET), a 15-station array across the northern TAMs and the WSB that will fill a major gap in seismic coverage. Data from TAMNNET will be combined with that from other previous and ongoing seismic initiatives and will be analyzed using proven modeling techniques to generate a detailed image of the seismic structure beneath the TAMs and the WSB. These data will be used to test three fundamental hypotheses: the TAMs are underlain by thickened crust, the WSB is characterized by thin crust and thick sedimentary layers, and slow seismic velocities are prevalent along strike beneath the TAMs. Results from the proposed study will provide new information about the nature and formation of the Antarctic continent and will help to advance our understanding of important global processes, such as mountain building and basin formation. The proposed research also has important implications for other fields of Antarctic science. Constraints on the origin of the TAMs uplift are critical for climate and ice sheet models, and new information acquired about variations in the thermal and lithospheric structure beneath the TAMs and the WSB will be used to estimate critical ice sheet boundary conditions. Broader impacts: This project incorporates three educational strategies to promote the integration of teaching and research. Graduate students will be trained in Antarctic tectonics and seismic processing through hands-on fieldwork and data analysis techniques. Through NSF's PolarTREC program, the PI will work with K-12 educators. The PI will develop a three-week summer field program for recent high school graduates and early-career undergraduate students from Minority-Serving Institutions in Alabama. Teaching materials and participant experiences will be shared with individuals outside the program via a course website. Following the summer program, participants who were particularly engaged will be offered internship opportunities to analyze TAMNNET data. In successive years, the students could assist with fieldwork and could be recruited into the graduate program under the PI's supervision. Ultimately, this program would not only serve to educate undergraduates but would also generate a pipeline of underrepresented students into the geosciences.
McConnell/1142166 This award supports a project to use unprecedented aerosol and continuous gas (methane, carbon monoxide) measurements of the deepest section of the West Antarctic Ice Sheet (WAIS) Divide ice core to investigate rapid climate changes in Antarctica during the ~60,000 year long Marine Isotope Stage 3 period of the late Pleistocene. These analyses, combined with others, will take advantage of the high snow accumulation of the WAIS Divide ice core to yield the highest time resolution glaciochemical and gas record of any deep Antarctic ice core for this time period. The research will expand already funded discrete gas measurements and extend currently funded continuous aerosol measurements on the WAIS Divide ice core from ~25,000 to ~60,000 years before present, spanning Heinrich events 3 to 6 and Antarctic Isotope Maximum (AIM, corresponding to the Northern Hemisphere Dansgaard-Oeschger) events 3 to 14. With other high resolution Greenland cores and lower resolution Antarctic cores, the combined record will yield new insights into worldwide climate dynamics and abrupt change. The intellectual merit of the work is that it will be used to address the science goals of the WAIS Divide project including the identification of dust and biomass burning tracers such as black carbon and carbon monoxide which reflect mid- and low-latitude climate and atmospheric circulation patterns, and fallout from these sources affects marine and terrestrial biogeochemical cycles. Similarly, sea salt and ocean productivity tracers reflect changes in sea ice extent, marine primary productivity, wind speeds above the ocean, and atmospheric circulation. Volcanic tracers address the relationship between northern, tropical, and southern climates as well as stability of the West Antarctic ice sheet and sea level change. When combined with other gas records from WAIS Divide, the records developed here will transform understanding of mid- and low-latitude drivers of Antarctic, Southern Hemisphere, and global climate rapid changes and the timing of such changes. The broader impacts of the work are that it will enhance infrastructure through expansion of continuous ice core analytical techniques, train students and support collaboration between two U.S. institutions (DRI and OSU). All data will be made available to the scientific community and the public and will include participation the WAIS Divide Outreach Program. Extensive graduate and undergraduate student involvement is planned. Student recruitment will be made from under-represented groups building on a long track record. Broad outreach will be achieved through collaborations with the global and radiative modeling communities, NESTA-related and other educational outreach efforts, and public lectures. This proposed project does not require field work in the Antarctic.
0539578<br/>Alley <br/>This award supports a five-year collaborative project to study the physical-properties of the planned deep ice core and the temperature of the ice in the divide region of the West Antarctic Ice Sheet. The intellectual merit of the proposed research is to provide fundamental information on the state of the ice sheet, to validate the integrity of the climate record, to help reconstruct the climate record, and to understand the flow state and history of the ice sheet. This information will initially be supplied to other investigators and then to the public and to appropriate databases, and will be published in the refereed scientific literature. The objectives of the proposed research are to aid in dating of the core through counting of annual layers, to identify any exceptionally warm intervals in the past through counting of melt layers, to learn as much as possible about the flow state and history of the ice through measurement of size, shape and arrangements of bubbles, clathrate inclusions, grains and their c-axes, to identify any flow disturbances through these indicators, and to learn the history of snow accumulation and temperature from analyses of bubbles and borehole temperatures combined with flow modeling and use of data from other collaborators. These results will then be synthesized and communicated. Failure to examine cores can lead to erroneous identification of flow features as climate changes, so careful examination is required. Independent reconstruction of accumulation rate provides important data on climate change, and improves confidence in interpretation of other climate indicators. Borehole temperatures are useful recorders of temperature history. Flow state and history are important in understanding climate history and potential contribution of ice to sea-level change. By contributing to all of these and additional issues, the proposed research will be of considerable value. The broader impacts of the research include making available to the public improved knowledge on societally central questions involving abrupt climate change and sea-level rise. The project will also contribute to the education of advanced students, will utilize results in education of introductory students, and will make vigorous efforts in outreach, informal science education, and supplying information to policy-makers as requested, thus contributing to a more-informed society.
Intellectual Merit: The PIs propose to address the question of whether ice surface melting zones developed at high elevations during warm climatic phases in the Transantarctic Mountains. Evidence from sediment cores drilled by the ANDRILL program indicates that open water in the Ross Sea could have been a source of warmth during Pliocene and Pleistocene. The question is whether marine warmth penetrated inland to the ice sheet margins. The glacial record may be ill suited to answer this question, as cold-based glaciers may respond too slowly to register brief warmth. Questions also surround possible orbital controls on regional climate and ice sheet margins. Northern Hemisphere insolation at obliquity and precession timescales is thought to control Antarctic climate through oceanic or atmospheric connections, but new thinking suggests that the duration of Southern Hemisphere summer may be more important. The PIs propose to use high elevation alluvial deposits in the Transantarctic Mountains as a proxy for inland warmth. These relatively young fans, channels, and debris flow levees stand out as visible evidence for the presence of melt water in an otherwise ancient, frozen landscape. Based on initial analyses of an alluvial fan in the Olympus Range, these deposits are sensitive recorders of rare melt events that occur at orbital timescales. For their study they will 1) map alluvial deposits using aerial photography, satellite imagery and GPS assisted field surveys to establish water sources and to quantify parameters effecting melt water production, 2) date stratigraphic sequences within these deposits using OSL, cosmogenic nuclide, and interbedded volcanic ash chronologies, 3) use paired nuclide analyses to estimate exposure and burial times, and rates of deposition and erosion, and 4) use micro and regional scale climate modeling to estimate paleoenvironmental conditions associated with melt events. Broader impacts: This study will produce a record of inland melting from sites adjacent to ice sheet margins to help determine controls on regional climate along margins of the East Antarctic Ice Sheet to aid ice sheet and sea level modeling studies. The proposal will support several graduate and undergraduates. A PhD student will be supported on existing funding. The PIs will work with multiple K 12 schools to conduct interviews and webcasts from Antarctica and they will make follow up visits to classrooms after the field season is complete.
1043517/Clark This award supports a project to develop a better understanding of the response of the WAIS to climate change. The timing of the last deglaciation of the western Ross Sea will be improved using in situ terrestrial cosmogenic nuclides (3He, 10Be, 14C, 26Al, 36Cl) to date glacial erratics at key areas and elevations along the western Ross Sea coast. A state-of-the art ice sheet-shelf model will be used to identify mechanisms of deglaciation of the Ross Sea sector of WAIS. The model results and forcing will be compared with observations including the new cosmogenic data proposed here, with the aim of better determining and understanding the history and causes of WAIS deglaciation in the Ross Sea. There is considerable uncertainty, however, in the history of grounding line retreat from its last glacial maximum position, and virtually nothing is known about the timing of ice- surface lowering prior to ~10,000 years ago. Given these uncertainties, we are currently unable to assess one of the most important questions regarding the last deglaciation of the global ice sheets, namely as to whether the Ross Sea sector of WAIS contributed significantly to meltwater pulse 1A (MWP-1A), an extraordinarily rapid (~500-year duration) episode of ~20 m sea-level rise that occurred ~14,500 years ago. The intellectual merit of this project is that recent observations of startling changes at the margins of the Greenland and Antarctic ice sheets indicate that dynamic responses to warming may play a much greater role in the future mass balance of ice sheets than considered in current numerical projections of sea level rise. The broader impacts of this work are that it has direct societal relevance to developing an improved understanding of the response of the West Antarctic ice sheet to current and possible future environmental changes including the sea-level response to glacier and ice sheet melting due to global warming. The PI will communicate results from this project to a variety of audiences through the publication of peer-reviewed papers and by giving talks to public audiences. Finally the project will support a graduate student and undergraduate students in all phases of field-work, laboratory work and data interpretation.
Steig/1043092 This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
The presence of ice ponds from surface melting of glacial ice can be a significant threshold in assessing the stability of ice sheets, and their overall response to a warming climate. Snow melt has a much reduced albedo, leading to additional seasonal melting from warming insolation. Water run-off not only contributes to the mass loss of ice sheets directly, but meltwater reaching the glacial ice bed may lubricate faster flow of ice sheets towards the ocean. Surficial meltwater may also reach the grounding lines of glacial ice through the wedging open of existing crevasses. The occurrence and amount of meltwater refreeze has even been suggested as a paleo proxy of near-surface atmospheric temperature regimes. Using contemporary remote sensing (microwave) satellite assessment of surface melt occurrence and extent, the predictive skill of regional meteorological models and reanalyses (e.g. WRF, ERA-Interim) to describe the synoptic conditions favourable to surficial melt is to be investigated. Statistical approaches and pattern recognition techniques are argued to provide a context for projecting future ice sheet change. The previous Intergovernmental Panel on Climate Change (IPCC AR4) commented on our lack of understanding of ice-sheet mass balance processes in polar regions and the potential for sea-level change. The IPPC suggested that the forthcoming AR5 efforts highlight regional cryosphere modeling efforts, such as is proposed here.
1043481/Creyts This award supports a project to develop models of subglacial hydrology in order to understand dynamics of water movement, lake drainage, and how drainage affects ice slip over deformable till with the goal of understanding present and future behavior of fast flowing regions of Antarctica. Drainage of subglacial water falls into two broad categories: distributed and channelized. In distributed systems, water is forced out along the ice?bed interface. Conversely, in channelized systems water is drawn toward a few major arteries. Observations of lake filling and draining sup- port changes in subglacial water flow and suggest a switch from a low to high discharge state or vice versa. Filling or draining can move the subglacial system from one type of drainage morphology to the other. A switch of drainage type will affect slip along the ice-bed interface because distributed morphologies tend to cause enhanced sliding whereas channelized morphologies tend to cause enhanced coupling of the ice-bed interface. Conditions beneath fast flowing ice streams of West Antarctica are ideal for switching between subglacial drainage morphologies. Fast flowing ice in West Antarctica commonly rests on sub- glacial tills and is coincident, in some areas, with observed subglacial lake filling and draining. The goal of the work is to develop the next generation of spatially distributed hydraulic models that capture lake filling and draining phenomena and investigate the effects on subglacial till. Models will be theoretical, process-based descriptions of water drainage and till failure along fast flowing ice streams. Models will be based on balance of mass, momentum, and energy. Building on previous studies, we will incorporate two dimensional movement of water to investigate distributed basal hydrology, distributed basal hydrology coupled to channels, and couple these models with till deformation. These models will provide a framework for determining how lake draining and filling affects ice discharge by providing a constraints on ice?bed coupling. The intellectual merit of the work is that it will advance knowledge about drainage of water subglacially beneath Antarctica and how water affects ice motion. Our modeling provides a unique opportunity to understand the role subglacial hydrology plays in the dynamics of key outlet glaciers and ice streams. The broader impacts of the work include training for one postdoctoral scientist and training for a summer student in simple laboratory techniques for analog experiments. In addition, the proposal dovetails into an existing polar education and outreach plan by including a component of physical, numerical, and scale models in programs developed for high school and middle school classroom visits, teacher workshops and community events. Additionally, because knowledge of glacial hydrology is increasing rapidly, we will convene a workshop on observations and models of subglacial hydrology to facilitate transfer of knowledge and ideas.
1043750/Chen This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.
Abstract The Erebus Bay population of Weddell seals in Antarctica?s Ross Sea is the most southerly breeding population of mammal in the world, closely associated with persistent shore-fast ice, and one that has been intensively studied since 1968. The resulting long-term database, which includes data for 20,586 marked individuals, contains detailed population information that provides an excellent opportunity to study linkages between environmental conditions and demographic processes in the Antarctic. The population?s location is of special interest as the Ross Sea is one of the most productive areas of the Southern Ocean, one of the few pristine marine environments remaining on the planet, and, in contrast to the Antarctic Peninsula and Arctic, is undergoing a gradual lengthening of the sea-ice season. The work to be continued here capitalizes on (1) long-term data for individual seals and their polar environment; (2) experience collecting and analyzing data from the extensive study population; and (3) recent statistical advances in hierarchical modeling that allow for rigorous treatment of individual heterogeneity (in mark-recapture and body mass data) and inclusion of diverse covariates hypothesized to explain variation in fitness components. Covariates to be considered include traits of individuals and their mothers and environmental conditions throughout life. The study will continue to (1) provide detailed data on known-age individuals to other science projects and (2) educate and mentor the next generation of ecologists through academic and professional training and research experiences.
Pettit/0948247<br/><br/>This award supports a project to study of the relationship between fabric and climate for the ice near the EPICA Dome C ice core site, East Antarctica. The work builds on an ongoing study at Siple Dome, West Antarctica and takes advantage of collaborations with European scientists and access to the Dome C borehole to make measurements of sonic velocity. The intellectual merit of the project is that a better understanding of how fabric preserves past climate information can improve models of the ice flow near ice core sites and the interpreta-tion of ice core data (particularly paleo-accumulation), and it may allow us to extract climate information directly from fabric data. In addition, because ice deformation is sensitive to the orientation of crystals, ice flow patterns are sensitive to the fabric. Thus, variations in the fabric between glacial and interglacial ice can affect how ice deforms and how fabric in the ice sheet develops. The Dome C site is particularly important for answering these questions, because the ice core shows evidence of eight glacial cycles, not just one as found at Siple Dome or the Greenland sites. The research will improve the understanding of the proxy relationship between sonic-velocity data and fabric; will help to model the pattern of ice flow caused by the fabric variation between glacial and interglacial time periods using these data, existing ice core chemistry and existing and new thin section data, improved surface strain data, and borehole deformation data; and will help to better understand the positive feedback mechanism that enhances fabric (and corresponding rheological) variability through a focused study of several climate transitions and the associated fabric changes. Borehole compressional-wave sonic-velocity will be measured which will complement the sonic-velocity data that already exist for boreholes in Greenland and West Antarctica. These will be the first sonic-velocity measurements in East Antarctica and the first measurements that extend for more than a single glacial/interglacial transition. The project will ultimately contribute to better interpretation of ice core records for both paleoclimate studies and for ice flow history, both of which connect to the broader questions of the role of ice in the climate system. This project will also strengthen the international collaborations within the paleoclimate and ice sheet modeling communities. This project will partially support a graduate student at the University of Alaska Fairbanks who is currently working on modeling ice including anisotropy and it will support the growth of a young scientist through a Post-Doc position. This Post Doc will gain important experience collaborating with the EPICA scientists in studying the climate-fabric relationship. Erin Pettit is active in field-science education for high school students, under-graduates, teachers, and adults. This project will help support the continued development and enhancement of Girls on Ice a program that encourages young women to explore science and the natural world.
