{"dp_type": "Project", "free_text": "Amundsen Sea"}
[{"awards": null, "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 13 Jun 2024 00:00:00 GMT", "description": "The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron, which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide iron to the Amundsen Sea ecosystem. However, sediment sources of iron have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment iron fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through the website CryoConnect.org. \u003cbr/\u003e\u003cbr/\u003eThis project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment iron (Fe) cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the ?Accelerating Thwaites Ecosystem Impacts for the Southern Ocean? (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography and beyond.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "SEDIMENT CHEMISTRY; TRACE ELEMENTS", "locations": null, "north": null, "nsf_funding_programs": null, "paleo_time": null, "persons": null, "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Benthic Iron Fluxes and Cycling in the Amundsen Sea", "uid": "p0010463", "west": null}, {"awards": "1939146 Siddoway, Christine; 1939139 Scherer, Reed", "bounds_geometry": "POLYGON((-120 -66,-117.5 -66,-115 -66,-112.5 -66,-110 -66,-107.5 -66,-105 -66,-102.5 -66,-100 -66,-97.5 -66,-95 -66,-95 -67.1,-95 -68.2,-95 -69.3,-95 -70.4,-95 -71.5,-95 -72.6,-95 -73.7,-95 -74.8,-95 -75.9,-95 -77,-97.5 -77,-100 -77,-102.5 -77,-105 -77,-107.5 -77,-110 -77,-112.5 -77,-115 -77,-117.5 -77,-120 -77,-120 -75.9,-120 -74.8,-120 -73.7,-120 -72.6,-120 -71.5,-120 -70.4,-120 -69.3,-120 -68.2,-120 -67.1,-120 -66))", "dataset_titles": "Pliocene diatom abundance, IODP 379-U1532; Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature; U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "datasets": [{"dataset_uid": "601804", "doi": "10.15784/601804", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Oceanography; Sabrina Coast; Sea Surface Temperature; Southern Ocean", "people": "Ruggiero, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Population morphometrics of the Southern Ocean diatom Fragilariopsis kerguelensis related to Sea Surface Temperature", "url": "https://www.usap-dc.org/view/dataset/601804"}, {"dataset_uid": "601769", "doi": null, "keywords": "Antarctica; Biogenic Silica; Diatom", "people": "Scherer, Reed Paul; Furlong, Heather", "repository": "USAP-DC", "science_program": null, "title": "Pliocene diatom abundance, IODP 379-U1532", "url": "https://www.usap-dc.org/view/dataset/601769"}, {"dataset_uid": "601828", "doi": "10.15784/601828", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Geochronology; Marie Byrd Land; Subglacial Bedrock; Thermochronology", "people": "Siddoway, Christine", "repository": "USAP-DC", "science_program": null, "title": "U-Pb zircon and apatite fission track dates for IRD (ice-rafted cobbles and mineral grains) from IODP379 drill sites", "url": "https://www.usap-dc.org/view/dataset/601828"}], "date_created": "Tue, 20 Feb 2024 00:00:00 GMT", "description": "Part I, Non-technical Abstract \u003cbr/\u003eConcerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts.\u003cbr/\u003e\u003cbr/\u003ePart 2, Technical Abstract\u003cbr/\u003e\u003cbr/\u003eNew drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events.\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": -95.0, "geometry": "POINT(-107.5 -71.5)", "instruments": null, "is_usap_dc": true, "keywords": "ICEBERGS; SEA SURFACE TEMPERATURE; Amundsen Sea; MICROFOSSILS", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY; PHANEROZOIC \u003e CENOZOIC \u003e NEOGENE \u003e PLIOCENE", "persons": "Scherer, Reed Paul; Siddoway, Christine", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica", "uid": "p0010451", "west": -120.0}, {"awards": "2333940 Zhong, Shijie", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 08 Jan 2024 00:00:00 GMT", "description": "Satellite observations of Earth?s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth?s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth?s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "WAIS; CRUSTAL MOTION; COMPUTERS; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE", "locations": "WAIS", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Zhong, Shijie", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -90.0, "title": "Investigating Effects of Transient and Non-Newtonian Mantle Viscosity on Glacial Isostatic Adjustment Process and their Implications for GPS Observations in Antarctica", "uid": "p0010441", "west": -180.0}, {"awards": "2152622 Morlighem, Mathieu", "bounds_geometry": "POLYGON((-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-103 -74,-102 -74,-101 -74,-100 -74,-100 -74.3,-100 -74.6,-100 -74.9,-100 -75.2,-100 -75.5,-100 -75.8,-100 -76.1,-100 -76.4,-100 -76.7,-100 -77,-101 -77,-102 -77,-103 -77,-104 -77,-105 -77,-106 -77,-107 -77,-108 -77,-109 -77,-110 -77,-110 -76.7,-110 -76.4,-110 -76.1,-110 -75.8,-110 -75.5,-110 -75.2,-110 -74.9,-110 -74.6,-110 -74.3,-110 -74))", "dataset_titles": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "datasets": [{"dataset_uid": "601658", "doi": "10.15784/601658", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites; Thwaites Glacier", "people": "Das, Indrani", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sliding-Law Parameter and Airborne Radar-Derived Basal Reflectivity Data Underneath Thwaites Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601658"}], "date_created": "Tue, 20 Dec 2022 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections.\r\n\r\nThe project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making.\r\n\r\nThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -100.0, "geometry": "POINT(-105 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; Amundsen Sea; ICE SHEETS", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "NOT APPLICABLE", "persons": "Morlighem, Mathieu; Das, Indrani", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "NSF-NERC: PROcesses, drivers, Predictions: Modeling the response of Thwaites Glacier over the next Century using Ice/Ocean Coupled Models (PROPHET)", "uid": "p0010400", "west": -110.0}, {"awards": "1644118 Dunbar, Robert", "bounds_geometry": "POLYGON((-108 -73,-107.3 -73,-106.6 -73,-105.9 -73,-105.2 -73,-104.5 -73,-103.8 -73,-103.1 -73,-102.4 -73,-101.7 -73,-101 -73,-101 -73.3,-101 -73.6,-101 -73.9,-101 -74.2,-101 -74.5,-101 -74.8,-101 -75.1,-101 -75.4,-101 -75.7,-101 -76,-101.7 -76,-102.4 -76,-103.1 -76,-103.8 -76,-104.5 -76,-105.2 -76,-105.9 -76,-106.6 -76,-107.3 -76,-108 -76,-108 -75.7,-108 -75.4,-108 -75.1,-108 -74.8,-108 -74.5,-108 -74.2,-108 -73.9,-108 -73.6,-108 -73.3,-108 -73))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}], "date_created": "Wed, 21 Sep 2022 00:00:00 GMT", "description": "Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt.\u003cbr/\u003e\u003cbr/\u003eThis research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing.", "east": -101.0, "geometry": "POINT(-104.5 -74.5)", "instruments": null, "is_usap_dc": true, "keywords": "Stable Isotopes; WATER TEMPERATURE; SALINITY; Oxygen Isotope; Meltwater Inventory; Pine Island Bay; OCEAN CHEMISTRY", "locations": "Pine Island Bay", "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Dunbar, Robert", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater", "uid": "p0010380", "west": -108.0}, {"awards": "2123491 John, Seth; 2123333 Fitzsimmons, Jessica; 2123354 Conway, Timothy", "bounds_geometry": "POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 08 Sep 2022 00:00:00 GMT", "description": "The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service.\r\n\r\nThe US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135\u00b0W) of the Antarctic Margin. The cruise will follow the Amundsen Sea \u2018conveyor belt\u2019 by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean?", "east": -100.0, "geometry": "POINT(-117.5 -71)", "instruments": null, "is_usap_dc": true, "keywords": "R/V NBP; Amundsen Sea; TRACE ELEMENTS; BIOGEOCHEMICAL CYCLES", "locations": "Amundsen Sea", "north": -66.0, "nsf_funding_programs": "Chemical Oceanography; Chemical Oceanography; Chemical Oceanography", "paleo_time": null, "persons": "Conway, Timothy; Fitzsimmons, Jessica; John, Seth", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repositories": null, "science_programs": null, "south": -76.0, "title": "Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals", "uid": "p0010374", "west": -135.0}, {"awards": "2212904 Herbert, Lisa", "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": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron (Fe), which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide Fe to the Amundsen Sea ecosystem. However, sediment sources of Fe have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment Fe fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through CryoConnect.org. \r\n\r\nThis project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment Fe cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the \u201cAccelerating Thwaites Ecosystem Impacts for the Southern Ocean\u201d (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography and beyond. \r\n", "east": -100.0, "geometry": "POINT(-110 -73)", "instruments": null, "is_usap_dc": true, "keywords": "TRACE ELEMENTS; SEDIMENT CHEMISTRY; Amundsen Sea", "locations": "Amundsen Sea", "north": -71.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Post Doc/Travel", "paleo_time": null, "persons": "Herbert, Lisa", "platforms": null, "repositories": null, "science_programs": null, "south": -75.0, "title": "OPP-PRF: Benthic Iron Fluxes and Cycling in the Amundsen Sea", "uid": "p0010362", "west": -120.0}, {"awards": "1744759 Dunham, Eric; 1246151 Bromirski, Peter; 1744856 Bromirski, Peter; 1744958 Wei, Yong", "bounds_geometry": null, "dataset_titles": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves; Model Tsunami Propagation Simulation From Circum-Pacific Subduction Zones to West Antarctic Ice Shelves; Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "datasets": [{"dataset_uid": "200323", "doi": "10.25740/qy001dt7463", "keywords": null, "people": null, "repository": "Stanford Digital Repository", "science_program": null, "title": "Data for: Ocean Surface Gravity Wave Excitation of Flexural Gravity and Extensional Lamb Waves in Ice Shelves", "url": "https://doi.org/10.25740/qy001dt7463"}, {"dataset_uid": "200424", "doi": "N/A", "keywords": null, "people": null, "repository": "NOAA Center for Tsunami Research (NCTR)", "science_program": null, "title": "Model Tsunami Propagation Simulation From Circum-Pacific Subduction Zones to West Antarctic Ice Shelves", "url": " https://nctr.pmel.noaa.gov/antarctica/ "}, {"dataset_uid": "601561", "doi": "10.15784/601561", "keywords": "Amundsen Sea; Antarctica; Glaciology", "people": "Almquist, Martin; Dunham, Eric; Tazhimbetov, Nurbek", "repository": "USAP-DC", "science_program": null, "title": "Simulation of flexural-gravity wave response of Antarctic ice shelves to tsunami and infragravity waves", "url": "https://www.usap-dc.org/view/dataset/601561"}], "date_created": "Mon, 16 May 2022 00:00:00 GMT", "description": "Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences.\u003cbr/\u003e\u003cbr/\u003eThis project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "COMPUTERS; AMD; Amd/Us; SEA ICE; Amundsen Sea; USAP-DC; USA/NSF; Ross Ice Shelf; MODELS", "locations": "Amundsen Sea; Ross Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Dunham, Eric; Bromirski, Peter; Wei, Yong", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "Stanford Digital Repository", "repositories": "NOAA Center for Tsunami Research (NCTR); Stanford Digital Repository; USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Do Ocean Wave Impacts Pose a Hazard to the Stability of West Antarctic Ice Shelves?", "uid": "p0010320", "west": null}, {"awards": "1643285 Joughin, Ian; 1643174 Padman, Laurence", "bounds_geometry": "POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73))", "dataset_titles": "Beta Version of Plume Model; Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier; icepack; Pine Island Basin Scale Model", "datasets": [{"dataset_uid": "200314", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "icepack", "url": "https://github.com/icepack/icepack"}, {"dataset_uid": "200315", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Pine Island Basin Scale Model", "url": "https://github.com/fastice/icesheetModels"}, {"dataset_uid": "200290", "doi": "http://hdl.handle.net/1773/46687", "keywords": null, "people": null, "repository": "Uni. Washington ResearchWorks Archive", "science_program": null, "title": "Data associated with Ice-Shelf Retreat Drives Recent Pine Island Glacier Speedup and Ocean-Induced Melt Volume Directly Paces Ice Loss from Pine Island Glacier", "url": "https://doi.org/10.6069/2MZZ-6B61"}, {"dataset_uid": "200313", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Beta Version of Plume Model", "url": "https://github.com/icepack/plumes"}], "date_created": "Fri, 13 May 2022 00:00:00 GMT", "description": "Overview: Several recent studies indicate continuing and increasing ice loss from the Amundsen Sea region of West Antarctica (chiefly Pine Island and Thwaites glaciers). This loss is initiated by thinning of the floating ice shelves by basal melting driven by circulation of relatively warm ocean water under the ice shelves. This thinning triggers ice-dynamics related feedbacks, which leads to loss of ice from the grounded ice sheet. Models suggest that, even though long-term committed ice loss might be governed by ice dynamics, the magnitude of ocean-driven melting at the base of the ice shelves plays a critical role in controlling the rate of ice loss. These conclusions, however, are based on simple parameterized models for melt rate that do not take into account how ocean circulation will change in future as large-scale climate forcing changes, and as the ice shelves thin and retreat through both excess melting and accelerated ice flow. Given that present global climate models struggle to resolve the modern ocean state close to the ice shelves around Antarctica, their projections of future impacts on basal melting and time scale of ice loss have large uncertainties.