{"dp_type": "Project", "free_text": "Organic Matter"}
[{"awards": "1841228 Lyons, W. Berry", "bounds_geometry": "POLYGON((163.37428 -77.558627,163.3922735 -77.558627,163.410267 -77.558627,163.4282605 -77.558627,163.446254 -77.558627,163.4642475 -77.558627,163.482241 -77.558627,163.5002345 -77.558627,163.518228 -77.558627,163.5362215 -77.558627,163.554215 -77.558627,163.554215 -77.56397510000001,163.554215 -77.5693232,163.554215 -77.5746713,163.554215 -77.5800194,163.554215 -77.5853675,163.554215 -77.59071560000001,163.554215 -77.5960637,163.554215 -77.60141180000001,163.554215 -77.6067599,163.554215 -77.612108,163.5362215 -77.612108,163.518228 -77.612108,163.5002345 -77.612108,163.482241 -77.612108,163.4642475 -77.612108,163.446254 -77.612108,163.4282605 -77.612108,163.410267 -77.612108,163.3922735 -77.612108,163.37428 -77.612108,163.37428 -77.6067599,163.37428 -77.60141180000001,163.37428 -77.5960637,163.37428 -77.59071560000001,163.37428 -77.5853675,163.37428 -77.5800194,163.37428 -77.5746713,163.37428 -77.5693232,163.37428 -77.56397510000001,163.37428 -77.558627))", "dataset_titles": "Commonwealth Stream Diel Water Chemistry; Hyporheic zone geochemistry of Wales Stream, Taylor Valley, Antarctica; isotopic signature of massive buried ice, eastern Taylor Valley, Antarctica", "datasets": [{"dataset_uid": "601847", "doi": null, "keywords": "Antarctica; Cryosphere; Nutrients; Stable Isotopes; Taylor Valley; Trace Elements", "people": "Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Hyporheic zone geochemistry of Wales Stream, Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601847"}, {"dataset_uid": "601848", "doi": null, "keywords": "Antarctica; Buried Ice; Cryosphere; Stable Isotopes; Stable Water Isotopes; Taylor Valley", "people": "Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "isotopic signature of massive buried ice, eastern Taylor Valley, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601848"}, {"dataset_uid": "601844", "doi": null, "keywords": "Antarctica; Commonwealth Stream; Cryosphere; Diel; Inlandwaters; McMurdo Dry Valleys; Stream Chemistry; Water Chemisty", "people": "Gardner, Christopher B.", "repository": "USAP-DC", "science_program": null, "title": "Commonwealth Stream Diel Water Chemistry", "url": "https://www.usap-dc.org/view/dataset/601844"}], "date_created": "Wed, 16 Oct 2024 00:00:00 GMT", "description": "Phytoplankton, or microscopic marine algae, are an important part of the carbon cycle and can lower the rates of atmospheric carbon dioxide by transferring the atmospheric carbon into the oceans. The concentration of phytoplankton in the Southern Ocean is regularly limited by the availability of marine iron. This in turn influences the rate of carbon transfer from the atmosphere to the ocean. The primary source of iron in the Southern Ocean is eroded continental rock. Understanding the current and future sources of iron to the Southern Ocean as a result of increased melting of terrestrial glaciers is necessary for predicting future concentrations of Southern Ocean phytoplankton and the subsequent influence on the carbon cycle. A poorly understood source of iron to the Southern Ocean is stream input from ice-free regions such as the McMurdo Dry Valleys in Antarctica. This source of iron is likely to become larger if glaciers retreat. This study investigates the sources and amount of iron transported by McMurdo Dry Valley streams directly into the Southern Ocean. Because not all forms of iron can be used by phytoplankton, experiments will be performed to determine how available iron is to phytoplankton and how iron mixes with seawater. Immersive 360-degree video, infographics, and educational videos of findings from this project will be shared on social media, at schools and science events, and in an urban science center.\u003cbr/\u003e\u003cbr/\u003eIn the Southern Ocean (SO) there is an excess of macronutrients but regional primary production is limited or co-limited due to iron. An addition of iron to the ocean will affect biochemical cycles, increase primary production, and affect the structure and composition of phytoplankton communities in the SO. Iron flux to the SO is globally significant, as increased Fe fertilization leads to increased carbon sequestration which acts as a negative feedback to increased atmospheric pCO2. One source of potentially bioavailable iron to the coastal regions of the SO is from direct sub-aerial stream discharge in ice-free areas of Antarctica, a source that may become more important if terrestrial glaciers retreat. It is imperative to understand the source, nature, potential fate, and flux of iron to the SO if better predictive models for the carbon cycle and atmospheric chemistry are to be developed. This project will investigate in-stream processes and characteristics controlling dissolved iron draining into the Ross Sea including photoreduction, temperature, and complexation with organic matter. The novel study will quantify bioavailability of particulate iron and bioavailability of dissolved iron in Antarctic in streams draining into the SO. On-site speciation measurements will be performed on dissolved iron species, particulate iron speciation will be determined using high-resolution spectroscopy, mixing experiments will be performed with coastal marine water, and the bioavailability of Fe will be determined through marine bioassays. This project will provide two students with valuable Antarctic field experience and reach thousands of individuals through existing partnerships with K-12 schools, public STEM events, an urban science center, and a strong social media presence.\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": 163.554215, "geometry": "POINT(163.4642475 -77.5853675)", "instruments": null, "is_usap_dc": true, "keywords": "SURFACE WATER CHEMISTRY; Iron Fertilization; McMurdo Dry Valleys; Weathering", "locations": "McMurdo Dry Valleys", "north": -77.558627, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Lyons, W. Berry; Gardner, Christopher B.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.612108, "title": "Fe Behavior and Bioavailability in Sub-aerial Runoff into the Ross Sea", "uid": "p0010483", "west": 163.37428}, {"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.\u003cbr/\u003e\u003cbr/\u003eThis 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.", "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": "Hawes, Ian; Mackey, Tyler; Juarez Rivera, Marisol; Sumner, Dawn; Paul, Ann", "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.", "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 Earth Sciences; Antarctic Organisms and Ecosystems", "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": "2325922 Couradeau, Estelle", "bounds_geometry": "POLYGON((-73.783 4.679,-73.7827 4.679,-73.7824 4.679,-73.7821 4.679,-73.7818 4.679,-73.7815 4.679,-73.7812 4.679,-73.7809 4.679,-73.7806 4.679,-73.7803 4.679,-73.78 4.679,-73.78 4.6789,-73.78 4.6788,-73.78 4.6787,-73.78 4.6786,-73.78 4.6785,-73.78 4.6784,-73.78 4.6783,-73.78 4.6782,-73.78 4.6781,-73.78 4.678,-73.7803 4.678,-73.7806 4.678,-73.7809 4.678,-73.7812 4.678,-73.7815 4.678,-73.7818 4.678,-73.7821 4.678,-73.7824 4.678,-73.7827 4.678,-73.783 4.678,-73.783 4.6781,-73.783 4.6782,-73.783 4.6783,-73.783 4.6784,-73.783 4.6785,-73.783 4.6786,-73.783 4.6787,-73.783 4.6788,-73.783 4.6789,-73.783 4.679))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Feb 2024 00:00:00 GMT", "description": "As climate change progresses, it is activating both master switches of microbial activity simultaneously: moisture and temperature. In soils, microbes serve critical ecosystem services including nutrient cycling and carbon sequestration. The fact that we do not fully understand how microbes act on carbon pools in soils and how these will change with the rapidly changing climate is extremely worrisome. Here we propose to tackle this question by initiating an interdisciplinary action studying the soils of the Colombian P\u00e1ramos. The P\u00e1ramos are a unique high-altitude hotspot of biodiversity in the Andes that render critical ecosystem services, including water capture and carbon sequestration. If the hydrology of the system has gained a lot of attention over the past few years, the fate of the extensive pools of organic carbon in these vast peatlands has remained unexplored. The unique geographic situation of the cold and humid P\u00e1ramos being already on the edge of their geo-climatic range provides us with an unparalleled opportunity to study a soil microbial community from carbon-rich soils that are extremely vulnerable to both the raise in temperature and decrease of moisture that will impact soils around the globe as climate change progresses. Our project aims at starting to address the need to disentangle the effect of moisture and temperature on the activity and composition of the microbial communities controlling the fate of organic carbon in soils (Objective 1), while assembling an international team of experts capable of scaling up the understanding of these processes at the landscape and regional level by integrating the functioning of the belowground microbial community with the above-ground vegetation (Objective 2).", "east": -73.78, "geometry": "POINT(-73.7815 4.6785)", "instruments": null, "is_usap_dc": true, "keywords": "TERRESTRIAL ECOSYSTEMS; Chingaza Paramos Colombia; ORGANIC MATTER; SOIL MECHANICS", "locations": "Chingaza Paramos Colombia", "north": 4.679, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Couradeau, Estelle; Maximova, Siela; Machado, Jose Luis", "platforms": null, "repositories": null, "science_programs": null, "south": 4.678, "title": "Collaborative Research: BoCP-Design: Climate change alteration of soils functional biodiversity of the P\u00e1ramos, Colombia", "uid": "p0010445", "west": -73.783}, {"awards": "2147045 Learman, Deric", "bounds_geometry": "POLYGON((-180 -60,-168 -60,-156 -60,-144 -60,-132 -60,-120 -60,-108 -60,-96 -60,-84 -60,-72 -60,-60 -60,-60 -62,-60 -64,-60 -66,-60 -68,-60 -70,-60 -72,-60 -74,-60 -76,-60 -78,-60 -80,-72 -80,-84 -80,-96 -80,-108 -80,-120 -80,-132 -80,-144 -80,-156 -80,-168 -80,180 -80,171 -80,162 -80,153 -80,144 -80,135 -80,126 -80,117 -80,108 -80,99 -80,90 -80,90 -78,90 -76,90 -74,90 -72,90 -70,90 -68,90 -66,90 -64,90 -62,90 -60,99 -60,108 -60,117 -60,126 -60,135 -60,144 -60,153 -60,162 -60,171 -60,-180 -60))", "dataset_titles": "Physical and geochemical data from shelf sediments eastern Antarctica", "datasets": [{"dataset_uid": "601876", "doi": null, "keywords": "Antarctica; Cryosphere", "people": "Learman, Deric", "repository": "USAP-DC", "science_program": null, "title": "Physical and geochemical data from shelf sediments eastern Antarctica", "url": "https://www.usap-dc.org/view/dataset/601876"}], "date_created": "Tue, 30 Aug 2022 00:00:00 GMT", "description": "Microbes in Antarctic surface marine sediments have an important role in degrading organic matter and releasing nutrients to the ocean. Organic matter degradation is at the center of the carbon cycle in the ocean, providing valuable information on nutrient recycling, food availability to animals and carbon dioxide release to the atmosphere. The functionality of these microbes has been inferred by their genomics, however these methods only address the possible function, not their actual rates. In this project the PIs plan to combine genomics methods with cellular estimates of enzyme abundance and activity as a way to determine the rates of carbon degradation. This project aims to sample in several regions of Antarctica to provide a large-scale picture of the processes under study and understand the importance of microbial community composition and environmental factors, such as primary productivity, have on microbial activity. The proposed work will combine research tools such as metagenomics, meta-transcriptomics, and metabolomics coupled with chemical data and enzyme assays to establish degradation of organic matter in Antarctic sediments. This project benefits NSFs goals of understanding the adaptation of Antarctic organisms to the cold and isolated environment, critical to predict effects of climate change to polar organisms, as well as contribute to our knowledge of how Antarctic organisms have adapted to this environment. Society will benefit from this project by education of 2 graduate students, undergraduates and K-12 students as well as increase public literacy through short videos production shared in YouTube.\r\n\r\nThe PIs propose to advance understanding of polar microbial community function, by measuring enzyme and gene function of complex organic matter degradation in several ocean regions, providing a circum-Antarctic description of sediment processes. Two hypotheses are proposed. The first hypothesis states that many genes for the degradation of complex organic matter will be shared in sediments throughout a sampling transect and that where variations in gene content occur, it will reflect differences in the quantity and quality of organic matter, not regional variability. The second hypothesis states that a fraction of gene transcripts for organic matter degradation will not result in measurable enzyme activity due to post-translational modification or rapid degradation of the enzymes. The PIs will analyze sediment cores already collected in a 2020 cruise to the western Antarctic Peninsula with the additional request of participating in a cruise in 2023 to East Antarctica. The PIs will analyze sediments for metagenomics, meta-transcriptomics, and metabolomics coupled with geochemical data and enzyme assays to establish microbial degradation of complex organic matter in Antarctic sediments. Organic carbon concentrations and content in sediments will be measured with \u03b413C, \u03b415N, TOC porewater fluorescence in bulk organic carbon. Combined with determination of geographical variability as well as dependence on carbon sources, results from this study could provide the basis for new hypotheses on how climate variability, with increased water temperature, affects geochemistry in the Southern Ocean.", "east": 90.0, "geometry": "POINT(-165 -70)", "instruments": null, "is_usap_dc": true, "keywords": "BENTHIC; ECOSYSTEM FUNCTIONS; Weddell Sea; Antarctic Peninsula; SEDIMENT CHEMISTRY; R/V NBP", "locations": "Antarctic Peninsula; Weddell Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Learman, Deric", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Collaborative Research: ANT LIA: Connecting Metagenome Potential to Microbial Function: Investigating Microbial Degradation of Complex Organic Matter Antarctic Benthic Sediments", "uid": "p0010373", "west": -60.0}, {"awards": "1847067 Levy, Joseph", "bounds_geometry": "POLYGON((161 -76,161.35 -76,161.7 -76,162.05 -76,162.4 -76,162.75 -76,163.1 -76,163.45 -76,163.8 -76,164.15 -76,164.5 -76,164.5 -76.2,164.5 -76.4,164.5 -76.6,164.5 -76.8,164.5 -77,164.5 -77.2,164.5 -77.4,164.5 -77.6,164.5 -77.8,164.5 -78,164.15 -78,163.8 -78,163.45 -78,163.1 -78,162.75 -78,162.4 -78,162.05 -78,161.7 -78,161.35 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76))", "dataset_titles": "Biogeochemical measurements of water tracks and adjacent dry soils from the McMurdo Dry Valleys; Surface Water Geochemistry from the McMurdo Dry Valleys", "datasets": [{"dataset_uid": "601684", "doi": "10.15784/601684", "keywords": "Antarctica; Cation Exchange; Chemistry:soil; Chemistry:Soil; Dry Valleys; Organic Matter; Salt; Soil", "people": "Levy, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Biogeochemical measurements of water tracks and adjacent dry soils from the McMurdo Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601684"}, {"dataset_uid": "601703", "doi": "10.15784/601703", "keywords": "Antarctica; Dry Valleys", "people": "Levy, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Surface Water Geochemistry from the McMurdo Dry Valleys", "url": "https://www.usap-dc.org/view/dataset/601703"}], "date_created": "Fri, 24 Dec 2021 00:00:00 GMT", "description": "Antarctic groundwater drives the regional carbon cycle, accelerates permafrost thaw, and shapes Antarctic climate response. However, groundwater extent, movement, and processes on a continent virtually locked in ice are poorly understood. The proposed work investigates the interplay between groundwater, sediment, and ice in Antarctica\u2019s cold desert landscapes to determine when, where, and why Antarctic groundwater is flowing, and how quickly it will switch Antarctic frozen deserts from dry and stable to wet and disintegrating. Little is known about the extent, chemistry, and duration of groundwater in Antarctic seasonal wetlands. Mapping the changing extent of Antarctic wetlands requires the ability to measure soil moisture rapidly and repeatedly and over large areas. Changing groundwater extent will be captured through an unmanned aerial vehicle (UAV)-based mapping approach. The project integrates a diverse range of sensors with new UAV technologies to provide a higher-resolution and more frequent assessment of Antarctic groundwater extent and composition than can be accomplished using satellite observations alone. To complement the research objectives, the PI will develop a new UAV summer field school, the Geosciences UAV Academy, focused on training undergraduate-level UAV pilots in conducting novel Earth science research using cutting edge imaging tools. The integration of research and technology will prepare students for careers in burgeoning UAV-related industries and research. The project will deliver new UAV tools and workflows for soil moisture mapping relevant to arid regions common not just to Antarctica but to temperate desert and dryland systems and will train student research pilots to tackle next generation airborne challenges. \r\n\r\nWater tracks are the basic hydrological unit that currently feeds the rapidly-changing polar and permafrost wetlands in the Antarctic McMurdo Dry Valleys (MDV). Despite the importance of water tracks in the MDV hydrologic cycle and their influence on biogeochemistry, little is known about how these water tracks control the unique brine processes operating in Antarctic ice-free areas. Both groundwater availability and geochemistry shape Antarctic microbial communities, connecting soil geology and hydrology to carbon cycling and ecosystem functioning. The objectives of this CAREER proposal are to 1) map water tracks to determine the spatial distribution and seasonal magnitude of groundwater impacts on the MDV near-surface environment to determine how water tracks drive irreversible permafrost thaw, how water tracks enhance chemical weathering and biogeochemical cycling, and how water tracks integrate and accelerate climate feedbacks between terrestrial Antarctic soils and the Southern Ocean; 2) establish a UAV academy training earth sciences students to answer geoscience questions using drone-based platforms and remote sensing techniques; and 3) provide a formative step in the development of the PI as a teacher-scholar. UAV-borne hyperspectral imaging complemented with field soil sampling will determine the aerial extent and timing of inundation, water level, and water budget of representative water tracks in the MDV. Soil moisture will be measured via near-infrared reflectance spectroscopy while bulk chemistry of soils and groundwater will be analyzed via ion chromatography and soil x-ray fluorescence. Sedimentological and hydrological properties (suction/matric potential, hydraulic conductivity, etc.) will be determined via analysis of intact core samples. These data will be used to test competing hypotheses regarding the origin of water track solutions and water movement through seasonal wetlands. The will provide a regional understanding of Antarctic groundwater sources, groundwater flux, and the influence of regional hydrogeology on solute export to the Southern Ocean and on soil/atmosphere linkages in earth\u2019s carbon budget. The UAV school will 1) provide comprehensive instruction at the undergraduate level in both how and why UAVs can be used in geoscience research and learning; and 2) provide a long-term piece of educational infrastructure in the form of an ultimately self-sustaining summer program for undergraduate UAV education. \r\n", "east": 164.5, "geometry": "POINT(162.75 -77)", "instruments": null, "is_usap_dc": true, "keywords": "FIELD SURVEYS; Amd/Us; USA/NSF; AMD; USAP-DC; FROZEN GROUND; Taylor Valley", "locations": "Taylor Valley", "north": -76.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Levy, Joseph", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -78.0, "title": "Linking Antarctic Cold Desert Groundwater to Thermokarst \u0026 Chemical Weathering in Partnership with the Geoscience UAV Academy", "uid": "p0010286", "west": 161.0}, {"awards": "1941308 Fitzsimmons, Jessica; 1941483 Yager, Patricia; 1941327 Stammerjohn, Sharon; 1941304 Sherrell, Robert; 1941292 St-Laurent, Pierre", "bounds_geometry": "POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.4,-100 -71.8,-100 -72.2,-100 -72.6,-100 -73,-100 -73.4,-100 -73.8,-100 -74.2,-100 -74.6,-100 -75,-102 -75,-104 -75,-106 -75,-108 -75,-110 -75,-112 -75,-114 -75,-116 -75,-118 -75,-120 -75,-120 -74.6,-120 -74.2,-120 -73.8,-120 -73.4,-120 -73,-120 -72.6,-120 -72.2,-120 -71.8,-120 -71.4,-120 -71))", "dataset_titles": "Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files; Expedition Data of NBP2202; Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica); Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea", "datasets": [{"dataset_uid": "601785", "doi": "10.15784/601785", "keywords": "Amundsen Sea; Antarctica; Cryosphere; CTD; NBP2202; Oceanography; R/v Nathaniel B. Palmer", "people": "Stammerjohn, Sharon", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Vertical ocean profiles collected by a Conductivity-Temperature-Depth (CTD) package in the Amundsen Sea", "url": "https://www.usap-dc.org/view/dataset/601785"}, {"dataset_uid": "200400", "doi": "10.17882/99231", "keywords": null, "people": null, "repository": "SEANOE", "science_program": null, "title": "Numerical experiments examining the response of onshore oceanic heat supply to yearly changes in the Amundsen Sea icescape (Antarctica)", "url": "https://doi.org/10.17882/99231"}, {"dataset_uid": "200399", "doi": "10.25773/bt54-sj65", "keywords": null, "people": null, "repository": "William \u0026 Mary ScholarWorks", "science_program": null, "title": "Dataset: A numerical simulation of the ocean, sea ice and ice shelves in the Amundsen Sea (Antarctica) over the period 2006-2022 and its associated code and input files", "url": "https://doi.org/10.25773/bt54-sj65"}, {"dataset_uid": "200311", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2202", "url": "https://www.rvdata.us/search/cruise/NBP2202"}], "date_created": "Fri, 20 Aug 2021 00:00:00 GMT", "description": " The Amundsen Sea hosts the most productive polynya in all of Antarctica, with its vibrant green waters visible from space, and an atmospheric CO2 uptake density 10x higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape, and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet (WAIS). ARTEMIS aims to characterize the climate-sensitive nature of glacial meltwater-driven micronutrient (iron, Fe) contributions driving ecosystem productivity and CO2 uptake in the coastal Antarctic. We propose to integrate observations and ocean modeling of these processes to enhance predictive capabilities. Currently, basal melt resulting from warm deep waters penetrating ice shelf cavities dominates mass losses of WAIS, contributing to sea level rise. These physical melting processes are being studied by the International Thwaites Glacier Collaboration (ITGC). The impact of melting on the marine ecosystem has also been explored, and we know that productivity is due in part to Fe-rich, glacial meltwater-driven outflow. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied, however. Improved knowledge would provide keys to understanding meltwater\u0027s future impact on the ecosystem. An ongoing field program (TARSAN, part of the ITGC) offers the ideal physical oceanographic framework for our biogeochemical effort. We propose here to collaborate with TARSAN-supported UK scientists, providing value added to both team efforts. ARTEMIS will add shipboard measurements (trace metals, carbonate system, nutrients, organic matter, microorganisms) and biogeochemical sensors on autonomous vehicles to gather critical knowledge needed to understand the impact of the melting WAIS on both the coastal ecosystem and the regional carbon (C) cycle. Driving questions include: 1) what are the fluxes and chemical forms of Fe, C, and microorganisms in the ice shelf outflow? 2) what are the relative contributions to the ouflow from deep water, benthic, and glacial melt sources, and how do these inputs combine to affect the bioavailability of Fe? 3) How are Fe and C compounds modified as the outflow advects along the coastal current and mixes into the bloom region? and 4) what will be the effect of increased glacial melting, changes in the coastal icescape, and declining sea ice on theecosystem of the Amundsen Sea? Such questions fall outside the focus of the ITGC, but are of keen interest to Antarctic Organisms and Ecosystems and Antarctic Integrated System Science programs.", "east": -100.0, "geometry": "POINT(-110 -73)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; USA/NSF; USAP-DC; AMD; Amundsen Sea; Amd/Us; SHIPS", "locations": "Amundsen Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "R2R; SEANOE; USAP-DC; William \u0026 Mary ScholarWorks", "science_programs": "Thwaites (ITGC)", "south": -75.0, "title": "NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)", "uid": "p0010249", "west": -120.0}, {"awards": "2031442 Learman, Deric", "bounds_geometry": "POLYGON((-180 -60,-167.5 -60,-155 -60,-142.5 -60,-130 -60,-117.5 -60,-105 -60,-92.5 -60,-80 -60,-67.5 -60,-55 -60,-55 -62,-55 -64,-55 -66,-55 -68,-55 -70,-55 -72,-55 -74,-55 -76,-55 -78,-55 -80,-67.5 -80,-80 -80,-92.5 -80,-105 -80,-117.5 -80,-130 -80,-142.5 -80,-155 -80,-167.5 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -78,160 -76,160 -74,160 -72,160 -70,160 -68,160 -66,160 -64,160 -62,160 -60,162 -60,164 -60,166 -60,168 -60,170 -60,172 -60,174 -60,176 -60,178 -60,-180 -60))", "dataset_titles": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "datasets": [{"dataset_uid": "601607", "doi": "10.15784/601607", "keywords": "Antarctica; Antarctic Peninsula; Grain Size; Grain Size Analysis; Marine Geoscience; Marine Sediments; Organic Matter Geochemistry; Sediment Core Data; Shelf Sediments; Weddell Sea", "people": "Learman, Deric", "repository": "USAP-DC", "science_program": null, "title": "Physical and geochemical data from shelf sediments near the Antartic Pennisula", "url": "https://www.usap-dc.org/view/dataset/601607"}], "date_created": "Wed, 28 Jul 2021 00:00:00 GMT", "description": "This proposal will provide genetic and enzymatic insight into how microbial communities in benthic sediments on the coastal shelf of Antarctica degrade complex organic matter. The current understanding of how benthic microbial communities respond and also degrade complex organic matter in Antarctica is fragmented. Recent work suggests benthic microbial communities are shaped by organic matter availability (encompassing both quantity and quality), however, these studies were observational and did not directly examine community function (e.g. enzyme activity and/or gene expression). Preliminary metagenomic data, collected from western Antarctica marine sediments, document gene potential for organic matter degradation throughout the entire sample set (spanning the Amundsen Sea, Bellingshausen Sea, and Ross Sea), but functional data was not collected. To date, studies have examined either enzyme activity or metagenomic potential but few have been able to directly connect the two. To address these gaps in knowledge, this proposal will utilize powerful tools such as metagenomics and metatranscriptomics, coupled with microcosm experiments, enzyme assays, and geochemical data. This hypothesis driven proposal will examine microbial communities from the continental shelf of Antarctica from two different regions (Bransfield Strait and Weddell Sea) to document the communities\u2019 enzymatic activity and genes used to degrade complex organic matter. These data will expand our current knowledge of genetic potential towards a more direct understanding of enzyme function as it relates to degradation of complex organic matter in marine sediments from Antarctica. ", "east": 160.0, "geometry": "POINT(-127.5 -70)", "instruments": null, "is_usap_dc": true, "keywords": "ECOSYSTEM FUNCTIONS; USAP-DC; Antarctic Peninsula; BENTHIC; SHIPS; SEDIMENT CHEMISTRY; Amd/Us; AMD; USA/NSF; Weddell Sea", "locations": "Antarctic Peninsula; Weddell Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Learman, Deric", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments", "uid": "p0010235", "west": -55.0}, {"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": "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. We 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, we 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. \r\n\r\nTo test our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We 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) We 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. We will integrate these data 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.\r\n", "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": "1341304 Sidor, Christian; 1341376 Tabor, Neil; 1341475 Smith, Nathan; 1341645 Makovicky, Peter; 2001033 Makovicky, Peter", "bounds_geometry": "POLYGON((-180 -84,-178 -84,-176 -84,-174 -84,-172 -84,-170 -84,-168 -84,-166 -84,-164 -84,-162 -84,-160 -84,-160 -84.3,-160 -84.6,-160 -84.9,-160 -85.2,-160 -85.5,-160 -85.8,-160 -86.1,-160 -86.4,-160 -86.7,-160 -87,-162 -87,-164 -87,-166 -87,-168 -87,-170 -87,-172 -87,-174 -87,-176 -87,-178 -87,180 -87,178.5 -87,177 -87,175.5 -87,174 -87,172.5 -87,171 -87,169.5 -87,168 -87,166.5 -87,165 -87,165 -86.7,165 -86.4,165 -86.1,165 -85.8,165 -85.5,165 -85.2,165 -84.9,165 -84.6,165 -84.3,165 -84,166.5 -84,168 -84,169.5 -84,171 -84,172.5 -84,174 -84,175.5 -84,177 -84,178.5 -84,-180 -84))", "dataset_titles": "Lower Triassic Antarctic vertebrate fossils at Field Museum, Chicago, IL", "datasets": [{"dataset_uid": "601511", "doi": "10.15784/601511", "keywords": "Allan Hills; Antarctica; Fremouw Formation; Lystrosaurus; Permo-Triassic Extinction; Prolacerta; Sample Location; Thrinaxofon; Triassic", "people": "Makovicky, Peter", "repository": "USAP-DC", "science_program": null, "title": "Lower Triassic Antarctic vertebrate fossils at Field Museum, Chicago, IL", "url": "https://www.usap-dc.org/view/dataset/601511"}], "date_created": "Tue, 29 Jun 2021 00:00:00 GMT", "description": "This project will advance our understanding of Antarctic life during the Permian and Triassic. We will apply an interdisciplinary approach to address relationships between environmental change, faunal composition, and biogeographic patterns in the context of the high-latitude strata preserved in the Buckley and Fremouw formations in the Shackleton Glacier region. We will use multiple types of data to assess paleoenvironment, including: 1) paleosol morphology; 2) paleosol geochemistry; 3) pedogenic organic matter; and 4) fossil wood chronology and stable isotopes. The Fremouw Formation of Antarctica preserves the highest paleolatitude tetrapod fauna of the entire Triassic (~70\u00b0 S) and thus has the potential to shed important light on the evolution of polar life during the early Mesozoic. We will collect new fossils from known localities to understand the relationship between Antarctic and southern African tetrapod faunas. Furthermore, we will refine the stratigraphic, sedimentological, and geochronological framework for these Mesozoic faunas, which will include using U/Pb detrital zircon dating to provide the first dates for these vertebrate assemblages. In the lab, we will examine the biology of Triassic vertebrates from Antarctica by comparing their bone and tusk histology to conspecifics from lower paleolatitudes. In addition, we will test Bergmann\u2019s Rule with six species (viz. Lystrosaurus curvatus, L. maccaigi, L. murrayi, Prolacerta broomi, Procolophon trigoniceps, and Thrinaxodon liorhinus). The Early Triassic presents a unique opportunity to perform such investigations as there is no other geologic interval in which species occurring in Antarctica can be compared to conspecifics across a range of paleolatitudes.", "east": -160.0, "geometry": "POINT(-177.5 -85.5)", "instruments": null, "is_usap_dc": true, "keywords": "REPTILES; FIELD SURVEYS; USA/NSF; PALEOCLIMATE RECONSTRUCTIONS; Triassic; USAP-DC; TERRESTRIAL ECOSYSTEMS; MACROFOSSILS; Amd/Us; Fossils; Shackleton Glacier; LAND RECORDS; ANIMALS/VERTEBRATES; AMD", "locations": "Shackleton Glacier", "north": -84.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Sidor, Christian; Smith, Nathan; Makovicky, Peter; Tabor, Neil", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -87.0, "title": "Collaborative Research: Understanding the evolution of high-latitude Permo-Triassic paleoenvironments and their vertebrate communities", "uid": "p0010213", "west": 165.0}, {"awards": "1643345 Popp, Brian; 1643466 Hollibaugh, James", "bounds_geometry": "POLYGON((-78.20206667 -64.03195833,-76.785055836 -64.03195833,-75.368045002 -64.03195833,-73.951034168 -64.03195833,-72.534023334 -64.03195833,-71.1170125 -64.03195833,-69.700001666 -64.03195833,-68.282990832 -64.03195833,-66.865979998 -64.03195833,-65.448969164 -64.03195833,-64.03195833 -64.03195833,-64.03195833 -64.554377497,-64.03195833 -65.076796664,-64.03195833 -65.599215831,-64.03195833 -66.121634998,-64.03195833 -66.644054165,-64.03195833 -67.166473332,-64.03195833 -67.688892499,-64.03195833 -68.211311666,-64.03195833 -68.733730833,-64.03195833 -69.25615,-65.448969164 -69.25615,-66.865979998 -69.25615,-68.282990832 -69.25615,-69.700001666 -69.25615,-71.1170125 -69.25615,-72.534023334 -69.25615,-73.951034168 -69.25615,-75.368045002 -69.25615,-76.785055836 -69.25615,-78.20206667 -69.25615,-78.20206667 -68.733730833,-78.20206667 -68.211311666,-78.20206667 -67.688892499,-78.20206667 -67.166473332,-78.20206667 -66.644054165,-78.20206667 -66.121634998,-78.20206667 -65.599215831,-78.20206667 -65.076796664,-78.20206667 -64.554377497,-78.20206667 -64.03195833))", "dataset_titles": "\"Collaborative research: Chemoautotrophy in Antarctic bacterioplankton communities supported by the oxidation of urea-derived nitrogen\"; Expedition data of LMG1801", "datasets": [{"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": "200193", "doi": "Not yet assigned", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "\"Collaborative research: Chemoautotrophy in Antarctic bacterioplankton communities supported by the oxidation of urea-derived nitrogen\"", "url": "https://www.bco-dmo.org/project/775717"}], "date_created": "Fri, 18 Dec 2020 00:00:00 GMT", "description": "The project addressed fundamental questions regarding the role of nitrification (the conversion of ammonium to nitrate by a two-step process involving two different guilds of microorganisms: ammonia- and nitrite-oxidizers) in the Antarctic marine ecosystem. Specifically, the project evaluated the contribution of carbon fixation supported by energy derived from the oxidation of nitrogen compounds (chemoautotrophy) to the overall supply of organic carbon to the food web of the Southern Ocean. Additionally, the project aimed to determine the significance of the contribution of other sources of reduced nitrogen, specifically organic nitrogen and urea, to nitrification because these contributions may not be assessed by standard protocols. \n\n\u003cbr\u003e\u003cbr\u003eWe quantified the oxidation rates of 15N supplied as ammonium, urea and nitrite, which allowed us to estimate the contribution of urea-derived N and complete nitrification (ammonia to nitrate, N-3 to N+5) to chemoautotrophy in Antarctic coastal waters. We compared these estimates to direct measurements of the incorporation of dissolved inorganic 14C into organic matter in the dark for an independent estimate of chemoautotrophy. We made measurements on samples taken from the major water masses: surface water (~10 m), winter water (35-174 m), circumpolar deep water (175-1000 m) and slope water (\u003e1000 m); on a cruise surveying the continental shelf and slope west of the Antarctic Peninsula in the austral summer of 2018 (LMG18-01). Samples were also taken to measure the concentrations of nitrite, ammonia, urea and polyamines; for qPCR analysis of the abundance of relevant marker genes; and for studies of processes related to the core questions of the study. The project relied on collaboration with the Palmer LTER for ancillary data (bacterioplankton abundance and production, chlorophyll, physical and additional chemical variables). The synergistic activities of this project along with the LTER activities provides a unique opportunity to assess chemoautotrophy in context of the overall ecosystem\u0027s dynamics, including both primary and secondary production processes.\n\u003cbr\u003e\u003cbr\u003eThis project resulted in the training of a postdoctoral researcher and provide undergraduate students opportunities to gain hand-on experience with research on microbial geochemistry. This project contributed substantially to understanding an important aspect of nitrogen cycling and bacterioplankton production in the study area. Both PIs participate fully in the education and outreach efforts of the Palmer LTER, including making highlights of the findings available for posting to the LTER project web site, posting material to web sites at their respective departments, and incorporating material from the study in lectures and seminars presented at their respective institutions. \n", "east": -64.03195833, "geometry": "POINT(-71.1170125 -66.644054165)", "instruments": null, "is_usap_dc": true, "keywords": "Pal-Lter; NITROGEN; SHIPS; USAP-DC; MARINE ECOSYSTEMS; BACTERIA/ARCHAEA; BIOGEOCHEMICAL CYCLES; Amd/Us; West Antarctic Shelf; USA/NSF; AMD", "locations": "West Antarctic Shelf; Pal-Lter", "north": -64.03195833, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Hollibaugh, James T.; Popp, Brian", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "R2R", "repositories": "BCO-DMO; R2R", "science_programs": null, "south": -69.25615, "title": "Collaborative Research: Chemoautotrophy in Antarctic Bacterioplankton Communities Supported by the Oxidation of Urea-derived Nitrogen", "uid": "p0010150", "west": -78.20206667}, {"awards": "1543453 Lyons, W. Berry; 1543405 Leventer, Amy; 1543537 Priscu, John; 1543441 Fricker, Helen; 1543396 Christner, Brent; 1543347 Rosenheim, Brad", "bounds_geometry": "POLYGON((-163.611 -84.33543,-162.200034 -84.33543,-160.789068 -84.33543,-159.378102 -84.33543,-157.967136 -84.33543,-156.55617 -84.33543,-155.145204 -84.33543,-153.734238 -84.33543,-152.323272 -84.33543,-150.912306 -84.33543,-149.50134 -84.33543,-149.50134 -84.3659157,-149.50134 -84.3964014,-149.50134 -84.4268871,-149.50134 -84.4573728,-149.50134 -84.4878585,-149.50134 -84.5183442,-149.50134 -84.5488299,-149.50134 -84.5793156,-149.50134 -84.6098013,-149.50134 -84.640287,-150.912306 -84.640287,-152.323272 -84.640287,-153.734238 -84.640287,-155.145204 -84.640287,-156.55617 -84.640287,-157.967136 -84.640287,-159.378102 -84.640287,-160.789068 -84.640287,-162.200034 -84.640287,-163.611 -84.640287,-163.611 -84.6098013,-163.611 -84.5793156,-163.611 -84.5488299,-163.611 -84.5183442,-163.611 -84.4878585,-163.611 -84.4573728,-163.611 -84.4268871,-163.611 -84.3964014,-163.611 -84.3659157,-163.611 -84.33543))", "dataset_titles": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset; Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset; Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland; CTD data from Mercer Subglacial Lake and access borehole; Discrete bulk sediment properties data from Mercer Subglacial Lake; Isotopic data from Whillans Ice Stream grounding zone, West Antarctica; Mercer Subglacial Lake radiocarbon and stable isotope data ; Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995); Mercer Subglacial Lake (SLM) noble gas and isotopic data; Mercer Subglacial Lake water column viral metagenomic sequencing; Salsa sediment cores; Sediment porewater properties data from Mercer Subglacial Lake; Water column biogeochemical data from Mercer Subglacial Lake", "datasets": [{"dataset_uid": "200217", "doi": "10.7283/3JMY-Y504", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA09-WIS_LAKES_09 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/3JMY-Y504"}, {"dataset_uid": "200216", "doi": "10.7283/F8NH-CV04", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA07-WIS_LAKES_07 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F8NH-CV04"}, {"dataset_uid": "601472", "doi": "10.15784/601472", "keywords": "Antarctica; Bistatic Radar; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS Data; Greenland; Lake Whillans; Radar; Store Glacier; Whillans Ice Stream; WISSARD", "people": "Bienert, Nicole; MacKie, Emma; Dawson, Eliza; Christoffersen, Poul; Schroeder, Dustin; Peters, Sean; Siegfried, Matthew", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Bistatic Radar Sounding of Whillans Ice Stream, Antarctica and Store Glacier, Greenland", "url": "https://www.usap-dc.org/view/dataset/601472"}, {"dataset_uid": "200215", "doi": "10.7283/C503-KS23", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA06-WIS_LAKES_06 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/C503-KS23"}, {"dataset_uid": "601664", "doi": "10.15784/601664", "keywords": "Antarctica; Gas; Geochemistry; Glacier; Glaciology; Mercer Subglacial Lake; Methane; SALSA; Sediment Core; West Antarctic Ice Sheet", "people": "Skidmore, Mark; Dore, John; Michaud, Alexander; Tranter, Martyn; Steigmeyer, August; Science Team, SALSA", "repository": "USAP-DC", "science_program": null, "title": "Sediment porewater properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601664"}, {"dataset_uid": "601360", "doi": "10.15784/601360", "keywords": "Antarctica; Radiocarbon; Sediment; Whillans Ice Stream", "people": "Venturelli, Ryan A", "repository": "USAP-DC", "science_program": "WISSARD", "title": "Isotopic data from Whillans Ice Stream grounding zone, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601360"}, {"dataset_uid": "200214", "doi": "10.7283/YW8Z-TK03", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - LA02-WIS_LAKES_02 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/YW8Z-TK03"}, {"dataset_uid": "200213", "doi": "10.7283/F7BB-JH05", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ13-WIS_GroundingZone_13 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/F7BB-JH05"}, {"dataset_uid": "200212", "doi": "10.7283/PT0Q-JB95", "keywords": null, "people": null, "repository": "UNAVCO", "science_program": null, "title": "Antarctica - PI Continuous - GZ01-WIS_GroundingZone_01 P.S. - GPS/GNSS Observations Dataset", "url": "https://www.unavco.org/data/doi/10.7283/PT0Q-JB95"}, {"dataset_uid": "200246", "doi": "", "keywords": null, "people": null, "repository": "OSU-MGR", "science_program": null, "title": "Salsa sediment cores", "url": "https://osu-mgr.org"}, {"dataset_uid": "601498", "doi": "10.15784/601498", "keywords": "Antarctica; Mercer Subglacial Lake; Noble Gas", "people": "Gardner, Christopher B.; Lyons, W. Berry", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake (SLM) noble gas and isotopic data", "url": "https://www.usap-dc.org/view/dataset/601498"}, {"dataset_uid": "200342", "doi": null, "keywords": null, "people": null, "repository": "GenBank", "science_program": null, "title": "Mercer Subglacial Lake water column viral metagenomic sequencing", "url": "https://www.ncbi.nlm.nih.gov/biosample/32811410"}, {"dataset_uid": "601657", "doi": "10.15784/601657", "keywords": "Antarctica; Conductivity; CTD; Depth; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Hot Water Drill; Mercer Subglacial Lake; Physical Properties; SALSA; Subglacial Lake; Temperature", "people": "Leventer, Amy; Priscu, John; Rosenheim, Brad; Dore, John", "repository": "USAP-DC", "science_program": null, "title": "CTD data from Mercer Subglacial Lake and access borehole", "url": "https://www.usap-dc.org/view/dataset/601657"}, {"dataset_uid": "601661", "doi": "10.15784/601661", "keywords": "Antarctica; Carbon; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Iron; Mercer Subglacial Lake; Mineralogy; Particle Size; Physical Properties; SALSA; Sediment Core; Sulfur; West Antarctic Ice Sheet", "people": "Michaud, Alexander; Campbell, Timothy; Dore, John; Venturelli, Ryan A; Science Team, SALSA; Skidmore, Mark; Tranter, Martyn; Hawkings, Jon", "repository": "USAP-DC", "science_program": null, "title": "Discrete bulk sediment properties data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601661"}, {"dataset_uid": "200282", "doi": "", "keywords": null, "people": null, "repository": "NCBI GenBank", "science_program": null, "title": "Mercer Subglacial Lake (SLM) microbial composition: 16S rRNA genes (Sequence Read Archive; BioProject: PRJNA790995)", "url": "https://www.ncbi.nlm.nih.gov/bioproject/?term=PRJNA790995"}, {"dataset_uid": "601663", "doi": "10.15784/601663", "keywords": "Antarctica; Carbon; Cell Counts; Geochemistry; Glacier; Glaciers/ice Sheet; Glaciers/Ice Sheet; Mercer Subglacial Lake; Microbes; Nutrients; SALSA; Stable Isotopes; Trace Elements; West Antarctic Ice Sheet", "people": "Li, Wei; Skidmore, Mark; Science Team, SALSA; Priscu, John; Hawkings, Jon; Dore, John; Steigmeyer, August; Tranter, Martyn; Barker, Joel", "repository": "USAP-DC", "science_program": null, "title": "Water column biogeochemical data from Mercer Subglacial Lake", "url": "https://www.usap-dc.org/view/dataset/601663"}, {"dataset_uid": "601672", "doi": "10.15784/601672", "keywords": "Antarctica; Isotope; Mercer Subglacial Lake; Radiocarbon; Subglacial Lake", "people": "Rosenheim, Brad; Venturelli, Ryan", "repository": "USAP-DC", "science_program": null, "title": "Mercer Subglacial Lake radiocarbon and stable isotope data ", "url": "https://www.usap-dc.org/view/dataset/601672"}], "date_created": "Thu, 16 Jul 2020 00:00:00 GMT", "description": "The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website.