Intellectual Merit: The PIs propose to investigate the impact of earth surface processes on the application of cosmogenic exposure dating in Antarctica by combining multi-nuclide techniques, detailed field experiments, rock-mechanic studies, and climate modeling. They will analyze cosmogenic-nuclide inventories for a suite of six alpine-moraine systems in inland regions of the McMurdo Dry Valleys. This area is ideally suited for this study because 1) the targeted alpine moraine sequences are critically important in helping to reconstruct past temperature and precipitation values over the last several million years, 2) the production rates for cosmogenic nuclides are typically high and well-known, and 3) the complexity of surface processes is relatively low. Their work has two specific goals: to evaluate the effects of episodic geomorphic events in modulating cosmogenic inventories in surface rocks in polar deserts and to generate an alpine glacier chronology that will serve as a robust record of regional climate variation over the last several million years. A key objective is to produce a unique sampling strategy that yields consistent exposure-age results by minimizing the effects of episodic geomorphic events that obfuscate cosmogenic-nuclide chronologies. They will link their moraine chronology with regional-scale atmospheric models developed by collaborators at University of Massachusetts Amherst. Broader impacts: This research is interdisciplinary and includes two early career scientists. Results of this work will be used to enhance undergraduate education by engaging two female students in Antarctic field and summer research projects. Extended outreach includes development of virtual Antarctic field trips for Colgate University?s Ho Tung Visualization Laboratory and Boston University?s Antarctic Digital Image Analyses Laboratory. The PIs will continue to work with the Los Angeles Valley Community College, which serves students of mostly Hispanic origin as part of the PolarTREC program. This project will contribute to the collaboration between LDEO and several New York City public high schools within the Lamont-Doherty Secondary School Field Program.
Intellectual Merit: Knowledge of englacial and subglacial conditions are critical for ice sheet models and predictions of sea-level change. Some of the critical variables that are poorly known but essential for improving flow models and predictions of sea-level change are: basal roughness, subglacial sedimentary and hydrologic conditions, and the temporal and spatial variability of the ice sheet flow field. Seismic reflection and refraction imaging and dense arrays of continuously operating GPS receivers can determine these parameters. The PIs propose to develop a network of wirelessly interconnected geophysical sensors (geoPebble) that will allow glaciologists to carry out these experiments simultaneously. This sensor web will provide a new way of imaging the ice sheet that is not possible with current instruments. With this sensor web, the PIs will extend the range of existing instruments from 2D to 3D, from low resolution to high resolution, but more importantly, all the geophysical measurements will be conducted synchronously. By the end of the proposal period the PIs will produce a network of 150-200 geoPebbles that will be available for NSF-sponsored glaciology research projects. Broader impacts: Improved knowledge of the flow law of ice, the sliding of glaciers and ice streams, and paleoclimate history will contribute to assessments of the potential for abrupt ice-sheet mass change, with consequent sea-level effects and significant societal impacts. This improved modeling ability will be a direct consequence of better knowledge of the physical properties of ice sheets, which this project will facilitate. The development effort will be integrated with the undergraduate education program via the capstone design classes in EE and the senior thesis requirement in Geoscience. The PIs will also form a cohort of first-year and sophomore students who will work in their labs from the beginning of the project to develop specifications through the commissioning of the network.
Intellectual Merit: The PIs propose to investigate the impact of earth surface processes on the application of cosmogenic exposure dating in Antarctica by combining multi-nuclide techniques, detailed field experiments, rock-mechanic studies, and climate modeling. They will analyze cosmogenic-nuclide inventories for a suite of six alpine-moraine systems in inland regions of the McMurdo Dry Valleys. This area is ideally suited for this study because 1) the targeted alpine moraine sequences are critically important in helping to reconstruct past temperature and precipitation values over the last several million years, 2) the production rates for cosmogenic nuclides are typically high and well-known, and 3) the complexity of surface processes is relatively low. Their work has two specific goals: to evaluate the effects of episodic geomorphic events in modulating cosmogenic inventories in surface rocks in polar deserts and to generate an alpine glacier chronology that will serve as a robust record of regional climate variation over the last several million years. A key objective is to produce a unique sampling strategy that yields consistent exposure-age results by minimizing the effects of episodic geomorphic events that obfuscate cosmogenic-nuclide chronologies. They will link their moraine chronology with regional-scale atmospheric models developed by collaborators at University of Massachusetts Amherst. Broader impacts: This research is interdisciplinary and includes two early career scientists. Results of this work will be used to enhance undergraduate education by engaging two female students in Antarctic field and summer research projects. Extended outreach includes development of virtual Antarctic field trips for Colgate University?s Ho Tung Visualization Laboratory and Boston University?s Antarctic Digital Image Analyses Laboratory. The PIs will continue to work with the Los Angeles Valley Community College, which serves students of mostly Hispanic origin as part of the PolarTREC program. This project will contribute to the collaboration between LDEO and several New York City public high schools within the Lamont-Doherty Secondary School Field Program.
Intellectual Merit: The PIs propose to quantify the hillslope water, solute, and carbon budgets for Taylor Valley in the McMurdo Dry Valleys, using water tracks to investigate near-surface geological processes and challenge the paradigm that shallow groundwater is minimal or non-exixtant. Water tracks are linear zones of high soil moisture that route shallow groundwater downslope in permafrost dominated soils. Four hypotheses will be tested: 1) water tracks are important pathways for water and solute transport; 2) water tracks transport more dissolved silica than streams in Taylor Valley indicating they are the primary site of chemical weathering for cold desert soils and bedrock; 3) water tracks that drain highland terrains are dominated by humidity-separated brines while water tracks that drain lowland terrains are dominated by marine aerosols; 4) water tracks are the sites of the highest terrestrial soil carbon concentrations and the strongest CO2 fluxes in Taylor Valley and their carbon content increases with soil age, while carbon flux decreases with age. To test these hypotheses the PIs will carry out a suite of field measurements supported by modeling and remote sensing. They will install shallow permafrost wells in water tracks that span the range of geological, climatological, and topographic conditions in Taylor Valley. Multifrequency electromagnetic induction sounding of the upper ~1 m of the permafrost will create the first comprehensive map of soil moisture in Taylor Valley, and will permit direct quantification of water track discharge across the valley. The carbon contents of water track soils will be measured and linked to global carbon dynamics. Broader impacts: Non-science majors at Oregon State University will be integrated into the proposed research through a new Global Environmental Change course focusing on the scientific method in Antarctica. Three undergraduate students, members of underrepresented minorities, will be entrained in the research, will contribute to all aspects of field and laboratory science, and will present results at national meetings.
The Office of Polar Programs, Antarctic Science Division, Ocean & Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. <br/>The region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. <br/>Broader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.
The Ross Sea continental shelf is one of the most productive areas in the Southern Ocean, and may comprise a significant, but unaccounted for, oceanic CO2 sink, largely driven by phytoplankton production. The processes that control the magnitude of primary production in this region are not well understood, but data suggest that iron limitation is a factor. Field observations and model simulations indicate four potential sources of dissolved iron to surface waters of the Ross Sea: (1) circumpolar deep water intruding from the shelf edge; (2) sediments on shallow banks and nearshore areas; (3) melting sea ice around the perimeter of the polynya; and (4) glacial meltwater from the Ross Ice Shelf. The principal investigators hypothesize that hydrodynamic transport via mesoscale currents, fronts, and eddies facilitate the supply of dissolved iron from these four sources to the surface waters of the Ross Sea polynya. These hypotheses will be tested through a combination of in situ observations and numerical modeling, complemented by satellite remote sensing. In situ observations will be obtained during a month-long cruise in the austral summer. The field data will be incorporated into model simulations, which allow quantification of the relative contributions of the various hypothesized iron supply mechanisms, and assessment of their impact on primary production. The research will provide new insights and a mechanistic understanding of the complex oceanographic phenomena that regulate iron supply, primary production, and biogeochemical cycling. The research will thus form the basis for predictions about how this system may change in a warming climate. The broader impacts include training of graduate and undergraduate students, international collaboration, and partnership with several ongoing outreach programs that address scientific research in the Southern Ocean. The research also will contribute to the goals of the international research programs ICED (Integrated Climate and Ecosystem Dynamics) and GEOTRACES (Biogeochemical cycling and trace elements in the marine environment).
The stability of the marine West Antarctic Ice Sheet (WAIS) remains an important, unresolved problem for predicting future sea level change. Recent studies indicate that the mass balance of the ice sheet today may be negative or positive. The apparent differences may stem in part from short-term fluctuations in flow. By comparison, geologic observations provide evidence of behavior over much longer time scales. Recent work involving glacial-geologic mapping, dating and ice-penetrating radar surveys suggests that deglaciation of both the Ross Sea Embayment and coastal Marie Byrd Land continued into the late Holocene, and leaves open the possibility of ongoing deglaciation and grounding-line retreat. However, previous work in the Ross Sea Embayment was based on data from just three locations that are all far to the north of the present grounding line. Additional data from farther south in the Ross Sea Embayment are needed to investigate whether recession has ended, or if the rate and pattern of deglaciation inferred from our previous study still apply to the present grounding line. This award provides support to reconstruct the evolution of Reedy Glacier, in the southern Transantarctic Mountains, since the Last Glacial Maximum (LGM). Because Reedy Glacier emerges from the mountains above the grounding line, its surface slope and elevation should record changes in thickness of grounded ice in the Ross Sea up to the present day. The deglaciation chronology of Reedy Glacier therefore can indicate whether Holocene retreat of the WAIS ended thousands of years ago, or is still continuing at present. This integrated glaciologic, glacial-geologic, and cosmogenic-isotope exposure- dating project will reconstruct past levels of Reedy Glacier. Over two field seasons, moraines will be mapped, dated and correlated at sites along the length of the glacier. Radar and GPS measurements will be made to supplement existing ice thickness and velocity data, which are needed as input for a model of glacier dynamics. The model will be used to relate geologic measurements to the grounding-line position downstream. Ultimately, the mapping, dating and ice-modeling components of the study will be integrated into a reconstruction that defines changes in ice thickness in the southern Ross Sea since the LGM, and relates these changes to the history of grounding-line retreat. This work directly addresses key goals of the West Antarctic Ice Sheet Initiative, which are to understand the dynamics, recent history and possible future behavior of the West Antarctic Ice Sheet.
ASPIRE is an NSF-funded project that will examine the ecology of the Amundsen Sea during the Austral summer of 2010. ASPIRE includes an international team of trace metal and carbon chemists, phytoplankton physiologists, microbial and zooplankton ecologists, and physical oceanographers, that will investigate why and how the Amundsen Sea Polynya is so much more productive than other polynyas and whether interannual variability can provide insight to climate-sensitive mechanisms driving carbon fluxes. This project will compliment the existing ASPIRE effort by using 1) experimental manipulations to understand photoacclimation of the dominant phytoplankton taxa under conditions of varying light and trace metal abundance, 2) nutrient addition bioassays to determine the importance of trace metal versus nitrogen limitation of phytoplankton growth, and 3) a numerical ecosystem model to understand the importance of differences in mixing regime, flow field, and Fe sources in controlling phytoplankton bloom dynamics and community composition in this unusually productive polynya system. The research strategy will integrate satellite remote sensing, field-based experimental manipulations, and numerical modeling. Outreach and education include participation in Stanford's Summer Program for Professional Development for Science Teachers, Stanford's School of Earth Sciences high school internship program, and development of curriculum for local science training centers, including the Chabot Space and Science Center. Undergraduate participation and training will include support for both graduate students and undergraduate assistants.
This award supports a project to understand the flow dynamics of large, fast-moving outlet glaciers that drain the East Antarctic Ice Sheet. The project includes an integrated field, remote sensing and modeling study of Byrd Glacier which is a major pathway for the discharge of mass from the East Antarctic Ice Sheet (EAIS) to the ocean. Recent work has shown that the glacier can undergo short-lived but significant changes in flow speed in response to perturbations in its boundary conditions. Because outlet glacier speeds exert a major control on ice sheet mass balance and modulate the ice sheet contribution to sea level rise, it is essential that their sensitivity to a range of dynamic processes is properly understood and incorporated into prognostic ice sheet models. The intellectual merit of the project is that the results from this study will provide critically important information regarding the flow dynamics of large EAIS outlet glaciers. The proposed study is designed to address variations in glacier behavior on timescales of minutes to years. A dense network of global positioning satellite (GPS) instruments on the grounded trunk and floating portions of the glacier will provide continuous, high-resolution time series of horizontal and vertical motions over a 26-month period. These results will be placed in the context of a longer record of remote sensing observations covering a larger spatial extent, and the combined datasets will be used to constrain a numerical model of the glacier's flow dynamics. The broader impacts of the work are that this project will generate results which are likely to be a significant component of next-generation ice sheet models seeking to predict the evolution of the Antarctic Ice Sheet and future rates of sea level rise. The most recent report from the Intergovernmental Panel on Climate Change (IPCC) highlights the imperfect understanding of outlet glacier dynamics as a major obstacle to the production of an accurate sea level rise projections. This project will provide significant research opportunities for several early-career scientists, including the lead PI for this proposal (she is both a new investigator and a junior faculty member at a large research university) and two PhD-level graduate students. The students will be trained in glaciology, geodesy and numerical modeling, contributing to society's need for experts in those fields. In addition, this project will strengthen international collaboration between polar scientists and geodesists in the US and Spain. The research team will work closely with science educators in the Center for Remote Sensing of Ice Sheets (CReSIS) outreach program to disseminate project results to non-specialist audiences.
This award supports a project to generate an absolute timescale for the Allan Hills Blue Ice Area (BIA), and then to reconstruct details of past climate changes and greenhouse gas concentrations for certain time periods back to 2.5 Ma. Ice ages will be determined by applying emerging methods for absolute and relative dating of trapped air bubbles (based on Argon-40/Argon-38, delta-18O of O2, and the O2/N2 ratio). To demonstrate the potential of the Allan Hills BIAs as a paleoclimate archive trenches and ice cores will be collected for age intervals corresponding to 110-140 ka, 1 Ma, and 2.5 Ma. During the proposed two field seasons a total of 6x100 m and additional 15 m cores will be combined with trenching. The intellectual merit of the proposed activity is that the results of this work will extend the landmark work of EPICA and other deep ice coring efforts, which give records dating back to 0.8 Ma, and will complement work planned by IPICS to drill a continuous Antarctic ice core extending to 1.5 Ma. The results will help to advance understanding of major climate regimes and transitions that took place between 0-2.5 Ma, including the 40 kyr world and the mid-Pleistocene climate transition. A major long-term scientific goal is to provide a transformative approach to the collection of paleoclimate records by establishing an "International Climate Park" in the Allan Hills BIA that would enable sampling of large quantities of known age ice as old as 2.5 Ma, by any interested American or foreign investigator. The broader impacts resulting from the proposed activity include training students who are well versed in advanced field, laboratory and numerical modeling methods combining geochemistry, glaciology, and paleoclimatology. We will include material relevant to our proposed research in our ongoing efforts in local education and in our outreach efforts for media. The University of Maine already has cyberinfrastructure, using state of the art web-based technology, which can provide a wide community of scientists with fast access to the results of our research. The work will contribute to the broad array of climate change studies that is informing worldwide understanding of natural and anthropogenic forced climate change, and the options for responding. This award has field work in Antarctica.