\r\nThis project is aimed at reducing these uncertainties though two approaches: (i) assessing, for a given ocean state, how the melt rates will change as ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of melt rates beneath the Pine Island and Thwaites ice shelves to changes in ocean state on the Amundsen Sea continental shelf. These studies will provide more realistic bounds on ice loss and sea level rise, and lay the groundwork for development of future fully-coupled ice sheet-ocean simulations.\r\nIntellectual Merit: Rather than pursue a strategy of using fully coupled models, this project adopts a simpler semi-coupled approach to understand the sensitivity of ice-shelf melting to future forcing. Specifically, the project focuses on using regional ocean circulation models to understand current and future patterns of melting in ice-shelf cavities. The project\u2019s preliminary stage will focus on developing high-resolution ice-shelf cavity-circulation models driven by modern observed regional ocean state and validated with current patterns of melt inferred from satellite observations. Next, an ice-flow model will be used to estimate the future grounding line at various stages of retreat. Using these results, an iterative process with the ocean-circulation and ice-flow models will be applied to determine melt rates at each stage of grounding line retreat. These results will help assess whether more physically constrained melt-rate estimates substantially alter the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway. Further, by multiple simulations with modified open-ocean boundary conditions, this study will provide a better understanding of the sensitivity of melt to future changes in regional forcing. For example, what is the sensitivity of melt to changes in Circumpolar Deep Water temperature and to changes in the thermocline height driven be changes in wind forcing? Finally, several semi-coupled ice-ocean simulations will be used to investigate the influence of the ocean-circulation driven distribution of melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response.\r\nBroader Impacts: Planning within the current large range of uncertainty in future sea level change leads to high social and economic costs for governments and businesses worldwide. Thus, our project to reduce sea-level rise uncertainty has strong societal as well as scientific interest. The findings and methods will be applicable to ice shelf cavities in other parts of Antarctica and northern Greenland, and will set the stage for future studies with fully coupled models as computational resources improve. This interdisciplinary work combines expertise of glaciologists and oceanographers, and will contribute to the education of new researchers in this field, with participation of graduate students and postdocs. Through several outreach activities, team members will help make the public aware of the dramatic changes occurring in Antarctica along with the likely consequences.\r\n\r\nThis proposal does not require fieldwork in the Antarctic.\r\n", "east": -86.0, "geometry": "POINT(-95 -77)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIER MOTION/ICE SHEET MOTION; USA/NSF; ICE SHEETS; AMD; USAP-DC; MODELS; Amd/Us; Pine Island Glacier", "locations": "Pine Island Glacier", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott", "platforms": "OTHER \u003e MODELS \u003e MODELS", "repo": "GitHub", "repositories": "GitHub; Uni. Washington ResearchWorks Archive", "science_programs": null, "south": -81.0, "title": "Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica ", "uid": "p0010318", "west": -104.0}, {"awards": "1745055 Stearns, Leigh; 1745043 Simkins, Lauren", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Circum-Antarctic grounding-line sinuosity; Elevation transects from Pine Island Bay; Pennell Trough, Ross Sea bathymetry and glacial landforms", "datasets": [{"dataset_uid": "601474", "doi": "10.15784/601474", "keywords": "Antarctica; Bathymetry; Elevation; Geomorphology; Glacial History; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marine Geoscience; NBP1502; Pennell Trough; Ross Sea; R/v Nathaniel B. Palmer", "people": "Eareckson, Elizabeth; Munevar Garcia, Santiago; Greenwood, Sarah; Simkins, Lauren; Prothro, Lindsay; Anderson, John", "repository": "USAP-DC", "science_program": null, "title": "Pennell Trough, Ross Sea bathymetry and glacial landforms", "url": "https://www.usap-dc.org/view/dataset/601474"}, {"dataset_uid": "601484", "doi": "10.15784/601484", "keywords": "Antarctica; Bed Roughness; Bed Slope; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Pinning Points", "people": "Riverman, Kiya; Simkins, Lauren; Stearns, Leigh", "repository": "USAP-DC", "science_program": null, "title": "Circum-Antarctic grounding-line sinuosity", "url": "https://www.usap-dc.org/view/dataset/601484"}, {"dataset_uid": "601774", "doi": "10.15784/601774", "keywords": "Antarctica; Bed Roughness; Cryosphere; Geomorphology; Pine Island Bay", "people": "Munevar Garcia, Santiago", "repository": "USAP-DC", "science_program": null, "title": "Elevation transects from Pine Island Bay", "url": "https://www.usap-dc.org/view/dataset/601774"}], "date_created": "Tue, 28 Sep 2021 00:00:00 GMT", "description": "The goals of this collaborative project are to merge empirical observations from the deglaciated Antarctic continental shelf and 1-D and 3-D numerical model experiments to test the sensitivity of marine-based ice sheets to subglacial topography with collaborators at the University of Kansas (L. Stearns, C. van der Veen). We focus on five glacial systems (i.e., flowlines) across the Amundsen Sea, Ross Sea, and George V Coast of Wilkes Land that extended to/near the continental shelf break at the Last Glacial Maximum \u2013 with a range of bed characteristics, topographic features, oceanographic and climatic conditions, and patterns of past ice flow and grounding line retreat. Specifically, at the University of Virginia, we (L. Simkins, S. Munevar Garcia) are: (ongoing) exploring bed roughness across the flowlines to determine the sensitivity of ice flow and grounding line behavior to different scales and wavelengths of bed topography/roughness; (upcoming) developing an empirical relationship between ice-marginal landform sediment volume and grounding line occupation time, and combining this with sedimentological analyses and new absolute age constraints to produce more comprehensive timelines of grounding line retreat, influential boundary conditions and processes, and determine the presence/absence of ice shelves; (ongoing) integrating quantitative and qualitative paleo- and offshore data to be incorporated into and/or validate 1-D and 3-D model experiments further testing the sensitivity of the five glacial systems to bed topography; and (completed) co-developing community engagement and education materials that focus on merging paleo-observations and model information of the Antarctic Ice Sheet from the LGM to the present \r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MARINE SEDIMENTS; USAP-DC; Amd/Us; GLACIERS; BATHYMETRY; GLACIAL LANDFORMS; Antarctica; AMD; USA/NSF; R/V NBP", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Simkins, Lauren; Stearns, Leigh; Anderson, John; van der Veen, Cornelis", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations", "uid": "p0010269", "west": -180.0}, {"awards": "9910267 Grunow, Anne; 2137467 Grunow, Anne; 0739480 Grunow, Anne; 1643713 Grunow, Anne; 1141906 Grunow, Anne; 0440695 Grunow, Anne", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Marine Geoscience Data System - cruise links; Polar Rock Repository; SESAR sample registration", "datasets": [{"dataset_uid": "200359", "doi": "", "keywords": null, "people": null, "repository": "PRR", "science_program": null, "title": "Polar Rock Repository", "url": "http://research.bpcrc.osu.edu/rr/"}, {"dataset_uid": "200243", "doi": "", "keywords": null, "people": null, "repository": "PRR", "science_program": null, "title": "Polar Rock Repository", "url": "https://prr.osu.edu/"}, {"dataset_uid": "200242", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Marine Geoscience Data System - cruise links", "url": "https://www.marine-geo.org/"}, {"dataset_uid": "200241", "doi": "", "keywords": null, "people": null, "repository": "SESAR", "science_program": null, "title": "SESAR sample registration", "url": "https://www.geosamples.org/about/services#igsnregistration"}], "date_created": "Thu, 09 Sep 2021 00:00:00 GMT", "description": "The Polar Rock Repository (PRR) was established to curate and loan geologic samples from polar regions to researchers and educators. OPP established the PRR in part to avoid redundant sample collection and thus reduce the environmental impact of polar research. The PRR also provides the research community with an important resource for developing new research projects. The PRR acquires rock collections through donations from institutions and scientists and makes these samples available as no-cost loans for research, education and museum exhibits. Sample metadata are available in an on-line database. The database also includes rock property information useful for geophysical studies. Researchers may request samples for analysis using an online request form. The PRR fulfills several data management directives, including the Scientific Committee on Antarctic Research, Antarctic Data Management directive of providing free, full and open access to both metadata and the samples.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; FIELD SURVEYS; Pacific Ocean; ROCKS/MINERALS/CRYSTALS; GLACIATION; AMD; Weddell Sea; Scotia Sea; TECTONICS; Antarctica; Southern Ocean; Amd/Us; USA/NSF; Amundsen Sea", "locations": "Pacific Ocean; Amundsen Sea; Scotia Sea; Weddell Sea; Antarctica; Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Grunow, Anne", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "PRR", "repositories": "MGDS; PRR; SESAR", "science_programs": null, "south": -90.0, "title": "Continuing Operations Proposal: \r\nThe Polar Rock Repository as a Resource for Earth Systems Science\r\n", "uid": "p0010259", "west": -180.0}, {"awards": "2114839 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 25 Aug 2021 00:00:00 GMT", "description": "The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of \u003e 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current \u201cicehouse\u201d period ~3.3 Ma.