\u003cbr/\u003e\u003cbr/\u003eSubglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \\\"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\\\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication.", "east": -149.50134, "geometry": "POINT(-156.55617 -84.4878585)", "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENTS; Antarctica; ISOTOPES; Subglacial Lake; USAP-DC; VIRUSES; PALEOCLIMATE RECONSTRUCTIONS; BACTERIA/ARCHAEA; LABORATORY; Radiocarbon; Whillans Ice Stream; AMD; SALSA; ECOSYSTEM FUNCTIONS; RADIOCARBON; FIELD INVESTIGATION; ICE MOTION; Mercer Ice Stream; Amd/Us; USA/NSF; GLACIERS/ICE SHEETS", "locations": "Antarctica; Mercer Ice Stream; Whillans Ice Stream", "north": -84.33543, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Glaciology; Antarctic Instrumentation and Support; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Rosenheim, Brad; Fricker, Helen; Priscu, John; Leventer, Amy; Dore, John; Lyons, W. Berry; Christner, Brent", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "UNAVCO", "repositories": "GenBank; NCBI GenBank; OSU-MGR; UNAVCO; USAP-DC", "science_programs": null, "south": -84.640287, "title": "Collaborative Research: Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated Study of Carbon Cycling in Hydrologically-active Subglacial Environments", "uid": "p0010119", "west": -163.611}, {"awards": "1544526 Omelon, Christopher", "bounds_geometry": "POLYGON((160 -76.5,160.37 -76.5,160.74 -76.5,161.11 -76.5,161.48 -76.5,161.85 -76.5,162.22 -76.5,162.59 -76.5,162.96 -76.5,163.33 -76.5,163.7 -76.5,163.7 -76.63,163.7 -76.76,163.7 -76.89,163.7 -77.02,163.7 -77.15,163.7 -77.28,163.7 -77.41,163.7 -77.54,163.7 -77.67,163.7 -77.8,163.33 -77.8,162.96 -77.8,162.59 -77.8,162.22 -77.8,161.85 -77.8,161.48 -77.8,161.11 -77.8,160.74 -77.8,160.37 -77.8,160 -77.8,160 -77.67,160 -77.54,160 -77.41,160 -77.28,160 -77.15,160 -77.02,160 -76.89,160 -76.76,160 -76.63,160 -76.5))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 09 May 2019 00:00:00 GMT", "description": "Cryptoendoliths are organisms that colonize microscopic cavities of rocks, which give them protection and allow them to inhabit extreme environments, such as the cold, arid desert of the Dry Valleys of Antarctica. Fossilized cryptoendoliths preserve the forms and features of organisms from the past and thus provide a unique opportunity to study the organisms\u0027 life histories and environments. To study this fossil record, there needs to be a better understanding of what environmental conditions allow these fossils to form. A climate gradient currently exists in the Dry Valleys that allows us to study living, dead, and fossilized cryptoendoliths from mild to increasingly harsh environments; providing insight to the limits of life and how these fossils are formed. This project will develop instruments to detect the biological activity of the live microorganisms and conduct laboratory experiments to determine the environmental limits of their survival. The project also will characterize the chemical and structural features of the living, dead, and fossilized cryptoendoliths to understand how they become fossilized. Knowing how microorganisms are preserved as fossils in cold and dry environments like Antarctica can help to refine methods that can be used to search for and identify evidence for extraterrestrial life in similar habitats on planets such as Mars. This project includes training of graduate and undergraduate students.\r\n\r\nLittle is known about cryptoendolithic microfossils and their formation processes in cold, arid terrestrial habitats of the Dry Valleys of Antarctica, where a legacy of activity is discernible in the form of biosignatures including inorganic materials and microbial fossils that preserve and indicate traces of past biological activity. The overarching goals of the proposed work are: (1) to determine how rates of microbial respiration and biodegradation of organic matter control microbial fossilization; and (2) to characterize microbial fossils and their living counterparts to elucidate mechanisms for fossilization. Using samples collected across an increasingly harsher (more cold and dry) climatic gradient that encompasses living, dead, and fossilized cryptoendolithic microorganisms, the proposed work will: (1) develop an instrument to be used in the field that can measure small concentrations of CO2 in cryptoendolithic habitats in situ; (2) use microscopy techniques to characterize endolithic microorganisms as well as the chemical and morphological characteristics of biosignatures and microbial fossils. A metagenomic survey of microbial communities in these samples will be used to characterize differences in diversity, identify if specific microorganisms (e.g. prokaryotes, eukaryotes) are more capable of surviving under these harsh climatic conditions, and to corroborate microscopic observations of the viability states of these microorganisms.", "east": 163.7, "geometry": "POINT(161.85 -77.15)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; NOT APPLICABLE; TERRESTRIAL ECOSYSTEMS", "locations": "Antarctica", "north": -76.5, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Omelon, Christopher; Breecker, Daniel; Bennett, Philip", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -77.8, "title": "Activity, Preservation and Fossilization of Cryptoendolithic Microorganisms in Antarctica", "uid": "p0010028", "west": 160.0}, {"awards": "1341669 DeMaster, David", "bounds_geometry": "POLYGON((-70 -62,-68.8 -62,-67.6 -62,-66.4 -62,-65.2 -62,-64 -62,-62.8 -62,-61.6 -62,-60.4 -62,-59.2 -62,-58 -62,-58 -62.6,-58 -63.2,-58 -63.8,-58 -64.4,-58 -65,-58 -65.6,-58 -66.2,-58 -66.8,-58 -67.4,-58 -68,-59.2 -68,-60.4 -68,-61.6 -68,-62.8 -68,-64 -68,-65.2 -68,-66.4 -68,-67.6 -68,-68.8 -68,-70 -68,-70 -67.4,-70 -66.8,-70 -66.2,-70 -65.6,-70 -65,-70 -64.4,-70 -63.8,-70 -63.2,-70 -62.6,-70 -62))", "dataset_titles": "DeMaster Compiled Larsen Ice Shelf and the West Antarctic Peninsula C14 Data; Expedition Data of NBP1203; Labile Organic Carbon distributions on the West Antarctic Peninsula Shelf; Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf; Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "datasets": [{"dataset_uid": "601082", "doi": "10.15784/601082", "keywords": null, "people": "DeMaster, David", "repository": "USAP-DC", "science_program": "LARISSA", "title": "DeMaster Compiled Larsen Ice Shelf and the West Antarctic Peninsula C14 Data", "url": "https://www.usap-dc.org/view/dataset/601082"}, {"dataset_uid": "001438", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP1203", "url": "https://www.rvdata.us/search/cruise/NBP1203"}, {"dataset_uid": "601304", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Biota; Box Corer; LARISSA; Larsen Ice Shelf; Macrofauna; Megafauna; NBP1203; Oceans; R/v Nathaniel B. Palmer; Seafloor Sampling; Species Abundance", "people": "Smith, Craig", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Species Abundance Data from the Larsen Ice Shelf Ice acquired during R/V Nathaniel B. Palmer expedition NBP1203", "url": "https://www.usap-dc.org/view/dataset/601304"}, {"dataset_uid": "601319", "doi": "10.15784/601319", "keywords": "Antarctica; Antarctic Peninsula; Biota; Bioturbation Coefficients; Diagenesis; Labile Organic Carbon; LOC Mean Residence Times; Marguerite Bay; Oceans; Organic Carbon Degradation Rates; Sediment Core", "people": "Taylor, Richard; Smith, Craig; Isla, Enrique; Thomas, Carrie; DeMaster, David", "repository": "USAP-DC", "science_program": null, "title": "Labile Organic Carbon distributions on the West Antarctic Peninsula Shelf", "url": "https://www.usap-dc.org/view/dataset/601319"}, {"dataset_uid": "601336", "doi": "10.15784/601336", "keywords": "Antarctica; Carbon-14; Larsen Ice Shelf; Lead-210; Marine Sediments; Radioisotope Analysis", "people": "DeMaster, David; Taylor, Richard", "repository": "USAP-DC", "science_program": "LARISSA", "title": "Radioisotope data (C-14 and Pb-210) from bulk sediments, Larsen A Ice Shelf", "url": "https://www.usap-dc.org/view/dataset/601336"}], "date_created": "Sat, 03 Feb 2018 00:00:00 GMT", "description": "The PI requests support to analyze sediments from multi-cores and mega-cores previously collected from beneath the former Larsen B and Larsen A ice shelves. These unique cores will allow the PI to develop a time-integrated understanding of the benthic response to ice shelf collapse off the East Antarctic Peninsula over time periods as short as 5 years following ice shelf collapse up to \u003e170 years after collapse. High latitudes are responding to climate change more rapidly than the rest of the planet and the disappearance of ice shelves are a key manifestation of climate warming. The PI will investigate the newly created benthic environments and associated ecosystems that have resulted from the re-initiation of fresh planktonic material to the sediment-water interface. This proposal will use a new geochemical technique, based on naturally occurring 14C that can be used to assess the distribution and inventory of recently produced organic carbon accumulating in the sediments beneath the former Larsen A and B ice shelves. The PI will couple 14C measurements with 210Pb analyses to assess turnover times for sedimentary labile organic matter. By comparing the distributions and inventories of labile organic matter as well as the bioturbation intensities among different locations as a function of time following ice shelf collapse/retreat, the nature and timing of the benthic response to ice shelf collapse can be assessed.", "east": -58.0, "geometry": "POINT(-64 -65)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Pb-210; C-14; NBP1203; Radioisotop; USAP-DC; R/V NBP; Species Abundance; Labile Organic Carbon; LABORATORY", "locations": null, "north": -62.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "DeMaster, David; Smith, Craig", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": "LARISSA", "south": -68.0, "title": "Using Radiochemical Data from Collapsed Ice Shelf Sediments to Understand the Nature and Timing of the Benthic Response to High-Latitude Climate Change", "uid": "p0000382", "west": -70.0}, {"awards": "1103428 Thurber, Andrew", "bounds_geometry": "POLYGON((165 -77,165.5 -77,166 -77,166.5 -77,167 -77,167.5 -77,168 -77,168.5 -77,169 -77,169.5 -77,170 -77,170 -77.1,170 -77.2,170 -77.3,170 -77.4,170 -77.5,170 -77.6,170 -77.7,170 -77.8,170 -77.9,170 -78,169.5 -78,169 -78,168.5 -78,168 -78,167.5 -78,167 -78,166.5 -78,166 -78,165.5 -78,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5,165 -77.4,165 -77.3,165 -77.2,165 -77.1,165 -77))", "dataset_titles": "McMurdo Spiophanes beds 16s V4 region community composition from sediment cores at McMurdo Station, Antarctia on Sept 9th, 2012 (McMurdo Benthos project); Stable isotopic composition of McMurdo Benthos", "datasets": [{"dataset_uid": "000201", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Stable isotopic composition of McMurdo Benthos", "url": "https://www.bco-dmo.org/dataset/716462"}, {"dataset_uid": "000202", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "McMurdo Spiophanes beds 16s V4 region community composition from sediment cores at McMurdo Station, Antarctia on Sept 9th, 2012 (McMurdo Benthos project)", "url": "https://www.bco-dmo.org/dataset/716443"}], "date_created": "Tue, 10 Oct 2017 00:00:00 GMT", "description": "The biota of the world\u0027s seafloor is fueled by bursts of seasonal primary production. For food-limited sediment communities to persist, a balance must exist between metazoan consumption of and competition with bacteria, a balance which likely changes through the seasons. Polar marine ecosystems are ideal places to study such complex interactions due to stark seasonal shifts between heterotrophic and autotrophic communities, and temperatures that may limit microbial processing of organic matter. The research will test the following hypotheses: 1) heterotrophic bacteria compete with macrofauna for food; 2) as phytoplankton populations decline macrofauna increasingly consume microbial biomass to sustain their populations; and 3) in the absence of seasonal photosynthetic inputs, macrofaunal biodiversity will decrease unless supplied with microbially derived nutrition. Observational and empirical studies will test these hypotheses at McMurdo Station, Antarctica, where a high-abundance macro-infaunal community is adapted to this boom-and-bust cycle of productivity. The investigator will mentor undergraduates from a predominantly minority-serving institution, in the fields of invertebrate taxonomy and biogeochemistry. The general public and young scientists will be engaged through lectures at local K-12 venues and launch of an interactive website. The results will better inform scientists and managers about the effects of climate change on polar ecosystems and the mechanisms of changing productivity patterns on global biodiversity.", "east": 170.0, "geometry": "POINT(167.5 -77.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.0, "nsf_funding_programs": null, "paleo_time": null, "persons": "Thurber, Andrew", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -78.0, "title": "PostDoctoral Research Fellowship", "uid": "p0000416", "west": 165.0}, {"awards": "1141993 Rich, Jeremy", "bounds_geometry": "POLYGON((-60 -70,-59.3 -70,-58.6 -70,-57.9 -70,-57.2 -70,-56.5 -70,-55.8 -70,-55.1 -70,-54.4 -70,-53.7 -70,-53 -70,-53 -70.9,-53 -71.8,-53 -72.7,-53 -73.6,-53 -74.5,-53 -75.4,-53 -76.3,-53 -77.2,-53 -78.1,-53 -79,-53.7 -79,-54.4 -79,-55.1 -79,-55.8 -79,-56.5 -79,-57.2 -79,-57.9 -79,-58.6 -79,-59.3 -79,-60 -79,-60 -78.1,-60 -77.2,-60 -76.3,-60 -75.4,-60 -74.5,-60 -73.6,-60 -72.7,-60 -71.8,-60 -70.9,-60 -70))", "dataset_titles": "Seasonal Succession of Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula", "datasets": [{"dataset_uid": "601032", "doi": "10.15784/601032", "keywords": "Antarctica; Antarctic Peninsula; Bacteria; Biota; Genetic; Geochemistry; Palmer Station; Sample/collection Description; Sample/Collection Description; Sea Water; Southern Ocean", "people": "Rich, Jeremy", "repository": "USAP-DC", "science_program": null, "title": "Seasonal Succession of Bacterial Communities in Coastal Waters of the Western Antarctic Peninsula", "url": "https://www.usap-dc.org/view/dataset/601032"}], "date_created": "Thu, 15 Jun 2017 00:00:00 GMT", "description": "The Western Antarctic Peninsula (WAP) has experienced unprecedented warming and shifts in sea ice cover over the past fifty years. How these changes impact marine microbial communities, and subsequently how these shifts in the biota may affect the carbon cycle in surface waters is unknown. This work will examine how these ecosystem-level changes affect microbial community structure and function. This research will use modern metagenomic and transcriptomic approaches to test the hypothesis that the introduction of organic matter from spring phytoplankton blooms drives turnover in microbial communities. This research will characterize patterns in bacterial and archaeal succession during the transition from the austral winter at two long-term monitoring sites: Palmer Station in the north and Rothera Station in the south. This project will also include microcosm incubations to directly assess the effects of additions of organic carbon and melted sea ice on microbial community structure and function. The results of this work will provide a broader understanding of the roles of both rare and abundant microorganisms in carbon cycling within the WAP region, and how these communities may shift in structure and function in response to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. The research will provide training opportunities for both graduate and undergraduate students and will enhance international collaborations with the British Antarctic Survey.", "east": -53.0, "geometry": "POINT(-56.5 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Rich, Jeremy", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula", "uid": "p0000409", "west": -60.0}, {"awards": "1141978 Foreman, Christine", "bounds_geometry": "POLYGON((160 -76,160.1 -76,160.2 -76,160.3 -76,160.4 -76,160.5 -76,160.6 -76,160.7 -76,160.8 -76,160.9 -76,161 -76,161 -76.1,161 -76.2,161 -76.3,161 -76.4,161 -76.5,161 -76.6,161 -76.7,161 -76.8,161 -76.9,161 -77,160.9 -77,160.8 -77,160.7 -77,160.6 -77,160.5 -77,160.4 -77,160.3 -77,160.2 -77,160.1 -77,160 -77,160 -76.9,160 -76.8,160 -76.7,160 -76.6,160 -76.5,160 -76.4,160 -76.3,160 -76.2,160 -76.1,160 -76))", "dataset_titles": "FT-ICR MS Metadata; Respiration Metadata; UPLC-Q-TOF data of Cotton Glacier exometabolites", "datasets": [{"dataset_uid": "601076", "doi": "10.15784/601076", "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; Fluorescence Spectroscopy; Mass Spectrometry", "people": "Foreman, Christine; Smith, Heidi", "repository": "USAP-DC", "science_program": null, "title": "Respiration Metadata", "url": "https://www.usap-dc.org/view/dataset/601076"}, {"dataset_uid": "601089", "doi": "10.15784/601089", "keywords": "Antarctica; Biota; Exometabolites; Mass Spectrometry; Microbes; Microbiology", "people": "Bothner, Brian; Tigges, Michelle; Foreman, Christine", "repository": "USAP-DC", "science_program": null, "title": "UPLC-Q-TOF data of Cotton Glacier exometabolites", "url": "https://www.usap-dc.org/view/dataset/601089"}, {"dataset_uid": "601077", "doi": "10.15784/601077", "keywords": "Antarctica; Biota; Chemistry:fluid; Chemistry:Fluid; Fluorescence Spectroscopy; Mass Spectrometry", "people": "D\u0027Andrilli, Juliana; Foreman, Christine", "repository": "USAP-DC", "science_program": null, "title": "FT-ICR MS Metadata", "url": "https://www.usap-dc.org/view/dataset/601077"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "Uncovering the dynamics of dissolved organic matter (DOM) is central to an understanding of the global carbon cycle, as organic material from lakes, streams, oceans and soils passes through this pool. DOM acts as a key energy source for microbes in many ecosystems and therefore can affect regional nutrient cycling patterns. For example, preliminary results suggest that organisms isolated from a supraglacial stream on Cotton Glacier, Antarctica, may be important in DOM cycling in this relatively simple, low temperature system. However, little is known about the functional attributes of the microbes that interact with DOM in the environment. This project will use state-of-the-art genomics, proteomics and metabolomics approaches to understand the mechanisms by which two microbial isolates, CG3 and CG9_1, affect DOM cycling. Liquid chromatography-mass spectrometry will also be used to better characterize the microbially-derived DOM from this ecosystem. This project will support the research and training of one undergraduate and two graduate students. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. Understanding the relationship between cold-adapted microbial metabolisms and DOM pools is important as more than 90% of the Earth?s oceans are below 5 degrees Celsius.", "east": 161.0, "geometry": "POINT(160.5 -76.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -76.