This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
Intellectual Merit: <br/>The northern Ford ranges in Marie Byrd Land, Antarctica, record events and processes that transformed a voluminous succession of Lower Paleozoic turbidites intruded by calc-alkaline plutonic rocks into differentiated continental crust along the margin of Gondwana. In this study the Fosdick migmatite?granite complex will be used to investigate crustal evolution through an integrated program of fieldwork, structural geology, petrology, mineral equilibria modeling, geochronology and geochemistry. The PIs propose detailed traverses at four sites within the complex to investigate Paleozoic and Mesozoic orogenic cycles. They will use petrological associations, structural geometry, and microstructures of host gneisses and leucogranites to distinguish the migration and coalescence patterns for remnant melt flow networks, and carry out detailed sampling for geochronology, geochemistry and isotope research. Mafic plutonic phases will be sampled to acquire information about mantle contributions at the source. Mineral equilibria modeling of source rocks and granite products, combined with in situ mineral dating, will be employed to resolve the P?T?t trajectories arising from thickening/thinning of crust during orogenic cycles and to investigate melting and melt loss history. <br/><br/>Broader impacts: <br/>This work involves research and educational initiatives for an early career female scientist, as well as Ph.D. and undergraduate students. Educational programs for high school audiences and undergraduate courses on interdisciplinary Antarctic science will be developed.
Intellectual Merit: This research will place the subsidence history of the southern Victoria Land Basin into a quantitative geodynamic context and will assess the influence of flexure associated with late Neogene volcanic loading of the crust by the Erebus Volcanic Group. This will be done by extending geodynamic models of extension in the West Antarctic Rift System to include extensional hiatuses hypothesized to have occurred during the Late Paleogene and Miocene, and by developing a new geodynamic model of volcanic loading and associated lithosphere flexure. Finite element and finite difference modeling methods will be used. In the first phase of the project, a series of extensional geodynamic models will be developed to examine the effect that proposed extensional hiatuses have on the style of extension, with emphasis placed on developing a process based understanding of the change in rift style from diffuse during the Late Cretaceous to more focused during the Cenozoic. The models will test the hypotheses that extensional hiatuses led to the change in rifting style, and will place constraints on the timing and duration of the hiatuses. The second phase of the project will use the thermal and rheological properties of the previous models to constrain the flexural rigidity of the lithosphere in order to model the flexural response to volcanic loading to test the hypotheses that flexural subsidence contributed to cyclic changes between grounded and floating ice at the ANDRILL AND-1A site, complicating interpretations of the climatic record from this core, and that flexure contributes to the stress orientation at the AND-2B site, which is inconsistent with the expected regional extensional stress orientation. Broader impacts: The project will train an undergraduate student and an M.S. student. Outreach activities include a planned series of talks at regional high schools, junior colleges, and 4-year colleges that have geology programs.
Intellectual Merit: Neogene sediment records recovered by ANDRILL suggest multiple events of open water conditions and elevated sea surface temperatures at times when terrestrial data from the McMurdo Dry Valleys indicate hyper arid, cold, desert conditions. Interpretation of the ANDRILL data suggests the West Antarctic Ice Sheet is highly sensitive to changes in Pliocene sea surface temperatures and this conclusion has been supported by recent Global Circulation Model results for the early to mid Pliocene. The PIs propose to model paleo-ice configurations and warm orbits associated with a WAIS collapse to assess potential climate change in East Antarctica. During such episodes of polar warmth they propose to answer: What is the limit of ablation along the East Antarctic Ice Sheet?; Are relict landforms in the Dry Valleys susceptible to modification from increase in maximum summertime temperatures?; and Is there sufficient increase in minimum wintertime temperatures to sustain a tundra environment in the Dry Valleys? Integration of depositional records and model outputs have the potential to test the performance of numerical models currently under development as part of ANDRILL; reconcile inconsistencies between marine and terrestrial paleoclimate records in high Southern Latitudes; and improve understanding of Antarctic climate and ice volume sensitivity to forcing for both the East Antarctic and West Antarctic Ice Sheets. Broader impacts: Results from this study have the potential to be used widely by the research community. Outreach to local elementary schools from other funded efforts will continue and be extended to homeschooled students. A Post Doc will be supported as part of this award.
The proposed work will investigate changes in the compositional variation of glacial tills over time across two concentric sequences of Pleistocene moraines located adjacent to the heads of East Antarctic outlet glaciers in the Transantarctic Mountains (TAM). The chronologic framework for this work will be generated from cosmogenic exposure ages of boulders on prominent morainal ridges. The PIs hypothesize that variations in till composition may indicate a change in ice flow direction or a change in the composition of the original source area, while ages of the moraines provide a long-term terrestrial perspective on ice sheet dynamics. Both results are vital for modeling experiments that aim to reconstruct the East Antarctic Ice Sheet and assess its role in the global climate system and its potential impact on global sea level rise. The variation of till compositions through time also allows for a more accurate interpretation of sediment cores from the Ross Sea and the Southern Ocean. Additionally, till exposures at the head of some East Antarctic outlet glaciers have been shown to contain subglacial material derived from East Antarctic bedrock, providing a window through the ice to view East Antarctica?s inaccessible bedrock. Till samples will be collected from two well-preserved sequences of moraine crests at Mt. Howe (head of Scott Glacier) and Mt. Achernar (between Beardmore and Nimrod Glaciers). Each size fraction in glacial till provides potentially valuable information, and the PIs will measure the petrography of the clast and sand fractions, quantitative X-ray diffraction on the crushed <2mm fraction, elemental abundance of the silt/clay fraction, and U/Pb of detrital zircons in the sand fraction. Data collection will rely on established methods previously used in this region and the PIs will also explore new methods to assess their efficacy. On the same moraines crests sampled for provenance studies, the PIs will sample for cosmogenic surface exposure analyses to provide a chronologic framework at the sites for provenance changes through time. <br/><br/>Broader Impact <br/>The proposed research involves graduate and undergraduate training in a diverse array of laboratory methods. Students and PIs will be make presentations to community and campus groups, as well as conduct interviews with local news outlets. The proposed work also establishes a new, potentially long-term, collaboration between scientists at IUPUI and LDEO and brings a new PI (Kaplan) into the field of Antarctic Earth Sciences.
Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.
MacAyeal/0944248<br/><br/>This award supports a project to develop a better understanding of the processes and conditions that trigger ice shelf instability and explosive disintegration. A significant product of the proposed research will be the establishment of parameterizations of micro- and meso-scale ice-shelf surface processes needed in large scale ice-sheet models designed to predict future sea level rise. The proposed research represents a 3-year effort to conduct numerical model studies of 6 aspects of surface-water evolution on Antarctic ice shelves. These 6 model-study areas include energy balance models of melting ice-shelf surfaces, with treatment of surface ponds and water-filled crevasses, distributed, Darcian water flow modeling to simulate initial firn melting, brine infiltration, pond drainage and crevasse filling, ice-shelf surface topography evolution modeling by phase change (surface melting and freezing), surface-runoff driven erosion and seepage flows, mass loading and flexure effects of ice-shelf and iceberg surfaces; feedbacks between surface-water loads and flexure stresses; possible seiche phenomena of the surface water, ice and underlying ocean that constitute a mechanism for, inducing surface crevassing., surface pond and crevasse convection, and basal crevasse thermohaline convection (as a phenomena related to area 5 above). The broader impacts of the proposed work bears on the socio-environmental concerns of climate change and sea-level rise, and will contribute to the important goal of advising public policy. The project will form the basis of a dissertation project of a graduate student whose training will contribute to the scientific workforce of the nation and the PI and graduate student will additionally participate in a summer science-enrichment program for high-school teachers organized by colleagues at the University of Chicago.
Abstract<br/>This award supports a seismological study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project will perform a passive seismic experiment deploying twenty-three seismic stations over the GSM to characterize the structure of the crust and upper mantle, and determine the processes driving uplift. The outcomes will also offer constraints on the terrestrial heat flux, a key variable in modeling ice sheet formation and behavior. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. <br/>Because of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this seismic experiment, NSF is also supporting an aerogeophysical survey of the GSM under award number 0632292. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach.
Abstract Antarctic notothenioid fishes have evolved in the Southern Ocean for 10-14 MY under an unusual set of circumstances. Their characteristics include the complete absence of the circulating oxygen-binding protein, hemoglobin (Hb) within the Channichthyid (Icefish) family of notothenioids. Moreover, some species within the 16 members of this family have also lost the ability to express the oxygen-binding and storage protein, myoglobin (Mb) in cardiac muscle. Our previous work has determined that the loss of Hb and/or Mb is correlated with significant increases in densities of mitochondria within oxidative tissues, and extensive remodeling of these vital organelles. To date, nothing is known about how modifications in mitochondrial architecture of icefishes affect organelle function, or more importantly, how they affect organismal-level physiology. Most critical for Antarctic fishes is that mitochondrial characteristics have been linked to how well ectotherms can withstand increases in temperature. This collaborative research project will address the hypothesis that the unusual mitochondrial architecture of Antarctic Channichthyids has led to changes in function that impact their ability to withstand elevations in temperature. Specifically, the research will (1) determine if the unusual mitochondrial architecture of icefishes affects function and contributes to organismal thermal sensitivity, (2) identify differences in organismal thermal tolerance between red- and white- blooded notothenioids, (3) identify molecular mechanisms regulating changes in mitochondrial structure in icefishes. The results may establish channichthyid icefishes as a sentinel taxon for signaling the impact of global warming on the Southern Ocean. Broad impacts of this project will be realized by participation of high school biology teachers in field work through cooperation with the ARMADA project at the University of Rhode Island, as well as graduate education.
The ocean plays a critical role in sequestering CO2 by exporting fixed carbon to the deep ocean through the biological pump. There is a pressing need to understand the systematics of carbon export in the Southern Ocean in the context of global warming because of the sensitivity of this region to climate change, already manifested as significant temperature increases. Numerous studies have indicated that Fe supply is a primary control on phytoplankton biomass and productivity in the Southern Ocean. The results from previous cruises in Feb-Mar 2004 and Jul-Aug 2006 have revealed the major natural Fe fertilization from Fe-rich shelf waters to the Fe-limited high nutrient low chlorophyll (HNLC) Antarctic Circumpolar Current Surface Water (ASW) in the southern Drake Passage, producing a series of phytoplankton blooms. Remaining questions include: How is natural Fe transported to the euphotic zone through small-meso-large scale horizontal-vertical transport and mixing in different HNLC ACC areas? How does plankton community structure evolve in response to a natural Fe addition, how does Fe speciation respond to biogeochemical processes, and how is Fe recycled to determine the longevity of phytoplankton blooms? How does the export of POC evolve as a function of upwelling-mixing, Fe addition-recycling and bacteria-plankton structure? This synthesis proposal will address these fundamental questions using a unique dataset combining multiyear physical, Fe and biogeochemical data collected between 2004 and 2006 from 2 NSF-funded Fe fertilization experiment cruises and 3 Antarctic Marine Living Resource (AMLR) cruises in the southern Drake Passage and southwestern Scotia Sea through collaboration with scientists in the AMLR program and US Southern Ocean GLOBEC projects. All investigators involved in this study are engaged in graduate and undergraduate instruction, and mentoring of postdoctoral researchers. Each P.I. will incorporate key elements of the proposed syntheses in our lectures, problem sets and group projects. The project includes support to convene a 4-5 day international workshop on natural Fe fertilization at Woods Hole Oceanographic Institution. The workshop will include scientists from United Kingdom, France and Germany who have conducted natural Fe fertilization experiments, and Korea and China who are planning to conduct natural Fe fertilization experiments. The participation of graduate students and postdoctoral scholars will be especially encouraged. The results will be published in a Deep-Sea Research II special issue.
Despite being an essential physiological component of homeotherm life in polar regions, little is known about the energetic requirements for thermoregulation in either air or water for high- latitude seals. In a joint field and modeling study, the principal investigators will quantify these costs for the Weddell seal under both ambient air and water conditions. The field research will include innovative heat flux, digestive and locomotor cost telemetry on 40 free-ranging seals combined with assessments of animal health (morphometrics, hematology and clinical chemistry panels), quantity (ultrasound) and quality (tissue biopsy) of blubber insulation, and determination of surface skin temperature patterns (infrared thermography). Field-collected data will be combined with an established individual based computational energetics model to define cost-added thresholds in body condition for different body masses. This study will fill a major knowledge gap by providing data essential to modeling all aspects of pinniped life history, in particular for ice seals. Such parameterization of energetic cost components will be essential for the accurate modeling of responses by pinnipeds to environmental variance, including direct and indirect effects driven by climate change. The study also will provide extensive opportunities in polar field work, animal telemetry, biochemical analyses and computational modeling for up to three undergraduate students and one post-doctoral researcher. Integrated education and outreach efforts will educate the public (K-12 through adult) on the importance of quantifying energetic costs of thermoregulation for marine mammals and the need to understand responses of species to environmental variance. This effort will include a custom-built, interactive hands-on mobile exhibit, and development of content for an Ocean Today kiosk.
Sergienko/0838811 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to conduct a modeling study of the ice stream ? sub-glacial water system. A suite of numerical models of various dimensionality and complexity will be constructed in a sequential, hierarchical fashion to formulate and test hypotheses regarding how sub-glacial lakes form under ice streams, determine the effect of sub-glacial lakes on ice-stream flow and mass balance, and to determine feedback effects whereby the ice stream ? sub-glacial water system can elicit both stable and unstable responses to environmental perturbations. This research will address one of the only observationally verified fast-time-scale processes apparent within the Antarctic Ice Stream system. The intellectual merit of the project is that understanding the origins and consequences of near-grounding-line sub-glacial lakes is a priority in glaciological research designed to predict short-term variations in Antarctica?s near-term future mass balance. The broader impacts of the proposed work are that it will contribute to better understanding of a system that has important societal relevance through contribution to sea level rise. Participation of a graduate student in the project will provide the student?s training and education in application of the numerical modeling in geosciences.
The climatic changes of late Precambrian time, 600-800 million years ago, included episodes of extreme glaciation, during which ice may have covered nearly the entire ocean for several million years, according to the Snowball Earth hypothesis. These episodes would hold an important place in Earth?s evolutionary history; they could have encouraged biodiversity by trapping life forms in small isolated ice-free areas, or they could have caused massive extinctions that cleared the path for new life forms to fill empty niches. What caused the Earth to become iced over, and what later caused the ice to melt? Scientific investigation of these questions will result in greater understanding of the climatic changes that the Earth can experience, and will enable better predictions of future climate. This project involves Antarctic field observations as well as laboratory studies and computer modeling. The aim of this project is not to prove or disprove the Snowball Earth hypothesis but rather to quantify processes that are important for simulating snowball events in climate models. The principal goal is to identify the types of ice that would have been present on the frozen ocean, and to determine how much sunlight they would reflect back to space. Reflection of sunlight by bright surfaces of snow and ice is what would maintain the cold climate at low latitudes. The melting of the ocean required buildup of greenhouse gases, but it was probably aided by deposition of desert dust and volcanic ash darkening the snow and ice. With so much ice on the Earth?s surface, even small differences in the amount of light that the ice absorbed or reflected could cause significant changes in climate. The properties of the ice would also determine where, and in what circumstances, photosynthetic life could have survived. Some kinds of ice that are rare on the modern Earth may have been pivotal in allowing the tropical ocean to freeze. The ocean surfaces would have included some ice types that now exist only in Antarctica: bare cold sea ice with precipitated salts, and "blue ice" areas of the Transantarctic Mountains that were exposed by sublimation and have not experienced melting. Field expeditions were mounted to examine these ice types, and the data analysis is underway. A third ice type, sea ice with a salt crust, is being studied in a freezer laboratory. Modeling will show how sunlight would interact with ice containing light-absorbing dust and volcanic ash. Aside from its reflection of sunlight, ice on the Snowball ocean would have been thick enough to flow under its own weight, invading all parts of the ocean. Yet evidence for the survival of photosynthetic life indicates that some regions of liquid water were maintained at the ocean surface. One possible refuge for photosynthetic organisms is a bay at the far end of a nearly enclosed tropical sea, formed by continental rifting and surrounded by desert, such as the modern Red Sea. A model of glacier flow is being developed to determine the dimensions of the channel, connecting the sea to the ocean, necessary to prevent invasion by the flowing ice yet maintain a water supply to replenish evaporation.