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; TERRIGENOUS SEDIMENTS; Amd/Us; SEDIMENTS; FIELD SURVEYS; Amundsen Sea; USAP-DC; AMD", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": null, "title": "West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum", "uid": "p0010252", "west": null}, {"awards": "1941292 St-Laurent, Pierre; 1941327 Stammerjohn, Sharon; 1941308 Fitzsimmons, Jessica; 1941304 Sherrell, Robert; 1941483 Yager, Patricia", "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": "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": "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": "200311", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2202", "url": "https://www.rvdata.us/search/cruise/NBP2202"}, {"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"}], "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": "William \u0026 Mary ScholarWorks", "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": "2023259 Thompson, Andrew; 2023244 Stewart, Andrew; 2023303 Purkey, Sarah", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Code for reproducing the ocean-biogeochemical experiments in Sun et al. (2024); Hydrographic data collected from the Bellingshausen and Amundsen seas (NCEI Accession 0210639); Ocean CFC reconstructed data product", "datasets": [{"dataset_uid": "200428", "doi": "", "keywords": null, "people": null, "repository": "NOAA\u0027s National Centers for Environmental Information (NCEI)", "science_program": null, "title": "Hydrographic data collected from the Bellingshausen and Amundsen seas (NCEI Accession 0210639)", "url": "https://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:0210639"}, {"dataset_uid": "601752", "doi": "10.15784/601752", "keywords": "Antarctica; CFCs; GLODAP; Ocean Model; Ocean Ventilation; Southern Ocean", "people": "Purkey, Sarah; Cimoli, Laura; Gebbie, Jack", "repository": "USAP-DC", "science_program": null, "title": "Ocean CFC reconstructed data product", "url": "https://www.usap-dc.org/view/dataset/601752"}, {"dataset_uid": "200427", "doi": "10.6084/m9.figshare.26787751", "keywords": null, "people": null, "repository": "Figshare (open repository)", "science_program": null, "title": "Code for reproducing the ocean-biogeochemical experiments in Sun et al. (2024)", "url": "https://doi.org/10.6084/m9.figshare.26787751"}], "date_created": "Thu, 01 Jul 2021 00:00:00 GMT", "description": "The formation of dense Antarctic Bottom Water (AABW) and its export northward from the Antarctic continent is one of the key components of the global ocean overturning circulation, and plays a critical role in regulating Earth\u0027s climate on multi-decadal-to-millennial time scales. Recent studies of the global ocean overturning circulation have increasingly emphasized its three-dimensional structure: AABW is produced in a handful of distinct sites around the Antarctic continent, and there is a pronounced asymmetry in the allocation of AABW transports into the Atlantic, Indian and Pacific basins. The connectivity of AABW between the Antarctic continental shelf and the northern basins is mediated by the Antarctic Circumpolar Current (ACC), a circumpolar eastward flow that also serves as the primary route for inter-basin exchange.\r\n\r\nThe mapping from different shelf AABW sources to the northern basins dictates the response of the global MOC to localized variability or shifts in the state of the Antarctic shelf, for example due to major glacier calving events or modified inputs of freshwater from the Antarctic ice sheet. At present this mapping is not well constrained, with conflicting conclusions drawn in previous studies: at one extreme the ACC has been suggested to be a ``conduit\u0027\u0027 that simply allows each variety of AABW to transit directly northward; at the other extreme, it has been suggested that the ACC ``blends\u0027\u0027 all shelf AABW sources together before they reach the northern basins. Such conflicts arise, in part, because little is understood about the physics that determines AABW\u0027s pathways across the ACC.\r\n\r\nTo close this gap in understanding, this collaborative project draws on three complementary analytical tools: process-oriented modeling of AABW export across the ACC, a high-resolution global ocean model, and an observationally-constrained estimate of the global circulation. The PIs will first identify and quantify the pathways of AABW across the ACC by using these tools to propagate passive tracers that identify each of the four major AABW formation sites. They will then use a suite of process model sensitivity experiments to develop a theory for what controls meridional versus inter-basin transport of AABW in the ACC, and transfer this theory to interpret the AABW pathways simulated in the global model. Finally, they will combine the process model, global model and the observationally-constrained circulation product to map the rates at which AABW is transformed into lighter waters, and relate these transformation rates to the diagnosed pathways of AABW across the ACC. This combination of approaches allow the PIs to not only constrain the three-dimensional circulation of AABW from Antarctica to the northern basins, but also provides a mechanistic understanding of the circulation that can be transferred to past or future climates.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e DATA ANALYSIS \u003e ENVIRONMENTAL MODELING \u003e COMPUTER", "is_usap_dc": true, "keywords": "AMD; MODELS; USAP-DC; WATER MASSES; Southern Ocean; Amd/Us; OCEAN CURRENTS; COMPUTERS; Antarctic Circumpolar Current; USA/NSF", "locations": "Southern Ocean", "north": -60.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences; Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Stewart, Andrew; Thompson, Andrew; Purkey, Sarah", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e MODELS \u003e MODELS", "repo": "NOAA\u0027s National Centers for Environmental Information (NCEI)", "repositories": "Figshare (open repository); NOAA\u0027s National Centers for Environmental Information (NCEI); USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters?", "uid": "p0010220", "west": -180.0}, {"awards": "1933764 Enderlin, Ellyn; 1643455 Enderlin, Ellyn", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Crane Glacier centerline observations and modeling results ; Remotely-sensed iceberg geometries and meltwater fluxes", "datasets": [{"dataset_uid": "601617", "doi": "10.15784/601617", "keywords": "Antarctica; Antarctic Peninsula; Crane Glacier; Glacier Dynamics; Glacier Mass Discharge; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling; Model Output", "people": "Enderlin, Ellyn; Marshall, Hans-Peter; Kopera, Michal; Meehan, Tate; Aberle, Rainey", "repository": "USAP-DC", "science_program": null, "title": "Crane Glacier centerline observations and modeling results ", "url": "https://www.usap-dc.org/view/dataset/601617"}, {"dataset_uid": "601679", "doi": "10.15784/601679", "keywords": "Antarctica; Elevation; Glaciology; Iceberg; Meltwater; Submarine Melt", "people": "Miller, Emily; Dryak, Mariama; Oliver, Caitlin; Aberle, Rainey; Enderlin, Ellyn; Dickson, Adam", "repository": "USAP-DC", "science_program": null, "title": "Remotely-sensed iceberg geometries and meltwater fluxes", "url": "https://www.usap-dc.org/view/dataset/601679"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "The project uses repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images are used to construct maps of iceberg surface elevation change over time, which are converted to estimates of area-averaged submarine melt rates. Where ocean temperature observations are available, the melt rates are compared to these data to determine if variations in ocean temperature can explain observed iceberg melt variability. The iceberg melt rates are also compared to glacier frontal ablation rates (flow towards the terminus minus changes in terminus position over time) and integrated into a numerical ice flow model in order to assess the importance of submarine melting on recent changes in terminus position, ice flow, and dynamic mass loss. Overall, the analysis will yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amery Ice Shelf; FIELD SURVEYS; Totten Glacier; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; USAP-DC; Antarctic Peninsula; ICEBERGS; Mertz Glacier; OCEAN TEMPERATURE; USA/NSF; Amd/Us; Amundsen Sea; Ronne Ice Shelf; Filchner Ice Shelf; AMD", "locations": "Antarctic Peninsula; Totten Glacier; Ronne Ice Shelf; Filchner Ice Shelf; Amery Ice Shelf; Mertz Glacier; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Enderlin, Ellyn", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Antarctic Submarine Melt Variability from Remote Sensing of Icebergs", "uid": "p0010210", "west": -180.0}, {"awards": "1935672 Ryan, Joseph; 1935635 Santagata, Scott", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "Understanding the genomic changes underlying adaptations to polar environments is critical for \r\npredicting how ecological changes will affect life in these fragile environments. Accomplishing these goals requires looking in detail at genome-scale data across a wide array of organisms in a phylogenetic framework. This study combines multifaceted computational and functional approaches that involves analyzing in the genic evolution of invertebrate organisms, known as the bryozoans or ectoprocts. In addition, the commonality of our results in other taxa will be tested by comparing the results to those produced from the previous and newly proposed workshops. Specific aims of this study include: 1) identifying genes involved in adaptation to Antarctic marine environments using transcriptomic and genomic data from bryozoans to test for positively selected genes in a phylogenetic framework, 2) experimentally testing identified candidate enzymes (especially those involved in calcium signaling, glycolysis, the citric acid cycle, and the cytoskeleton) for evidence of cold adaption, and 3) conducting computational workshops aimed at training scientists in techniques for the identification of genetic adaptations to polar and other disparate environments. The proposed work provides critical insights into the molecular rules of life in rapidly changing Antarctic environments, and provides important information for understanding how Antarctic taxa will respond to future environmental conditions.\r\n", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USAP-DC; USA/NSF; Ross Sea; Ant Lia; ANIMALS/INVERTEBRATES; FIELD SURVEYS; Weddell Sea; Bellingshausen Sea; Amundsen Sea; Antarctic Peninsula; Amd/Us; AMD", "locations": "Amundsen Sea; Antarctic Peninsula; Bellingshausen Sea; Ross Sea; Weddell Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Ryan, Joseph; Santagata, Scott", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repositories": null, "science_programs": null, "south": -90.0, "title": "ANT LIA Collaborative Research: Interrogating Molecular and Physiological Adaptations in Antarctic Marine Animals.", "uid": "p0010212", "west": -180.0}, {"awards": "1644159 Jacobs, Stanley", "bounds_geometry": "POLYGON((-180 -72.5,-177 -72.5,-174 -72.5,-171 -72.5,-168 -72.5,-165 -72.5,-162 -72.5,-159 -72.5,-156 -72.5,-153 -72.5,-150 -72.5,-150 -73.15,-150 -73.8,-150 -74.45,-150 -75.1,-150 -75.75,-150 -76.4,-150 -77.05,-150 -77.7,-150 -78.35,-150 -79,-153 -79,-156 -79,-159 -79,-162 -79,-165 -79,-168 -79,-171 -79,-174 -79,-177 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.35,162 -77.7,162 -77.05,162 -76.4,162 -75.75,162 -75.1,162 -74.45,162 -73.8,162 -73.15,162 -72.5,163.8 -72.5,165.6 -72.5,167.4 -72.5,169.2 -72.5,171 -72.5,172.8 -72.5,174.6 -72.5,176.4 -72.5,178.2 -72.5,-180 -72.5))", "dataset_titles": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020; Ross Island area salinity and temperature records 1956 to 2020", "datasets": [{"dataset_uid": "601611", "doi": "10.15784/601611", "keywords": "Amundsen Sea; Antarctica; Chemistry:Water; CTD; D18O; NBP0001; NBP0702; NBP0901; NBP1901; NBP2002; Oceans; Oxygen Isotope; R/v Nathaniel B. Palmer; Seawater Isotope; Southern Ocean", "people": "Hennig, Andrew", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Seawater d18O isotope data from SE Amundsen Sea: 2000, 2007, 2009, 2019, 2020", "url": "https://www.usap-dc.org/view/dataset/601611"}, {"dataset_uid": "601458", "doi": "10.15784/601458", "keywords": "Antarctica; CTD; Oceans; Physical Oceanography; Ross Island; Ross Sea; Salinity; Temperature", "people": "Jacobs, Stanley; Giulivi, Claudia F.", "repository": "USAP-DC", "science_program": null, "title": "Ross Island area salinity and temperature records 1956 to 2020", "url": "https://www.usap-dc.org/view/dataset/601458"}], "date_created": "Fri, 25 Jun 2021 00:00:00 GMT", "description": "This project extended and combined historical and recent ocean data sets to investigate ice-ocean-interactions along the Pacific continental margin of the West Antarctic Ice Sheet. The synthesis focused on the strikingly different environments on and near the cold Ross Sea and warm Amundsen Sea continental shelves, where available measurements reach back to 1911 and 1994, respectively. On the more extensively covered Ross Sea continental shelf, multiple reoccupations of ocean stations and transects since the 1950s were used to extend our knowledge of ocean thermohaline change and variability. The more rugged Amundsen Sea continental shelf contains the earth\u0027s fastest melting ice shelves, which Holland et al (2019) show can be linked to decadal-scale variability in the tropical Pacific, and Jacobs et al. (2021) document as being the primary influence on freshening downstream in the Ross Sea. Recent and potential future rates of sea level rise are the primary broad-scale impacts revealed by the observations of ice and ocean changes in these study areas. More regionally, freshening also influences the properties of slope front and coastal currents, and abyssal water mass formation. The overriding question in such work is whether their contributions to global and regional sea levels will continue to increase ~linearly, perhaps allowing greenhouse gas reductions to head off the worst consequences, or accelerate and contribute to major social and economic upheavals. The compiled ocean station profile data has been derived from measurements made from 16 ships operated by 6 countries, from 5 projects using holes through fast and glacier ice, and from 3 studies using drifting floats. We are grateful to the many individuals who have acquired, processed and provided the data, along with their supporting agencies, and welcome corrections and updates to this archive.