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Foreman, Christine; Bothner, Brian", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Multidimensional \"omics\" characterization of microbial metabolism and dissolved organic matter in Antarctica", "uid": "p0000408", "west": 160.0}, {"awards": "1142117 Hansell, Dennis; 1142065 DiTullio, Giacomo; 1142044 Dunbar, Robert; 1142097 Bochdansky, Alexander", "bounds_geometry": "POLYGON((165 -52,166 -52,167 -52,168 -52,169 -52,170 -52,171 -52,172 -52,173 -52,174 -52,175 -52,175 -54.65,175 -57.3,175 -59.95,175 -62.6,175 -65.25,175 -67.9,175 -70.55,175 -73.2,175 -75.85,175 -78.5,174 -78.5,173 -78.5,172 -78.5,171 -78.5,170 -78.5,169 -78.5,168 -78.5,167 -78.5,166 -78.5,165 -78.5,165 -75.85,165 -73.2,165 -70.55,165 -67.9,165 -65.25,165 -62.6,165 -59.95,165 -57.3,165 -54.650000000000006,165 -52))", "dataset_titles": "Carbon chemistry from CTD; Deployment: NBP1302; NBP1302 data; Video Particle Profiler (VPP) and Digital Inline Holographic Microscopy (DIHM) data from cruise NBP1302", "datasets": [{"dataset_uid": "000221", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Deployment: NBP1302", "url": "http://www.bco-dmo.org/deployment/547873"}, {"dataset_uid": "000179", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1302 data", "url": "https://www.rvdata.us/search/cruise/NBP1302"}, {"dataset_uid": "000220", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Carbon chemistry from CTD", "url": "http://www.bco-dmo.org/dataset/658394"}, {"dataset_uid": "600388", "doi": "10.15784/600388", "keywords": "Antarctica; Biota; Holographic Microscopy; Oceans; Photo/video; Photo/Video; Phytoplankton; Ross Sea; Sample/collection Description; Sample/Collection Description; Southern Ocean; Video Particle Profiler", "people": "Bochdansky, Alexander", "repository": "USAP-DC", "science_program": null, "title": "Video Particle Profiler (VPP) and Digital Inline Holographic Microscopy (DIHM) data from cruise NBP1302", "url": "https://www.usap-dc.org/view/dataset/600388"}], "date_created": "Wed, 26 Aug 2015 00:00:00 GMT", "description": "Intellectual Merit: \u003cbr/\u003eSinking particles are a major element of the biological pump and they are commonly assigned to two fates: mineralization in the water column and accumulation at the seafloor. However, there is another fate of export hidden within the vertical decline of carbon, the transformation of sinking organic matter to fine suspended and/or dissolved organic fractions. This process has been suggested but has rarely been observed or quantified. As a result, it is presumed that the solubilized fraction is largely mineralized over short time scales. However, global ocean surveys of dissolved organic carbon are demonstrating a significant water column accumulation of organic matter under high productivity environments. This proposal will investigate the transformation of organic particles from sinking to solubilized phases of the export flux in the Ross Sea. The Ross Sea experiences high export particle production, low dissolved organic carbon export with overturning circulation, and the area has a predictable succession of production and export events. In addition, the basin is shallow (\u003c 000 m) so the products the PIs will target are relatively concentrated. To address the proposed hypothesis, the PIs will use both well-established and novel biochemical and optical measures of export production and its fate. The outcomes of this work will help researchers close the carbon budget in the Ross Sea.\u003cbr/\u003e\u003cbr/\u003eBroader impacts: \u003cbr/\u003eThis research will support graduate and undergraduate students and will provide undergraduates and pre-college students with field-based research experience. Scientifically, this research will increase understanding of carbon sinks in the Ross Sea and will help develop new tools for identifying, quantifying, and tracking that carbon. The PIs will interface with K-12 students through daily reports from the field and through educational modules developed by several of the PIs in collaboration with science education specialists and college students. A K-12 educator will be included on the research cruises. Outreach will be through COSEE Florida and the Maritime Center in Norfolk, VA.", "east": 175.0, "geometry": "POINT(170 -65.25)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e DIHM; 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": "Not provided; NBP1302; Phaeocystis; R/V NBP", "locations": null, "north": -52.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Bochdansky, Alexander; Dunbar, Robert; DiTullio, Giacomo; Ditullio, Giacomo; Harry, Dennis L.; HANSELL, DENNIS", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "BCO-DMO", "repositories": "BCO-DMO; R2R; USAP-DC", "science_programs": null, "south": -78.5, "title": "Collaborative research: TRacing the fate of Algal Carbon Export in the Ross Sea (TRACERS)", "uid": "p0000307", "west": 165.0}, {"awards": "1141275 Warren, Stephen", "bounds_geometry": null, "dataset_titles": "Antarctic field campaign data page", "datasets": [{"dataset_uid": "001399", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Antarctic field campaign data page", "url": "http://www.atmos.washington.edu/articles/EastAntarctica_SeaIceAlbedos_SnowImpurities/"}], "date_created": "Fri, 30 Jan 2015 00:00:00 GMT", "description": "The albedo, or reflection coefficient, is a measure of the diffuse reflectivity of an irradiated surface. With the sunlit atmosphere as a light source, and sea-ice as a diffuse reflecting surface, the albedo would be the fraction of incident light that is returned to the atmosphere. A perfect (white) reflecting surface would have an albedo of 1; a perfect (black) absorbing surface would have an albedo of 0. The albedo of sea-ice is needed to assess the solar energy budget of the marginal ice zone, to compute the partial solar bands in radiation budgets in general circulation and earth system models, and is also needed to interpret remote sensing imagery data products.\u003cbr/\u003eApplications requiring albedos further into the near IR, out to 2500nm, are assumed or approximated. Modern spectral radiometers, such as will be used in this campaign on a Southern Ocean voyage from Hobart to Antarctica, can extend these measurements of albedo from 350 to 2500nm, allowing earlier estimates to be verified, or corrected. \u003cbr/\u003e\u003cbr/\u003eSurfaces to be encountered on this research cruise are expected to include open water, grease ice, nila ice, pancake ice, young grey ice, young grey-white ice, along with first year ice. The presence of variable amounts of snow on these surfaces is also of interest. Light absorbing impurities in the snow and ice, including black carbon and organic matter (brown carbon) are different from those found in Arctic Sea ice, the Antarctic being so remote from combustion sources. This may allow better understanding of the seasonal cycles, energy budgets and their recent trends in spatial extent and thickness. The project will also broaden the educational experiences of both US and Australian students participating in the measurement campaign", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Radiometers; Radiation Budgets; Sea Ice; Energy Budgets; Impurities; COMPUTERS; Albedo; Spectral; LABORATORY; Antarctica; Snow Temperature; Reflecting Surface; Snow Density; R/V AA", "locations": "Antarctica", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Warren, Stephen; Zatko, Maria", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V AA", "repo": "PI website", "repositories": "PI website", "science_programs": null, "south": null, "title": "Spectral and Broadband Albedo of Antarctic Sea-ice Types", "uid": "p0000375", "west": null}, {"awards": "0838970 Foreman, Christine", "bounds_geometry": "POINT(161.667 -77.117)", "dataset_titles": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "datasets": [{"dataset_uid": "600104", "doi": "10.15784/600104", "keywords": "Antarctica; Biota; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Microbiology", "people": "Foreman, Christine", "repository": "USAP-DC", "science_program": null, "title": "The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/600104"}], "date_created": "Fri, 10 Oct 2014 00:00:00 GMT", "description": "Dissolved organic matter (DOM) comprises a significant pool of Earth\u0027s organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls\u0027 schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer.", "east": 161.667, "geometry": "POINT(161.667 -77.117)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.117, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Foreman, Christine", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.117, "title": "Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica", "uid": "p0000458", "west": 161.667}, {"awards": "0838830 Cottrell, Matthew", "bounds_geometry": "POLYGON((-64.079666 -64.77966,-64.07576590000001 -64.77966,-64.0718658 -64.77966,-64.0679657 -64.77966,-64.0640656 -64.77966,-64.06016550000001 -64.77966,-64.0562654 -64.77966,-64.0523653 -64.77966,-64.04846520000001 -64.77966,-64.0445651 -64.77966,-64.040665 -64.77966,-64.040665 -64.78326100000001,-64.040665 -64.786862,-64.040665 -64.790463,-64.040665 -64.794064,-64.040665 -64.797665,-64.040665 -64.801266,-64.040665 -64.804867,-64.040665 -64.808468,-64.040665 -64.812069,-64.040665 -64.81567,-64.0445651 -64.81567,-64.04846520000001 -64.81567,-64.0523653 -64.81567,-64.0562654 -64.81567,-64.06016550000001 -64.81567,-64.0640656 -64.81567,-64.0679657 -64.81567,-64.0718658 -64.81567,-64.07576590000001 -64.81567,-64.079666 -64.81567,-64.079666 -64.812069,-64.079666 -64.808468,-64.079666 -64.804867,-64.079666 -64.801266,-64.079666 -64.797665,-64.079666 -64.794064,-64.079666 -64.790463,-64.079666 -64.786862,-64.079666 -64.78326100000001,-64.079666 -64.77966))", "dataset_titles": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "datasets": [{"dataset_uid": "600097", "doi": "10.15784/600097", "keywords": "Antarctic Peninsula; Biota; LTER Palmer Station; Microbiology; Oceans; Southern Ocean", "people": "Kirchman, David; Cottrell, Matthew", "repository": "USAP-DC", "science_program": null, "title": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "url": "https://www.usap-dc.org/view/dataset/600097"}], "date_created": "Mon, 16 Dec 2013 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/\u003eLight quality and availability are likely to change in polar ecosystems as ice coverage and thickness decrease. How microbes adjust to these and other changes will have huge impacts on the polar marine ecosystems. Little is known about photoheterotrophic prokaryotes, which are hypothesized to gain a metabolic advantage by harvesting light energy in addition to utilizing dissolved organic matter (DOM). Photoheterotrophy is not included in current models of carbon cycling and energy flow. This research will examine three questions: 1. Are photoheterotrophic microbes present and active in Antarctic waters in winter and summer? 2. Does community structure of photoheterotrophs shift between summer and winter? 3. Which microbial groups assimilate more DOM in light than in the dark? The research will test hypotheses about activity of photoheterotrophs in winter and in summer, shifts in community structure between light and dark seasons and the potentially unique impacts of photoheterotrophs on biogeochemical processes in the Antarctic. The project will directly support a graduate student, will positively impact the NSF REU program at the College of Marine and Earth Studies, and will include students from the nation?s oldest historical minority college. The results will be featured during weekly tours of Lewes facilities (about 1000 visitors per year) and during Coast Day, an annual open-house that attracts about 10,000 visitors.", "east": -64.040665, "geometry": "POINT(-64.0601655 -64.797665)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.77966, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Cottrell, Matthew; David, Kirchman", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -64.81567, "title": "Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem", "uid": "p0000473", "west": -64.079666}, {"awards": "1039365 Rimmer, Susan", "bounds_geometry": null, "dataset_titles": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "datasets": [{"dataset_uid": "600121", "doi": "10.15784/600121", "keywords": "Antarctica; Chemistry:rock; Chemistry:Rock; Geochemistry; Solid Earth; Transantarctic Mountains", "people": "Rimmer, Susan", "repository": "USAP-DC", "science_program": null, "title": "The Permian-Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuations in Terrestrial Organic Matter", "url": "https://www.usap-dc.org/view/dataset/600121"}], "date_created": "Wed, 30 Jan 2013 00:00:00 GMT", "description": "This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. \u003cbr/\u003eThe broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Rimmer, Susan", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter", "uid": "p0000507", "west": null}, {"awards": "0739684 Hatcher, Patrick", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 26 Sep 2012 00:00:00 GMT", "description": "This award supports a project to fully develop the analytical protocols needed to exploit a relatively new technique for the analysis of soluble organic matter in ice core samples. The technique couples Electrospray ionization to high resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). Sample volume will be reduced and pre-concentration steps will be eliminated. Following method optimization a suite of ice core samples will be studied from several Antarctic and Greenland locations to address several hypothesis driven research questions. Preliminary results show that a vast record of relatively high molecular weight organic material exists in ice core samples and intriguing results from a few samples warrant further investigation. Several important questions related to developing a better understanding of the nature and paleo record of organic matter in ice cores will be addressed. These include developing a better understanding of the origin of nitrogen and sulfur isotopes in pre-industrial vs. modern samples, developing the methods to apply molecular biomarker techniques, routinely used by organic geochemists for sediment analyses, to the analysis of organic matter in ice cores, tracking the level of oxidation of homologous series of compounds and using them as a proxy for atmospheric oxidant levels in the past and determining whether or not high resolution FTICR mass spectral analysis can provide the ice core community with a robust method to analyze organic materials at the molecular level. The intellectual merit of this work is that this analytical method will provide a new understanding of the nature of organic matter in ice, possibly leading to the discovery of multitudes of molecular species indicative of global change processes whose abundances can be compared with other change proxies. The proposed studies are of an exploratory nature and potentially transformative for the field of ice core research and cryobiology. The broader impacts of these studies are that they should provide compelling evidence regarding organic matter sources, atmospheric processing and anthropogenic inputs to polar ice and how these have varied over time. The collaborative work proposed here will partner atmospheric chemistry/polar ice chemistry expertise with organic geochemistry expertise, resulting in significant contributions to both fields of study and significant advances in ice core analysis. Training of both graduate and undergraduate students will be a key component of the project and students will be involved in collaborative research using advanced analytical instrumentation, presentation of research results at national meetings, and will participate in manuscript preparation.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "Ice Core; Isotope; Organic Matter; Nitrogen; Sulfur; Not provided; LABORATORY; Mass Spectrometry; COMPUTERS; Molecular", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hatcher, Patrick; Grannas, Amanda", "platforms": "Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Molecular Level Characterization of Organic Matter in Ice Cores using High-resolution FTICR mass spectrometry", "uid": "p0000707", "west": null}, {"awards": "0230497 Kiene, Ronald", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0409", "datasets": [{"dataset_uid": "002640", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0409", "url": "https://www.rvdata.us/search/cruise/NBP0409"}, {"dataset_uid": "001616", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0409"}], "date_created": "Tue, 17 Jan 2012 00:00:00 GMT", "description": "Areas of the Southern Ocean have spectacular blooms of phytoplankton during the austral spring and early summer. One of the dominant phytoplankton species, the haptophyte Phaeocystis antarctica, is a prolific producer of the organic sulfur compound dimethylsulfoniopropionate (DMSP) and Phaeocystis blooms are associated with some of the world\u0027s highest concentrations of DMSP and its volatile degradation product, dimethylsulfide (DMS). Sulfur, in the form of DMS, is transferred from the oceans to the atmosphere and can affect the chemistry of precipitation and influence cloud properties and possibly climate. DMSP and DMS are also quantitatively significant components of the carbon, sulfur and energy flows in many marine food webs, although very little information is available on these processes in high latitude systems. \u003cbr/\u003e\u003cbr/\u003eThis project will study how solar radiation and iron cycling affect DMSP and DMS production by phytoplankton, and the subsequent utilization of these labile forms of organic matter by the microbial food web. Four interrelated hypotheses will be tested in field-based experiments and in situ observations: 1) solar radiation, including enhanced UV-B due to seasonal ozone depletion, plays an important role in determining the net ecosystem production of DMS in the Ross Sea; 2) development of shallow mixed layers promotes the accumulation of DMS in surface waters, because of enhanced exposure of plankton communities to high doses of solar radiation; 3) DMSP production and turnover represent a significant part of the carbon and sulfur flux through polar food webs; 4) bloom development and resulting nutrient depletion (e.g., iron) will result in high production rates of DMSP and high DMS concentrations and atmospheric fluxes. Results from this study will greatly improve understanding of the underlying mechanisms controlling DMSP and DMS concentrations in polar waters, thereby improving our ability to predict DMS fluxes to the atmosphere from this important climatic region. \u003cbr/\u003e\u003cbr/\u003eBoth Drs. Kieber and Kiene actively engage high school, undergraduate and graduate students in their research and are involved in formal programs that target underrepresented groups (NSF-REU and the American Chemical Society-SEED). This project will continue this type of educational outreach. The PIs also teach undergraduate and graduate courses and incorporation of research experiences into their classes will enrich student learning experiences.", "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": "Kiene, Ronald", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Impact of Solar Radiation and Nutrients on Biogeochemical Cycling of DMSP and DMS in the Ross Sea, Antarctica", "uid": "p0000832", "west": null}, {"awards": "0230499 Kieber, David", "bounds_geometry": "POLYGON((-179.99998 -43.58056,-143.999984 -43.58056,-107.999988 -43.58056,-71.999992 -43.58056,-35.999996 -43.58056,0 -43.58056,35.999996 -43.58056,71.999992 -43.58056,107.999988 -43.58056,143.999984 -43.58056,179.99998 -43.58056,179.99998 -46.971468,179.99998 -50.362376,179.99998 -53.753284,179.99998 -57.144192,179.99998 -60.5351,179.99998 -63.926008,179.99998 -67.316916,179.99998 -70.707824,179.99998 -74.098732,179.99998 -77.48964,143.999984 -77.48964,107.999988 -77.48964,71.999992 -77.48964,35.999996 -77.48964,0 -77.48964,-35.999996 -77.48964,-71.999992 -77.48964,-107.999988 -77.48964,-143.999984 -77.48964,-179.99998 -77.48964,-179.99998 -74.098732,-179.99998 -70.707824,-179.99998 -67.316916,-179.99998 -63.926008,-179.99998 -60.5351,-179.99998 -57.144192,-179.99998 -53.753284,-179.99998 -50.362376,-179.99998 -46.971468,-179.99998 -43.58056))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001616", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0409"}], "date_created": "Tue, 17 Jan 2012 00:00:00 GMT", "description": "Areas of the Southern Ocean have spectacular blooms of phytoplankton during the austral spring and early summer. One of the dominant phytoplankton species, the haptophyte Phaeocystis antarctica, is a prolific producer of the organic sulfur compound dimethylsulfoniopropionate (DMSP) and Phaeocystis blooms are associated with some of the world\u0027s highest concentrations of DMSP and its volatile degradation product, dimethylsulfide (DMS). Sulfur, in the form of DMS, is transferred from the oceans to the atmosphere and can affect the chemistry of precipitation and influence cloud properties and possibly climate. DMSP and DMS are also quantitatively significant components of the carbon, sulfur and energy flows in many marine food webs, although very little information is available on these processes in high latitude systems. \u003cbr/\u003e\u003cbr/\u003eThis project will study how solar radiation and iron cycling affect DMSP and DMS production by phytoplankton, and the subsequent utilization of these labile forms of organic matter by the microbial food web. Four interrelated hypotheses will be tested in field-based experiments and in situ observations: 1) solar radiation, including enhanced UV-B due to seasonal ozone depletion, plays an important role in determining the net ecosystem production of DMS in the Ross Sea; 2) development of shallow mixed layers promotes the accumulation of DMS in surface waters, because of enhanced exposure of plankton communities to high doses of solar radiation; 3) DMSP production and turnover represent a significant part of the carbon and sulfur flux through polar food webs; 4) bloom development and resulting nutrient depletion (e.g., iron) will result in high production rates of DMSP and high DMS concentrations and atmospheric fluxes. Results from this study will greatly improve understanding of the underlying mechanisms controlling DMSP and DMS concentrations in polar waters, thereby improving our ability to predict DMS fluxes to the atmosphere from this important climatic region. \u003cbr/\u003e\u003cbr/\u003eBoth Drs. Kieber and Kiene actively engage high school, undergraduate and graduate students in their research and are involved in formal programs that target underrepresented groups (NSF-REU and the American Chemical Society-SEED). This project will continue this type of educational outreach. The PIs also teach undergraduate and graduate courses and incorporation of research experiences into their classes will enrich student learning experiences.", "east": 179.99998, "geometry": "POINT(0 -89.999)", "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": -43.58056, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Kiene, Ronald", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -77.48964, "title": "Collaborative Research: Impact of Solar Radiation and Nutrients on Biogeochemical Cycling of DMSP and DMS in the Ross Sea, Antarctica", "uid": "p0000582", "west": -179.99998}, {"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": "9726186 Pilskaln, Cynthia", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0101", "datasets": [{"dataset_uid": "002641", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0101", "url": "https://www.rvdata.us/search/cruise/NBP0101"}, {"dataset_uid": "002580", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0101", "url": "https://www.rvdata.us/search/cruise/NBP0101"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "This proposed work is a study of the biological production and export flux of biogenic matter in response to ventilation of intermediate and deep water masses within the Polar Front zone. It is a collaborative work between the University of Maine and the Chinese Antarctic Research Expedition (CHINARE). The shipboard work is proposed for the Chinese antarctic resupply vessel off Prydz Bay in the Indian Ocean sector. In the austral Spring, this region experiences phytoplankton blooms that are thought to be the result of nutrient transport by the ventilation of intermediate and deep water masses. On an annual basis, it is believed that such blooms are the primary source of particulate organic carbon and biogenic silica flux to the ocean bottom. At this time however no data exists on the amount of particulate organic matter that sinks through the water column, leaving the quantitative relationships between production and export largely undefined in this region. The initial phase of the work consists of setting out a time-series sediment trap mooring at approximately 64 deg S latitude and 73 deg E longitude to take advantage of the historical data set that CHINARE has obtained in this area over the past decade. The biweekly to monthly trap samples will be analyzed for their organic constituents, and in conjunction with primary productivity observations will provide the basic data from which export values can be derived. This work will be carried out in collaboration with the State Oceanic Administration of the People\u0027s Republic of China, and the Chinese Antarctic Research Expedition. In addition to providing time on the antarctic resupply vessel, the SOA will sponsor the shipboard primary productivity experiments and the supporting hydrographic measurements. The collaborating American scientists will provide guidance in making these observations to standards developed for the Joint Global Ocean Flux Study, and provide the hardware for the moored sediment trap. There will be a mutual sharing between the U.S. and Chinese investigators of all samples and data sets, and the data analysis will be carried out jointly. ***", "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 Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Leventer, Amy", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "POC Production and Export in the Indian Ocean Sector of the Southern Ocean: A US-China Collaborative Research Program", "uid": "p0000800", "west": null}, {"awards": "9527255 Mopper, Kenneth", "bounds_geometry": null, "dataset_titles": "Expedition data of LMG9809", "datasets": [{"dataset_uid": "002719", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of LMG9809", "url": "https://www.rvdata.us/search/cruise/LMG9809"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "ACT K. Mopper \u0026 D. Kieber OPP 9527255 \u0026 OPP 9527314 PHOTOCHEMICAL AND OPTICAL PROPERTIES OF ANTARCTIC WATERS IN RESPONSE TO CHANGING UV-B FLUXES The decrease in stratospheric ozone over the Antarctic results in an increase in the UV-B flux in the euphotic zone. The increase leads to cellular damage to aquatic organisms, as documented by photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transients. The extent of this extracellular damage will depend on the photochemistry of the seawater surrounding the cell. Until recently, nothing was known about the type of photochemical processes, rates, and steady state concentrations of transients in Antarctic waters. It is proposed that field experiments be performed which will allow the construction of predictive models of photochemical production rates in surface waters and with depth. These studies will involve further quantum yield measurementts, development of a sensitive underwater actinometer system, and use of a new underwater multichannel photometer. The model will allow the prediction of the impact of varying levels of UV-B on the photoproduction and steady state concentration of several key reactive transient species in the upper water column. In addition to this effort, experiments will also be performed to study the photodegradation of dissolved organic matter and to determine whether biologically utilizable substrates that are formed photochemically can enhance secondary productivity in Antarctic waters.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Mopper, Kenneth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative Research: Photochemical and Optical Properties of Antarctic Waters in Response to Changing UV-B Fluxes", "uid": "p0000870", "west": null}, {"awards": "9221598 Mopper, Kenneth", "bounds_geometry": null, "dataset_titles": "Expedition Data", "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"}], "date_created": "Fri, 19 Jun 2009 00:00:00 GMT", "description": "Decreases in stratospheric ozone over the Antarctic result in an increase in the ultraviolet radiation flux in the euphotic zone of the ocean. This increase may lead to cellular damage in aquatic organisms resulting in photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transient species. Extracellular damage will depend to a large degree on the photochemistry of the seawater surrounding the cell. To date, little is known about the photochemistry of the unique Antarctic waters. This project integrates a field and laboratory approach to obtain baseline information regarding the marine photochemistry of the euphotic zone in Antarctica waters as related to changes in ultraviolet radiation levels. In situ photochemical production rates and steady state concentrations of a suite of reactive species and dissolved organic matter degradation products as well as downwelling ultraviolet radiation will be measured. Additionally, flux by in situ chemical actinometry, action spectra for photochemical production of various reactive species and dissolved organic matter degradation products, and fluorescence and absorbance properties of dissolved organic matter will be determined. This information will serve as a basis for understanding and predicting the effects of ultraviolet radiation-induced marine photochemical processes on the productivity and ecology in the euphotic zone of the Antarctic Ocean.", "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": "Mopper, Kenneth; Neale, Patrick", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Photochemistry of Antarctic Waters in Repsonse to Changing Ultraviolet Radiation Fluxes", "uid": "p0000649", "west": null}, {"awards": "0440478 Tang, Kam", "bounds_geometry": "POINT(166.66267 -77.85067)", "dataset_titles": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "datasets": [{"dataset_uid": "600043", "doi": "10.15784/600043", "keywords": "Biota; McMurdo Sound; Oceans; Phytoplankton; Ross Sea; Southern Ocean; Zooplankton", "people": "Tang, Kam; Smith, Walker", "repository": "USAP-DC", "science_program": null, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial Forms of Phaeocystis Antarctica", "url": "https://www.usap-dc.org/view/dataset/600043"}], "date_created": "Mon, 04 May 2009 00:00:00 GMT", "description": "Phaeocystis Antarctica is a widely distributed phytoplankton that forms dense blooms and aggregates in the Southern Ocean. This phytoplankton and plays important roles in polar ecology and biogeochemistry, in part because it is a dominant primary producer, a main component of organic matter vertical fluxes, and the principal producer of volatile organic sulfur in the region. Yet P. Antarctica is also one of the lesser known species in terms of its physiology, life history and trophic relationships with other organisms; furthermore, information collected on other Phaeocystis species and from different locations may not be applicable to P. Antarctica in the Ross Sea. P. Antarctica occurs mainly as two morphotypes: solitary cells and mucilaginous colonies, which differ significantly in size, architecture and chemical composition. Relative dominance between solitary cells and colonies determines not only the size spectrum of the population, but also its carbon dynamics, nutrient uptake and utilization. Conventional thinking of the planktonic trophic processes is also challenged by the fact that colony formation could effectively alter the predator-prey interactions and interspecific competition. However, the factors that regulate the differences between solitary and colonial forms of P. Antarctica are not well-understood. The research objective of this proposal is therefore to address these over-arching questions:\u003cbr/\u003eo Do P. Antarctica solitary cells and colonies differ in growth, composition and\u003cbr/\u003ephotosynthetic rates?\u003cbr/\u003eo How do nutrients and grazers affect colony development and size distribution of P. \u003cbr/\u003eAntarctica?\u003cbr/\u003eo How do nutrients and grazers act synergistically to affect the long-term population\u003cbr/\u003edynamics of P. Antarctica? Experiments will be conducted in the McMurdo station with natural P. Antarctica assemblages and co-occurring grazers. Laboratory experiments will be conducted to study size-specific growth and photosynthetic rates of P. Antarctica, size-specific grazing mortality due to microzooplankton and mesozooplankton, the effects of macronutrients on the (nitrogen compounds) relative dominance of solitary cells and colonies, and the effects of micronutrient (Fe) and grazing related chemical signals on P. Antarctica colony development. Because this species is of critical importance in the Southern Ocean, and because this research will provide critical information on factors that regulate the role of P.Antarctica in food webs and biogeochemical cycles, a major gap in knowledge will be addressed. This project will train two marine science PhD students. The investigators will also collaborate with the School of Education and a marine science museum to communicate polar science to a broader audience.", "east": 166.66267, "geometry": "POINT(166.66267 -77.85067)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -77.85067, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Tang, Kam; Smith, Walker", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.85067, "title": "Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial forms of Phaeocystis antarctica", "uid": "p0000214", "west": 166.66267}, {"awards": "0338260 Chin, Yu-Ping; 0338342 Foreman, Christine", "bounds_geometry": "POINT(166.167 -77.55)", "dataset_titles": "Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island", "datasets": [{"dataset_uid": "600168", "doi": "10.15784/600168", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Critical Zone; Ross Island; Sample/collection Description; Sample/Collection Description; Water Samples", "people": "Foreman, Christine; Chin, Yu-Ping", "repository": "USAP-DC", "science_program": null, "title": "Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island", "url": "https://www.usap-dc.org/view/dataset/600168"}], "date_created": "Mon, 16 Mar 2009 00:00:00 GMT", "description": "Dissolved organic matter (DOM) is a significant chemical component in aquatic systems because it acts as an important carbon source for microorganisms, absorbs harmful radiation in sunlight, is able to complex metals, and can participate in important biogeochemical reactions. This study will investigate the biogeochemical cycling of DOM in a small coastal Antarctic pond, Pony Lake, located on Cape Royds, Ross Island. Because there are no higher plants present at this site all of the DOM in this lake is derived from microorganisms. Thus, Pony Lake is an ideal site to study the effect of physical, chemical, and microbial processes on the composition and character of the DOM pool. Finally, Pony Lake is also an ideal site to collect an International Humic Substances Society (IHSS) fulvic acid standard. Unlike other IHSS standards, this standard will not contain DOM components derived from higher land plants. To better understand the role of physical influences, the project will study the changes in the DOM pool as the lake evolves from ice-covered to ice-free conditions during the summer, as well as the relationship of DOM to the observed turnover of dominant microbial communities in the lake. Scientists will also monitor changes in microbial abundance, diversity, and productivity that may occur during the ice to open-water transition period. This research will provide much needed information regarding the relationship between microbial diversity and DOM biogeochemistry. Middle school science students will be active participants in this project through the Internet, while scientists are in the field, and in the lab.", "east": 166.167, "geometry": "POINT(166.167 -77.55)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided; FIELD SURVEYS", "locations": null, "north": -77.55, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Foreman, Christine; Chin, Yu-Ping", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.55, "title": "Collaborative Research: Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island", "uid": "p0000548", "west": 166.167}, {"awards": "0126270 Doran, Peter", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 05 Feb 2007 00:00:00 GMT", "description": "Polar Programs, provides funds for a study of sediment cores from the McMurdo Dry Valley lakes. The Dry Valley lakes have a long history of fluctuating levels reflecting regional climate change. The history of lake level fluctuations is generally known from the LGM to early Holocene through 14C dates of buried organic matter in paleolake deposits. However, the youngest paleolake deposits available are between 8000 to 9000 14C yr BP, suggesting that lake levels were at or below current levels for much of the Holocene. Thus, any information about the lake history and climate controls for the Holocene is largely contained in bottom sediments. This project will attempt to extract paleoclimatic information from sediment cores for a series of closed-basin dry valley lakes under study by the McMurdo LTER site. This work involves multiple approaches to dating the sediments and use of several climate proxy approaches to extract century to millennial scale chronologies from Antarctic lacustrine deposits. This research uses knowledge on lake processes gained over the past eight years by the LTER to calibrate climate proxies from lake sediments. Proxies for lake depth and ice thickness, which are largely controlled by summer climate, are the focus of this work. This study focuses on four key questions: 1. How sensitively do dry valley lake sediments record Holocene environmental and climate variability? 2. What is the paleoclimatic variability in the dry valleys on a century and millennial scale throughout the Holocene? Especially, is the 1200 yr evaporative event unique, or are there other such events in the record? 3. Does a mid-Holocene (7000 to 5000 yr BP) climate shift occur in the dry valleys as documented elsewhere in the polar regions? 4. Is there evidence, in the dry valley lake record of the 1500 yr Holocene periodicities recently recognized in the Taylor Dome record? Core collection will be performed with LTER support using a state-of-the-art percussion/piston corer system that has been used successfully to retrieve long cores (10 to 20 m) from other remote polar locations. Analyses to be done include algal pigments, biogenic silica, basic geochemistry, organic and inorganic carbon and nitrogen content, stable isotopes of carbon, nitrogen, and oxygen, carbonate phases, salt content and mineralogy, and grain size. In addition this project will pursue a multi-chronometer approach to assess the age of the core through optically-stimulated luminescence, 226Ra/230Th , 230Th/234U, and 14C techniques. New experimentation with U-series techniques will be performed to allow for greater precision in the dry valley lake sediments. Compound specific isotopes and lipid biomarkers , which are powerful tools for inferring past lake conditions, will also be assessed. Combined, these analyses will provide a new century to millennial scale continuous record of the Holocene climate change in the Ross Sea region.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Doran, Peter", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Paleoclimate Inferred from Lake Sediment Cores in Taylor Valley, Antarctica", "uid": "p0000092", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||||||
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Fe Behavior and Bioavailability in Sub-aerial Runoff into the Ross Sea
|
1841228 |
2024-10-16 | Lyons, W. Berry; Gardner, Christopher B. | Phytoplankton, or microscopic marine algae, are an important part of the carbon cycle and can lower the rates of atmospheric carbon dioxide by transferring the atmospheric carbon into the oceans. The concentration of phytoplankton in the Southern Ocean is regularly limited by the availability of marine iron. This in turn influences the rate of carbon transfer from the atmosphere to the ocean. The primary source of iron in the Southern Ocean is eroded continental rock. Understanding the current and future sources of iron to the Southern Ocean as a result of increased melting of terrestrial glaciers is necessary for predicting future concentrations of Southern Ocean phytoplankton and the subsequent influence on the carbon cycle. A poorly understood source of iron to the Southern Ocean is stream input from ice-free regions such as the McMurdo Dry Valleys in Antarctica. This source of iron is likely to become larger if glaciers retreat. This study investigates the sources and amount of iron transported by McMurdo Dry Valley streams directly into the Southern Ocean. Because not all forms of iron can be used by phytoplankton, experiments will be performed to determine how available iron is to phytoplankton and how iron mixes with seawater. Immersive 360-degree video, infographics, and educational videos of findings from this project will be shared on social media, at schools and science events, and in an urban science center.<br/><br/>In the Southern Ocean (SO) there is an excess of macronutrients but regional primary production is limited or co-limited due to iron. An addition of iron to the ocean will affect biochemical cycles, increase primary production, and affect the structure and composition of phytoplankton communities in the SO. Iron flux to the SO is globally significant, as increased Fe fertilization leads to increased carbon sequestration which acts as a negative feedback to increased atmospheric pCO2. One source of potentially bioavailable iron to the coastal regions of the SO is from direct sub-aerial stream discharge in ice-free areas of Antarctica, a source that may become more important if terrestrial glaciers retreat. It is imperative to understand the source, nature, potential fate, and flux of iron to the SO if better predictive models for the carbon cycle and atmospheric chemistry are to be developed. This project will investigate in-stream processes and characteristics controlling dissolved iron draining into the Ross Sea including photoreduction, temperature, and complexation with organic matter. The novel study will quantify bioavailability of particulate iron and bioavailability of dissolved iron in Antarctic in streams draining into the SO. On-site speciation measurements will be performed on dissolved iron species, particulate iron speciation will be determined using high-resolution spectroscopy, mixing experiments will be performed with coastal marine water, and the bioavailability of Fe will be determined through marine bioassays. This project will provide two students with valuable Antarctic field experience and reach thousands of individuals through existing partnerships with K-12 schools, public STEM events, an urban science center, and a strong social media presence.<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. | POLYGON((163.37428 -77.558627,163.3922735 -77.558627,163.410267 -77.558627,163.4282605 -77.558627,163.446254 -77.558627,163.4642475 -77.558627,163.482241 -77.558627,163.5002345 -77.558627,163.518228 -77.558627,163.5362215 -77.558627,163.554215 -77.558627,163.554215 -77.56397510000001,163.554215 -77.5693232,163.554215 -77.5746713,163.554215 -77.5800194,163.554215 -77.5853675,163.554215 -77.59071560000001,163.554215 -77.5960637,163.554215 -77.60141180000001,163.554215 -77.6067599,163.554215 -77.612108,163.5362215 -77.612108,163.518228 -77.612108,163.5002345 -77.612108,163.482241 -77.612108,163.4642475 -77.612108,163.446254 -77.612108,163.4282605 -77.612108,163.410267 -77.612108,163.3922735 -77.612108,163.37428 -77.612108,163.37428 -77.6067599,163.37428 -77.60141180000001,163.37428 -77.5960637,163.37428 -77.59071560000001,163.37428 -77.5853675,163.37428 -77.5800194,163.37428 -77.5746713,163.37428 -77.5693232,163.37428 -77.56397510000001,163.37428 -77.558627)) | POINT(163.4642475 -77.5853675) | false | false | ||||||||||
Projecting the Biological Carbon Pump and Climate Feedback in the Rapidly Changing West Antarctic Peninsula: A Hybrid Modeling Study
|
2332062 |
2024-08-05 | Kim, Heather | No dataset link provided | 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.<br/><br/>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. | 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)) | POINT(-64 -67) | false | false | |||||||||
RAPID: Is Biomass Mobilization at Ice-covered Lake Fryxell, Antarctica reaching a Critical Threshold?