Hulbe/0838810 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a modeling study of the processes in West Antarctic grounding zones, the transition from ice resting on bedrock to ice floating on the ocean surface with an eye toward understanding the interrelated causes of rapid change in grounding line configuration and outlet flow. A combination of satellite remote sensing and numerical modeling will be used to investigate both past and ongoing patterns of change. New high-resolution surface elevation maps made from a novel combination of satellite laser altimetry and remotely observed surface shape provide a unique view of grounding zones. These data will be used to diagnose events associated with the shutdown of Kamb Ice Stream, to investigate a recent discharge event on Institute Ice Stream and to investigate ongoing change at the outlet of Whillans Ice Stream, along with other modern processes around the West Antarctic. An existing numerical model of coupled ice sheet, ice stream, and ice shelf flow will be used and improved as part of the research project. The broader impacts of the project relate to the importance of understanding the role of polar ice sheets in global sea level rise. The work will contribute to the next round of deliberations for the Intergovernmental Panel on Climate Change (IPCC). Improved views, interpretations, and insights into the physical processes that govern variability in ice sheet outlet streams will help correct the shortcomings of the last IPCC report that didn?t include the role of ice sheets in sea level rise. The PIs have a strong record of public outreach, involvement in the professional community, and student training.
Since 1990, Palmer LTER (PAL) research has been guided by the hypothesis that variability in the polar marine ecosystem is mechanistically coupled to changes in the annual advance, retreat and spatial extent of sea ice. Since that time, the hypothesis has been modified to incorporate climate migration, i.e. the displacement of a cold, dry polar climate by a warm, moist climate regime in the northern component of the PAL region, producing fundamental changes in food web structure and elemental cycling. The observed northern changes are affecting all trophic levels and elemental cycling, and the primary mechanism of change involves match-mismatch dynamics. The proposed research builds on previous findings, with a new emphasis on process studies and modeling to elucidate the mechanistic links between teleconnections, climate change, physical oceanographic forcing and ecosystem dynamics. The proposed research will examine the hypothesis that regional warming and sea ice decline associated with historical and on-going climate migration in the northern part of the study area have altered key phenological relationships, leading to changes in species distributions, increasing trophic mismatches and changes in habitat, food availability, ecosystem dynamics and biogeochemical cycling. Through targeted process studies linked to numerical model simulations, the research also will test the hypothesis that deep cross-shelf canyons characterizing the core study region are focal areas for ecosystem processes that result in predictable, elevated food resources for top-predators. The effort includes the addition of 3 new PIs: a zooplankton ecologist with expertise in biogeochemical fluxes, a phytoplankton ecologist focusing on bio-optics and autonomous observations using gliders, and a numerical simulation modeler specializing in coupled global models of ocean circulation, plankton ecology and biogeochemical cycles. The program will add trace metal sampling and analysis, moored physical oceanographic sensors, a moored sediment trap in the south, drifting sediment traps and stable carbon (del 13C) and nitrogen (del 15N) isotope analyses. Missions lasting up to 45 days using gliders deployed before, during and after summer cruises will, along with moorings and satellite remote sensing of sea ice, ocean color, sea surface temperatures and wind fields, greatly extend the observational program in space and time. <br/><br/>Since its inception, PAL has been a leader in Information Management to enable knowledge-building within and beyond the Antarctic, oceanographic and LTER communities. PAL has designed and deployed a new information infrastructure with a relational database architecture to facilitate data distribution and sharing. The Education and Outreach program capitalizes on the public's fascination with Antarctica to promote scientific literacy from kindergarten students to adult citizens concerned with climate change and environmental sustainability. Through communicating results to the public and working with scientific assessment bodies (e.g., IPCC) and Antarctic Treaty parties to protect Earth's last frontier, PAL researchers contribute to the national scientific agenda and the greater public benefit.
Bell/0636883<br/><br/>This award support a project to study the role that subglacial water plays in the overall stability of major ice sheets. An estimated 22,000 km3 of water is currently stored within Antarctica's subglacial lakes. Movement of this water occurs through a complex and largely inferred drainage system in both East and West Antarctica. Geomorphic evidence for the catastrophic drainage of subglacial lakes documents repeated events. These major flood events appear to have drained the largest subglacial lakes situated in the relatively stable interior of the East Antarctic ice sheet. Emerging evidence suggests there is a close connection between significant subglacial lakes and the onset of the Recovery Ice Stream one of the largest in East Antarctica. Our preliminary analysis of the Recovery Lakes region, East Antarctica suggests a direct linkage between lakes and streaming ice flow, specifically the 800 km long Recovery Ice Stream and its tributaries. Located just upslope of the Recovery Ice Stream, the Recovery Lakes Region is composed of 3 well-defined lakes and a fourth, ambiguous, 'lake-like' feature. While other large lakes have a localized impact on ice surface slope, the Recovery Lakes Region lakes are coincident with an abrupt regional change in the ice sheet surface slope. Satellite imagery demonstrates that the downslope margin of this lake area contains distinct flow strips and crevasses: both indicative of increasing ice velocities. The discovery of a series of large lakes coincident with the onset of rapid ice flow in East Antarctica clearly links subglacial lakes and ice sheet dynamics for the first time. The evidence linking the onset of streaming in the Recovery Drainage Ice Stream to the series of large subglacial lakes raises the fundamental question: How can subglacial lakes trigger the onset of ice streaming? We advance two possible mechanisms: (i) Subglacial lakes can produce accelerated ice flow through the drainage of lake water beneath the ice sheet downslope of the lakes. (ii) Subglacial lakes can produce accelerated ice flow accelerated ice flow by modifying the basal thermal gradient via basal accretion over the lakes so when the ice sheet regrounds basal melting dominates. To evaluate the contribution of lake water and the changing basal thermal gradient, we propose an integrated program incorporating satellite imagery analysis, a series of reconnaissance aerogeophysical profiles over the Recovery Lake Region and the installation of continuous GPS sites over the Recovery Lakes. This analysis and new data will enable us (1) to produce a velocity field over the Recovery Lakes Region, (2) to map the ice thickness changes over the lakes due to acceleration triggered thinning, basal melting and freezing, (3) determine the depth and possible the tectonic origin of the Recovery Lakes and (4) determine the stability of these lakes over time. These basic data sets will enable us to advance our understanding of how subglacial lakes trigger the onset of streaming. The intellectual merit of this project is that it will be the first systematic analysis of ice streams triggering the onset of ice streams. This work has profound implications for the modeling of ice sheet behavior in the future, the geologic record of abrupt climate changes and the longevity of subglacial lakes. The broader impacts of the project are programs that will reach students of all ages through undergraduates involved in the research, formal presentations in teacher education programs and ongoing public outreach efforts at major science museums. Subglacial Antarctic lake environments are emerging as a premier, major frontier for exploration during the IPY 2007-2009.
This project studies formation of the TransAntarctic Mountains (TAM) through numerical modeling based on cooling histories of apatite mineral grains. The TAM are the highest and longest rift-related mountain range in the world. Various models for their uplift have been proposed, the most provocative of which is that they are not uplifted, but instead are the eroded remnant of a plateau. This project evaluates that hypothesis by collecting apatites from around Byrd Glacier for fission track thermochronology. Results will be combined with a kinematic and thermal model to determine the TAM?s structural evolution. The plateau model, if correct, implies that the Byrd Glacier originated not as a glacier-carved valley through the TAM, but as a river system flowing in the opposite direction. Given that the Byrd Glacier is a key drainage for the East Antarctic ice sheet, this result has important implications for ice sheet models and interpretation of both regional geology and sediment records.<br/><br/>The main broader impacts are undergraduate research and a new collaboration between a primarily undergraduate and a research institution. Students will be involved in the field program, sample analyses, and numerical modeling.
This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this "pulse of activity" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.
0538674<br/>Matsuoka<br/>This award supports a project to evaluate radio-echo intensities in the available SOAR ice-penetrating radar data along grids covering Lake Vostok, and along four regional tracks from Ridge B toward the lake. The project has two objectives; first, it will examine the upper surface of the lake and reflectors hypothesized to be a boundary between the meteoric and accreted ice. They will provide crucial knowledge on the dynamic evolution of the lake. Second, this project will examine a poorly understood echo-free zone within the deep ice in central East Antarctica. This zone may consist of distorted stagnant ice, while its upper boundary may be a shear zone. The SOAR radar data provide a unique resource to examine spatiotemporal water circulation patterns that should be understood in order to select the best direct-sampling strategy to the lake. The Vostok ice core provides a unique opportunity to do this work. First, the path effects, i.e. propagation loss and birefringence, will be derived at the ice-core site using ice temperature, chemistry, and fabric data. Second, lateral variations of the propagation loss will be estimated by tracking chemistry associated with radar-detected isochronous layers, and by inferring temperatures from an ice-flow model that can replicate those layers. Ice-fabric patterns will be inferred from anisotropy in the reflectivity at about 100 radar-track cross-over sites. In terms of broader impacts, a graduate student will be trained to interpret the radar data in the light of radar theory and glaciological context of Lake Vostok and summer workshops for K-12 teachers will be provided in Seattle and New York. This project will contribute to ongoing efforts to study Lake Vostok and will complement the site selection for a North Vostok ice core, which has been proposed by Russia and France as an IPY program.
Studinger/0636584<br/><br/>This award supports a project to estimate the salinity of subglacial Lake Vostok, Lake Concordia and the 90 deg.E lake using existing airborne ice-penetrating radar and laser altimeter data. These lakes have been selected because of the availability of modern aerogeophysical data and because they are large enough for the floating ice to be unaffected by boundary stresses near the grounding lines. The proposed approach is based on the assumption that the ice sheet above large subglacial lakes is in hydrostatic equilibrium and the density and subsequently salinity of the lake's water can be estimated from the (linear) relationship between ice surface elevation and ice thickness of the floating ice. The goal of the proposed work is to estimate the salinity of Lake Vostok and determine spatial changes and to compare the salinity estimates of 3 large subglacial lakes in East Antarctica. The intellectual merits of the project are that this work will contribute to the knowledge of the physical and chemical processes operating within subglacial lake environments. Due to the inaccessibility of subglacial lakes numerical modeling of the water circulation is currently the only way forward to develop a conceptual understanding of the circulation and melting and freezing regimes in subglacial lakes. Numerical experiments show that the salinity of the lake's water is a crucial input parameter for the 3-D fluid dynamic models. Improved numerical models will contribute to our knowledge of water circulation in subglacial lakes, its effects on water and heat budgets, stratification, melting and freezing, and the conditions that support life in such extreme environments. The broader impacts of the project are that subglacial lakes have captured the interest of many people, scientists and laymen. The national and international press frequently reports about the research of the Principal Investigator. His Lake Vostok illustrations have been used in math and earth science text books. Lake Vostok will be used for education and outreach in the Earth2Class project. Earth2Class is a highly successful science/math/technology learning resource for K-12 students, teachers, and administrators in the New York metropolitan area. Earth2Class is created through collaboration by research scientists at the Lamont- Doherty Earth Observatory; curriculum and educational technology specialists from Teachers College, Columbia University; and classroom teachers in the New York metropolitan area.
Joughin 0631973<br/><br/>This award supports a project to gather data to better understand the mass balance of the West Antarctic Ice Sheet, in the Pine Island and Thwaites region, through the combination of radar altimetry and surface-based ice-core measurements of accumulation. The intellectual merit of the project is that the results of the field work will provide information on decadal-scale average accumulation extending back through the last century and will help constrain a modeling effort to determine how coastal changes propagate inland, to allow better prediction of future change. Comparison of the basin averaged accumulation with ice discharge determined using Interferometric Synthetic Aperture Radar (InSAR) velocity data will provide improved mass-balance estimates. Study of changes in flow speed will produce a record of mass balance over the last three decades. Analysis of the satellite altimeter record in conjunction with annual accumulation estimates also will provide estimates of changes and variability in mass balance. The broader impacts of the work are that it will make a significant contribution to future IPCC estimates of sea level, which are important for projection of the impacts of increased sea level on coastal communities. The research will contribute to the graduate education of students at the Universities of Washington and Kansas and will enrich K-12 education through the direct participation of the PIs in classroom activities. Informal science education includes 4-day glacier flow demonstrations at the Polar Science Weekend held annually at the Pacific Science Center in Seattle. The project also will communicate results through Center for the Remote Sensing of Ice Sheets (CReSIS) outreach effort. All field and remotely-sensed data sets will be archived and distributed by the National Snow and Ice Data Center. This project is relevant to IPY in that the West Antarctic Ice Sheet is losing mass, in large part because of rapid thinning of the Amundsen Coast glaciers so, it will directly address the NSF IPY emphasis on "ice sheet history and dynamics." The project is also international in scope.
This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program's emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: "investigation of the physics of fast glacier flow with emphasis on processes at glacier beds"; "investigation of ice-shelf stability"; and "identification and quantification of the feedback between ice dynamics and climate change". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.
This award supports a three-year modeling effort to understand the dynamics surrounding ice-air surface slope reversals on ice streams and ice shelves, with implications for the creation and stability of subglacial lakes. Local reversal of the ice-air surface slope may lead, through a reversal of the hydraulic gradient, to the trapping of basal and surface water, producing subglacial and supraglacial lakes, respectively. In the case of subglacial lakes, once such a sizable reservoir of pressurized water is created the potential exists for drainage, in the form of large outburst floods or as smaller, but sustained, periods of increased subglacial water flow. The research seeks to extend some initial work that has been done to include time-dependence and a wider array of parameters and geometries. The methods will involve the use of a suite of models, all of which will include longitudinal deviatoric and basal-shear stresses, with some also taking account of lateral drag and internal vertical shear. The intellectual merit of the proposed activity includes an improved understanding of the processes and parameters involved in the formation of surface-slope reversals in ice-stream/ice-shelf systems, as well as insight into the stability of subglacial lakes formed as a consequence of slope reversals. The broader impacts resulting from this activity include the provision of tools to study the dynamics of ice-stream/ice-shelf systems, an improved understanding of the physics behind outburst floods, and insights into the coupling of ice streams with their subglacial water systems. The research will support the studies of a beginning postdoctoral researcher. Results of the research will be incorporated into courses and public outreach serving anywhere from hundreds to thousands of people per year.
Pettit/0636795<br/><br/>This award supports a project to constrain the accumulation rate, thickness, and temperature history for Siple Dome using a vertical velocity profile that includes the effects of an evolving fabric on deformation through time, to invert the depth-profile of fabric determined from sonic velocity measurements and grain size observed in thin sections in Siple Dome for the surface temperature and accumulation rate changes in the past, focusing on the apparent abrupt climate change events at 22ka and 15ka. The intellectual merit of the work is that it will extract past climate information from a number of physical properties of the deep ice using a coupled fabric evolution and ice-sheet flow model. The focus will be on the deep ice-age ice at Siple Dome, where the ice-core record shows puzzling signals and where modeling results imply intriguing deformation patterns. The method will also be applied to the records from Byrd Station and Taylor Dome to ultimately form a basis for future analysis of the West Antarctic Divide core. The broader impacts of the project are that it will ultimately contribute to our understanding of the effects of anisotropy on ice flow dynamics in West Antarctica. It will contribute to our understanding of the connection between ice flow and the paleoclimate record in ice cores, particularly with respect to the relationship between the chemical record and ice deformation. And it will contribute a new ice-flow model that includes the effects of anisotropy and fabric evolution. The project will also contribute to advancing the career of a new, young, female investigator and will support a couple of graduate students. Finally, the work will encouraging diversity in the physical sciences by directly helping to support the Girls on Ice a program that encourages young women to explore science and the natural world.