\n\n", "east": -150.0, "geometry": "POINT(-174 -75.75)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; AMD; USA/NSF; COMPUTERS; Ross Sea; SHIPS; USAP-DC; SALINITY/DENSITY; OCEAN TEMPERATURE", "locations": "Ross Sea", "north": -72.5, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.0, "title": "West Antarctic Ice Shelf- Ocean Interactions ", "uid": "p0010208", "west": 162.0}, {"awards": "1738989 Venturelli, Ryan; 2317097 Venturelli, Ryan", "bounds_geometry": "POLYGON((-114 -74,-112.2 -74,-110.4 -74,-108.6 -74,-106.8 -74,-105 -74,-103.2 -74,-101.4 -74,-99.6 -74,-97.8 -74,-96 -74,-96 -74.2,-96 -74.4,-96 -74.6,-96 -74.8,-96 -75,-96 -75.2,-96 -75.4,-96 -75.6,-96 -75.8,-96 -76,-97.8 -76,-99.6 -76,-101.4 -76,-103.2 -76,-105 -76,-106.8 -76,-108.6 -76,-110.4 -76,-112.2 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica; Cosmogenic-Nuclide data at ICE-D; Firn and Ice Density at Winkie Nunatak; Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif; Ice-penetrating radar data from the Thwaites Glacier grounding zone; In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers; NBP1902 Expedition data; Pine Island Bay Relative Sea-Level Data", "datasets": [{"dataset_uid": "601860", "doi": "10.15784/601860", "keywords": "Antarctica; Cryosphere; Grounding Zone; Ice Penetrating Radar; Thwaites Glacier", "people": "Balco, Greg; Goehring, Brent; Campbell, Seth", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Ice-penetrating radar data from the Thwaites Glacier grounding zone", "url": "https://www.usap-dc.org/view/dataset/601860"}, {"dataset_uid": "200296", "doi": "", "keywords": null, "people": null, "repository": "ICE-D", "science_program": null, "title": "Cosmogenic-Nuclide data at ICE-D", "url": "https://version2.ice-d.org/antarctica/nsf/"}, {"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}, {"dataset_uid": "601554", "doi": "10.15784/601554", "keywords": "Antarctica; Pine Island Bay; Radiocarbon; Raised Beaches", "people": "Braddock, Scott; Hall, Brenda", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Pine Island Bay Relative Sea-Level Data", "url": "https://www.usap-dc.org/view/dataset/601554"}, {"dataset_uid": "601838", "doi": "10.15784/601838", "keywords": "Antarctica; Cryosphere; Density; Firn; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Density; Ice Core Records; Snow/ice; Snow/Ice", "people": "Venturelli, Ryan", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Firn and Ice Density at Winkie Nunatak", "url": "https://www.usap-dc.org/view/dataset/601838"}, {"dataset_uid": "601705", "doi": "10.15784/601705", "keywords": "Antarctica; Cosmogenic Radionuclides; Mount Murphy; Subglacial Bedrock", "people": "Venturelli, Ryan; Goehring, Brent; Balco, Gregory", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "In situ 14C data from a subglacial bedrock core near Pope and Thwaites glaciers", "url": "https://www.usap-dc.org/view/dataset/601705"}, {"dataset_uid": "601677", "doi": "10.15784/601677", "keywords": "Antarctica; Ice Penetrating Radar; Pine Island Glacier; Subglacial Bedrock", "people": "Braddock, Scott", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "200 MHz ground-penetrating radar from Winkie Nunatak, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/601677"}, {"dataset_uid": "601834", "doi": "10.15784/601834", "keywords": "Antarctica; Cryosphere; Mount Murphy", "people": "Campbell, Seth; Goehring, Brent; Balco, Greg", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Ice-penetrating radar data from the northern embayment of the Mt. Murphy massif", "url": "https://www.usap-dc.org/view/dataset/601834"}], "date_created": "Tue, 16 Mar 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Thwaites Glacier system dominates the contribution to sea-level rise from Antarctica. Predicting how this system will evolve in coming decades, and thereby its likely contribution to sea level, requires detailed understanding of how it has responded to changes in climate and oceanographic conditions in the past. This project will provide a record of regional sea-level change by establishing chronologies for raised marine beaches as well as the timing and duration of periods of retreat of Thwaites Glacier during the past 10,000 years by sampling and dating bedrock presently covered by Thwaites Glacier via subglacial drilling. Together with climatic and oceanographic conditions from other records, these will provide boundary conditions for past-to-present model simulations as well as those used to predict future glacier changes under a range of climate scenarios. Specifically, the project will test the hypothesis--implied by existing geological evidence from the region--that present rapid retreat of the Thwaites Glacier system is reversible. \r\n\r\nThe team aims to utilize two approaches: 1. To reconstruct relative sea level during the Holocene, it will map and date raised marine and shoreline deposits throughout Pine Island Bay. Chronological constraints on sea-level change will be provided by radiocarbon dating of organic material in landforms and sediments that are genetically related to past sea level, such as shell fragments, bones of marine fauna, and penguin guano. 2. To obtain geological evidence for past episodes of grounding-line retreat, the team will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed for subglacial bedrock recovery, the team will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding-line position in the Thwaites system (specifically in the Hudson Mountains, and near Mount Murphy). Observation of significant cosmogenic-nuclide concentrations--the team will primarily measure Beryllium-10 and in situ Carbon-14--in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding-line retreat as well as constraints on their timing and duration.", "east": -96.0, "geometry": "POINT(-105 -75)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; FIELD INVESTIGATION; GLACIERS/ICE SHEETS; GLACIAL LANDFORMS; LABORATORY; Amd/Us; USAP-DC; GLACIATION; Amundsen Sea; USA/NSF", "locations": "Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Goehring, Brent; Hall, Brenda; Campbell, Seth; Venturelli, Ryan A; Balco, Gregory", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "ICE-D; R2R; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System", "uid": "p0010165", "west": -114.0}, {"awards": "2001714 Muto, Atsuhiro; 2002346 Tinto, Kirsteen", "bounds_geometry": "POLYGON((-115 -70,-113 -70,-111 -70,-109 -70,-107 -70,-105 -70,-103 -70,-101 -70,-99 -70,-97 -70,-95 -70,-95 -70.8,-95 -71.6,-95 -72.4,-95 -73.2,-95 -74,-95 -74.8,-95 -75.6,-95 -76.4,-95 -77.2,-95 -78,-97 -78,-99 -78,-101 -78,-103 -78,-105 -78,-107 -78,-109 -78,-111 -78,-113 -78,-115 -78,-115 -77.2,-115 -76.4,-115 -75.6,-115 -74.8,-115 -74,-115 -73.2,-115 -72.4,-115 -71.6,-115 -70.8,-115 -70))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 02 Mar 2021 00:00:00 GMT", "description": "Predictions of future changes of the Antarctic ice sheet are essential for understanding changes in the global sea level expected for the coming centuries. These predictions rely on models of ice-sheet flow that in turn rely on knowledge of the physical conditions of the Antarctic continent beneath the ice. Exploration of Antarctica by land, sea, and air has advanced our understanding of the geological material under the Antarctic ice sheet, but this information has not yet been fully integrated into ice-sheet models. This project will take advantage of existing data from decades of US and international investment in geophysical surveys to create a new understanding of the geology underlying the Amundsen Sea and the adjacent areas of the West Antarctic Ice Sheet?a portion of Antarctica that is considered particularly vulnerable to collapse. A series of new datasets called ?Bed Classes? will be developed that will translate the geological properties of the Antarctic continent in ways that can be incorporated into ice-sheet models. \u003cbr/\u003e\u003cbr/\u003eThis project will develop a new regional geologic/tectonic framework for the Amundsen Sea Embayment and its ice catchments using extensive marine and airborne geophysical data together with ground-based onshore geophysical and geological constraints to delineate sedimentary basins, bedrock ridges, faults, and volcanic structures. Using this new geologic interpretation of the region, several key issues regarding the geologic influence on ice-sheet stability will be addressed: whether the regional heat flow is dominated by localization along the faults or lithology; the role of geology on the sources, sinks, and flow-paths of subglacial water; the distribution of sediments that determine bed-character variability; and the extent of geologic control on the current Thwaites Glacier grounding line. The impact of improved geological knowledge on ice-sheet models will be tested with the development of a set of ?Bed Class? grids to capture these new insights for use in the models. Bed Classes will be tested within the Parallel Ice Sheet Model framework with initial experiments to identify the sensitivity of model simulations to geological parameterizations. Through a series of workshops with ice-sheet modelers, the Bed Classes will be refined and made accessible to the broader modelling community. This work aims to ensure that the Bed-Class concept can be applied more broadly to ice-sheet models working in different geographic areas and on different timescales.\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": -95.0, "geometry": "POINT(-105 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Amundsen Sea; COMPUTERS; GRAVITY ANOMALIES; Amd/Us; GLACIERS/ICE SHEETS; AMD; USA/NSF; USAP-DC", "locations": "Amundsen Sea", "north": -70.0, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Glaciology; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Tinto, Kirsty; Bell, Robin; Porter, David; Muto, Atsu", "platforms": "OTHER \u003e MODELS \u003e COMPUTERS", "repositories": null, "science_programs": null, "south": -78.0, "title": "Collaborative Research: Building Geologically Informed Bed Classes to Improve Projections of Ice Sheet Change", "uid": "p0010164", "west": -115.0}, {"awards": "1929991 Pettit, Erin C; 1738992 Pettit, Erin C", "bounds_geometry": "POLYGON((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74))", "dataset_titles": "AMIGOS-IIIa \"Cavity\" Aquadopp current data Jan 2020 - Mar 2021; AMIGOS-IIIa \"Cavity\" Seabird CTD data Jan 2020 - Dec 2021; AMIGOS-III Cavity and Channel Snow Height and Thermistor Snow Temperature Data; AMIGOS-IIIc \"Channel\" Aquadopp current data Jan 2020 - Mar 2021; AMIGOS-IIIc \"Channel\" Seabird CTD data Jan 2020 - Dec 2021; CTD data from the NBP 19/02 cruise as part of the TARSAN project in the Amundsen Sea during austral summer 2018/2019; Dotson-Crosson Ice Shelf data from a tale of two ice shelves paper; SIIOS Temporary Deployment; Sub-ice-shelf seafloor elevation derived from point-source active-seismic data on Thwaites Eastern Ice Shelf and Dotson Ice Shelf, December 2019 and January 2020; Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation; Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020; Visala WXT520 weather station data at the Cavity and Channel AMIGOS-III sites", "datasets": [{"dataset_uid": "200204", "doi": "https://doi.org/10.7914/SN/1L_2019", "keywords": null, "people": null, "repository": "International Federation of Digital Seismograph Networks", "science_program": null, "title": "SIIOS Temporary Deployment", "url": "http://www.fdsn.org/networks/detail/1L_2019/"}, {"dataset_uid": "601552", "doi": "10.15784/601552", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Pine Island Bay; Snow Accumulation; Snow Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-III Cavity and Channel Snow Height and Thermistor Snow Temperature Data", "url": "https://www.usap-dc.org/view/dataset/601552"}, {"dataset_uid": "601549", "doi": "10.15784/601549", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Pine Island Bay; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Visala WXT520 weather station data at the Cavity and Channel AMIGOS-III sites", "url": "https://www.usap-dc.org/view/dataset/601549"}, {"dataset_uid": "601548", "doi": "10.15784/601548", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIc \"Channel\" Aquadopp current data Jan 2020 - Mar 2021", "url": "https://www.usap-dc.org/view/dataset/601548"}, {"dataset_uid": "601547", "doi": "10.15784/601547", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIa \"Cavity\" Aquadopp current data Jan 2020 - Mar 2021", "url": "https://www.usap-dc.org/view/dataset/601547"}, {"dataset_uid": "601578", "doi": "10.15784/601578", "keywords": "Antarctica; Dotson Ice Shelf; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Segabinazzi-Dotto, Tiago; Wild, Christian", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Dotson-Crosson Ice Shelf data from a tale of two ice shelves paper", "url": "https://www.usap-dc.org/view/dataset/601578"}, {"dataset_uid": "601545", "doi": "10.15784/601545", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Salinity; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIc \"Channel\" Seabird CTD data Jan 2020 - Dec 2021", "url": "https://www.usap-dc.org/view/dataset/601545"}, {"dataset_uid": "601544", "doi": "10.15784/601544", "keywords": "Amundsen Sea; Antarctica; Ice Shelf; Mooring; Pine Island Bay; Pressure; Salinity; Temperature; Thwaites Glacier", "people": "Scambos, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "AMIGOS-IIIa \"Cavity\" Seabird CTD data Jan 2020 - Dec 2021", "url": "https://www.usap-dc.org/view/dataset/601544"}, {"dataset_uid": "200321", "doi": "10.5285/e338af5d-8622-05de-e053-6c86abc06489", "keywords": null, "people": null, "repository": "British Oceanographic Data Centre", "science_program": null, "title": "CTD data from the NBP 19/02 cruise as part of the TARSAN project in the Amundsen Sea during austral summer 2018/2019", "url": "https://www.bodc.ac.uk/data/published_data_library/catalogue/10.5285/e338af5d-8622-05de-e053-6c86abc06489/"}, {"dataset_uid": "601499", "doi": "10.15784/601499", "keywords": "Amundsen Sea; Antarctica; Glaciology; Grounding Line; Ice Shelf; Thwaites Glacier", "people": "Alley, Karen; Scambos, Ted; Truffer, Martin; Wild, Christian; Pettit, Erin; Muto, Atsu", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Thwaites Glacier grounding lines for 2014 and 2019/20 from height above flotation", "url": "https://www.usap-dc.org/view/dataset/601499"}, {"dataset_uid": "601827", "doi": "10.15784/601827", "keywords": "Antarctica; Cryosphere; Dotson Ice Shelf; Thwaites Glacier", "people": "Wallin, Bruce; Muto, Atsuhiro; Alley, Karen; Roccaro, Alexander; Pettit, Erin; Truffer, Martin; Scambos, Ted; Wild, Christian; Pomraning, Dale", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Sub-ice-shelf seafloor elevation derived from point-source active-seismic data on Thwaites Eastern Ice Shelf and Dotson Ice Shelf, December 2019 and January 2020", "url": "https://www.usap-dc.org/view/dataset/601827"}, {"dataset_uid": "601478", "doi": "10.15784/601478", "keywords": "Antarctica; Glaciology; Ice Shelf; Ice Velocity; Strain Rate; Thwaites Glacier", "people": "Klinger, Marin; Wallin, Bruce; Truffer, Martin; Muto, Atsu; Pettit, Erin; Wild, Christian; Scambos, Ted; Alley, Karen", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Two-year velocity and strain-rate averages from the Thwaites Eastern Ice Shelf, 2001-2020", "url": "https://www.usap-dc.org/view/dataset/601478"}], "date_created": "Mon, 22 Feb 2021 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. \u003cbr/\u003e \u003cbr/\u003eCurrent and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team\u0027s specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a \"Live from the Ice\" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations.\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": -104.0, "geometry": "POINT(-109 -75)", "instruments": null, "is_usap_dc": true, "keywords": "Thwaites Glacier; FIELD SURVEYS; GLACIERS/ICE SHEETS", "locations": "Thwaites Glacier", "north": -74.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences; Antarctic Integrated System Science; Antarctic Ocean and Atmospheric Sciences; Antarctic Glaciology; Antarctic Glaciology; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Scambos, Ted; Muto, Atsu; Heywood, Karen; Boehme, Lars; Hall, Robert; Wahlin, Anna; Lenaerts, Jan; Pettit, Erin", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "International Federation of Digital Seismograph Networks", "repositories": "British Oceanographic Data Centre; International Federation of Digital Seismograph Networks; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment", "uid": "p0010162", "west": -114.0}, {"awards": "1043623 Miller, Scott", "bounds_geometry": "POLYGON((117.5 -47,120.35 -47,123.2 -47,126.05 -47,128.9 -47,131.75 -47,134.6 -47,137.45 -47,140.3 -47,143.15 -47,146 -47,146 -49.04,146 -51.08,146 -53.12,146 -55.16,146 -57.2,146 -59.24,146 -61.28,146 -63.32,146 -65.36,146 -67.4,143.15 -67.4,140.3 -67.4,137.45 -67.4,134.6 -67.4,131.75 -67.4,128.9 -67.4,126.05 -67.4,123.2 -67.4,120.35 -67.4,117.5 -67.4,117.5 -65.36,117.5 -63.32,117.5 -61.28,117.5 -59.24,117.5 -57.2,117.5 -55.16,117.5 -53.12,117.5 -51.08,117.5 -49.04,117.5 -47))", "dataset_titles": "Eddy covariance air-sea momentum, heat, and carbon dioxide fluxes in the Southern Ocean from the N.B. Palmer cruise NBP1210; Eddy covariance air-sea momentum, heat, and carbon dioxide fluxes in the Southern Ocean from the N.B. Palmer cruise NBP1402; Expedition Data", "datasets": [{"dataset_uid": "601309", "doi": "10.15784/601309", "keywords": "Air-Sea Flux; Air Temperature; Amundsen Sea; Antarctica; Antarctic Peninsula; Atmosphere; CO2; Flux; Meteorology; NBP1210; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Southern Ocean; Water Temperature; Wind Direction; Wind Speed", "people": "Miller, Scott; Butterworth, Brian", "repository": "USAP-DC", "science_program": null, "title": "Eddy covariance air-sea momentum, heat, and carbon dioxide fluxes in the Southern Ocean from the N.B. Palmer cruise NBP1210", "url": "https://www.usap-dc.org/view/dataset/601309"}, {"dataset_uid": "601308", "doi": null, "keywords": "Air-Sea Flux; Air Temperature; Antarctica; Atmosphere; CO2; CO2 Concentrations; East Antarctica; Flux; Meteorology; NBP1402; Oceans; Relative Humidity; Salinity; Totten Glacier; Water Measurements; Water Temperature; Weather Station Data; Wind Direction; Wind Speed", "people": "Butterworth, Brian; Miller, Scott", "repository": "USAP-DC", "science_program": null, "title": "Eddy covariance air-sea momentum, heat, and carbon dioxide fluxes in the Southern Ocean from the N.B. Palmer cruise NBP1402", "url": "https://www.usap-dc.org/view/dataset/601308"}, {"dataset_uid": "001414", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1402"}, {"dataset_uid": "001427", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1210"}], "date_created": "Fri, 09 Oct 2020 00:00:00 GMT", "description": "Accurate parameterizations of the air-sea fluxes of CO2 into the Southern Ocean, in particular at high wind velocity, are needed to better assess how projections of global climate warming in a windier world could affect the ocean carbon uptake, and alter the ocean heat budget at high latitudes. \u003cbr/\u003e\u003cbr/\u003eAir-sea fluxes of momentum, sensible and latent heat (water vapor) and carbon dioxide (CO2) are to be measured continuously underway on cruises using micrometeorological eddy covariance techniques adapted to ship-board use. The measured gas transfer velocity (K) is then to be related to other parameters known to affect air-sea-fluxes.\u003cbr/\u003e\u003cbr/\u003eA stated goal of this work is the collection of a set of direct air-sea flux measurements at high wind speeds, conditions where parameterization of the relationship of gas exchange to wind-speed remains contentious. The studies will be carried out at sites in the Southern Ocean using the USAP RV Nathaniel B Palmer as measurment platform. Co-located pCO2 data, to be used in the overall analysis and enabling internal consistency checks, are being collected from existing underway systems aboard the USAP research vessel under other NSF awards.", "east": 146.0, "geometry": "POINT(131.75 -57.2)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "HEAT FLUX; DISSOLVED GASES; Antarctica; USAP-DC; NOT APPLICABLE", "locations": "Antarctica", "north": -47.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Miller, Scott", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -67.4, "title": "Air-Sea Fluxes of Momentum, Heat, and Carbon Dioxide at High Wind Speeds in the Southern Ocean", "uid": "p0010137", "west": 117.5}, {"awards": "1738913 Scambos, Ted", "bounds_geometry": "POLYGON((-118 -70,-116 -70,-114 -70,-112 -70,-110 -70,-108 -70,-106 -70,-104 -70,-102 -70,-100 -70,-98 -70,-98 -71,-98 -72,-98 -73,-98 -74,-98 -75,-98 -76,-98 -77,-98 -78,-98 -79,-98 -80,-100 -80,-102 -80,-104 -80,-106 -80,-108 -80,-110 -80,-112 -80,-114 -80,-116 -80,-118 -80,-118 -79,-118 -78,-118 -77,-118 -76,-118 -75,-118 -74,-118 -73,-118 -72,-118 -71,-118 -70))", "dataset_titles": "Profile CTD Data During Installation of AMIGOS-III Cavity and Channel On-Ice Moorings", "datasets": [{"dataset_uid": "601623", "doi": "10.15784/601623", "keywords": "Amundsen Sea; Antarctica; CTD; Ice Shelf", "people": "SCAMBOS, Ted", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Profile CTD Data During Installation of AMIGOS-III Cavity and Channel On-Ice Moorings", "url": "https://www.usap-dc.org/view/dataset/601623"}], "date_created": "Wed, 09 Sep 2020 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Science Coordination Office will facilitate planning and coordination of the science and broader impacts of several international research projects studying Thwaites Glacier--one of the largest glaciers in Antarctica. The glacier is located on the Pacific coast of the Antarctic continent. It is flowing almost twice as fast now as in the 1970s, and is one of the largest likely contributors to sea-level rise over the coming decades to centuries. Many of the factors that will affect the speed and retreat of Thwaites Glacier will be addressed by the set of projects funded by the Thwaites initiative. The Science Coordination Office comprises a US-UK science and communications team that will work with each project\u0027s scientists and students, logistics planners, and NSF and NERC to ensure the overall success of the project. The Office will maintain an informative website, and will produce content to explain the activities of the scientists and highlight the results of the work. \u003cbr/\u003e\u003cbr/\u003eThe role of the Science Coordination Office will be to enhance integration and coordination among the science projects selected for the joint NSF-NERC Thwaites initiative to achieve maximum collective scientific and societal impact. The Office will facilitate scientific and logistical planning; facilitate data management, sharing, and discovery; and facilitate and support web content, outreach, and education for this high-profile research endeavor. The Office\u0027s role will be key to enabling the program to achieve its scientific goals and for the program to be broadly recognized and valued by scientists, the public, and policymakers.