|
2336354 |
2024-07-05 | Juarez Rivera, Marisol |
|
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. | 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)) | POINT(162.25 -77.5) | false | false | |||||||||
Collaborative Research: BoCP-Design: Climate change alteration of soils functional biodiversity of the Páramos, Colombia
|
2325922 |
2024-02-06 | Couradeau, Estelle; Maximova, Siela; Machado, Jose Luis | No dataset link provided | As climate change progresses, it is activating both master switches of microbial activity simultaneously: moisture and temperature. In soils, microbes serve critical ecosystem services including nutrient cycling and carbon sequestration. The fact that we do not fully understand how microbes act on carbon pools in soils and how these will change with the rapidly changing climate is extremely worrisome. Here we propose to tackle this question by initiating an interdisciplinary action studying the soils of the Colombian Páramos. The Páramos are a unique high-altitude hotspot of biodiversity in the Andes that render critical ecosystem services, including water capture and carbon sequestration. If the hydrology of the system has gained a lot of attention over the past few years, the fate of the extensive pools of organic carbon in these vast peatlands has remained unexplored. The unique geographic situation of the cold and humid Páramos being already on the edge of their geo-climatic range provides us with an unparalleled opportunity to study a soil microbial community from carbon-rich soils that are extremely vulnerable to both the raise in temperature and decrease of moisture that will impact soils around the globe as climate change progresses. Our project aims at starting to address the need to disentangle the effect of moisture and temperature on the activity and composition of the microbial communities controlling the fate of organic carbon in soils (Objective 1), while assembling an international team of experts capable of scaling up the understanding of these processes at the landscape and regional level by integrating the functioning of the belowground microbial community with the above-ground vegetation (Objective 2). | POLYGON((-73.783 4.679,-73.7827 4.679,-73.7824 4.679,-73.7821 4.679,-73.7818 4.679,-73.7815 4.679,-73.7812 4.679,-73.7809 4.679,-73.7806 4.679,-73.7803 4.679,-73.78 4.679,-73.78 4.6789,-73.78 4.6788,-73.78 4.6787,-73.78 4.6786,-73.78 4.6785,-73.78 4.6784,-73.78 4.6783,-73.78 4.6782,-73.78 4.6781,-73.78 4.678,-73.7803 4.678,-73.7806 4.678,-73.7809 4.678,-73.7812 4.678,-73.7815 4.678,-73.7818 4.678,-73.7821 4.678,-73.7824 4.678,-73.7827 4.678,-73.783 4.678,-73.783 4.6781,-73.783 4.6782,-73.783 4.6783,-73.783 4.6784,-73.783 4.6785,-73.783 4.6786,-73.783 4.6787,-73.783 4.6788,-73.783 4.6789,-73.783 4.679)) | POINT(-73.7815 4.6785) | false | false | |||||||||
Collaborative Research: ANT LIA: Connecting Metagenome Potential to Microbial Function: Investigating Microbial Degradation of Complex Organic Matter Antarctic Benthic Sediments
|
2147045 |
2022-08-30 | Learman, Deric |
|
Microbes in Antarctic surface marine sediments have an important role in degrading organic matter and releasing nutrients to the ocean. Organic matter degradation is at the center of the carbon cycle in the ocean, providing valuable information on nutrient recycling, food availability to animals and carbon dioxide release to the atmosphere. The functionality of these microbes has been inferred by their genomics, however these methods only address the possible function, not their actual rates. In this project the PIs plan to combine genomics methods with cellular estimates of enzyme abundance and activity as a way to determine the rates of carbon degradation. This project aims to sample in several regions of Antarctica to provide a large-scale picture of the processes under study and understand the importance of microbial community composition and environmental factors, such as primary productivity, have on microbial activity. The proposed work will combine research tools such as metagenomics, meta-transcriptomics, and metabolomics coupled with chemical data and enzyme assays to establish degradation of organic matter in Antarctic sediments. This project benefits NSFs goals of understanding the adaptation of Antarctic organisms to the cold and isolated environment, critical to predict effects of climate change to polar organisms, as well as contribute to our knowledge of how Antarctic organisms have adapted to this environment. Society will benefit from this project by education of 2 graduate students, undergraduates and K-12 students as well as increase public literacy through short videos production shared in YouTube. The PIs propose to advance understanding of polar microbial community function, by measuring enzyme and gene function of complex organic matter degradation in several ocean regions, providing a circum-Antarctic description of sediment processes. Two hypotheses are proposed. The first hypothesis states that many genes for the degradation of complex organic matter will be shared in sediments throughout a sampling transect and that where variations in gene content occur, it will reflect differences in the quantity and quality of organic matter, not regional variability. The second hypothesis states that a fraction of gene transcripts for organic matter degradation will not result in measurable enzyme activity due to post-translational modification or rapid degradation of the enzymes. The PIs will analyze sediment cores already collected in a 2020 cruise to the western Antarctic Peninsula with the additional request of participating in a cruise in 2023 to East Antarctica. The PIs will analyze sediments for metagenomics, meta-transcriptomics, and metabolomics coupled with geochemical data and enzyme assays to establish microbial degradation of complex organic matter in Antarctic sediments. Organic carbon concentrations and content in sediments will be measured with δ13C, δ15N, TOC porewater fluorescence in bulk organic carbon. Combined with determination of geographical variability as well as dependence on carbon sources, results from this study could provide the basis for new hypotheses on how climate variability, with increased water temperature, affects geochemistry in the Southern Ocean. | POLYGON((-180 -60,-168 -60,-156 -60,-144 -60,-132 -60,-120 -60,-108 -60,-96 -60,-84 -60,-72 -60,-60 -60,-60 -62,-60 -64,-60 -66,-60 -68,-60 -70,-60 -72,-60 -74,-60 -76,-60 -78,-60 -80,-72 -80,-84 -80,-96 -80,-108 -80,-120 -80,-132 -80,-144 -80,-156 -80,-168 -80,180 -80,171 -80,162 -80,153 -80,144 -80,135 -80,126 -80,117 -80,108 -80,99 -80,90 -80,90 -78,90 -76,90 -74,90 -72,90 -70,90 -68,90 -66,90 -64,90 -62,90 -60,99 -60,108 -60,117 -60,126 -60,135 -60,144 -60,153 -60,162 -60,171 -60,-180 -60)) | POINT(-165 -70) | false | false | |||||||||
Linking Antarctic Cold Desert Groundwater to Thermokarst & Chemical Weathering in Partnership with the Geoscience UAV Academy
|
1847067 |
2021-12-24 | Levy, Joseph |
|
Antarctic groundwater drives the regional carbon cycle, accelerates permafrost thaw, and shapes Antarctic climate response. However, groundwater extent, movement, and processes on a continent virtually locked in ice are poorly understood. The proposed work investigates the interplay between groundwater, sediment, and ice in Antarctica’s cold desert landscapes to determine when, where, and why Antarctic groundwater is flowing, and how quickly it will switch Antarctic frozen deserts from dry and stable to wet and disintegrating. Little is known about the extent, chemistry, and duration of groundwater in Antarctic seasonal wetlands. Mapping the changing extent of Antarctic wetlands requires the ability to measure soil moisture rapidly and repeatedly and over large areas. Changing groundwater extent will be captured through an unmanned aerial vehicle (UAV)-based mapping approach. The project integrates a diverse range of sensors with new UAV technologies to provide a higher-resolution and more frequent assessment of Antarctic groundwater extent and composition than can be accomplished using satellite observations alone. To complement the research objectives, the PI will develop a new UAV summer field school, the Geosciences UAV Academy, focused on training undergraduate-level UAV pilots in conducting novel Earth science research using cutting edge imaging tools. The integration of research and technology will prepare students for careers in burgeoning UAV-related industries and research. The project will deliver new UAV tools and workflows for soil moisture mapping relevant to arid regions common not just to Antarctica but to temperate desert and dryland systems and will train student research pilots to tackle next generation airborne challenges. Water tracks are the basic hydrological unit that currently feeds the rapidly-changing polar and permafrost wetlands in the Antarctic McMurdo Dry Valleys (MDV). Despite the importance of water tracks in the MDV hydrologic cycle and their influence on biogeochemistry, little is known about how these water tracks control the unique brine processes operating in Antarctic ice-free areas. Both groundwater availability and geochemistry shape Antarctic microbial communities, connecting soil geology and hydrology to carbon cycling and ecosystem functioning. The objectives of this CAREER proposal are to 1) map water tracks to determine the spatial distribution and seasonal magnitude of groundwater impacts on the MDV near-surface environment to determine how water tracks drive irreversible permafrost thaw, how water tracks enhance chemical weathering and biogeochemical cycling, and how water tracks integrate and accelerate climate feedbacks between terrestrial Antarctic soils and the Southern Ocean; 2) establish a UAV academy training earth sciences students to answer geoscience questions using drone-based platforms and remote sensing techniques; and 3) provide a formative step in the development of the PI as a teacher-scholar. UAV-borne hyperspectral imaging complemented with field soil sampling will determine the aerial extent and timing of inundation, water level, and water budget of representative water tracks in the MDV. Soil moisture will be measured via near-infrared reflectance spectroscopy while bulk chemistry of soils and groundwater will be analyzed via ion chromatography and soil x-ray fluorescence. Sedimentological and hydrological properties (suction/matric potential, hydraulic conductivity, etc.) will be determined via analysis of intact core samples. These data will be used to test competing hypotheses regarding the origin of water track solutions and water movement through seasonal wetlands. The will provide a regional understanding of Antarctic groundwater sources, groundwater flux, and the influence of regional hydrogeology on solute export to the Southern Ocean and on soil/atmosphere linkages in earth’s carbon budget. The UAV school will 1) provide comprehensive instruction at the undergraduate level in both how and why UAVs can be used in geoscience research and learning; and 2) provide a long-term piece of educational infrastructure in the form of an ultimately self-sustaining summer program for undergraduate UAV education. | POLYGON((161 -76,161.35 -76,161.7 -76,162.05 -76,162.4 -76,162.75 -76,163.1 -76,163.45 -76,163.8 -76,164.15 -76,164.5 -76,164.5 -76.2,164.5 -76.4,164.5 -76.6,164.5 -76.8,164.5 -77,164.5 -77.2,164.5 -77.4,164.5 -77.6,164.5 -77.8,164.5 -78,164.15 -78,163.8 -78,163.45 -78,163.1 -78,162.75 -78,162.4 -78,162.05 -78,161.7 -78,161.35 -78,161 -78,161 -77.8,161 -77.6,161 -77.4,161 -77.2,161 -77,161 -76.8,161 -76.6,161 -76.4,161 -76.2,161 -76)) | POINT(162.75 -77) | false | false | |||||||||
NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)
|
1941308 1941483 1941327 1941304 1941292 |
2021-08-20 | Yager, Patricia; Medeiros, Patricia; Sherrell, Robert; St-Laurent, Pierre; Fitzsimmons, Jessica; Stammerjohn, Sharon | The Amundsen Sea hosts the most productive polynya in all of Antarctica, with its vibrant green waters visible from space, and an atmospheric CO2 uptake density 10x higher than the Southern Ocean average. The region is vulnerable to climate change, experiencing rapid losses in sea ice, a changing icescape, and some of the fastest melting glaciers flowing from the West Antarctic Ice Sheet (WAIS). ARTEMIS aims to characterize the climate-sensitive nature of glacial meltwater-driven micronutrient (iron, Fe) contributions driving ecosystem productivity and CO2 uptake in the coastal Antarctic. We propose to integrate observations and ocean modeling of these processes to enhance predictive capabilities. Currently, basal melt resulting from warm deep waters penetrating ice shelf cavities dominates mass losses of WAIS, contributing to sea level rise. These physical melting processes are being studied by the International Thwaites Glacier Collaboration (ITGC). The impact of melting on the marine ecosystem has also been explored, and we know that productivity is due in part to Fe-rich, glacial meltwater-driven outflow. The biogeochemical composition of the outflow from the glaciers surrounding the Amundsen Sea is largely unstudied, however. Improved knowledge would provide keys to understanding meltwater's future impact on the ecosystem. An ongoing field program (TARSAN, part of the ITGC) offers the ideal physical oceanographic framework for our biogeochemical effort. We propose here to collaborate with TARSAN-supported UK scientists, providing value added to both team efforts. ARTEMIS will add shipboard measurements (trace metals, carbonate system, nutrients, organic matter, microorganisms) and biogeochemical sensors on autonomous vehicles to gather critical knowledge needed to understand the impact of the melting WAIS on both the coastal ecosystem and the regional carbon (C) cycle. Driving questions include: 1) what are the fluxes and chemical forms of Fe, C, and microorganisms in the ice shelf outflow? 2) what are the relative contributions to the ouflow from deep water, benthic, and glacial melt sources, and how do these inputs combine to affect the bioavailability of Fe? 3) How are Fe and C compounds modified as the outflow advects along the coastal current and mixes into the bloom region? and 4) what will be the effect of increased glacial melting, changes in the coastal icescape, and declining sea ice on theecosystem of the Amundsen Sea? Such questions fall outside the focus of the ITGC, but are of keen interest to Antarctic Organisms and Ecosystems and Antarctic Integrated System Science programs. | POLYGON((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.4,-100 -71.8,-100 -72.2,-100 -72.6,-100 -73,-100 -73.4,-100 -73.8,-100 -74.2,-100 -74.6,-100 -75,-102 -75,-104 -75,-106 -75,-108 -75,-110 -75,-112 -75,-114 -75,-116 -75,-118 -75,-120 -75,-120 -74.6,-120 -74.2,-120 -73.8,-120 -73.4,-120 -73,-120 -72.6,-120 -72.2,-120 -71.8,-120 -71.4,-120 -71)) | POINT(-110 -73) | false | false | ||||||||||
RAPID: Meta-genomic and Transcriptomic Investigation of Complex Organic Matter Degradation in Antarctic Benthic Sediments
|
2031442 |
2021-07-28 | Learman, Deric |
|
This proposal will provide genetic and enzymatic insight into how microbial communities in benthic sediments on the coastal shelf of Antarctica degrade complex organic matter. The current understanding of how benthic microbial communities respond and also degrade complex organic matter in Antarctica is fragmented. Recent work suggests benthic microbial communities are shaped by organic matter availability (encompassing both quantity and quality), however, these studies were observational and did not directly examine community function (e.g. enzyme activity and/or gene expression). Preliminary metagenomic data, collected from western Antarctica marine sediments, document gene potential for organic matter degradation throughout the entire sample set (spanning the Amundsen Sea, Bellingshausen Sea, and Ross Sea), but functional data was not collected. To date, studies have examined either enzyme activity or metagenomic potential but few have been able to directly connect the two. To address these gaps in knowledge, this proposal will utilize powerful tools such as metagenomics and metatranscriptomics, coupled with microcosm experiments, enzyme assays, and geochemical data. This hypothesis driven proposal will examine microbial communities from the continental shelf of Antarctica from two different regions (Bransfield Strait and Weddell Sea) to document the communities’ enzymatic activity and genes used to degrade complex organic matter. These data will expand our current knowledge of genetic potential towards a more direct understanding of enzyme function as it relates to degradation of complex organic matter in marine sediments from Antarctica. | POLYGON((-180 -60,-167.5 -60,-155 -60,-142.5 -60,-130 -60,-117.5 -60,-105 -60,-92.5 -60,-80 -60,-67.5 -60,-55 -60,-55 -62,-55 -64,-55 -66,-55 -68,-55 -70,-55 -72,-55 -74,-55 -76,-55 -78,-55 -80,-67.5 -80,-80 -80,-92.5 -80,-105 -80,-117.5 -80,-130 -80,-142.5 -80,-155 -80,-167.5 -80,180 -80,178 -80,176 -80,174 -80,172 -80,170 -80,168 -80,166 -80,164 -80,162 -80,160 -80,160 -78,160 -76,160 -74,160 -72,160 -70,160 -68,160 -66,160 -64,160 -62,160 -60,162 -60,164 -60,166 -60,168 -60,170 -60,172 -60,174 -60,176 -60,178 -60,-180 -60)) | POINT(-127.5 -70) | false | false | |||||||||
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
|
2000992 |
2021-07-06 | Patterson, Molly; Ash, Jeanine; Kulhanek, Denise; Ash, Jeannie |
|
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. We 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, we 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 our hypothesis, we will analyze sediment from IODP Site U1524 (recovered in 2018 during International Ocean Discovery Program Expedition 374) and focus on three data sets. (1) We will use the occurrence, frequency, and character of mm-scale turbidite beds as a proxy of dense-shelf-water cascading outflow and AABW production. We will estimate the down-slope flux via numerical modeling of turbidity current properties using morphology, grain size, and bed thickness as input parameters. (2) We 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) We 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. We will integrate these data 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. | POINT(-172.873074 -74.274008) | POINT(-172.873074 -74.274008) | false | false | |||||||||
Collaborative Research: Understanding the evolution of high-latitude Permo-Triassic paleoenvironments and their vertebrate communities
|
1341304 1341376 1341475 1341645 2001033 |
2021-06-29 | Sidor, Christian; Smith, Nathan; Makovicky, Peter; Tabor, Neil |
|
This project will advance our understanding of Antarctic life during the Permian and Triassic. We will apply an interdisciplinary approach to address relationships between environmental change, faunal composition, and biogeographic patterns in the context of the high-latitude strata preserved in the Buckley and Fremouw formations in the Shackleton Glacier region. We will use multiple types of data to assess paleoenvironment, including: 1) paleosol morphology; 2) paleosol geochemistry; 3) pedogenic organic matter; and 4) fossil wood chronology and stable isotopes. The Fremouw Formation of Antarctica preserves the highest paleolatitude tetrapod fauna of the entire Triassic (~70° S) and thus has the potential to shed important light on the evolution of polar life during the early Mesozoic. We will collect new fossils from known localities to understand the relationship between Antarctic and southern African tetrapod faunas. Furthermore, we will refine the stratigraphic, sedimentological, and geochronological framework for these Mesozoic faunas, which will include using U/Pb detrital zircon dating to provide the first dates for these vertebrate assemblages. In the lab, we will examine the biology of Triassic vertebrates from Antarctica by comparing their bone and tusk histology to conspecifics from lower paleolatitudes. In addition, we will test Bergmann’s Rule with six species (viz. Lystrosaurus curvatus, L. maccaigi, L. murrayi, Prolacerta broomi, Procolophon trigoniceps, and Thrinaxodon liorhinus). The Early Triassic presents a unique opportunity to perform such investigations as there is no other geologic interval in which species occurring in Antarctica can be compared to conspecifics across a range of paleolatitudes. | POLYGON((-180 -84,-178 -84,-176 -84,-174 -84,-172 -84,-170 -84,-168 -84,-166 -84,-164 -84,-162 -84,-160 -84,-160 -84.3,-160 -84.6,-160 -84.9,-160 -85.2,-160 -85.5,-160 -85.8,-160 -86.1,-160 -86.4,-160 -86.7,-160 -87,-162 -87,-164 -87,-166 -87,-168 -87,-170 -87,-172 -87,-174 -87,-176 -87,-178 -87,180 -87,178.5 -87,177 -87,175.5 -87,174 -87,172.5 -87,171 -87,169.5 -87,168 -87,166.5 -87,165 -87,165 -86.7,165 -86.4,165 -86.1,165 -85.8,165 -85.5,165 -85.2,165 -84.9,165 -84.6,165 -84.3,165 -84,166.5 -84,168 -84,169.5 -84,171 -84,172.5 -84,174 -84,175.5 -84,177 -84,178.5 -84,-180 -84)) | POINT(-177.5 -85.5) | false | false | |||||||||
Collaborative Research: Chemoautotrophy in Antarctic Bacterioplankton Communities Supported by the Oxidation of Urea-derived Nitrogen
|
1643345 1643466 |
2020-12-18 | Hollibaugh, James T.; Popp, Brian |
|
The project addressed fundamental questions regarding the role of nitrification (the conversion of ammonium to nitrate by a two-step process involving two different guilds of microorganisms: ammonia- and nitrite-oxidizers) in the Antarctic marine ecosystem. Specifically, the project evaluated the contribution of carbon fixation supported by energy derived from the oxidation of nitrogen compounds (chemoautotrophy) to the overall supply of organic carbon to the food web of the Southern Ocean. Additionally, the project aimed to determine the significance of the contribution of other sources of reduced nitrogen, specifically organic nitrogen and urea, to nitrification because these contributions may not be assessed by standard protocols. <br><br>We quantified the oxidation rates of 15N supplied as ammonium, urea and nitrite, which allowed us to estimate the contribution of urea-derived N and complete nitrification (ammonia to nitrate, N-3 to N+5) to chemoautotrophy in Antarctic coastal waters. We compared these estimates to direct measurements of the incorporation of dissolved inorganic 14C into organic matter in the dark for an independent estimate of chemoautotrophy. We made measurements on samples taken from the major water masses: surface water (~10 m), winter water (35-174 m), circumpolar deep water (175-1000 m) and slope water (>1000 m); on a cruise surveying the continental shelf and slope west of the Antarctic Peninsula in the austral summer of 2018 (LMG18-01). Samples were also taken to measure the concentrations of nitrite, ammonia, urea and polyamines; for qPCR analysis of the abundance of relevant marker genes; and for studies of processes related to the core questions of the study. The project relied on collaboration with the Palmer LTER for ancillary data (bacterioplankton abundance and production, chlorophyll, physical and additional chemical variables). The synergistic activities of this project along with the LTER activities provides a unique opportunity to assess chemoautotrophy in context of the overall ecosystem's dynamics, including both primary and secondary production processes. <br><br>This project resulted in the training of a postdoctoral researcher and provide undergraduate students opportunities to gain hand-on experience with research on microbial geochemistry. This project contributed substantially to understanding an important aspect of nitrogen cycling and bacterioplankton production in the study area. Both PIs participate fully in the education and outreach efforts of the Palmer LTER, including making highlights of the findings available for posting to the LTER project web site, posting material to web sites at their respective departments, and incorporating material from the study in lectures and seminars presented at their respective institutions. | POLYGON((-78.20206667 -64.03195833,-76.785055836 -64.03195833,-75.368045002 -64.03195833,-73.951034168 -64.03195833,-72.534023334 -64.03195833,-71.1170125 -64.03195833,-69.700001666 -64.03195833,-68.282990832 -64.03195833,-66.865979998 -64.03195833,-65.448969164 -64.03195833,-64.03195833 -64.03195833,-64.03195833 -64.554377497,-64.03195833 -65.076796664,-64.03195833 -65.599215831,-64.03195833 -66.121634998,-64.03195833 -66.644054165,-64.03195833 -67.166473332,-64.03195833 -67.688892499,-64.03195833 -68.211311666,-64.03195833 -68.733730833,-64.03195833 -69.25615,-65.448969164 -69.25615,-66.865979998 -69.25615,-68.282990832 -69.25615,-69.700001666 -69.25615,-71.1170125 -69.25615,-72.534023334 -69.25615,-73.951034168 -69.25615,-75.368045002 -69.25615,-76.785055836 -69.25615,-78.20206667 -69.25615,-78.20206667 -68.733730833,-78.20206667 -68.211311666,-78.20206667 -67.688892499,-78.20206667 -67.166473332,-78.20206667 -66.644054165,-78.20206667 -66.121634998,-78.20206667 -65.599215831,-78.20206667 -65.076796664,-78.20206667 -64.554377497,-78.20206667 -64.03195833)) | POINT(-71.1170125 -66.644054165) | false | false | |||||||||