Abstract<br/><br/><br/>By using a tool-box of particle flux and characterization techniques appropriate to the study of particulate organic carbon fluxes out of the upper sunlit zone, WHOI researchers will attempt to evaluate the so called 'biological pump' term at the Palmer Long Term Ecological Research (PAL) site in the Western Antarctic Peninsula (WAP). The goal of these measurements is to describe the seasonal dynamics of production, export (sinking) and at-depth remineralization rates of organic matter produced in the Antarctic photic zone. This should lead to a better understanding of the biogeochemical controls on the carbon cycle in this difficult to access region. Additionally, how much of the newly fixed organic carbon is exported off the shelf, effectively driving an influx of atmospheric (including anthropogenic) CO2 to be sequestered into the deep ocean is not presently known. Comparison of prior time series sediment traps in the WAP seem to indicate smaller sinking C fluxes than other, as equally as productive Antarctic coastal regions, e.g. the Ross Sea. New observations and modeling activities will attempt to explain this discrepancy, and to account for the apparently inefficient particle export. <br/><br/><br/>"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."
This award supports a project to investigate fabrics with ground-based radar measurements near the Ross/Amundsen Sea ice-flow divide where a deep ice core will be drilled. The alignment of crystals in ice (crystal-orientation fabric) has an important effect on ice deformation. As ice deforms, anisotropic fabrics are produced, which, in turn, influence further deformation. Measurement of ice fabric variations can help reveal the deformation history of the ice and indicate how the ice will deform in the future. Ice cores provide opportunities to determine a vertical fabric profile, but horizontal variations of fabrics remain unknown. Remote sensing with ice-penetrating radar is the only way to do that over large areas. Preliminary results show that well-established polarimetric methods can detect the degree of horizontal anisotropy of fabrics and their orientation, even when they are nearly vertical-symmetric fabrics. In conjunction with ice deformation history, our first mapping of ice fabrics will contribute to modeling ice flow near the future ice core site. The project will train a graduate student and provide research experiences for two under graduate students both in field and laboratory. The project will contribute to ongoing West Antarctic ice sheet program efforts to better understand the impact of the ice sheet on global sea level rise. This project also supports an international collaboration between US and Japanese scientists.
Tulaczyk/0636970<br/><br/>This award supports a project to study elevation change anomalies (henceforth ECAs), which are oval-shaped, 5-to-10 km areas observed in remote sensing images in several locations within the Ross Sea sector of the West Antarctic Ice Sheet (WAIS). Within these anomalies, surface elevation changes at rates of up to ~1 to ~2 cm per day, significantly faster than in surrounding regions. These anomalies are thought to result from filling and draining of multi-kilometer-scale subglacial water pockets. The intellectual merit of this project is that these ECA's represent an unprecedented window into the elusive world of water drainage dynamics beneath the modern Antarctic ice sheet. Although subglacial water fluxes are small compared to normal terrestrial conditions, they play an important role in controlling fast ice streaming and, potentially, stability of the ice sheet. The dearth of observational constraints on sub-ice sheet water dynamics represents one of the most important limitations on progress in quantitative modeling of ice streams and ice sheets. Such models are necessary to assess future ice sheet mass balance and to reconstruct the response of ice sheets to past climate changes. The dynamic sub-ice sheet water transport indicated by the ECAs may have also implications for studies of subglacial lakes and other subglacial environments, which may harbor life adapted to such extreme conditions. The broader impacts of this project are that it will provide advanced training opportunities to one postdoctoral fellow (UW), two female doctoral students (UCSC), who will enhance diversity in polar sciences, and at least three undergraduate students (UCSC). Project output will be relevant to broad scientific and societal interests, such as the future global sea level changes and the response of Polar Regions to climate changes. Douglas Fox, a freelance science journalist, is interested in joining the first field season to write feature articles to popular science magazines and promote the exposure of this project, and Antarctic Science in general, to mass media.
This award supports a project to understand how recent changes in atmospheric chemistry, and historical changes as recorded in snow, firn and ice, have affected atmospheric photochemistry over Antarctica. Atmospheric, snow and firn core measurements of selected gas, meteorological and snow physical properties will be made and modeling of snow-atmosphere exchange will be carried out. The intellectual merit of the project is that it will lead to a better an understanding of the atmospheric chemistry in West Antarctica, its bi-directional linkages with the snowpack, and how it responds to regional influences. There are at least four broader impacts of this work. First is education of university students at both the graduate and undergraduate levels. One postdoctoral researcher and one graduate student will carry out much of the work, and a number of undergraduates will be involved. Second, involvement with the WAIS-Divide coring program will be used to help recruit under-represented groups as UC Merced students. As part of UC Merced's outreach efforts in the San Joaquin Valley, whose students are under-represented in the UC system, the PI and co-PI give short research talks to groups of prospective students, community college and high school educators and other groups. They will develop one such talk highlighting this project. Including high-profile research in these recruiting talks has proven to be an effective way to promote dialog, and interest students in UC Merced. Third, talks such as this also contribute to the scientific literacy of the general public. The PI and grad student will all seek opportunities to share project information with K-14 and community audiences. Fourth, results of the research will be disseminated broadly to the scientific community, and the researchers will seek additional applications for the transfer functions as tools to improve interpretation of ice-cores. This research is highly collaborative, and leverages the expertise and data from a number of other groups.
This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbræ. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.<br/><br/>The intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. <br/><br/>As lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.
This collaborative study between the Desert Research Institute, the University of California, Santa Barbara (0529087; Robin Ross), and the University of California, San Diego (0528728; Maria Vernet) will examine the relationship between sea ice extent along the Antarctic Peninsula and the life history of krill (Euphausia superba), by developing, refining, and linking diagnostic datasets and models of phytoplankton decreases in the fall, phytoplankton biomass incorporation into sea ice, sea ice growth dynamics, sea ice algal production and biomass accumulation, and larval krill energetics, condition, and survival. Krill is a key species in the food web of the Southern Ocean ecosystem, and one that is intricately involved with seasonal sea ice dynamics. Results from the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec) field work as well as historical information on sea ice dynamics and krill recruitment suggest a shift in the paradigm that all pack ice is equally good krill habitat.<br/><br/>SO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the lower trophic levels, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>The Amundsen Sea Polynya is areally the most productive Antarctic polynya, exhibits higher chlorophyll levels during peak bloom and greater interannual variability than the better-studied Ross Sea Polynya ecosystem. Polynyas may be the key to understanding the future of polar regions as their extent is expected to increase with anthropogenic warming. The project will examine 1) sources of iron to the Amundsen Sea Polynya as a function of climate forcing, 2) phytoplankton community structure in relation to iron supply and mixed-layer depths, 3) the efficiency of the biological pump of carbon to depth and 4) the net flux of carbon as a function of climate and micronutrient forcing. The research also will compare results for the Amundsen Sea to existing data synthesis and modeling efforts for the Palmer LTER and Ross Sea. The project will 1) build close scientific collaborations between US and Swedish researchers; 2) investigate climate change implications with broad societal relevance; 3) train new researchers; 4) encourage participation in research science by underrepresented groups, and 5) involve broad dissemination of results via scientific literature and public outreach, including close interactions with NSF-supported PolarTrec and COSEE K-12 teachers.
This award supports a project to test whether Kamb Ice Stream (formerly Ice Stream C (ISC)), an ice stream<br/>that is thought to have stopped ~150 years ago, may be already in the process of restarting. If yes, it will help establish what is the rate of ice stream reactivation and what mechanisms are controlling this rate. If there is no evidence for ongoing ice stream reactivation, the physical controls that are preventing it will be examined and alternative scenarios for near-future evolution of this ice stream will be explored. One such scenario is an increase in ice diversion toward the neighboring Whillans Ice Stream. Such diversion may help prevent a complete stoppage of Whillans Ice Stream,which has been slowing down for at least the last 24 years. This project will consist of two components: (1) field observations of bed properties,geometry of internal radar reflectors, as well as surface strain rates and velocity/topography changes using Ice-Penetrating Radar and differential Global Positioning System, (2) numerical modeling study of near future(~100-1000 years) evolution of Kamb Ice Stream. The field component will be focused on the bulge-to-trunk transition, which is located at the present time just downstream of the so-called camp UpC. Reactivation of Kamb Ice Stream should be reflected in a downstream migration of the bulge-trunk transition at possibly high rates (bulge migration rates of ~km/yr occur on surging mountain glaciers). The modeling<br/>component will be used to generate predictions regarding the near-future behavior of Kamb Ice Stream. This project will provide training opportunities for at least two undergraduate students (per year) at St. Olaf College and for one<br/>undergraduate student (per year) at UCSC. This collaboration will bring together scientists from three different types of US institutions: (1) a liberal arts college (St.Olaf College), (2) a public research university (UCSC) and (3) a NASA research laboratory (JPL). The project will also help build a new glaciological research program at UCSC. Project results will be incorporated into undergraduate and graduate courses at UCSC and will be made available<br/>to the general public and educators through downloadable graphics and animations posted on the research website of the UCSC PI. Field data resulting from the project will be posted in the Antarctic Glaciological Data Center for use by other investigators.
Abstract<br/><br/><br/><br/>This project performs a paleomagnetic survey of sediment cores from Antarctica's continental margin. Its goal is to refine the magnetostratigraphy to improve regional stratigraphic correlations, help date cores that lack biostratigraphic indicators, and understand paleoenvironmental conditions and climate change. As well, these cores record the earth's magnetic field near the magnetic pole, which may offer important information to scientists modeling the geodynamo.<br/><br/>The broader impacts of this work include postdoctoral and undergraduate education. There are also implications for society's understanding of global climate change, since these techniques offer a different perspective on climate change from Antarctic marine sediment cores, which are critical to understanding the behavior of the ice sheets and their links to the global climate.
Johnson/0632161<br/><br/>This award supports a project to create a "Community Ice Sheet Model (CISM)". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating "a new generation" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.
The goal of this proposal to bring two groups of undergraduate students to the Antarctic, where they will participate in the collection of data on seabird abundance and behavior. This proposal combines research on the dynamics of seabirds that feed on Antarctic krill, with the teaching of mathematical modeling of foraging behavior and spatial statistics. Students will learn a broad collection of skills through collection of data on physical and biological oceanography as part of the research project that focuses on seabirds. The research goal of this proposal is to learn how foraging seabirds in the Antarctic respond to changes in the abundance and distribution of their prey, primarily Antarctic krill. The approach will be to study bird behavior in the vicinity of krill swarms, and to contrast this behavior to that in areas lacking krill. From these comparisons, foraging models that will make predictions about the dispersion of birds under differing levels of krill abundance will be built. The long-term goal is to be able to make predictions about the impact upon seabirds of future changes in krill stocks. Field work will be conducted in the vicinity of Elephant Island in two field seasons. In each season, the insular shelf north of Elephant Island will be surveyed and the abundance, distribution and behavior of seabirds will be recorded. The primary objective will be to quantify the linkage between prey abundance and bird behavior, with the long-term goal of using information on bird behavior to index long-term changes in the prey base. The teaching goal of this proposal is twofold. First, the project will expose inner city college students to a spectacular and economically important ecosystem. Through their work on an oceanographic research vessel, students will be exposed to a broad diversity of research topics and methods, ranging from behavioral ecology to physical oceanography. Second, back at Staten Island, students will participate in the development of a mathematical biology initiative at the College of Staten Island. Here students will be encouraged to apply basic mathematical reasoning and computer modeling to a real problem - that of determining how foraging choices made by seabirds can ultimately impact their reproductive success.
Salps are planktonic grazers that have a life history, feeding biology and population dynamic strikingly different from krill, copepods or other crustacean zooplankton. Salps can occur in very dense population blooms that cover large areas and have been shown to have major impacts due to the their grazing and the production of fast-sinking fecal pellets. Although commonly acknowledged as a major component of the Southern Ocean zooplankton community, often comparable in biomass and distribution to krill, salps have received relatively little attention. Although extensive sampling has documented the seasonal abundance of salps in the Southern Ocean, there is a paucity of data on important rates that determine population growth and the role of this species in grazing and vertical flux of particulates. This proposed study will include: measurements of respiration and excretion rates for solitary and aggregate salps of all sizes; measurements of ingestion rates, including experiments to determine the size or concentration of particulates that can reduce ingestion; and determination of growth rates of solitaries and aggregates. In addition to the various rate measurements, this study will include quantitative surveys of salp horizontal and vertical distribution to determine their biomass and spatial distribution, and to allow a regional assessment of their effects. Measurements of the physical characteristics of the water column and the quantity and quality of particulate food available for the salps at each location will also be made. Satellite imagery and information on sea-ice cover will be used to test hypotheses about conditions that result in high densities of salps. Results will be used to construct a model of salp population dynamics, and both experimental and modeling results will be interpreted within the context of the physical and nutritional conditions to which the salps are exposed. This integrated approach will provide a good basis for understanding the growth dynamics of salp blooms in the Southern Ocean. Two graduate students will be trained on this project, and cruise and research experience will be provided for two undergraduate students. A portion of a website allowing students to be a virtual participant in the research will be created to strengthen students' quantitative skills. Both PI's will participate in teacher-researcher workshops, and collaboration with a regional aquarium will be developed in support of public education.
The Antarctic is now experiencing large springtime losses of stratospheric ozone, resulting in an increase in ultraviolet B (UVB, 280-320nm) radiation. The magnitude of ultraviolet radiation reaching the surface now approaches that measured in tropical latitudes. Perhaps more importantly, UVB radiation has increased in the Antarctic while both UVA (320-400nm) and photosynthetically available radiation (PAR, 400-700nm) have remained unchanged. Recent improvements in atmospheric modeling and technology in oceanographic instrumentation will be used in a six week field study during the austral spring 1990. The prime objective will be to document the impact of UV radiation on the phytoplankton community during the ice-edge spring bloom. During this time, oceanographic processes create favorable conditions for increased UVB susceptibility. Biological and bio-optical information will be used to define and quantify linkages between ozone-dependent oscillations in UV to PAR ratios and phytoplankton productivity. Special emphasis will be placed on defining biological restraints imposed by enhanced UVB and altered UVB:UVA:PAR ratios on the balance of UVB photodamage to photorepair, photoprotective and photosynthetic mechanisms operating in the Southern Ocean. The overall aim is to test the hypothesis that phytoplankton in Antarctic waters are adversely influenced by ozone depletion.
The U.S. Global Ocean Ecosystems Dynamics (U.S. GLOBEC) program has the goal of understanding and ultimately predicting how populations of marine animal species respond to natural and anthropogenic changes in climate. Research in the Southern Ocean (SO) indicates strong coupling between climatic processes and ecosystem dynamics via the annual formation and destruction of sea ice. The Southern Ocean GLOBEC Program (SO GLOBEC) will investigate the dynamic relationship between physical processes and ecosystem responses through identification of critical parameters that affect the distribution, abundance and population dynamics of target species. The overall goals of the SO GLOBEC program are to elucidate shelf circulation processes and their effect on sea ice formation and krill distribution, and to examine the factors which govern krill survivorship and availability to higher trophic levels, including penguins, seals and whales. The focus of the U.S. contribution to the international SO GLOBEC program will be on winter processes. This component will focus on water-column primary production using direct experimental estimates, modeling restuls from a fast repetition rate fluorometer and modeling of primary production from both optical as well as biophysical models. This research will be coordinated with components focused on sea ice production and sea ice habitat. The result of the integrated SO GLOBEC program will be to improve the predictability of living marine resources, especially with respect to local and global climatic shifts.