\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": -98.0, "geometry": "POINT(-108 -75)", "instruments": null, "is_usap_dc": true, "keywords": "OCEAN TEMPERATURE; GLACIER MOTION/ICE SHEET MOTION; BATHYMETRY; FIELD INVESTIGATION; FIELD SURVEYS; SNOW; SEDIMENTS; Antarctic Ice Sheet; WATER MASSES; GLACIER MASS BALANCE/ICE SHEET MASS BALANCE; GLACIERS/ICE SHEETS; MARINE GEOPHYSICS", "locations": "Antarctic Ice Sheet", "north": -70.0, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Vaughan, David G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "NSF-NERC The Future of Thwaites Glacier and its Contribution to Sea-level Rise Science Coordination Office", "uid": "p0010127", "west": -118.0}, {"awards": "1341496 Girton, James", "bounds_geometry": "POLYGON((-142 -66,-135.3 -66,-128.6 -66,-121.9 -66,-115.2 -66,-108.5 -66,-101.8 -66,-95.1 -66,-88.4 -66,-81.7 -66,-75 -66,-75 -66.8,-75 -67.6,-75 -68.4,-75 -69.2,-75 -70,-75 -70.8,-75 -71.6,-75 -72.4,-75 -73.2,-75 -74,-81.7 -74,-88.4 -74,-95.1 -74,-101.8 -74,-108.5 -74,-115.2 -74,-121.9 -74,-128.6 -74,-135.3 -74,-142 -74,-142 -73.2,-142 -72.4,-142 -71.6,-142 -70.8,-142 -70,-142 -69.2,-142 -68.4,-142 -67.6,-142 -66.8,-142 -66))", "dataset_titles": "Bottom Photographs from the Antarctic Peninsula acquired during R/V Laurence M. Gould expedition LMG1703; Expedition Data; Expedition data of NBP1701", "datasets": [{"dataset_uid": "002661", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1701", "url": "https://www.rvdata.us/search/cruise/NBP1701"}, {"dataset_uid": "601302", "doi": null, "keywords": "Antarctica; Antarctic Peninsula; Benthic Images; Benthos; Biota; LMG1708; Oceans; Photo; Photo/video; Photo/Video; R/v Laurence M. Gould; Ship; Yoyo Camera", "people": "Girton, James", "repository": "USAP-DC", "science_program": null, "title": "Bottom Photographs from the Antarctic Peninsula acquired during R/V Laurence M. Gould expedition LMG1703", "url": "https://www.usap-dc.org/view/dataset/601302"}, {"dataset_uid": "001369", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP1701"}], "date_created": "Tue, 10 Dec 2019 00:00:00 GMT", "description": "Current oceanographic interest in the interaction of relatively warm water of the Southern Ocean Circumpolar Deep Water (CDW) as it moves southward to the frigid waters of the Antarctic continental shelves is based on the potential importance of heat transport from the global ocean to the base of continental ice shelves. This is needed to understand the longer term mass balance of the continent, the stability of the vast Antarctic ice sheets and the rate at which sea-level will rise in a warming world. Improved observational knowledge of the mechanisms of how warming CDW moves across the Antarctic Circumpolar Current (ACC) is needed. Understanding this dynamical transport, believed to take place through the eddy flux of time-varying mesoscale circulation features, will improve coupled ocean-atmospheric climate models. The development of the next generation of coupled ocean-ice-climate models help us understand future changes in atmospheric heat fluxes, glacial and sea-ice balance, and changes in the Antarctic ecosystems. A recurring obstacle to our understanding is the lack of data in this distant region. In this project, a total of 10 subsurface profiling EM-APEX floats adapted to operate under sea ice were launched in 12 missions (and 2 recoveries) from 4 cruises of opportunity to the Amundsen Sea sector of the Antarctic continental margin during Austral summer. The floats were launched south of the Polar Front and measured shear, turbulence, temperature, and salinity to 2000m depth for 1-2 year missions while drifting with the CDW layer between profiles.", "east": -75.0, "geometry": "POINT(-108.5 -70)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERA", "is_usap_dc": true, "keywords": "OCEAN TEMPERATURE; R/V NBP; USAP-DC; ICE DEPTH/THICKNESS; HEAT FLUX; OCEAN CURRENTS; SALINITY/DENSITY; LMG1703; Bellingshausen Sea; Yoyo Camera; WATER MASSES; R/V LMG; NBP1701", "locations": "Bellingshausen Sea", "north": -66.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Girton, James; Rynearson, Tatiana", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -74.0, "title": "Collaborative Research: Pathways of Circumpolar Deep Water to West Antarctica from Profiling Float and Satellite Measurements", "uid": "p0010074", "west": -142.0}, {"awards": "1738942 Wellner, Julia", "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 -71.5,-100 -72,-100 -72.5,-100 -73,-100 -73.5,-100 -74,-100 -74.5,-100 -75,-100 -75.5,-100 -76,-102 -76,-104 -76,-106 -76,-108 -76,-110 -76,-112 -76,-114 -76,-116 -76,-118 -76,-120 -76,-120 -75.5,-120 -75,-120 -74.5,-120 -74,-120 -73.5,-120 -73,-120 -72.5,-120 -72,-120 -71.5,-120 -71))", "dataset_titles": "A multibeam-bathymetric compilation for the southern Amundsen Sea shelf, 1999-2019; Expedition Data of NBP2002; NBP1902 Expedition data; Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "datasets": [{"dataset_uid": "200083", "doi": "10.7284/908147", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1902 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1902"}, {"dataset_uid": "200248", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data of NBP2002", "url": "https://www.rvdata.us/search/cruise/NBP2002"}, {"dataset_uid": "601514", "doi": "10.15784/601514", "keywords": "Antarctica; Chemistry:sediment; Chemistry:Sediment; Glaciomarine Sediment; Grain Size; Magnetic Susceptibility; Marine Geoscience; Marine Sediments; NBP1902; NBP2002; Physical Properties; R/v Nathaniel B. Palmer; Sediment Core Data; Thwaites Glacier; Trace Elements; XRF", "people": "Lepp, Allison", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Physical and geochemical data from sediment cores collected offshore Thwaites Glacier", "url": "https://www.usap-dc.org/view/dataset/601514"}, {"dataset_uid": "200161", "doi": "10.5285/F2DFEDA9-BF44-4EF5-89A3-EE5E434A385C", "keywords": null, "people": null, "repository": "UK PDC", "science_program": null, "title": "A multibeam-bathymetric compilation for the southern Amundsen Sea shelf, 1999-2019", "url": "https://doi.org/10.5285/F2DFEDA9-BF44-4EF5-89A3-EE5E434A385C"}], "date_created": "Fri, 01 Nov 2019 00:00:00 GMT", "description": "This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Satellite observations extending over the last 25 years show that Thwaites Glacier is rapidly thinning and accelerating. Over this same period, the Thwaites grounding line, the point at which the glacier transitions from sitting on the seabed to floating, has retreated. Oceanographic studies demonstrate that the main driver of these changes is incursion of warm water from the deep ocean that flows beneath the floating ice shelf and causes basal melting. The period of satellite observation is not long enough to determine how a large glacier, such as Thwaites, responds to long-term and near-term changes in the ocean or the atmosphere. As a result, records of glacier change from the pre-satellite era are required to build a holistic understanding of glacier behavior. Ocean-floor sediments deposited at the retreating grounding line and further offshore contain these longer-term records of changes in the glacier and the adjacent ocean. An additional large unknown is the topography of the seafloor and how it influences interactions of landward-flowing warm water with Thwaites Glacier and affects its stability. Consequently, this project focuses on the seafloor offshore from Thwaites Glacier and the records of past glacial and ocean change contained in the sediments deposited by the glacier and surrounding ocean.\u003cbr/\u003e\u003cbr/\u003eUncertainty in model projections of the future of Thwaites Glacier will be significantly reduced by cross-disciplinary investigations seaward of the current grounding line, including extracting the record of decadal to millennial variations in warm water incursion, determining the pre-satellite era history of grounding-line migration, and constraining the bathymetric pathways that control flow of warm water to the grounding line. Sedimentary records and glacial landforms preserved on the seafloor will allow reconstruction of changes in drivers and the glacial response to them over a range of timescales, thus providing reference data that can be used to initiate and evaluate the reliability of models. Such data will further provide insights on the influence of poorly understood processes on marine ice sheet dynamics. This project will include an integrated suite of marine and sub-ice shelf research activities aimed at establishing boundary conditions seaward of the Thwaites Glacier grounding line, obtaining records of the external drivers of change, improving knowledge of processes leading to collapse of Thwaites Glacier, and determining the history of past change in grounding line migration and conditions at the glacier base. These objectives will be achieved through high-resolution geophysical surveys of the seafloor and analysis of sediments collected in cores from the inner shelf seaward of the Thwaites Glacier grounding line using ship-based equipment, and from beneath the ice shelf using a corer deployed through the ice shelf via hot water drill holes.\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": -100.0, "geometry": "POINT(-110 -73.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SEDIMENT CORERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS", "is_usap_dc": true, "keywords": "BATHYMETRY; Antarctica; MARINE SEDIMENTS; AMD; MARINE GEOPHYSICS; Amd/Us; USAP-DC; Thwaites Glacier; LABORATORY; Southern Ocean; ICE SHEETS; USA/NSF; GLACIERS/ICE SHEETS; R/V NBP", "locations": "Antarctica; Southern Ocean; Thwaites Glacier", "north": -71.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Wellner, Julia; Larter, Robert; Minzoni, Rebecca; Hogan, Kelly; Anderson, John; Graham, Alastair; Hillenbrand, Claus-Dieter; Nitsche, Frank O.; Simkins, Lauren; Smith, James A.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; UK PDC; USAP-DC", "science_programs": "Thwaites (ITGC)", "south": -76.0, "title": "NSF-NERC: THwaites Offshore Research (THOR)", "uid": "p0010062", "west": -120.0}, {"awards": "1745137 Schroeder, Dustin", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Antarctic topographic and subglacial lake geostatistical simulations; Radar Sounding Observations of the Amundsen Sea Embayment, 2004-2005", "datasets": [{"dataset_uid": "601436", "doi": "10.15784/601436", "keywords": "Amundsen Sea; Antarctica; Bed Reflectivity; Ice Penetrating Radar; Radar Echo Sounder", "people": "Vaughan, David G.; Seroussi, Helene; Young, Duncan A.; Jordan, Thomas M.; Schroeder, Dustin; Culberg, Riley; Hilger, Andrew M.; Chu, Winnie", "repository": "USAP-DC", "science_program": null, "title": "Radar Sounding Observations of the Amundsen Sea Embayment, 2004-2005", "url": "https://www.usap-dc.org/view/dataset/601436"}, {"dataset_uid": "601213", "doi": "10.15784/601213", "keywords": "Active Lakes; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Model Data; Snow/ice; Snow/Ice; Subglacial Lakes; Topography", "people": "Scheidt, Celine; MacKie, Emma; Schroeder, Dustin; Caers, Jef; Siegfried, Matt", "repository": "USAP-DC", "science_program": null, "title": "Antarctic topographic and subglacial lake geostatistical simulations", "url": "https://www.usap-dc.org/view/dataset/601213"}], "date_created": "Sat, 12 Oct 2019 00:00:00 GMT", "description": "Earth\u0027s geologic record shows that the great ice sheets have contributed to rates of sea-level rise that have been much higher than those observed today. That said, some sectors of the current Antarctic ice sheet are losing mass at large and accelerating rates. One of the primary challenges for placing these recent and ongoing changes in the context of geologically historic rates, and for making projections decades to centuries into the future, is the difficulty of observing conditions and processes beneath the ice sheet. Whereas satellite observations allow tracking of the ice-surface velocity and elevation on the scale of glacier catchments to ice sheets, airborne ice-penetrating radar has been the only approach for assessing conditions on this scale beneath the ice. These radar observations have been made since the late 1960s, but, because many different instruments have been used, it is difficult to track change in subglacial conditions through time. This project will develop the technical tools and approaches required to cross-compare among these measurements and thus open up opportunities for tracking and understanding changes in the critical subglacial environment. Intertwined with the research and student training on this project will be an outreach education effort to provide middle school and high school students with improved resources and enhanced exposure to geophysical, glaciological, and remote-sensing topics through partnership with the National Science Olympiad.\u003cbr/\u003e\u003cbr/\u003eThe radar sounding of ice sheets is a powerful tool for glaciological science with broad applicability across a wide range of cryosphere problems and processes. Radar sounding data have been collected with extensive spatial and temporal coverage across the West Antarctic Ice Sheet, including areas where multiple surveys provide observations that span decades in time or entire cross-catchment ice-sheet sectors. However, one major obstacle to realizing the scientific potential of existing radar sounding observations in Antarctica is the lack of analysis approaches specifically developed for cross-instrument interpretation. Radar is also spatially limited and often has gaps of many tens of kilometers between data points. Further work is needed to investigate ways of extrapolating radar information beyond the flight lines. This project aims to directly address these barriers to full utilization of the collective Antarctic radar sounding record by developing a suite of processing and interpretation techniques to enable the synthesis of radar sounding data sets collected with systems that range from incoherent to coherent, single-channel to swath-imaging, and digital to optically-recorded radar sounders. This includes a geostatistical analysis of ice sheet and radar datasets to make probabilistic predictions of conditions at the bed. The approaches will be assessed for two target regions: the Amundsen Sea Embayment and the Siple Coast. All pre- and post-processed sounding data produced by this project will be publically hosted for use by the wider research community.