Collaborative Research: Subglacial Antarctic Lakes Scientific Access (SALSA): Integrated Study of Carbon Cycling in Hydrologically-active Subglacial Environments
|
1543453 1543405 1543537 1543441 1543396 1543347 |
2020-07-16 | Rosenheim, Brad; Fricker, Helen; Priscu, John; Leventer, Amy; Dore, John; Lyons, W. Berry; Christner, Brent | The Antarctic subglacial environment remains one of the least explored regions on Earth. This project will examine the physical and biological characteristics of Subglacial Lake Mercer, a lake that lies 1200m beneath the West Antarctic Ice Sheet. This study will address key questions relating to the stability of the ice sheet, the subglacial hydrological system, and the deep-cold subglacial biosphere. The education and outreach component aims to widely disseminate results to the scientific community and to the general public through short films, a blog, and a website.<br/><br/>Subglacial Lake Mercer is one of the larger hydrologically active lakes in the southern basin of the Whillans Ice Plain, West Antarctica. It receives about 25 percent of its water from East Antarctica with the remainder originating from West Antarctica, is influenced by drain/fill cycles in a lake immediately upstream (Subglacial Lake Conway), and lies about 100 km upstream of the present grounding line of the Ross Ice Shelf. This site will yield information on the history of the Whillans and Mercer Ice Streams, and on grounding line migration. The integrated study will include direct sampling of basal ice, water, and sediment from the lake in concert with surface geophysical surveys over a three-year period to define the hydrological connectivity among lakes on the Whillans Ice Plain and their flow paths to the sea. The geophysical surveys will furnish information on subglacial hydrology, aid the site selection for hot-water drilling, and provide spatial context for interpreting findings. The hot-water-drilled boreholes will be used to collect basal ice samples, provide access for direct measurement of subglacial physical, chemical, and biological conditions in the water column and sediments, and to explore the subglacial water cavities using a remotely operated vehicle equipped with sensors, cameras, and sampling equipment. Data collected from this study will address the overarching hypothesis \"Contemporary biodiversity and carbon cycling in hydrologically-active subglacial environments associated with the Mercer and Whillans ice streams are regulated by the mineralization and cycling of relict marine organic matter and through interactions among ice, rock, water, and sediments\". The project will be undertaken by a collaborative team of scientists, with expertise in microbiology, biogeochemistry, hydrology, geophysics, glaciology, marine geology, paleoceanography, and science communication. | POLYGON((-163.611 -84.33543,-162.200034 -84.33543,-160.789068 -84.33543,-159.378102 -84.33543,-157.967136 -84.33543,-156.55617 -84.33543,-155.145204 -84.33543,-153.734238 -84.33543,-152.323272 -84.33543,-150.912306 -84.33543,-149.50134 -84.33543,-149.50134 -84.3659157,-149.50134 -84.3964014,-149.50134 -84.4268871,-149.50134 -84.4573728,-149.50134 -84.4878585,-149.50134 -84.5183442,-149.50134 -84.5488299,-149.50134 -84.5793156,-149.50134 -84.6098013,-149.50134 -84.640287,-150.912306 -84.640287,-152.323272 -84.640287,-153.734238 -84.640287,-155.145204 -84.640287,-156.55617 -84.640287,-157.967136 -84.640287,-159.378102 -84.640287,-160.789068 -84.640287,-162.200034 -84.640287,-163.611 -84.640287,-163.611 -84.6098013,-163.611 -84.5793156,-163.611 -84.5488299,-163.611 -84.5183442,-163.611 -84.4878585,-163.611 -84.4573728,-163.611 -84.4268871,-163.611 -84.3964014,-163.611 -84.3659157,-163.611 -84.33543)) | POINT(-156.55617 -84.4878585) | false | false | ||||||||||
Activity, Preservation and Fossilization of Cryptoendolithic Microorganisms in Antarctica
|
1544526 |
2019-05-09 | Omelon, Christopher; Breecker, Daniel; Bennett, Philip | No dataset link provided | Cryptoendoliths are organisms that colonize microscopic cavities of rocks, which give them protection and allow them to inhabit extreme environments, such as the cold, arid desert of the Dry Valleys of Antarctica. Fossilized cryptoendoliths preserve the forms and features of organisms from the past and thus provide a unique opportunity to study the organisms' life histories and environments. To study this fossil record, there needs to be a better understanding of what environmental conditions allow these fossils to form. A climate gradient currently exists in the Dry Valleys that allows us to study living, dead, and fossilized cryptoendoliths from mild to increasingly harsh environments; providing insight to the limits of life and how these fossils are formed. This project will develop instruments to detect the biological activity of the live microorganisms and conduct laboratory experiments to determine the environmental limits of their survival. The project also will characterize the chemical and structural features of the living, dead, and fossilized cryptoendoliths to understand how they become fossilized. Knowing how microorganisms are preserved as fossils in cold and dry environments like Antarctica can help to refine methods that can be used to search for and identify evidence for extraterrestrial life in similar habitats on planets such as Mars. This project includes training of graduate and undergraduate students. Little is known about cryptoendolithic microfossils and their formation processes in cold, arid terrestrial habitats of the Dry Valleys of Antarctica, where a legacy of activity is discernible in the form of biosignatures including inorganic materials and microbial fossils that preserve and indicate traces of past biological activity. The overarching goals of the proposed work are: (1) to determine how rates of microbial respiration and biodegradation of organic matter control microbial fossilization; and (2) to characterize microbial fossils and their living counterparts to elucidate mechanisms for fossilization. Using samples collected across an increasingly harsher (more cold and dry) climatic gradient that encompasses living, dead, and fossilized cryptoendolithic microorganisms, the proposed work will: (1) develop an instrument to be used in the field that can measure small concentrations of CO2 in cryptoendolithic habitats in situ; (2) use microscopy techniques to characterize endolithic microorganisms as well as the chemical and morphological characteristics of biosignatures and microbial fossils. A metagenomic survey of microbial communities in these samples will be used to characterize differences in diversity, identify if specific microorganisms (e.g. prokaryotes, eukaryotes) are more capable of surviving under these harsh climatic conditions, and to corroborate microscopic observations of the viability states of these microorganisms. | POLYGON((160 -76.5,160.37 -76.5,160.74 -76.5,161.11 -76.5,161.48 -76.5,161.85 -76.5,162.22 -76.5,162.59 -76.5,162.96 -76.5,163.33 -76.5,163.7 -76.5,163.7 -76.63,163.7 -76.76,163.7 -76.89,163.7 -77.02,163.7 -77.15,163.7 -77.28,163.7 -77.41,163.7 -77.54,163.7 -77.67,163.7 -77.8,163.33 -77.8,162.96 -77.8,162.59 -77.8,162.22 -77.8,161.85 -77.8,161.48 -77.8,161.11 -77.8,160.74 -77.8,160.37 -77.8,160 -77.8,160 -77.67,160 -77.54,160 -77.41,160 -77.28,160 -77.15,160 -77.02,160 -76.89,160 -76.76,160 -76.63,160 -76.5)) | POINT(161.85 -77.15) | false | false | |||||||||
Using Radiochemical Data from Collapsed Ice Shelf Sediments to Understand the Nature and Timing of the Benthic Response to High-Latitude Climate Change
|
1341669 |
2018-02-03 | DeMaster, David; Smith, Craig | The PI requests support to analyze sediments from multi-cores and mega-cores previously collected from beneath the former Larsen B and Larsen A ice shelves. These unique cores will allow the PI to develop a time-integrated understanding of the benthic response to ice shelf collapse off the East Antarctic Peninsula over time periods as short as 5 years following ice shelf collapse up to >170 years after collapse. High latitudes are responding to climate change more rapidly than the rest of the planet and the disappearance of ice shelves are a key manifestation of climate warming. The PI will investigate the newly created benthic environments and associated ecosystems that have resulted from the re-initiation of fresh planktonic material to the sediment-water interface. This proposal will use a new geochemical technique, based on naturally occurring 14C that can be used to assess the distribution and inventory of recently produced organic carbon accumulating in the sediments beneath the former Larsen A and B ice shelves. The PI will couple 14C measurements with 210Pb analyses to assess turnover times for sedimentary labile organic matter. By comparing the distributions and inventories of labile organic matter as well as the bioturbation intensities among different locations as a function of time following ice shelf collapse/retreat, the nature and timing of the benthic response to ice shelf collapse can be assessed. | POLYGON((-70 -62,-68.8 -62,-67.6 -62,-66.4 -62,-65.2 -62,-64 -62,-62.8 -62,-61.6 -62,-60.4 -62,-59.2 -62,-58 -62,-58 -62.6,-58 -63.2,-58 -63.8,-58 -64.4,-58 -65,-58 -65.6,-58 -66.2,-58 -66.8,-58 -67.4,-58 -68,-59.2 -68,-60.4 -68,-61.6 -68,-62.8 -68,-64 -68,-65.2 -68,-66.4 -68,-67.6 -68,-68.8 -68,-70 -68,-70 -67.4,-70 -66.8,-70 -66.2,-70 -65.6,-70 -65,-70 -64.4,-70 -63.8,-70 -63.2,-70 -62.6,-70 -62)) | POINT(-64 -65) | false | false | ||||||||||
PostDoctoral Research Fellowship
|
1103428 |
2017-10-10 | Thurber, Andrew | The biota of the world's seafloor is fueled by bursts of seasonal primary production. For food-limited sediment communities to persist, a balance must exist between metazoan consumption of and competition with bacteria, a balance which likely changes through the seasons. Polar marine ecosystems are ideal places to study such complex interactions due to stark seasonal shifts between heterotrophic and autotrophic communities, and temperatures that may limit microbial processing of organic matter. The research will test the following hypotheses: 1) heterotrophic bacteria compete with macrofauna for food; 2) as phytoplankton populations decline macrofauna increasingly consume microbial biomass to sustain their populations; and 3) in the absence of seasonal photosynthetic inputs, macrofaunal biodiversity will decrease unless supplied with microbially derived nutrition. Observational and empirical studies will test these hypotheses at McMurdo Station, Antarctica, where a high-abundance macro-infaunal community is adapted to this boom-and-bust cycle of productivity. The investigator will mentor undergraduates from a predominantly minority-serving institution, in the fields of invertebrate taxonomy and biogeochemistry. The general public and young scientists will be engaged through lectures at local K-12 venues and launch of an interactive website. The results will better inform scientists and managers about the effects of climate change on polar ecosystems and the mechanisms of changing productivity patterns on global biodiversity. | POLYGON((165 -77,165.5 -77,166 -77,166.5 -77,167 -77,167.5 -77,168 -77,168.5 -77,169 -77,169.5 -77,170 -77,170 -77.1,170 -77.2,170 -77.3,170 -77.4,170 -77.5,170 -77.6,170 -77.7,170 -77.8,170 -77.9,170 -78,169.5 -78,169 -78,168.5 -78,168 -78,167.5 -78,167 -78,166.5 -78,166 -78,165.5 -78,165 -78,165 -77.9,165 -77.8,165 -77.7,165 -77.6,165 -77.5,165 -77.4,165 -77.3,165 -77.2,165 -77.1,165 -77)) | POINT(167.5 -77.5) | false | false | ||||||||||
Collaborative Research: Microbial Community Assembly in Coastal Waters of the Western Antarctic Peninsula
|
1141993 |
2017-06-15 | Rich, Jeremy |
|
The Western Antarctic Peninsula (WAP) has experienced unprecedented warming and shifts in sea ice cover over the past fifty years. How these changes impact marine microbial communities, and subsequently how these shifts in the biota may affect the carbon cycle in surface waters is unknown. This work will examine how these ecosystem-level changes affect microbial community structure and function. This research will use modern metagenomic and transcriptomic approaches to test the hypothesis that the introduction of organic matter from spring phytoplankton blooms drives turnover in microbial communities. This research will characterize patterns in bacterial and archaeal succession during the transition from the austral winter at two long-term monitoring sites: Palmer Station in the north and Rothera Station in the south. This project will also include microcosm incubations to directly assess the effects of additions of organic carbon and melted sea ice on microbial community structure and function. The results of this work will provide a broader understanding of the roles of both rare and abundant microorganisms in carbon cycling within the WAP region, and how these communities may shift in structure and function in response to climate change. Results will be widely disseminated through publications as well as through presentations at national and international meetings. The research will provide training opportunities for both graduate and undergraduate students and will enhance international collaborations with the British Antarctic Survey. | POLYGON((-60 -70,-59.3 -70,-58.6 -70,-57.9 -70,-57.2 -70,-56.5 -70,-55.8 -70,-55.1 -70,-54.4 -70,-53.7 -70,-53 -70,-53 -70.9,-53 -71.8,-53 -72.7,-53 -73.6,-53 -74.5,-53 -75.4,-53 -76.3,-53 -77.2,-53 -78.1,-53 -79,-53.7 -79,-54.4 -79,-55.1 -79,-55.8 -79,-56.5 -79,-57.2 -79,-57.9 -79,-58.6 -79,-59.3 -79,-60 -79,-60 -78.1,-60 -77.2,-60 -76.3,-60 -75.4,-60 -74.5,-60 -73.6,-60 -72.7,-60 -71.8,-60 -70.9,-60 -70)) | POINT(-56.5 -74.5) | false | false | |||||||||
Multidimensional "omics" characterization of microbial metabolism and dissolved organic matter in Antarctica
|
1141978 |
2017-04-25 | Foreman, Christine; Bothner, Brian |
|
Uncovering the dynamics of dissolved organic matter (DOM) is central to an understanding of the global carbon cycle, as organic material from lakes, streams, oceans and soils passes through this pool. DOM acts as a key energy source for microbes in many ecosystems and therefore can affect regional nutrient cycling patterns. For example, preliminary results suggest that organisms isolated from a supraglacial stream on Cotton Glacier, Antarctica, may be important in DOM cycling in this relatively simple, low temperature system. However, little is known about the functional attributes of the microbes that interact with DOM in the environment. This project will use state-of-the-art genomics, proteomics and metabolomics approaches to understand the mechanisms by which two microbial isolates, CG3 and CG9_1, affect DOM cycling. Liquid chromatography-mass spectrometry will also be used to better characterize the microbially-derived DOM from this ecosystem. This project will support the research and training of one undergraduate and two graduate students. Results will be widely disseminated through publications as well as through presentations at national and international meetings. In addition, raw data will be made available through open-access databases. Understanding the relationship between cold-adapted microbial metabolisms and DOM pools is important as more than 90% of the Earth?s oceans are below 5 degrees Celsius. | POLYGON((160 -76,160.1 -76,160.2 -76,160.3 -76,160.4 -76,160.5 -76,160.6 -76,160.7 -76,160.8 -76,160.9 -76,161 -76,161 -76.1,161 -76.2,161 -76.3,161 -76.4,161 -76.5,161 -76.6,161 -76.7,161 -76.8,161 -76.9,161 -77,160.9 -77,160.8 -77,160.7 -77,160.6 -77,160.5 -77,160.4 -77,160.3 -77,160.2 -77,160.1 -77,160 -77,160 -76.9,160 -76.8,160 -76.7,160 -76.6,160 -76.5,160 -76.4,160 -76.3,160 -76.2,160 -76.1,160 -76)) | POINT(160.5 -76.5) | false | false | |||||||||
Collaborative research: TRacing the fate of Algal Carbon Export in the Ross Sea (TRACERS)
|
1142117 1142065 1142044 1142097 |
2015-08-26 | Bochdansky, Alexander; Dunbar, Robert; DiTullio, Giacomo; Ditullio, Giacomo; Harry, Dennis L.; HANSELL, DENNIS |
|
Intellectual Merit: <br/>Sinking particles are a major element of the biological pump and they are commonly assigned to two fates: mineralization in the water column and accumulation at the seafloor. However, there is another fate of export hidden within the vertical decline of carbon, the transformation of sinking organic matter to fine suspended and/or dissolved organic fractions. This process has been suggested but has rarely been observed or quantified. As a result, it is presumed that the solubilized fraction is largely mineralized over short time scales. However, global ocean surveys of dissolved organic carbon are demonstrating a significant water column accumulation of organic matter under high productivity environments. This proposal will investigate the transformation of organic particles from sinking to solubilized phases of the export flux in the Ross Sea. The Ross Sea experiences high export particle production, low dissolved organic carbon export with overturning circulation, and the area has a predictable succession of production and export events. In addition, the basin is shallow (< 000 m) so the products the PIs will target are relatively concentrated. To address the proposed hypothesis, the PIs will use both well-established and novel biochemical and optical measures of export production and its fate. The outcomes of this work will help researchers close the carbon budget in the Ross Sea.<br/><br/>Broader impacts: <br/>This research will support graduate and undergraduate students and will provide undergraduates and pre-college students with field-based research experience. Scientifically, this research will increase understanding of carbon sinks in the Ross Sea and will help develop new tools for identifying, quantifying, and tracking that carbon. The PIs will interface with K-12 students through daily reports from the field and through educational modules developed by several of the PIs in collaboration with science education specialists and college students. A K-12 educator will be included on the research cruises. Outreach will be through COSEE Florida and the Maritime Center in Norfolk, VA. | POLYGON((165 -52,166 -52,167 -52,168 -52,169 -52,170 -52,171 -52,172 -52,173 -52,174 -52,175 -52,175 -54.65,175 -57.3,175 -59.95,175 -62.6,175 -65.25,175 -67.9,175 -70.55,175 -73.2,175 -75.85,175 -78.5,174 -78.5,173 -78.5,172 -78.5,171 -78.5,170 -78.5,169 -78.5,168 -78.5,167 -78.5,166 -78.5,165 -78.5,165 -75.85,165 -73.2,165 -70.55,165 -67.9,165 -65.25,165 -62.6,165 -59.95,165 -57.3,165 -54.650000000000006,165 -52)) | POINT(170 -65.25) | false | false | |||||||||
Spectral and Broadband Albedo of Antarctic Sea-ice Types
|
1141275 |
2015-01-30 | Warren, Stephen; Zatko, Maria |
|
The albedo, or reflection coefficient, is a measure of the diffuse reflectivity of an irradiated surface. With the sunlit atmosphere as a light source, and sea-ice as a diffuse reflecting surface, the albedo would be the fraction of incident light that is returned to the atmosphere. A perfect (white) reflecting surface would have an albedo of 1; a perfect (black) absorbing surface would have an albedo of 0. The albedo of sea-ice is needed to assess the solar energy budget of the marginal ice zone, to compute the partial solar bands in radiation budgets in general circulation and earth system models, and is also needed to interpret remote sensing imagery data products.<br/>Applications requiring albedos further into the near IR, out to 2500nm, are assumed or approximated. Modern spectral radiometers, such as will be used in this campaign on a Southern Ocean voyage from Hobart to Antarctica, can extend these measurements of albedo from 350 to 2500nm, allowing earlier estimates to be verified, or corrected. <br/><br/>Surfaces to be encountered on this research cruise are expected to include open water, grease ice, nila ice, pancake ice, young grey ice, young grey-white ice, along with first year ice. The presence of variable amounts of snow on these surfaces is also of interest. Light absorbing impurities in the snow and ice, including black carbon and organic matter (brown carbon) are different from those found in Arctic Sea ice, the Antarctic being so remote from combustion sources. This may allow better understanding of the seasonal cycles, energy budgets and their recent trends in spatial extent and thickness. The project will also broaden the educational experiences of both US and Australian students participating in the measurement campaign | None | None | false | false | |||||||||
Collaborative Research: The Biogeochemical Evolution of Dissolved Organic Matter in a Fluvial System on the Cotton Glacier, Antarctica
|
0838970 |
2014-10-10 | Foreman, Christine |
|
Dissolved organic matter (DOM) comprises a significant pool of Earth's organic carbon that dwarfs the amount present in living aquatic organisms. The properties and reactivity of DOM are not well defined, and the evolution of autochthonous DOM from its precursor materials in freshwater has not been observed. Recent sampling of a supraglacial stream formed on the Cotton Glacier in the Transantarctic Mountains revealed DOM that more closely resembles an assemblage of recognizable precursor organic compounds, based upon its UV-VIS and fluorescence spectra. It is suggested that the DOM from this water evolved over time to resemble materials present in marine and many inland surface waters. The transient nature of the system i.e., it reforms seasonally, also prevents any accumulation of the refractory DOM present in most surface waters. Thus, the Cotton Glacier provides us with a unique environment to study the formation of DOM from precursor materials. An interdisciplinary team will study the biogeochemistry of this progenitor DOM and how microbes modify it. By focusing on the chemical composition of the DOM as it shifts from precursor material to the more humified fractions, the investigators will relate this transition to bioavailability, enzymatic activity, community composition and microbial growth efficiency. This project will support education at all levels, K-12, high school, undergraduate, graduate and post-doc and will increase participation by under-represented groups in science. Towards these goals, the investigators have established relationships with girls' schools and Native American programs. Additional outreach will be carried out in coordination with PolarTREC, PolarPalooza, and if possible, an Antarctic Artist and Writer. | POINT(161.667 -77.117) | POINT(161.667 -77.117) | false | false | |||||||||
Photoheterotrophic Microbes in the West Antarctic Peninsula Marine Ecosystem
|
0838830 |
2013-12-16 | Cottrell, Matthew; David, Kirchman |
|
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>Light quality and availability are likely to change in polar ecosystems as ice coverage and thickness decrease. How microbes adjust to these and other changes will have huge impacts on the polar marine ecosystems. Little is known about photoheterotrophic prokaryotes, which are hypothesized to gain a metabolic advantage by harvesting light energy in addition to utilizing dissolved organic matter (DOM). Photoheterotrophy is not included in current models of carbon cycling and energy flow. This research will examine three questions: 1. Are photoheterotrophic microbes present and active in Antarctic waters in winter and summer? 2. Does community structure of photoheterotrophs shift between summer and winter? 3. Which microbial groups assimilate more DOM in light than in the dark? The research will test hypotheses about activity of photoheterotrophs in winter and in summer, shifts in community structure between light and dark seasons and the potentially unique impacts of photoheterotrophs on biogeochemical processes in the Antarctic. The project will directly support a graduate student, will positively impact the NSF REU program at the College of Marine and Earth Studies, and will include students from the nation?s oldest historical minority college. The results will be featured during weekly tours of Lewes facilities (about 1000 visitors per year) and during Coast Day, an annual open-house that attracts about 10,000 visitors. | POLYGON((-64.079666 -64.77966,-64.07576590000001 -64.77966,-64.0718658 -64.77966,-64.0679657 -64.77966,-64.0640656 -64.77966,-64.06016550000001 -64.77966,-64.0562654 -64.77966,-64.0523653 -64.77966,-64.04846520000001 -64.77966,-64.0445651 -64.77966,-64.040665 -64.77966,-64.040665 -64.78326100000001,-64.040665 -64.786862,-64.040665 -64.790463,-64.040665 -64.794064,-64.040665 -64.797665,-64.040665 -64.801266,-64.040665 -64.804867,-64.040665 -64.808468,-64.040665 -64.812069,-64.040665 -64.81567,-64.0445651 -64.81567,-64.04846520000001 -64.81567,-64.0523653 -64.81567,-64.0562654 -64.81567,-64.06016550000001 -64.81567,-64.0640656 -64.81567,-64.0679657 -64.81567,-64.0718658 -64.81567,-64.07576590000001 -64.81567,-64.079666 -64.81567,-64.079666 -64.812069,-64.079666 -64.808468,-64.079666 -64.804867,-64.079666 -64.801266,-64.079666 -64.797665,-64.079666 -64.794064,-64.079666 -64.790463,-64.079666 -64.786862,-64.079666 -64.78326100000001,-64.079666 -64.77966)) | POINT(-64.0601655 -64.797665) | false | false | |||||||||