This project is a contribution to a coordinated attempt to understand the interactions of biological and physical dynamics by developing mechanistic links between the evolution of the antarctic winter ice and snow cover, and biological habitat variability, through modeling the optical properties of the environment. The work will be carried out in the context of the Southern Ocean Experiment of the Global Ocean Ecosystem Dynamics Study (Globec), a large, multi-investigator study of the winter survival strategy of krill under the antarctic sea ice. The optical properties of snow and sea ice evolve through the winter and vary greatly both spectrally and spatially. These properties are an important element of the physical environment that strongly influences both the distribution of and the resources available to antarctic krill. The intensity of incident radiant energy and its distribution within the snow, ice, and water column environment, and the linked physical, optical, chemical, and biological processes that modulate its distribution are generally known but poorly quantified. The optical properties of snow and ice also influence snow algae, ice algae, and water column productivity, as well as visibility for both predator and prey. Furthermore, optical properties play an essential role in satellite observations as proxy indicators of geophysical sea ice parameters which permit local observations to be more accurately extrapolated in space and time, thus providing regional coverage that would otherwise not be possible. What is proposed is the deployment of an array of instrumented ice beacons, augmented by periodic ship-based and satellite observations, along with theoretical studies to create improved quantitative models with which to follow the temporal and spatial evolution of this snow and ice marine ecosystem. The specific objective is to develop a thermodynamic sea ice/ecosystem model through coupling of existing components in order to test our understanding of the system, determine its sensitivities, and to provide an organizing mechanism for integrating the Southern Ocean Globec observations. ***
This project is an examination of the physical and structural properties of the antarctic ice pack in the Amundsen, Bellingshausen, and Ross Seas, with the goal of defining the geographical variability of various ice types, the deformation processes that are active in the antarctic ice pack, and the large-scale thermodynamics and heat exchange processes of the ice- covered Southern Ocean. An additional goal is to relate specific characteristics of antarctic sea ice to its synthetic aperture radar (SAR) signature as observed from satellites. Physical properties include the salinity, temperature, and brine volumes, while structural properties include the fraction of frazil, platelet, and congelation ice of the seasonal antarctic pack ice. Differences in ice types are the result of differences in the environment in which the ice forms: frazil ice is formed in supercooled sea water, normally through wind or wave-induced turbulence, while platelet and congelation ice is formed under quiescent conditions. The fraction of frazil ice (which has been observed to be generally in excess of 50% in Weddell Sea ice floes) is an important variable in the energy budget of the upper ocean, and contributes significantly to the stabilization of the surface layers. The integration of sea ice field observations and synthetic aperture radar data analysis and modeling studies will contribute to a better understanding of sea ice parameters and their geophysical controls, and will be useful in defining the kind of air-ice-ocean interactions that can be studied using SAR data, as well as having broader relevance and application to atmospheric, biological, and oceanographic investigations of the Southern Ocean.
9528807 Gordon The proposed project is part of a multi-institutional integrated study of the outflow of newly formed bottom water from the Weddell Sea and its dispersion into the South Atlantic Ocean. It builds upon earlier successful studies of the inflow of intermediate water masses into the Eastern Weddell Sea, their modification within the Weddell Gyre, and their interaction with bottom water formation processes in the western Weddell Sea. The study is called Deep Ocean Ventilation Through Antarctic Intermediate Layers (DOVETAIL) and includes six components involving hydrographic measurements, natural tracer experiments, and modeling studies. The study will be centered east of the Drake Passage where water masses from the Weddell Sea and the Scotia Sea come together in the Weddell-Scotia Confluence, and will be carried out in cooperation with the national antarctic programs of Germany and Spain. This particular component concerns observations of the temperature and salinity structure, as well as the chemical nature of the water column in the confluence region. The study has four related objectives. The first is to assess the quantity and the physical and chemical characteristics of Weddell Sea source waters for the confluence. The second is to describe the dominant processes associated with spreading and sinking of dense antarctic waters within the Weddell-Scotia Confluence. The third is to estimate the ventilation rate of the world ocean, and the fourth is to estimate seasonal fluctuations in the regional ocean transport and hydrographic structure and to assess the likely influence of seasonal to interannual variability on rates of ventilation by Weddell Sea waters. Ventilation of the deep ocean -- the rising of sub-surface water masses to the surface to be recharged with atmospheric gases and to give up heat to the atmosphere -- is a uniquely antarctic phenomenon that has significant consequences for global change by affecting the g lobal reservoir of carbon dioxide, and by modulating the amount and extent of seasonal sea ice in the southern hemisphere. This component will make systematic observations of the temperature salinity structure of the water and undertake an extensive sampling program for other chemical studies. The purpose is to identify the individual water masses and to relate their temperature and salinity characteristics to the modification processes within the Weddell Sea. ***
This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change.
The objective of the proposed work is to provide for the operation of a Planning Office for the synthesis and modeling phase of the Southern Ocean Global Ocean Ecosystems Dynamics (SO-Globec) program. The office will ensure that synthesis and integration activities that are developed as part of SO-Globec are coordinated with those undertaken by the international and U.S. Globec programs through: 1) organization of special sessions at meetings, 2) preparation of dedicated publications focused on program results, 3) maintenance of a project web site, 4) development of program outreach efforts, and 5) ensuring coordination with International Globec and other national and international programs and organizations. The office will consist of one faculty member and one program specialist.<br/><br/>SO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. Extensive studies describing the ecology and physiology of important species at all trophic levels contributed to the ecosystem approach which is the essence of SO-Globec. The Planning Office will provide a central focal point for ensuring that the results from SO-Globec are made available to the broader scientific community and to the general public, and that the results will be incorporated into the planning of future Southern Ocean programs.
The annual advance and retreat of pack ice may be the major physical determinant of spatial and temporal changes in the structure and function of antarctic marine communities. Interannual cycles and/or trends in the annual extent of pack ice may also have significant effects on all levels of the food web, from total annual primary production to breeding success in seabirds. Historical records indicate a six to eight year cycle in the maximum extent of pack ice in the winter. During this decade, winters were colder in 1980 and 1981, and again in 1986 and 1987. Winter-over survival in Adelie penguins varied on the same cycle, higher in winters with heavy pack ice. This Long Term Ecological Research (LTER) project will define ecological processes linking the extent of annual pack ice with the biological dynamics of different trophic levels within antarctic marine communities. The general focus is on interannual variability in representative populations from the antarctic marine food web and on mechanistic linkages that control the observed variability in order to develop broader generalizations applicable to other large marine environments. To achieve these objectives, data from several spatial and temporal scales, including remote sensing, a field approach that includes an annual monitoring program, a series of process-oriented research cruises, and a modeling effort to provide linkages on multiple spatial and temporal scales between biological and environmental components of the ecosystem will be employed.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). <br/><br/>This award supports a project to reconstruct the past physical and chemical climate of Antarctica, with an emphasis on the region surrounding the Ross Sea Embayment, using >60 ice cores collected in this region by US ITASE and by Australian, Brazilian, Chilean, and New Zealand ITASE teams. The ice core records are annually resolved and exceptionally well dated, and will provide, through the analyses of stable isotopes, major soluble ions and for some trace elements, instrumentally calibrated proxies for past temperature, precipitation, atmospheric circulation, chemistry of the atmosphere, sea ice extent, and volcanic activity. These records will be used to understand the role of solar, volcanic, and human forcing on Antarctic climate and to investigate the character of recent abrupt climate change over Antarctica in the context of broader Southern Hemisphere and global climate variability. The intellectual merit of the project is that ITASE has resulted in an array of ice core records, increasing the spatial resolution of observations of recent Antarctic climate variability by more than an order of magnitude and provides the basis for assessment of past and current change and establishes a framework for monitoring of future climate change in the Southern Hemisphere. This comes at a critical time as global record warming and other impacts are noted in the Southern Ocean, the Antarctic Peninsula, and on the Antarctic ice sheet. The broader impacts of the project are that Post-doctoral and graduate students involved in the project will benefit from exposure to observational and modeling approaches to climate change research and working meetings to be held at the two collaborating institutions plus other prominent climate change institutions. The results are of prime interest to the public and the media Websites hosted by the two collaborating institutions contain climate change position papers, scientific exchanges concerning current climate change issues, and scientific contribution series.
This award supports a study of the physical nature and environmental origin of optical features (light and dark zones) observed by video in boreholes in polar ice. These features appear to include an annual signal, as well as longer period signals. Borehole logs exist from a previous project, and in this lab-based project the interpretation of these logs will be improved. The origin of the features is of broad interest to the ice-core community. If some components relate to changes in the depositional environment beyond seasonality, important climatic cycles may be seen. If some components relate to post-depositional reworking, insights will be gained into the physical processes that change snow and firn, and the implications for interpretation of the chemical record in terms of paleoclimate. In order to exploit these features to best advantage in future ice-core and climate-change research, the two principal objectives of this project are to determine what physically causes the optical differences that we see and to determine the environmental processes that give rise to these physical differences. In the laboratory at NICL the conditions of a log of a borehole wall will be re-created as closely as possible by running the borehole video camera along sections of ice core, making an optical log of light reflected from the core. Combinations of physical variables that are correlated with optical features will be identified. A radiative-transfer model will be used to aid in the interpretation of these measurements, and to determine the optimum configuration for an improved future logging tool. An attempt will be made to determine the origin of the features. Two broad possibilities exist: 1) temporal changes in the depositional environment, and 2) post-depositional reworking. This project represents an important step toward a new way of learning about paleoclimate with borehole optical methods. Broader impacts include enhancing the infrastructure for research and education, since this instrument will complement high-resolution continuous-melter chemistry techniques and provide a rapid way to log physical variables using optical features as a proxy for climate signals. Since no core is required for this method, it can be used in rapidly drilled access holes or where core quality is poor. This project will support a graduate student who will carry out this project under the direction of the Principal Investigator. K-12 education will be enhanced through an ongoing collaboration with a science and math teacher from a local middle school. International collaboration will be expanded through work on this project with colleagues at the Norwegian Polar Institute and broad dissemination of results will occur through a project website for the general public.
This award supports development of a new modeling approach that will extract information about past snow accumulation rate in both space and time in the vicinity of the future ice core near the Ross-Amundsen divide of the West Antarctic Ice Sheet (WAIS). Internal layers, detected by ice-penetrating radar, are isochrones, or former ice-sheet surfaces that have been buried by subsequent snowfall, and distorted by ice flow. Extensive ice-penetrating radar data are available over the inland portion of the WAIS. Layers have been dated back to 17,000 years before present. The radar data add the spatial dimension to the temporally resolved accumulation record from ice cores. Accumulation rates are traditionally derived from the depths of young, shallow layers, corrected for strain using a local 1-D ice-flow model. Older, deeper layers have been more affected by flow over large horizontal distances. However, it is these deeper layers that contain information on longer-term climate patterns. This project will use geophysical inverse theory and a 2.5D flow-band ice-flow forward model comprising ice-surface and layer-evolution modules, to extract robust transient accumulation patterns by assimilating multiple deeper, more-deformed layers that have previously been intractable. Histories of divide migration, geothermal flux, and surface evolution will also be produced. The grant will support the PhD research of a female graduate student who is a mentor to female socio-economically disadvantaged high-school students interested in science, through the University of Washington Women's Center. It will also provide a research<br/>experience for an undergraduate student, and contribute to a freshman seminar on Scientific Research.
This award supports a project to develop a quantitative understanding of the processes active in isotopic exchange between snow/firn and water vapor, which is of paramount importance to ice core interpretation. Carefully controlled laboratory studies will be conducted at a variety of temperatures to empirically measure the mass transfer coefficient (the rate at which water moves from the solid to the vapor phase) for sublimating snow and to determine the time scale for isotopic equilibration between water vapor and ice. In addition the isotopic fractionation coefficient for vapor derived from sublimating ice will be determined and the results will be used to update existing models of mass transfer and isotopic evolution in firn. It is well known that water vapor moves through firn due to diffusion, free convection and forced convection. Although vapor movement through variably-saturated firn due to these processes has been modeled, because of a lack of laboratory data the mass transfer coefficient had to be estimated. Field studies have documented the magnitudes of post-depositional changes, but field studies do not permit rigorous analysis of the relative importance of the many processes which are likely to act in natural snow packs. The results of these laboratory investigations will be broadly applicable to a number of studies and will allow for improvement of existing physically-based models of post-depositional isotopic change, isotopic diffusion in firn, and vapor motion in firn. A major component of this project will be the design and fabrication of the necessary, novel experimental apparatus, which will be facilitated by existing technical expertise, cold room facilities, and laboratory equipment at CRREL. This project is a necessary step toward a quantitative understanding of the isotopic effects of water vapor movement in firn. The proposed work has broader impacts in several different areas. The modeling results will be applicable to a wide range of studies of water in the polar environment, including studies of wind-blown or drifting snow. The proposed collaborative study will partially support a Dartmouth graduate student for three years. This project will also provide support for a young first-time NSF investigator at the University of Vermont. Undergraduate students from Dartmouth will be involved in the research through the Women in Science Project and undergraduate students at the University of Vermont will be supported through the Research Experiences for Undergraduates program. The principal investigators and graduate student will continue their tradition of k-12 school outreach by giving science lessons and talks in local schools each year. Research results will be disseminated through scientific conferences, journal publications, and institutional seminars.
OPP-0230285/OPP-0230356<br/>PIs: Wilson, Terry J./Hothem, Larry D.<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to conduct GPS measurements of bedrock crustal motions in an extended Transantarctic Mountains Deformation network (TAMDEF) to document neotectonic displacements due to tectonic deformation within the West Antarctic rift and/or to mass change of the Antarctic ice sheets. Horizontal displacements related to active neotectonic rifting, strike-slip translations, and volcanism will be tightly constrained by monitoring the combined TAMDEF and Italian VLNDEF networks of bedrock GPS stations along the Transantarctic Mountains and on offshore islands in the Ross Sea. Glacio-isostatic adjustments due to deglaciation since the Last Glacial Maximum and to modern mass change of the ice sheets will be modeled from GPS-derived crustal motions together with new information from other programs on the configurations, thicknesses, deglaciation history and modern mass balance of the ice sheets. Tectonic and rheological information from ongoing structural and seismic investigations in the Victoria Land region will also be integrated in the modeling. The integrative and iterative modeling will yield a holistic interpretation of neotectonics and ice sheet history that will help us to discriminate tectonic crustal displacements from viscoelastic/elastic glacio-isostatic motions. These results will provide key information to interpret broad, continental-scale crustal motion patterns detected by sparse, regionally distributed GPS continuous trackers and by spaceborne instruments. This study will contribute to international programs focused on Antarctic neotectonic and global change issues.<br/><br/>Strategies to meet these science objectives include repeat surveys of key sites in the existing TAMDEF network, extension of the array of TAMDEF sites southward about 250 km along the Transantarctic Mountains, linked measurements with the VLNDEF network, and integration of quasi-continuous trackers within the campaign network. By extending the array of bedrock sites southward, these measurements will cross gradients in predicted vertical motion due to viscoelastic rebound. The southward extension will also allow determination of the southern limit of the active Terror Rift and will provide a better baseline for constraints on any ongoing tectonic displacements across the West Antarctic rift system as a whole that might be possible using GPS data collected by the West Antarctic GPS Network. This project will also investigate unique aspects of GPS geodesy in Antarctica to determine how the error spectrum compares to mid-latitude regions and to identify the optimum measurement and data processing schemes for Antarctic conditions. The geodetic research will improve position accuracies within our network and will also yield general recommendations for deformation monitoring networks in polar regions.<br/><br/>An education and outreach program is planned and will be targeted at non-science-major undergraduate students taking Earth System Science at Ohio State University. The objective will be to illuminate the research process for nonscientists. This effort will educate students on the process of science and inform them about Antarctica and how it relates to global science issues.