\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": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS", "is_usap_dc": true, "keywords": "GLACIER TOPOGRAPHY/ICE SHEET TOPOGRAPHY; Amd/Us; Airborne Radar; USA/NSF; ICE DEPTH/THICKNESS; Antarctica; Radar; AMD; USAP-DC", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Instrumentation and Support; Antarctic Glaciology", "paleo_time": null, "persons": "Schroeder, Dustin; MacKie, Emma", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "CAREER: Cross-Instrument Synthesis of Antarctic Radar Sounding Observations", "uid": "p0010058", "west": -180.0}, {"awards": "1443190 Parizek, Byron", "bounds_geometry": "POLYGON((-130 -73,-125.5 -73,-121 -73,-116.5 -73,-112 -73,-107.5 -73,-103 -73,-98.5 -73,-94 -73,-89.5 -73,-85 -73,-85 -73.9,-85 -74.8,-85 -75.7,-85 -76.6,-85 -77.5,-85 -78.4,-85 -79.3,-85 -80.2,-85 -81.1,-85 -82,-89.5 -82,-94 -82,-98.5 -82,-103 -82,-107.5 -82,-112 -82,-116.5 -82,-121 -82,-125.5 -82,-130 -82,-130 -81.1,-130 -80.2,-130 -79.3,-130 -78.4,-130 -77.5,-130 -76.6,-130 -75.7,-130 -74.8,-130 -73.9,-130 -73))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 16 Sep 2019 00:00:00 GMT", "description": "Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region as well as processes governing changes in outlet glacier flow. To this end, we will test an ice-sheet model against existing observations and improve treatment of key processes within ice sheet models.\r\n\r\nThis is a four-year (one year of no-cost extension) modeling study using the open-source Ice Sheet System Model in coordination with other models to help improve projections of future sea-level change. Overall project goals, which are distributed across the collaborating institutions, are to:\r\n1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance;\r\n2. utilize observations from glacial settings and efficient process-oriented models to develop a better understanding of key processes associated with outlet glacier dynamics and to create numerically efficient parameterizations for these often sub-grid-scale processes;\r\n3. project a range of evolutions of the Amundsen Sea Embayment sector in the next several centuries given various forcings and inclusion or omission of physical processes in the model.\r\n", "east": -85.0, "geometry": "POINT(-107.5 -77.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; Antarctica; GLACIER MOTION/ICE SHEET MOTION; NOT APPLICABLE", "locations": "Antarctica", "north": -73.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Pollard, David; Parizek, Byron R.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repositories": null, "science_programs": null, "south": -82.0, "title": "Collaborative Research: Evaluating Retreat in the Amundsen Sea Embayment: Assessing Controlling Processes, Uncertainties, and Projections", "uid": "p0010054", "west": -130.0}, {"awards": "1643684 Saito, Mak; 1644073 DiTullio, Giacomo", "bounds_geometry": "POLYGON((-180 -72,-173.6 -72,-167.2 -72,-160.8 -72,-154.4 -72,-148 -72,-141.6 -72,-135.2 -72,-128.8 -72,-122.4 -72,-116 -72,-116 -72.7,-116 -73.4,-116 -74.1,-116 -74.8,-116 -75.5,-116 -76.2,-116 -76.9,-116 -77.6,-116 -78.3,-116 -79,-122.4 -79,-128.8 -79,-135.2 -79,-141.6 -79,-148 -79,-154.4 -79,-160.8 -79,-167.2 -79,-173.6 -79,180 -79,178 -79,176 -79,174 -79,172 -79,170 -79,168 -79,166 -79,164 -79,162 -79,160 -79,160 -78.3,160 -77.6,160 -76.9,160 -76.2,160 -75.5,160 -74.8,160 -74.1,160 -73.4,160 -72.7,160 -72,162 -72,164 -72,166 -72,168 -72,170 -72,172 -72,174 -72,176 -72,178 -72,-180 -72))", "dataset_titles": "Algal pigment concentrations from the Ross Sea; Biogenic silica concentrations from the Ross Sea; NBP1801 Expedition data; Nutrients from NBP18-01 CICLOPS", "datasets": [{"dataset_uid": "200056", "doi": "10.7284/907753", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1801 Expedition data", "url": "https://www.rvdata.us/search/cruise/NBP1801"}, {"dataset_uid": "601428", "doi": "10.15784/601428", "keywords": "Amundsen Sea; Antarctica; NBP1801; Nitrate; Nitrite; Nutrients; Phosphate; Ross Sea; R/v Nathaniel B. Palmer; Silicic Acid; Terra Nova Bay", "people": "Saito, Mak", "repository": "USAP-DC", "science_program": null, "title": "Nutrients from NBP18-01 CICLOPS", "url": "https://www.usap-dc.org/view/dataset/601428"}, {"dataset_uid": "601205", "doi": "10.15784/601205", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Chlorophyll; Chromatography; Liquid Chromatograph; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Water; Seawater Measurements; Southern Ocean; Water Measurements; Water Samples", "people": "Ditullio, Giacomo", "repository": "USAP-DC", "science_program": null, "title": "Algal pigment concentrations from the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601205"}, {"dataset_uid": "601225", "doi": "10.15784/601225", "keywords": "Antarctica; Biogenic Silica; Biogenic Silica Concentrations; Chemistry:Water; Geochemistry; NBP1801; Oceans; Ross Sea; R/v Nathaniel B. Palmer; Sea Water; Southern Ocean; Spectroscopy; Water Measurements; Water Samples", "people": "Ditullio, Giacomo; Schanke, Nicole", "repository": "USAP-DC", "science_program": null, "title": "Biogenic silica concentrations from the Ross Sea", "url": "https://www.usap-dc.org/view/dataset/601225"}], "date_created": "Thu, 08 Aug 2019 00:00:00 GMT", "description": "Phytoplankton blooms in the coastal waters of the Ross Sea, Antarctica are typically dominated by either diatoms or Phaeocystis Antarctica (a flagellated algae that often can form large colonies in a gelatinous matrix). The project seeks to determine if an association of bacterial populations with Phaeocystis antarctica colonies can directly supply Phaeocystis with Vitamin B12, which can be an important co-limiting micronutrient in the Ross Sea. The supply of an essential vitamin coupled with the ability to grow at lower iron concentrations may put Phaeocystis at a competitive advantage over diatoms. Because Phaeocystis cells can fix more carbon than diatoms and Phaeocystis are not grazed as efficiently as diatoms, the project will help in refining understanding of carbon dynamics in the region as well as the basis of the food web webs. Such understanding also has the potential to help refine predictive ecological models for the region. The project will conduct public outreach activities and will contribute to undergraduate and graduate research. Engagement of underrepresented students will occur during summer student internships. A collaboration with Italian Antarctic researchers, who have been studying the Terra Nova Bay ecosystem since the 1980s, aims to enhance the project and promote international scientific collaborations. \u003cbr/\u003e\u003cbr/\u003eThe study will test whether a mutualistic symbioses between attached bacteria and Phaeocystis provides colonial cells a mechanism for alleviating chronic Vitamin B12 co-limitation effects thereby conferring them with a competitive advantage over diatom communities. The use of drifters in a time series study will provide the opportunity to track in both space and time a developing algal bloom in Terra Nova Bay and to determine community structure and the physiological nutrient status of microbial populations. A combination of flow cytometry, proteomics, metatranscriptomics, radioisotopic and stable isotopic labeling experiments will determine carbon and nutrient uptake rates and the role of bacteria in mitigating potential vitamin B12 and iron limitation. Membrane inlet and proton transfer reaction mass spectrometry will also be used to estimate net community production and release of volatile organic carbon compounds that are climatically active. Understanding how environmental parameters can influence microbial community dynamics in Antarctic coastal waters will advance an understanding of how changes in ocean stratification and chemistry could impact the biogeochemistry and food web dynamics of Southern Ocean ecosystems.", "east": 160.0, "geometry": "POINT(-158 -75.5)", "instruments": null, "is_usap_dc": true, "keywords": "BIOGEOCHEMICAL CYCLES; NBP1801; Amd/Us; USA/NSF; USAP-DC; NUTRIENTS; PIGMENTS; CHLOROPHYLL; R/V NBP; Ross Sea; AMD", "locations": "Ross Sea", "north": -72.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Integrated System Science; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "DiTullio, Giacomo; Lee, Peter", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Cobalamin and Iron Co-Limitation Of Phytoplankton Species in Terra Nova Bay", "uid": "p0010045", "west": -116.0}, {"awards": "1443356 Conway, Howard; 1443552 Paul Winberry, J.", "bounds_geometry": "POLYGON((-175 -82.7,-173.9 -82.7,-172.8 -82.7,-171.7 -82.7,-170.6 -82.7,-169.5 -82.7,-168.4 -82.7,-167.3 -82.7,-166.2 -82.7,-165.1 -82.7,-164 -82.7,-164 -82.77,-164 -82.84,-164 -82.91,-164 -82.98,-164 -83.05,-164 -83.12,-164 -83.19,-164 -83.26,-164 -83.33,-164 -83.4,-165.1 -83.4,-166.2 -83.4,-167.3 -83.4,-168.4 -83.4,-169.5 -83.4,-170.6 -83.4,-171.7 -83.4,-172.8 -83.4,-173.9 -83.4,-175 -83.4,-175 -83.33,-175 -83.26,-175 -83.19,-175 -83.12,-175 -83.05,-175 -82.98,-175 -82.91,-175 -82.84,-175 -82.77,-175 -82.7))", "dataset_titles": "2015_Antarctica_Ground; Geophysical data from Crary Ice Rise, Ross Sea Embayment", "datasets": [{"dataset_uid": "200177", "doi": "", "keywords": null, "people": null, "repository": "CReSIS/ku.edu", "science_program": null, "title": "2015_Antarctica_Ground", "url": "https://data.cresis.ku.edu/data/accum/2015_Antarctica_Ground/"}, {"dataset_uid": "601181", "doi": "10.15784/601181", "keywords": "Antarctica; Bed Elevation; Crary Ice Rise; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Ice Penetrating Radar; Ice Sheet Elevation; Ice Shelf; Ice Thickness; Internal Stratigraphy; Radar; Ross Ice Shelf; Snow/ice; Snow/Ice; Surface Elevation", "people": "Paden, John; Koutnik, Michelle; Winberry, Paul; Conway, Howard", "repository": "USAP-DC", "science_program": null, "title": "Geophysical data from Crary Ice Rise, Ross Sea Embayment", "url": "https://www.usap-dc.org/view/dataset/601181"}], "date_created": "Mon, 06 May 2019 00:00:00 GMT", "description": "Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities.\u003cbr/\u003e\u003cbr/\u003eNew tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change?", "east": -164.0, "geometry": "POINT(-169.5 -83.05)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Amd/Us; FIELD SURVEYS; Antarctica; USA/NSF; AMD; USAP-DC; Radar; GLACIERS/ICE SHEETS", "locations": "Antarctica", "north": -82.7, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Koutnik, Michelle; Winberry, Paul", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "CReSIS/ku.edu", "repositories": "CReSIS/ku.edu; USAP-DC", "science_programs": null, "south": -83.4, "title": "Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited", "uid": "p0010026", "west": -175.0}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": "POLYGON((140 -65,141 -65,142 -65,143 -65,144 -65,145 -65,146 -65,147 -65,148 -65,149 -65,150 -65,150 -65.3,150 -65.6,150 -65.9,150 -66.2,150 -66.5,150 -66.8,150 -67.1,150 -67.4,150 -67.7,150 -68,149 -68,148 -68,147 -68,146 -68,145 -68,144 -68,143 -68,142 -68,141 -68,140 -68,140 -67.7,140 -67.4,140 -67.1,140 -66.8,140 -66.5,140 -66.2,140 -65.9,140 -65.6,140 -65.3,140 -65))", "dataset_titles": "Expedition Data; R/V Nathaniel B. Palmer NBP0008 - Expedition Data; \r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "200022", "doi": "10.15784/601161 ", "keywords": null, "people": null, "repository": "USAP-DC", "science_program": null, "title": "\r\nSummer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}, {"dataset_uid": "200023", "doi": "10.7284/905461", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "R/V Nathaniel B. Palmer NBP0008 - Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}], "date_created": "Mon, 11 Mar 2019 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999.", "east": 150.0, "geometry": "POINT(145 -66.5)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC; Southern Ocean; WATER MASSES; Antarctica", "locations": "Southern Ocean; Antarctica", "north": -65.