Collaborative Research: The Permian -Triassic Transition in Antarctica: Evaluating the Rates and Variability of Carbon Isotope Fluctuatios in Terrestrial Organic Matter
|
1039365 |
2013-01-30 | Rimmer, Susan |
|
This project studies the Permian-Triassic extinction event as recorded in sedimentary rocks from the Transantarctic Mountains of Antarctica. Two hundred and fifty million years ago most life on Earth was wiped out in a geologic instant. The cause is a subject of great debate. Researchers have identified a unique stratigraphic section near Shackleton glacier laid down during the extinction event. Organic matter from these deposits will be analyzed by density gradient centrifugation (DGC), which will offer detailed information on the carbon isotope composition. The age of these layers will be precisely dated by U/Pb-zircon-dating of intercalated volcanics. Combined, these results will offer detailed constraints on the timing and duration of carbon isotope excursions during the extinction, and offer insight into the coupling of marine and terrestrial carbon cycles. <br/>The broader impacts of this project include graduate and undergraduate student research, K12 outreach and teacher involvement, and societal relevance of the results, since the P/T extinction may have been caused by phenomena such as methane release, which could accompany global warming. | None | None | false | false | |||||||||
Collaborative Research: Molecular Level Characterization of Organic Matter in Ice Cores using High-resolution FTICR mass spectrometry
|
0739684 |
2012-09-26 | Hatcher, Patrick; Grannas, Amanda | No dataset link provided | This award supports a project to fully develop the analytical protocols needed to exploit a relatively new technique for the analysis of soluble organic matter in ice core samples. The technique couples Electrospray ionization to high resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). Sample volume will be reduced and pre-concentration steps will be eliminated. Following method optimization a suite of ice core samples will be studied from several Antarctic and Greenland locations to address several hypothesis driven research questions. Preliminary results show that a vast record of relatively high molecular weight organic material exists in ice core samples and intriguing results from a few samples warrant further investigation. Several important questions related to developing a better understanding of the nature and paleo record of organic matter in ice cores will be addressed. These include developing a better understanding of the origin of nitrogen and sulfur isotopes in pre-industrial vs. modern samples, developing the methods to apply molecular biomarker techniques, routinely used by organic geochemists for sediment analyses, to the analysis of organic matter in ice cores, tracking the level of oxidation of homologous series of compounds and using them as a proxy for atmospheric oxidant levels in the past and determining whether or not high resolution FTICR mass spectral analysis can provide the ice core community with a robust method to analyze organic materials at the molecular level. The intellectual merit of this work is that this analytical method will provide a new understanding of the nature of organic matter in ice, possibly leading to the discovery of multitudes of molecular species indicative of global change processes whose abundances can be compared with other change proxies. The proposed studies are of an exploratory nature and potentially transformative for the field of ice core research and cryobiology. The broader impacts of these studies are that they should provide compelling evidence regarding organic matter sources, atmospheric processing and anthropogenic inputs to polar ice and how these have varied over time. The collaborative work proposed here will partner atmospheric chemistry/polar ice chemistry expertise with organic geochemistry expertise, resulting in significant contributions to both fields of study and significant advances in ice core analysis. Training of both graduate and undergraduate students will be a key component of the project and students will be involved in collaborative research using advanced analytical instrumentation, presentation of research results at national meetings, and will participate in manuscript preparation. | None | None | false | false | |||||||||
Collaborative Research: Impact of Solar Radiation and Nutrients on Biogeochemical Cycling of DMSP and DMS in the Ross Sea, Antarctica
|
0230497 |
2012-01-17 | Kiene, Ronald |
|
Areas of the Southern Ocean have spectacular blooms of phytoplankton during the austral spring and early summer. One of the dominant phytoplankton species, the haptophyte Phaeocystis antarctica, is a prolific producer of the organic sulfur compound dimethylsulfoniopropionate (DMSP) and Phaeocystis blooms are associated with some of the world's highest concentrations of DMSP and its volatile degradation product, dimethylsulfide (DMS). Sulfur, in the form of DMS, is transferred from the oceans to the atmosphere and can affect the chemistry of precipitation and influence cloud properties and possibly climate. DMSP and DMS are also quantitatively significant components of the carbon, sulfur and energy flows in many marine food webs, although very little information is available on these processes in high latitude systems. <br/><br/>This project will study how solar radiation and iron cycling affect DMSP and DMS production by phytoplankton, and the subsequent utilization of these labile forms of organic matter by the microbial food web. Four interrelated hypotheses will be tested in field-based experiments and in situ observations: 1) solar radiation, including enhanced UV-B due to seasonal ozone depletion, plays an important role in determining the net ecosystem production of DMS in the Ross Sea; 2) development of shallow mixed layers promotes the accumulation of DMS in surface waters, because of enhanced exposure of plankton communities to high doses of solar radiation; 3) DMSP production and turnover represent a significant part of the carbon and sulfur flux through polar food webs; 4) bloom development and resulting nutrient depletion (e.g., iron) will result in high production rates of DMSP and high DMS concentrations and atmospheric fluxes. Results from this study will greatly improve understanding of the underlying mechanisms controlling DMSP and DMS concentrations in polar waters, thereby improving our ability to predict DMS fluxes to the atmosphere from this important climatic region. <br/><br/>Both Drs. Kieber and Kiene actively engage high school, undergraduate and graduate students in their research and are involved in formal programs that target underrepresented groups (NSF-REU and the American Chemical Society-SEED). This project will continue this type of educational outreach. The PIs also teach undergraduate and graduate courses and incorporation of research experiences into their classes will enrich student learning experiences. | None | None | false | false | |||||||||
Collaborative Research: Impact of Solar Radiation and Nutrients on Biogeochemical Cycling of DMSP and DMS in the Ross Sea, Antarctica
|
0230499 |
2012-01-17 | Kiene, Ronald |
|
Areas of the Southern Ocean have spectacular blooms of phytoplankton during the austral spring and early summer. One of the dominant phytoplankton species, the haptophyte Phaeocystis antarctica, is a prolific producer of the organic sulfur compound dimethylsulfoniopropionate (DMSP) and Phaeocystis blooms are associated with some of the world's highest concentrations of DMSP and its volatile degradation product, dimethylsulfide (DMS). Sulfur, in the form of DMS, is transferred from the oceans to the atmosphere and can affect the chemistry of precipitation and influence cloud properties and possibly climate. DMSP and DMS are also quantitatively significant components of the carbon, sulfur and energy flows in many marine food webs, although very little information is available on these processes in high latitude systems. <br/><br/>This project will study how solar radiation and iron cycling affect DMSP and DMS production by phytoplankton, and the subsequent utilization of these labile forms of organic matter by the microbial food web. Four interrelated hypotheses will be tested in field-based experiments and in situ observations: 1) solar radiation, including enhanced UV-B due to seasonal ozone depletion, plays an important role in determining the net ecosystem production of DMS in the Ross Sea; 2) development of shallow mixed layers promotes the accumulation of DMS in surface waters, because of enhanced exposure of plankton communities to high doses of solar radiation; 3) DMSP production and turnover represent a significant part of the carbon and sulfur flux through polar food webs; 4) bloom development and resulting nutrient depletion (e.g., iron) will result in high production rates of DMSP and high DMS concentrations and atmospheric fluxes. Results from this study will greatly improve understanding of the underlying mechanisms controlling DMSP and DMS concentrations in polar waters, thereby improving our ability to predict DMS fluxes to the atmosphere from this important climatic region. <br/><br/>Both Drs. Kieber and Kiene actively engage high school, undergraduate and graduate students in their research and are involved in formal programs that target underrepresented groups (NSF-REU and the American Chemical Society-SEED). This project will continue this type of educational outreach. The PIs also teach undergraduate and graduate courses and incorporation of research experiences into their classes will enrich student learning experiences. | POLYGON((-179.99998 -43.58056,-143.999984 -43.58056,-107.999988 -43.58056,-71.999992 -43.58056,-35.999996 -43.58056,0 -43.58056,35.999996 -43.58056,71.999992 -43.58056,107.999988 -43.58056,143.999984 -43.58056,179.99998 -43.58056,179.99998 -46.971468,179.99998 -50.362376,179.99998 -53.753284,179.99998 -57.144192,179.99998 -60.5351,179.99998 -63.926008,179.99998 -67.316916,179.99998 -70.707824,179.99998 -74.098732,179.99998 -77.48964,143.999984 -77.48964,107.999988 -77.48964,71.999992 -77.48964,35.999996 -77.48964,0 -77.48964,-35.999996 -77.48964,-71.999992 -77.48964,-107.999988 -77.48964,-143.999984 -77.48964,-179.99998 -77.48964,-179.99998 -74.098732,-179.99998 -70.707824,-179.99998 -67.316916,-179.99998 -63.926008,-179.99998 -60.5351,-179.99998 -57.144192,-179.99998 -53.753284,-179.99998 -50.362376,-179.99998 -46.971468,-179.99998 -43.58056)) | POINT(0 -89.999) | false | false | |||||||||
WAPflux - New Tools to Study the Fate of Phytoplankton Production in the West Antarctic Peninsula
|
0838866 |
2011-08-31 | Buesseler, Ken; Valdes, James |
|
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)." | 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)) | POINT(-70 -66) | false | false | |||||||||
POC Production and Export in the Indian Ocean Sector of the Southern Ocean: A US-China Collaborative Research Program
|
9726186 |
2011-03-03 | Leventer, Amy |
|
This proposed work is a study of the biological production and export flux of biogenic matter in response to ventilation of intermediate and deep water masses within the Polar Front zone. It is a collaborative work between the University of Maine and the Chinese Antarctic Research Expedition (CHINARE). The shipboard work is proposed for the Chinese antarctic resupply vessel off Prydz Bay in the Indian Ocean sector. In the austral Spring, this region experiences phytoplankton blooms that are thought to be the result of nutrient transport by the ventilation of intermediate and deep water masses. On an annual basis, it is believed that such blooms are the primary source of particulate organic carbon and biogenic silica flux to the ocean bottom. At this time however no data exists on the amount of particulate organic matter that sinks through the water column, leaving the quantitative relationships between production and export largely undefined in this region. The initial phase of the work consists of setting out a time-series sediment trap mooring at approximately 64 deg S latitude and 73 deg E longitude to take advantage of the historical data set that CHINARE has obtained in this area over the past decade. The biweekly to monthly trap samples will be analyzed for their organic constituents, and in conjunction with primary productivity observations will provide the basic data from which export values can be derived. This work will be carried out in collaboration with the State Oceanic Administration of the People's Republic of China, and the Chinese Antarctic Research Expedition. In addition to providing time on the antarctic resupply vessel, the SOA will sponsor the shipboard primary productivity experiments and the supporting hydrographic measurements. The collaborating American scientists will provide guidance in making these observations to standards developed for the Joint Global Ocean Flux Study, and provide the hardware for the moored sediment trap. There will be a mutual sharing between the U.S. and Chinese investigators of all samples and data sets, and the data analysis will be carried out jointly. *** | None | None | false | false | |||||||||
Collaborative Research: Photochemical and Optical Properties of Antarctic Waters in Response to Changing UV-B Fluxes
|
9527255 |
2010-05-04 | Mopper, Kenneth |
|
ACT K. Mopper & D. Kieber OPP 9527255 & OPP 9527314 PHOTOCHEMICAL AND OPTICAL PROPERTIES OF ANTARCTIC WATERS IN RESPONSE TO CHANGING UV-B FLUXES The decrease in stratospheric ozone over the Antarctic results in an increase in the UV-B flux in the euphotic zone. The increase leads to cellular damage to aquatic organisms, as documented by photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transients. The extent of this extracellular damage will depend on the photochemistry of the seawater surrounding the cell. Until recently, nothing was known about the type of photochemical processes, rates, and steady state concentrations of transients in Antarctic waters. It is proposed that field experiments be performed which will allow the construction of predictive models of photochemical production rates in surface waters and with depth. These studies will involve further quantum yield measurementts, development of a sensitive underwater actinometer system, and use of a new underwater multichannel photometer. The model will allow the prediction of the impact of varying levels of UV-B on the photoproduction and steady state concentration of several key reactive transient species in the upper water column. In addition to this effort, experiments will also be performed to study the photodegradation of dissolved organic matter and to determine whether biologically utilizable substrates that are formed photochemically can enhance secondary productivity in Antarctic waters. | None | None | false | false | |||||||||
Photochemistry of Antarctic Waters in Repsonse to Changing Ultraviolet Radiation Fluxes
|
9221598 |
2009-06-19 | Mopper, Kenneth; Neale, Patrick |
|
Decreases in stratospheric ozone over the Antarctic result in an increase in the ultraviolet radiation flux in the euphotic zone of the ocean. This increase may lead to cellular damage in aquatic organisms resulting in photo-inhibition and decreased productivity. Cellular damage can occur either intracellularly, or externally at the cell surface from biomolecular reactions with externally-generated reactive transient species. Extracellular damage will depend to a large degree on the photochemistry of the seawater surrounding the cell. To date, little is known about the photochemistry of the unique Antarctic waters. This project integrates a field and laboratory approach to obtain baseline information regarding the marine photochemistry of the euphotic zone in Antarctica waters as related to changes in ultraviolet radiation levels. In situ photochemical production rates and steady state concentrations of a suite of reactive species and dissolved organic matter degradation products as well as downwelling ultraviolet radiation will be measured. Additionally, flux by in situ chemical actinometry, action spectra for photochemical production of various reactive species and dissolved organic matter degradation products, and fluorescence and absorbance properties of dissolved organic matter will be determined. This information will serve as a basis for understanding and predicting the effects of ultraviolet radiation-induced marine photochemical processes on the productivity and ecology in the euphotic zone of the Antarctic Ocean. | None | None | false | false | |||||||||
Environmental and Ecological Regulation of Differences and Interactions between Solitary and Colonial forms of Phaeocystis antarctica
|
0440478 |
2009-05-04 | Tang, Kam; Smith, Walker |
|
Phaeocystis Antarctica is a widely distributed phytoplankton that forms dense blooms and aggregates in the Southern Ocean. This phytoplankton and plays important roles in polar ecology and biogeochemistry, in part because it is a dominant primary producer, a main component of organic matter vertical fluxes, and the principal producer of volatile organic sulfur in the region. Yet P. Antarctica is also one of the lesser known species in terms of its physiology, life history and trophic relationships with other organisms; furthermore, information collected on other Phaeocystis species and from different locations may not be applicable to P. Antarctica in the Ross Sea. P. Antarctica occurs mainly as two morphotypes: solitary cells and mucilaginous colonies, which differ significantly in size, architecture and chemical composition. Relative dominance between solitary cells and colonies determines not only the size spectrum of the population, but also its carbon dynamics, nutrient uptake and utilization. Conventional thinking of the planktonic trophic processes is also challenged by the fact that colony formation could effectively alter the predator-prey interactions and interspecific competition. However, the factors that regulate the differences between solitary and colonial forms of P. Antarctica are not well-understood. The research objective of this proposal is therefore to address these over-arching questions:<br/>o Do P. Antarctica solitary cells and colonies differ in growth, composition and<br/>photosynthetic rates?<br/>o How do nutrients and grazers affect colony development and size distribution of P. <br/>Antarctica?<br/>o How do nutrients and grazers act synergistically to affect the long-term population<br/>dynamics of P. Antarctica? Experiments will be conducted in the McMurdo station with natural P. Antarctica assemblages and co-occurring grazers. Laboratory experiments will be conducted to study size-specific growth and photosynthetic rates of P. Antarctica, size-specific grazing mortality due to microzooplankton and mesozooplankton, the effects of macronutrients on the (nitrogen compounds) relative dominance of solitary cells and colonies, and the effects of micronutrient (Fe) and grazing related chemical signals on P. Antarctica colony development. Because this species is of critical importance in the Southern Ocean, and because this research will provide critical information on factors that regulate the role of P.Antarctica in food webs and biogeochemical cycles, a major gap in knowledge will be addressed. This project will train two marine science PhD students. The investigators will also collaborate with the School of Education and a marine science museum to communicate polar science to a broader audience. | POINT(166.66267 -77.85067) | POINT(166.66267 -77.85067) | false | false | |||||||||
Collaborative Research: Biogeochemistry of Dissolved Organic Matter in Pony Lake, Ross Island
|
0338260 0338342 |
2009-03-16 | Foreman, Christine; Chin, Yu-Ping |
|
Dissolved organic matter (DOM) is a significant chemical component in aquatic systems because it acts as an important carbon source for microorganisms, absorbs harmful radiation in sunlight, is able to complex metals, and can participate in important biogeochemical reactions. This study will investigate the biogeochemical cycling of DOM in a small coastal Antarctic pond, Pony Lake, located on Cape Royds, Ross Island. Because there are no higher plants present at this site all of the DOM in this lake is derived from microorganisms. Thus, Pony Lake is an ideal site to study the effect of physical, chemical, and microbial processes on the composition and character of the DOM pool. Finally, Pony Lake is also an ideal site to collect an International Humic Substances Society (IHSS) fulvic acid standard. Unlike other IHSS standards, this standard will not contain DOM components derived from higher land plants. To better understand the role of physical influences, the project will study the changes in the DOM pool as the lake evolves from ice-covered to ice-free conditions during the summer, as well as the relationship of DOM to the observed turnover of dominant microbial communities in the lake. Scientists will also monitor changes in microbial abundance, diversity, and productivity that may occur during the ice to open-water transition period. This research will provide much needed information regarding the relationship between microbial diversity and DOM biogeochemistry. Middle school science students will be active participants in this project through the Internet, while scientists are in the field, and in the lab. | POINT(166.167 -77.55) | POINT(166.167 -77.55) | false | false | |||||||||
Paleoclimate Inferred from Lake Sediment Cores in Taylor Valley, Antarctica
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0126270 |
2007-02-05 | Doran, Peter | No dataset link provided | Polar Programs, provides funds for a study of sediment cores from the McMurdo Dry Valley lakes. The Dry Valley lakes have a long history of fluctuating levels reflecting regional climate change. The history of lake level fluctuations is generally known from the LGM to early Holocene through 14C dates of buried organic matter in paleolake deposits. However, the youngest paleolake deposits available are between 8000 to 9000 14C yr BP, suggesting that lake levels were at or below current levels for much of the Holocene. Thus, any information about the lake history and climate controls for the Holocene is largely contained in bottom sediments. This project will attempt to extract paleoclimatic information from sediment cores for a series of closed-basin dry valley lakes under study by the McMurdo LTER site. This work involves multiple approaches to dating the sediments and use of several climate proxy approaches to extract century to millennial scale chronologies from Antarctic lacustrine deposits. This research uses knowledge on lake processes gained over the past eight years by the LTER to calibrate climate proxies from lake sediments. Proxies for lake depth and ice thickness, which are largely controlled by summer climate, are the focus of this work. This study focuses on four key questions: 1. How sensitively do dry valley lake sediments record Holocene environmental and climate variability? 2. What is the paleoclimatic variability in the dry valleys on a century and millennial scale throughout the Holocene? Especially, is the 1200 yr evaporative event unique, or are there other such events in the record? 3. Does a mid-Holocene (7000 to 5000 yr BP) climate shift occur in the dry valleys as documented elsewhere in the polar regions? 4. Is there evidence, in the dry valley lake record of the 1500 yr Holocene periodicities recently recognized in the Taylor Dome record? Core collection will be performed with LTER support using a state-of-the-art percussion/piston corer system that has been used successfully to retrieve long cores (10 to 20 m) from other remote polar locations. Analyses to be done include algal pigments, biogenic silica, basic geochemistry, organic and inorganic carbon and nitrogen content, stable isotopes of carbon, nitrogen, and oxygen, carbonate phases, salt content and mineralogy, and grain size. In addition this project will pursue a multi-chronometer approach to assess the age of the core through optically-stimulated luminescence, 226Ra/230Th , 230Th/234U, and 14C techniques. New experimentation with U-series techniques will be performed to allow for greater precision in the dry valley lake sediments. Compound specific isotopes and lipid biomarkers , which are powerful tools for inferring past lake conditions, will also be assessed. Combined, these analyses will provide a new century to millennial scale continuous record of the Holocene climate change in the Ross Sea region. | None | None | false | false |