0122520<br/>Gogineni<br/><br/>Sea level has been rising over the last century. Although the immediate impact of sea level rise may be less severe than other effects of global climate change, the long-term consequences can be much more devastating since nearly 60% of the world population lives in coastal regions. Scientists have postulated that excess water is being released from polar ice sheets due to long-term, global climate change, but there are insufficient data to confirm these theories. Understanding the interactions between the ice sheets, oceans and atmosphere is essential to quantifying the role of ice sheets in sea level rise. Toward that end, this research project involves the innovative application of information technology in the development and deployment of intelligent radar sensors for measuring key glaciological parameters. <br/><br/>Radar instrumentation will consist of a synthetic aperture radar (SAR) that can operate in bistatic or monostatic mode. One important application of the SAR will be in the determination of basal conditions, particularly the presence and distribution of basal water. Basal water lubricates the ice/bed interface, enhancing flow, and increasing the amount of ice discharged into the ocean. Another application of the SAR will be to measure ice thickness and map internal layers in both shallow and deep ice. Information on near-surface internal layers will be used to estimate the average, recent accumulation rate, while the deeper layers provide a history of past accumulation and flow rates. A tracked vehicle and an automated snowmobile will be used to test and demonstrate the utility of an intelligent radar in glaciological investigations.<br/><br/>The system will be developed to collect, process and analyze data in real time and in conjunction with a priori information derived from archived sources. The combined real time and archived information will be used onboard the vehicles to select and generate an optimum sensor configuration. This project thus involves innovative research in intelligent systems, sounding radars and ice sheet modeling. In addition it has a very strong public outreach and education program, which include near-real-time image broadcasts via the world wide web
This collaborative study between Old Dominion University, the College of William and Mary, Earth and Space Research, and the Woods Hole Oceanographic Institution will examine the interactions among the ocean circulation, vertical mixing, sea ice, and marine biological processes on the western Antarctic Peninsula continental shelf. The study will result in analytical and numerical modeling tools that are based on, and will have been tested against the extensive data set obtained in the course of the Southern Ocean experiment of the Global Ocean Ecosystems Dynamics program (SO-Globec). These models will provide insight into circulation and biological dynamics that will be applicable to the development and refinement of physical and biological models for other high latitude systems. <br/><br/>SO-Globec is a multidisciplinary effort focused on understanding the physical and biological factors that influence growth, reproduction, recruitment and survival of Antarctic krill (Euphausia superba). The program uses a multi-trophic level approach that includes the predators and competitors of Antarctic krill, represented by other zooplankton, fish, penguins, seals, and cetaceans. It is currently in a synthesis and modeling phase. This collaborative project is concerned with the environmental setting and dynamics that constrain ecological processes, and will be integrated with other synthesis and modeling studies that deal with grazers, predators, and other higher trophic levels
Increases in middle ultraviolet radiation associated with the Antarctic ozone hole have been shown to inhibit the photosynthesis of phytoplankton, and results have been extrapolated to estimate the effect of ozone depletion on primary productivity in the marginal ice zone. This research will refine the assessment by specifying detailed wavelength-dependent biological weighting functions for the inhibition of photosynthesis by ultraviolet radiation, and by considering the mitigating effects of vertical mixing. Biological weighting functions of phytoplankton in the marginal ice zone will be measured under controlled conditions and applied in a new model of photosynthesis to predict primary productivity in situ, as well as under altered ultraviolet irradiance. These predictions will be compared with observations on samples from the water column and with measurements during incubations of several hours under different irradiance regimes. Results of these comparisons will be used to test the model and to quantify the potential artifact of long incubations. Assumptions about the kinetics of photoinhibition and recovery, critical to modeling the effects of vertical mixing, will be examined with time-course experiments. Results will be incorporated into a model of photosynthesis and photoinhibition in the water column that will be used to predict the influence of ozone depletion on marine primary production, particularly in the marginal zone.
0538195<br/>Marone<br/>This award supports a project to conduct laboratory experiments and numerical modeling to determine the constitutive properties of subglacial till under dynamic stressing and to test the hypothesis that granular properties of till are sufficient, when coupled elastically to a large ice stream, to reproduce the field observations of triggered slip and subglacial seismicity. Testing will be carried out in a servo-controlled biaxial shear device under controlled temperature and stress conditions, which will allow both sliding and microstructural processes to be studied in detail. The main focus of the work will be on laboratory measurements. In addition, we will construct continuum models to evaluate whether our results can predict complex ice sheet motions and observed characteristics of subglacial seismicity. In terms of broader impacts, the proposed work will encourage interactions between the rock-mechanics and glaciology communities and will bring together members of different scientific backgrounds and vocabularies, but similar problems and data. The project will train undergraduate and graduate students at Penn State University and the scientists involved plan to give presentations to grade school classes, scout groups, and at community open houses. Results will be presented at professional meetings and will be published in a timely manner. The work will result in a better understanding of glacial motion and the physics of earthquake slip, which is essential for understanding ice sheet dynamics and earthquake hazard.
This project uses cosmogenic nuclide dating and LIDAR studies of surface roughness to understand weathering and landscape evolution in the Dry Valleys of Antarctica. The work focuses on two processes: cryoturbation of frozen soils and the development of patterned, frozen ground on ancient lava flows. The approach includes innovative uses of He3 profiling. Results will also be applied to understanding the glacial history of the Dry Valleys. There are potential applications to understanding the history of the East Antarctic Ice Sheet and the formation of Martian landscapes. The broader impacts include graduate student education. As well, the work may contribute to our understanding of the history of the Antarctic ice sheets, which is important to modeling their behavior during global climate change.
This project will continue the operation of surface-based magnetometers, imaging and broadbeam riometers (relative ionospheric opacity instruments), and two-wavelength zenith photometers at South Pole and McMurdo stations in Antarctica, and imaging riometers at Iqaluit (nominally conjugate to South Pole) and Sondrestrom in the Arctic. Additionally, the data acquisition systems at South Pole and McMurdo for the common recording of other geophysical data, and the provision of these data to collaborating investigators will be continued. The Antarctic data sets are web-based, and can be accessed in near-real time. <br/>The continuation of the activities in the 2004-2006 time frame will contribute to several major science initiatives, including the GEM (Geospace Environment Modeling), CEDAR (Coupling, Energetics and Dynamics of Atmospheric Regions), ISTP/GGS (International Solar-Terrestrial Project/Global Geospace Science), and National Space Weather programs. The overall objective of the project is to understand the relevant physical processes that produce the observed phenomena, and how they relate to driving forces, either internal, such as magnetospheric/ionospheric instabilities, or external, such as solar wind/interplanetary magnetic field variations. It is expected that this project will lead to an enhanced capability to predict sufficiently in advance the possible occurrence of events that might have negative technological or societal impacts, and thus provide time to lessen their effects.
This award supports a project to test whether Kamb Ice Stream (formerly Ice Stream C (ISC)), an ice stream<br/>that is thought to have stopped ~150 years ago, may be already in the process of restarting. If yes, it will help establish what is the rate of ice stream reactivation and what mechanisms are controlling this rate. If there is no evidence for ongoing ice stream reactivation, the physical controls that are preventing it will be examined and alternative scenarios for near-future evolution of this ice stream will be explored. One such scenario is an increase in ice diversion toward the neighboring Whillans Ice Stream. Such diversion may help prevent a complete stoppage of Whillans Ice Stream,which has been slowing down for at least the last 24 years. This project will consist of two components: (1) field observations of bed properties,geometry of internal radar reflectors, as well as surface strain rates and velocity/topography changes using Ice-Penetrating Radar and differential Global Positioning System, (2) numerical modeling study of near future(~100-1000 years) evolution of Kamb Ice Stream. The field component will be focused on the bulge-to-trunk transition, which is located at the present time just downstream of the so-called camp UpC. Reactivation of Kamb Ice Stream should be reflected in a downstream migration of the bulge-trunk transition at possibly high rates (bulge migration rates of ~km/yr occur on surging mountain glaciers). The modeling<br/>component will be used to generate predictions regarding the near-future behavior of Kamb Ice Stream. This project will provide training opportunities for at least two undergraduate students (per year) at St. Olaf College and for one<br/>undergraduate student (per year) at UCSC. This collaboration will bring together scientists from three different types of US institutions: (1) a liberal arts college (St.Olaf College), (2) a public research university (UCSC) and (3) a NASA research laboratory (JPL). The project will also help build a new glaciological research program at UCSC. Project results will be incorporated into undergraduate and graduate courses at UCSC and will be made available<br/>to the general public and educators through downloadable graphics and animations posted on the research website of the UCSC PI. Field data resulting from the project will be posted in the Antarctic Glaciological Data Center for use by other investigators.
This award supports a comprehensive study of land-based polar ice cliffs. Through field measurements, modeling, and remote sensing, the physics underlying the formation of ice cliffs at the margin of Taylor Glacier in the McMurdo Dry Valleys will be investigated. At three sites, measurements of ice deformation and temperature fields near the cliff face will be combined with existing energy balance data to quantify ice-cliff evolution over one full seasonal cycle. In addition, a small seismic network will monitor local "ice quakes" associated with calving events. Numerical modeling, validated by the field data, will enable determination of the sensitivity of ice cliff evolution to environmental variables. There are both local and global motivations for studying the ice cliffs of Taylor Glacier. On a global scale, this work will provide insight into the fundamental processes of calving and glacier terminus A better grasp of ice cliff processes will also improve boundary conditions required for predicting glaciers' response to climate change. Locally, the Taylor Glacier is an important component of the McMurdo Dry Valleys landscape and the results of this study will aid in defining ecologically-important sources of glacial meltwater and will lead to a better understanding of moraine formation at polar ice cliffs. This study will help launch the career of a female scientist, will support one graduate student, and provide experiential learning experiences for two undergraduates. The post-doctoral researcher will also use this research in the curriculum of a wilderness science experiential education program for high school girls.
Major portions of the Antarctic Ice Sheet float in the surrounding ocean, at the physical and intellectual boundaries of oceanography and glaciology. These ice shelves lose mass continuously by melting into the sea, and periodically by the calving of icebergs. Those losses are compensated by the outflow of grounded ice, and by surface accumulation and basal freezing. Ice shelf sources and sinks vary on several time scales, but their wastage terms are not yet well known. Reports of substantial ice shelf retreat, regional ocean freshening and increased ice velocity and thinning are of particular concern at a time of warming ocean temperatures in waters that have access to deep glacier grounding lines.<br/>This award supports a study of the attrition of Antarctic ice shelves, using recent ocean geochemical measurements and drawing on numerical modeling and remote sensing resources. In cooperation with associates at Columbia University and the British Antarctic Survey, measurements of chlorofluorocarbon, helium, neon and oxygen isotopes will be used to infer basal melting beneath the Ross Ice Shelf, and a combination of oceanographic and altimeter data will be used to investigate the mass balance of George VI Ice Shelf. Ocean and remote sensing observations will also be used to help refine numerical models of ice cavity circulations. The objectives are to reduce uncertainties between different estimates of basal melting and freezing, evaluate regional variability, and provide an update of an earlier assessment of circumpolar net melting.<br/>A better knowledge of ice shelf attrition is essential to an improved understanding of ice shelf response to climate change. Large ice shelf calving events can alter the ocean circulation and sea ice formation, and can lead to logistics problems such as those recently experienced in the Ross Sea. Broader impacts include the role of ice shelf meltwater in freshening and stabilizing the upper ocean, and in the formation of Antarctic Bottom Water, which can be traced far into the North Atlantic. To the extent that ice shelf attrition influences the flow of grounded ice, this work also has implications for ice sheet stability and sea level rise.
Anandakrishnan, Sridhar; Alley, Richard; Voigt, Donald E.
No dataset link provided
This award supports a project to investigate the new-found, startling sensitivity of two major West Antarctic ice streams to tidal oscillations to learn the extent and character of the effect and its ramifications for future ice-stream behavior. Ice streams D, C and Whillans (B) all show strong but distinct tidal signals. The ice plain of Whillans is usually stopped outright, forward motion being limited to two brief periods each day, at high tide and on the falling tide. Motion events propagate across the ice plain at seismic wave velocities. Near the mouth of D, tides cause a diurnal variation of about 50% in ice-stream speed that propagates upglacier more slowly than on Whillans, and seismic data show that C experiences even slower upglacier propagation of tidal signals. Tidal influences are observed more than 100 km upglacier on C, more than 40 km upglacier on D, and may be responsible for fluctuations in basal water pressure reported 400 km upstream on Whillans, nearly the full length of the ice stream. During the first year, the spatial extent of this behavior will be measured on Whillans Ice Stream and ice stream D by five coordinated seismic and GPS instrument packages at 100-km spacing on each ice stream. These packages will be deployed by Twin Otter at sites selected by review of satellite imagery and will operate autonomously through a combination of solar and battery power for two lunar cycles to study the sensitivity of the ice stream motion to spring and neap tides. Additionally, existing data sets will be examined further for clues to the mechanisms involved, and preliminary models will be developed to reconcile the seemingly contrasting behaviors observed on the ice streams. The second and third field seasons will examine in greater detail the tidal behavior of Whillans (year 2) and D (year 3). Work will especially focus on detailed study of at least one source area for events on Whillans, assuming that source areas inferred from preliminary data remain active. Vertical motions have not yet been detected, but differential GPS will increase our detection sensitivity. Seismic instrumentation will greatly increase temporal resolution and the ability to measure the propagation speed and any spatial heterogeneity. Modeling will be refined as more is learned from the field experiments. The project should yield numerous broader impacts. The improved knowledge of ice-stream behavior from this study will contribute to assessment of the potential for rapid ice-sheet change affecting global sea level with societal consequences. Results will be disseminated through scientific publication and talks at professional meetings, as well as contacts with the press, university classes taught by the PIs, visits to schools and community groups, and other activities. Two graduate students will be educated through the project.
This award supports a comprehensive study of rift growth on the Amery Ice Shelf (AIS), East Antarctica, using a combination of in situ and remote sensing data with numerical modeling. On the AIS there is an opportunity to examine an active rift system, which is a combination of two longitudinal-to-flow rifts, which originated at the ice shelf front in the suture zones between merging flowbands, and two transverse-to-flow rifts, which formed at the tip of the western longitudinal rift around 1996. Work in progress indicates that these two transverse rifts do not propagate independently of each other, but somehow grow more or less synchronously. The longest of these rifts-the eastern one-grows at an average rate of about 8m per day. When it meets the eastern longitudinal rift, an event that is expected to occur during the funding period (mid-2006), an iceberg (~30 x 30 km) will calve. Based on observations collected over the past half century, there is reason to believe that such a calving event may be a part of a repetitive sequence. In the proposed project, the expansion and propagation of both transverse rifts will be studied using a network of GPS and seismometers deployed around the tip of each transverse rift. Once the iceberg has calved, the effects its calving has on the dynamics of the ice shelf and the activation of previously inactive rifts will also be studied. Insofar as the rate of calving activity is a proxy for local and regional climate conditions, a broader impact of the proposed work is directly related to the socio-environmental topics of climate and sea-level change. The subject of iceberg calving has a history of sparking a great deal of interest from the media and the public alike, especially since the recent large calving events from the Ross and Ronne ice shelves and the remarkably sudden break-up of the Larsen Ice Shelf. The work will involve at least one graduate student, and will involve a partnership with a local charter high school. Field work, instrument deployments, and data collection and analysis will be conducted in close collaboration with the Australian Antarctic Division and the University of Tasmania, which has been a crucial component of research conducted to date. This project will also make use of the Scripps Institution of Oceanography Visualization Center as a means to display results to faculty and researchers of the University of California, San Diego, undergraduate and graduate students, to school children and their teachers, and ultimately to the visiting public.
This project determines the recent history of the West Antarctic Ice Sheet (WAIS) through a multidisciplinary study of the seabed in the Ross Sea of Antarctica. WAIS is perhaps the world's most critical ice sheet to sea level rise dut to near-future global warming. its history has been a key focus for the past decade, but there are significant questions as to whether WAIS was stable during the last glacial maximum--about 20,000 years ago--or undergoing advance and retreat. This project studies grounding zone translantions in Eastern Basin to constrain WAIS movements using a multidisciplinary approach that integrates multibeam bathymetry, seismic stratigraphy, sedimentology, diatom biostratigraphy, radiocarbon dating, 10Be concentration analyses, and numerical modeling.<br/><br/>The broader impacts include improving society's understanding of sea level rise linked to global warming; postdoctoral, graduate, and undergraduate education; and expanding the participation of groups underrepresented in Earth sciences through links with LSU's Geoscience Alliance to Encourage Minority Participation.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports research to apply numerical modeling to constrain the uplift and exhumation history of the Transantarctic Mountains. The Transantarctic Mountains (TAM) are an anomalously high (>4500 m) and relatively broad (up to 200 km) rift-flank uplift demarcating the boundary between East and West Antarctica. Dynamics of the East Antarctic ice-sheet and the climate are affected by the mountain range, and an understanding of the uplift history of the mountain range is critical to understanding these processes. This project will constrain the uplift and denudation history of the Transantarctic Mountains based on thermo-mechanical modeling held faithful to thermochronological, geological, and geophysical data. The research will be the primary responsibility of post-doctoral researcher Audrey Huerta, working in collaboration with Dennis Harry, 1 undergraduate student, and 1 graduate student.<br/><br/>Thermochronologic evidence of episodic Cretaceous through Cenozoic rapid cooling within the TAM indicates distinct periods of uplift and exhumation. However, a more detailed interpretation of the uplift history is difficult without an understanding of the evolving thermal structure and topography of the TAM prior to and during uplift. These aspects of the mountain range can best be constrained by an understanding of the evolving regional tectonic setting. Proximity of the TAM to the West Antarctic Rift System (WARS) suggests a link between uplift of the TAM and extension within the WARS.<br/><br/>The project will integrate two techniques: lithospheric-scale geodynamic modeling and crustal-scale thermal modeling. The lithospheric-scale deformational and thermal evolution of TAM will be modeled by a finite element model designed to track the thermal and deformational response of the Antarctic lithosphere to a protracted extensional environment. Previous investigators have linked the high elevation and broad width of the TAM to a deep level of necking in which mantle thinning is offset from the location of crustal extension. In this study, a three-dimensional dynamic model will be used to track the uplift and thermal evolution of the TAM in a setting in which necking is at a deep level, and in which extension within the crust and extension within the mantle are offset. Velocity boundary conditions applied to the edges of the model will vary through time to simulate the extensional and transtensional evolution of the WARS. Because the model is dynamic, the thermal structure, strength, and strain field, evolve naturally in response to these initial and boundary conditions.<br/><br/>Dynamic models are uniquely suited to understanding lithospheric deformational and thermal evolution, however kinematic models are best suited for addressing the detailed thermal and exhumation history of crustal uplifts. Thus, a 2-dimensional kinematic-thermal model will be designed to simulate the uplift history of the TAM and the resulting erosional, topographic, and thermal evolution. Uplift will be modeled as normal-fault movement on a set of discrete fault planes with uplift rate varying through time. Erosion will be modeled as a diffusive process in which erosion rates can be varied through time (simulating climate changes), and vary spatially as a linear function of gradient and distance from the drainage divide. Synthetic time-temperature (t-T) histories will be calculated to compare model results to thermochronologic data.
Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice<br/>sheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.
9814816 Blankenship This award supports a four year project to develop of better understanding the ice streams of the Ross Sea Embayment (A--F) which drain the interior West Antarctic Ice Sheet (WAIS) by rapidly moving vast quantities of ice to the calving front of the Ross Ice Shelf. The project will examine the role of these ice streams as buffers between the interior ice and the floating ice shelves. The reasons for their fast flow, the factors controlling their current grounding-line-, margin-, and head-positions are crucial to any attempt at modeling the WAIS system and predicting the future of the ice sheet. For the Antarctic ice streams of the Siple Coast, the transition from no-sliding (or all internal deformation) to motion dominated by sliding is defined as the "onset-region". To fully understand (and adequately model) the WAIS, this onset region must be better understood. The lateral margins of the ice streams are also a transition that need better explanation. Hypotheses on controls of the location of the onset region range from the "purely-glaciologic" to the "purely-geologic. Thus, to model the ice sheet accurately, the basal boundary conditions (roughness, wetness, till properties) and a good subglacial geologic map, showing the distribution, thickness, and properties of the sedimentary basins, are required. These parameters can be estimated from seismic, radar, and other geophysical methods. The transition region of ice stream D will be studied in detail with this coupled geophysical experiment. In addition, selected other locations on ice streams C & D will be made, to compare and contrast conditions with the main site on ice stream D. Site-selection for the main camp will be based on existing radar, GPS, and satellite data as well as input from the modeling community.
This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical<br/>data will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.<br/>The West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea<br/>level rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical<br/>centers. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.<br/>The results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.<br/>Through its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.
This award is for support for a research program involving the use of passive microwave data to validate key paleoclimate indicators used in glaciologic research. The specific contributions of this research are: 1) to define the timing and spatial extent of hoar complexes, which may serve as visible, annual stratigraphic markers in ice cores, through a combination of satellite passive microwave data and field observations; and 2) to monitor temperature trends at the site with calibrated passive microwave brightness temperatures and to correlate these trends to proxy temperatures provided by oxygen and hydrogen stable isotope ratio profiles from snow pits and/or ice cores. The work will take place at Siple Dome, Antarctica as part of the field activities associated with the ice core drilling program there.
This award supports a study of the chemical composition of air in the snow layer (firn) in a region of "megadunes" near Vostok station, Antarctica. It will test the hypothesis that a deep "convective zone" of vigorous wind-driven mixing can prevent gas fractionation in the upper one-third of the polar firn layer. In the megadunes, ultralow snow accumulation rates lead to structural changes (large grains, pipes, and cracks) that make the permeability of firn to air movement orders of magnitude higher than normal. The unknown thickness of the convective zone has hampered the interpretation of ice core 15N/14N and 40Ar/36Ar ratios as indicators of past firn thickness, which is a key constraint on the climatically important variables of temperature, accumulation rate, and gas age-ice age difference. Studying this "extreme end-member" example will better define the role of the convective zone in gas reconstructions. This study will pump air from a profile of ~20 depths in the firn, to definitively test for the presence of a convective zone based on the fit of observed 15 N/14N and 40Ar/36Ar to a molecular- and eddy-diffusion model. Permeability measurements on the core and 2-D air flow modeling (in collaboration with M. Albert) will permit a more physically realistic interpretation of the isotope data and will relate mixing vigor to air velocities. A new proxy indicator of convective zone thickness will be tested on firn and ice core bubble air, based on the principle that isotopes of slow-diffusing heavy noble gases (Kr, Xe) should be more affected by convection than isotopes of fast-diffusing N2 . These tools will be applied to a test of the hypothesis that the megadunes and a deep convective zone existed at the Vostok site during glacial periods, which would explain the anomalously low 15N/14N and 40Ar/36Ar in the Vostok ice core glacial periods. The broader impacts of this work include 1) clarification of phase relationships of greenhouse gases and temperature in ice core records, with implications for understanding of past and future climates, 2) education of one graduate student, and 3) building of collaborative relationships with five investigators.
This award supports a project to characterize the morphology, ice motion velocity and mass balance of Lambert Glacier, Antarctica using state-of-the-art remote sensing and GIS techniques. Lambert Glacier is the largest ice stream in the world. Because of its size, it plays a fundamental role in the study of glacial dynamics and mass budget in response to present and future climate changes. Along with the bedrock topography and ice thickness data derived from airborne radio echo soundings and snow accumulation data compiled from ground-based measurements, the dynamic behavior and mass balance of the Lambert glacial basin in a Geographic Information Systems (GIS) environment will be examined. Specific objectives are to: (1) Extract two-dimensional ice velocity field over the entire Lambert glacial basin using speckle matching and differential interferometric SAR (InSAR) techniques, and produce a full coverage of radar coherence map over the drainage basin. With the ice velocity data, calculate the strain rate field from the initiation areas of the ice stream onto the Amery Ice Shelf; (2) Derive high-resolution digital elevation model (DEM) over the Lambert glacial drainage basin using SAR stereo, differential interferometric SAR, and GLAS laser altimetry techniques. Based on the DEM, extract ice divides and ice flow directions, delineate the snow catchment basin, and calculate the balance deformation velocity and the basal shear stress; (3) Interpolate traverse ice thickness data collected by Australian and Russian airborne radio echo sounding surveys into a regular grid, and derive a regular grid of bedrock topography in combination with the DEM; (4) Integrate newly derived ice velocity and ice thickness data as well as snow accumulation rate data compiled from previous ground-based measurements into a geographic information system (GIS), and calculate the mass flux through the ice stream at the grounding lines and net mass balance throughout the drainage basin. With these new measurements and calculations derived from advanced remote sensing techniques, we will be able to improve our understanding of dynamic behavior and current mass balance status of the Lambert glacial basin, gain an insight on the relationship between ice mass change and the variation in regional and global climate at decadal scale, and provide an evaluation on the issue of whether the Lambert glacier basin is subject to surging in the context of future climate change.
0126187<br/>Alley<br/><br/>This award provides support for a 2 year modeling effort to study the dynamics of Pine Island Glacier (PIG). The discharge from the PIG constitutes the largest mass loss from any single West Antarctic ice stream. Satellite observations indicate that this outlet glacier is experiencing ongoing thinning and acceleration. The emphasis of this work will be on understanding the cause and the near-term projection of the observed thinning of PIG. Model experiments will address the hypothesis that the observed changes were caused by the loss of a buttressing ice shelf, and that the changes will continue in the form of an upglacier propagating wave of thinning and acceleration. To perform this work a numerical model of the coupled mass, energy, and momentum balance of Pine Island Glacier basin will be developed. The model will comprise four modular components, which will be coupled and then benchmarked against the European Ice Sheet Modeling Inititative (EISMINT) model intercomparison. The model will then be applied to the thinning of Pine Island Glacier using likely ice-shelf histories and possible basal boundary conditions to learn which may be accurate and to assess possible future behavior. The primary expected result will be an improved understanding of the importance of ice-shelf buttressing and the potential for inland thinning due to the reduction of ice-shelf drag.
Bell, Robin; Tremblay, Bruno; Hohmann, Roland; Clarke, Garry; Studinger, Michael S.
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0088047<br/>Bell<br/><br/>This award supports a two year project to address fundamental questions about the mass and energy flux through Lake Vostok, a subglacial lake in East Antarctica, sealed beneath almost 4 kilometers of ice. The project will involve developing lake circulation models, complemented by the analysis of new ice penetrating radar data over the lake and surrounding regions. This project will help to accurately define the regions of melting and freezing within the lake and help to provide an improved estimate of the form of the lake. The combined data analysis and modeling effort will provide a critical framework for developing international plans to sample the waters of Lake Vostok for biota and to recover sediments from Lake Vostok for paleoclimate studies.
9909518 Raymond This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide "shutdown" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.
0135989<br/>Wilen<br/><br/>This is a collaborative proposal by Principal Investigators at the University of Washington and Ohio University. Detailed knowledge about the interactions between micro-structure of ice and its deformation is needed to assess the integrity of stratigraphic layering and the depth-age relationship in ice cores, which is essential for interpreting the paleoclimate record. The Principal Investigators will use micro-structure to study fabric, the orientation distribution of crystal c-axes, and texture, the size and shape of crystals. Numerical modeling of ice deformation is a useful tool in understanding these interactions. Accurate modeling of ice deformation is complicated by factors, such as the fabric, grain size, dynamic recrystallization, stress level, and precise knowledge of initial conditions. For example, ice fabric evolves as the ice is strained and the deformation depends on the fabric. This complicated feedback mechanism must be understood to correctly model ice deformation. In another example, the usual assumption is that the initial fabric is isotropic or random, but there are excellent examples of near-surface ice in the ice cores that are apparently not isotropic. One must know the initial fabric to calculate the deformation rate in ice sheets. Dr. Wilen will combine results of his new automatic fabric analyzer (AFA) with predictions of detailed ice deformation models (Dr. Thorsteinsson) to refine and better constrain such models. The AFA gives new information in thin sections because the precision and number of measured c-axis orientations are greatly improved. The Principal Investigators will analyze existing data and collect new data on fabric and texture from ice cores to address questions regarding near-surface fabric, deformation mechanisms, dynamic recrystallization, and potential sources of layer disturbances. The data will be used to constrain models of fabric evolution and recrystallization processes. With the more refined models, scientists can address different questions and important problems related to ice deformation and ice cores. For example, the recent agreement between the climate records from the Greenland Ice Core Project (GRIP) and Greenland Ice Sheet Project 2 (GISP2) ice cores of the upper-90%, and the disagreement in the lower-10% emphasizes the need to understand and predict the mechanisms and probable depths of disruption in these and future deep ice cores. Evidence suggests that the stratigraphic disturbances arise from the anisotropic nature of ice crystals at a variety of scales. To properly model the deformation of anisotropic ice, the influence of fabric on deformation must be well known.
9909469 Scambos This award provides support for three years of funding to study the scar-like features that are well-known from the Siple Coast ice stream system in West Antarctica. The objective of the proposed field work is to identify the nature of several as yet unvisited scars, and to further characterize previously-identified margin scars that are poorly dated. Advanced Very High Resolution Radiometer (AVHRR) and Radarsat image data will be used to locate and map the features, and place them in a regional context. The study seeks to describe the recent history of the Siple Coast glaciers and investigate the causes of their changes in configuration. The main investigative tools will be low-frequency RES and high-frequency ground penetrating radar (GPR) profiles to image internal layers and measure depths to buried crevasses or disrupted layering. This, coupled with accumulation rates determined from shallow ice cores, will provide "shutdown" ages for the margin features. The field data will provide input parameters for simple models of ice flow for margins and inter-ice stream ridges during active shearing and after shutdown. This modeling will estimate the initial elevation of a scar at the time of shut down and the corresponding ice stream elevation at that time.
This award is for support for a program of measurements to improve our understanding of the relationship between formaldehyde (HCHO) and hydrogen peroxide (H2O2) in the atmosphere and the concentrations of the same species in Antarctic snow, firn and ice. This work aims to relate changes in concentrations in the snow, firn and ice to corresponding changes in tropospheric chemistry. Atmospheric and firn sampling for formaldehyde and hydrogen peroxide at one or more of the WAIS ice core drilling sites will be undertaken and controlled laboratory studies to estimate thermodynamic and rate parameters will be performed. In addition, this work will involve modeling of atmosphere-snow exchange processes to infer the "transfer function" for reactive species at the sites and atmospheric photochemical modeling to relate changes in concentrations of formaldehyde and hydrogen peroxide in snow, firn and ice to atmospheric oxidation capacity. This work will contribute to a better understanding of the relationship between atmospheric concentrations of various species and those same species measured in snow and ice samples.
9530379 Anderson This research project is part of the US Joint Global Ocean Flux Study (JGOFS) Southern Ocean Program aimed at (1) a better understanding of the fluxes of carbon, both organic and inorganic, in the Southern Ocean, (2) identifying the physical, ecological and biogeochemical factors and processes which regulate the magnitude and variability of these fluxes, and (3) placing these fluxes into the context of the contemporary global carbon cycle. This work is one of forty-four projects that are collaborating in the Southern Ocean Experiment, a three- year effort south of the Antarctic Polar Frontal Zone to track the flow of carbon through its organic and inorganic pathways from the air-ocean interface through the entire water column into the bottom sediment. The experiment will make use of the RVIB Nathaniel B. Palmer and the R/V Thompson. This component is a study of how naturally radioactive material in the ocean sediment may be used to reconstruct the flux of biogenic material through the water column to the sediment, and by inference, the productivity of the surface layers. There is evidence that the current surface conditions of high nutrient levels, but low chlorophyll levels do not extend back into colder climatic epochs, and that an examination of radionuclides may allow the reconstruction of rates of paleoproductivity. Two aspects of the biogeochemical cycling and physical transport of radionuclide tracers in the modern ocean will be investigated. In the first part, the concentration of a series of natural radionuclide tracers (thorium-230, protactinium-231, and Beryllium-10) in the Southern Ocean will be measured for their scavenging behavior both in the water column and in particulate material collected by sediment traps. The goal is to test the proposed use of radionuclide ratios as proxy variables for the export flux. In the second part, the concentration values will be introduced into an ocean general circulat ion model to evaluate the transport of radionuclides by the ocean circulation on scales that are larger than the spatial gradients in particle flux. These combined efforts will better define our ability to use radionuclide ratios to evaluate past changes in ocean productivity, and improve our understanding of the response of ocean productivity to climate variability. ***