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Visbeck, Martin", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -68.0, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0010019", "west": 140.0}, {"awards": "1644159 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "CTDP/LADCP profile data along Dotson ice shelf calving front from 2000 to 2016", "datasets": [{"dataset_uid": "601105", "doi": "10.15784/601105", "repository": "USAP-DC", "science_program": null, "title": "CTDP/LADCP profile data along Dotson ice shelf calving front from 2000 to 2016", "url": "http://www.usap-dc.org/view/dataset/601105"}], "date_created": "Thu, 12 Jul 2018 00:00:00 GMT", "description": null, "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Amundsen Sea; Antarctica; Dotson Ice Shelf; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ocean Properties; Oceans; Physical Oceanography; West Antarctica", "locations": "Antarctica; West Antarctica; Amundsen Sea; Dotson Ice Shelf", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Dutrieux, Pierre; Stammerjohn, Sharon; Jenkins, Adrian; Jacobs, Stanley", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": null, "uid": null, "west": null}, {"awards": "0838735 Nitsche, Frank O.", "bounds_geometry": "POLYGON((-140 -68,-136 -68,-132 -68,-128 -68,-124 -68,-120 -68,-116 -68,-112 -68,-108 -68,-104 -68,-100 -68,-100 -68.75,-100 -69.5,-100 -70.25,-100 -71,-100 -71.75,-100 -72.5,-100 -73.25,-100 -74,-100 -74.75,-100 -75.5,-104 -75.5,-108 -75.5,-112 -75.5,-116 -75.5,-120 -75.5,-124 -75.5,-128 -75.5,-132 -75.5,-136 -75.5,-140 -75.5,-140 -74.75,-140 -74,-140 -73.25,-140 -72.5,-140 -71.75,-140 -71,-140 -70.25,-140 -69.5,-140 -68.75,-140 -68))", "dataset_titles": "Bathymetry compilation of Pine Island Bay, Amundsen Sea, Antarctica; OSO0910 Expedition Data", "datasets": [{"dataset_uid": "000525", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "OSO0910 Expedition Data", "url": "https://www.marine-geo.org/tools/search/entry.php?id=OSO0910"}, {"dataset_uid": "000225", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Bathymetry compilation of Pine Island Bay, Amundsen Sea, Antarctica", "url": "http://dx.doi.org/10.1594/IEDA/320080"}], "date_created": "Fri, 26 Jan 2018 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The West Antarctic Ice Sheet is believed to be vulnerable to climate change as it is grounded below sea level, is drained by rapidly flowing ice streams and is fringed by floating ice shelves subject to melting by incursions of relatively warm Antarctic circumpolar water. Currently, the most rapidly thinning glaciers in Antarctica occur in the Amundsen and Bellingshausen Sea sectors. This study seeks to place the present day observations into a longer-term geological context over a broad scale by high-resolution swath bathymetric mapping of continental shelf sea floor features that indicate past ice presence and behavior. Gaps in existing survey coverage of glacial lineations and troughs indicating ice flow direction and paleo-grounding zone wedges over the Ross, Amundsen and Bellingshausen Sea sectors are targeted. The surveys will be conducted as part of the 2010 Icebreaker Oden science opportunity and will take advantage of the vessel?s state-of-the-art swath mapping system.\u003cbr/\u003e\u003cbr/\u003eBroader impacts:\u003cbr/\u003eThis activity will supplement and complement more focused regional studies by US, Swedish, UK, French, Japanese and Polish collaborators also sailing on the Oden. The PI will compile bathymetric data to be acquired by the Oden and other ships in the region over the duration of the project into the existing bathymetric data base. The compiled data set will be made publically available through the NSF founded Antarctic Multibeam Bathymetry and Geophysical Data Synthesis (AMBS) site. It will also be integrated into the GEBCO International Bathymetric Chart of the Southern Ocean (IBCSO) and so significantly improve the basis for ship navigation in the Pacific sector of the Southern Ocean. Undergraduate students will be involved in the research under supervision of the PI via the Lamont summer internship program. The PI is a young investigator and this will be his first NSF grant as a PI.", "east": -100.0, "geometry": "POINT(-120 -71.75)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES", "is_usap_dc": true, "keywords": "BATHYMETRY; SHIPS; Southern Ocean; Antarctica; Polar; GLACIERS/ICE SHEETS; R/V NBP", "locations": "Polar; Southern Ocean; Antarctica", "north": -68.0, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Nitsche, Frank O.", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repo": "MGDS", "repositories": "MGDS", "science_programs": null, "south": -75.5, "title": "Ice sheet Dynamics and Processes along the West Antarctic Continental Shelf", "uid": "p0010001", "west": -140.0}, {"awards": "1043750 Chen, Jianli", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "datasets": [{"dataset_uid": "600159", "doi": "10.15784/600159", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; GRACE; Potential Field; Satellite Data", "people": "Chen, Jianli", "repository": "USAP-DC", "science_program": null, "title": "Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "url": "https://www.usap-dc.org/view/dataset/600159"}], "date_created": "Fri, 13 May 2016 00:00:00 GMT", "description": "1043750/Chen\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e LASER RANGING \u003e GRACE LRR", "is_usap_dc": true, "keywords": "SATELLITES; GRACE; Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Chen, Jianli; Wilson, Clark; Blankenship, Donald D.; Tapley, Byron", "platforms": "Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e NASA EARTH SYSTEM SCIENCE PATHFINDER \u003e GRACE; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements", "uid": "p0000415", "west": -180.0}, {"awards": "1043454 Kooyman, Gerald", "bounds_geometry": "POLYGON((-172.642 -72.55,-170.9074 -72.55,-169.1728 -72.55,-167.4382 -72.55,-165.7036 -72.55,-163.969 -72.55,-162.2344 -72.55,-160.4998 -72.55,-158.7652 -72.55,-157.0306 -72.55,-155.296 -72.55,-155.296 -73.0743,-155.296 -73.5986,-155.296 -74.1229,-155.296 -74.6472,-155.296 -75.1715,-155.296 -75.6958,-155.296 -76.2201,-155.296 -76.7444,-155.296 -77.2687,-155.296 -77.793,-157.0306 -77.793,-158.7652 -77.793,-160.4998 -77.793,-162.2344 -77.793,-163.969 -77.793,-165.7036 -77.793,-167.4382 -77.793,-169.1728 -77.793,-170.9074 -77.793,-172.642 -77.793,-172.642 -77.2687,-172.642 -76.7444,-172.642 -76.2201,-172.642 -75.6958,-172.642 -75.1715,-172.642 -74.6472,-172.642 -74.1229,-172.642 -73.5986,-172.642 -73.0743,-172.642 -72.55))", "dataset_titles": "NBP1302 data; Pre and Post Molt Biology of Emperor Penguins - Oden Trans - Ross / Amundsen Sea Cruise", "datasets": [{"dataset_uid": "600149", "doi": "10.15784/600149", "keywords": "Amundsen Sea; Biota; Oceans; Penguin; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Kooyman, Gerald", "repository": "USAP-DC", "science_program": null, "title": "Pre and Post Molt Biology of Emperor Penguins - Oden Trans - Ross / Amundsen Sea Cruise", "url": "https://www.usap-dc.org/view/dataset/600149"}, {"dataset_uid": "000179", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP1302 data", "url": "https://www.rvdata.us/search/cruise/NBP1302"}], "date_created": "Sat, 12 Dec 2015 00:00:00 GMT", "description": "The emperor penguin dives deeper and longer, fasts longer, and endures the harshest weather conditions of all diving birds. It spends about four and half months per annum deep in Antarctic pack ice away from shore and stations, and thus is largely unavailable for study. This time includes preparation for the molt, and travel to the colony to breed, a time period in which great swings in body weight occur. This study will fill an important gap in what we know about the biology of the annual cycle of the emperor by examining the molt-post molt period. The P.I. proposes to traverse the Amundsen and Bellingshausen seas on the Oden, to locate and tag emperor penguins during the molt season. The objectives are to (1) Place satellite tags on 20 adult post molt birds to determine their route, rate of travel, and diving behavior as they return back to their breeding colonies, (2) Obtain an index of body condition, (3) Collect guano to determine the type of food consumed by emperor penguins in the region, (4) Conduct shipboard surveys to sight and plot the location and abundance of adult and juvenile birds on the ship\u0027s track. The PI hypothesizes that bird dives will be shallow during the initial post-molt phase, and that food will consist primarily of krill; that there will be differential dispersal of birds from the Ross Sea vs. Marie Byrd Land, with Ross Sea birds traveling farther; and that the greatest adult mortality occurs during the molt and early post molt period. Broader impacts include training of a post doc, a graduate student, and an aquarium volunteer. The P.I. also will present findings through a website, through public lectures, and in collaboration with the Birch aquarium.", "east": -155.296, "geometry": "POINT(-163.969 -75.1715)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e FLUOROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e PROFILERS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e XBT; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ECHO SOUNDERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MBES; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e THERMOSALINOGRAPHS", "is_usap_dc": true, "keywords": "R/V NBP; Not provided", "locations": null, "north": -72.55, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Kooyman, Gerald", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "USAP-DC", "repositories": "R2R; USAP-DC", "science_programs": null, "south": -77.793, "title": "Pre and post molt biology of emperor penguins - Oden trans - Ross / Amundsen Sea cruise", "uid": "p0000325", "west": -172.642}, {"awards": "1042883 Mayewski, Paul", "bounds_geometry": null, "dataset_titles": "LA-ICP-MS Results: 3 Siple Dome A Glacial Age Archives; Roosevelt Island Climate Evolution Ice Core ICP-MS data", "datasets": [{"dataset_uid": "609636", "doi": "10.7265/N5WS8R6H", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Haines, Skylar; Kurbatov, Andrei V.; Mayewski, Paul A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "LA-ICP-MS Results: 3 Siple Dome A Glacial Age Archives", "url": "https://www.usap-dc.org/view/dataset/609636"}, {"dataset_uid": "609621", "doi": "10.7265/N52J68SQ", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; ICP-MS; Roosevelt Island; Ross Ice Shelf", "people": "Beers, Thomas M.; Mayewski, Paul A.; Kurbatov, Andrei V.", "repository": "USAP-DC", "science_program": null, "title": "Roosevelt Island Climate Evolution Ice Core ICP-MS data", "url": "https://www.usap-dc.org/view/dataset/609621"}], "date_created": "Tue, 27 Oct 2015 00:00:00 GMT", "description": "1042883/Mayewski\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to analyze a deep ice core which will be drilled by a New Zealand research team at Roosevelt Island. The objectives are to process the ice core at very high resolution to (a) better understand phasing sequences in Arctic/Antarctic abrupt climate change, even at the level of individual storm events; (b) determine the impact of changes in the Westerlies and the Amundsen Sea Low on past/present/future climate change; (c) determine how sea ice extent has varied in the area; (d) compare the response of West Antarctica climate to other regions during glacial/interglacial cycles; and (e) determine how climate of the Ross Sea Embayment changed during the transition from Ross Ice Sheet to Ross Ice Shelf. The intellectual merit of the RICE deep ice core project is that it is expected to provide a 30kyr long (and possibly 150kyr long) extremely high-resolution view of climate change in the Ross Sea Embayment Region and data essential to test and understand critical questions that have emerged as a consequence of the recent synthesis of Antarctic and Southern Ocean climate change presented in the Scientific Commission for Antarctic Research document: Antarctic Climate Change and the Environment (ACCE, 2009). Ice core processing and analysis will be performed jointly by University of Maine and the collaborators from New Zealand. Co-registered sampling for all chemical analyses will be accomplished by a joint laboratory effort at the IGNS NZ ice core facility using a continuous melter system developed by the University of Maine. The RICE deep ice core record will provide information necessary in unraveling the significance of multi-millennial underpinning for climate change and in the understanding of observed and projected climate change in light of current dramatic human impact on Antarctica and the Southern Ocean. The broader impacts of the project include the fact that two CCI graduate students will be funded through the project, and will be involved in all aspects of field research, core sampling, sample processing, analytical and numerical analyses, data interpretation, writing of manuscripts, and presentation of results at national and international conferences. Data and ideas developed in this project and associated work will be used in several courses taught at the University of Maine. Innovative cyberinfrastructure will be incorporated into this work and ground breaking analytical technologies, and data access/storage tools will be used.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e LA-ICP-MS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e ICP-MS", "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Haines, Skylar; Kurbatov, Andrei V.; Mayewski, Paul A.; Beers, Thomas M.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Roosevelt Island Climate Evolution Project (RICE): US Deep Ice Core Glaciochemistry Contribution (2011- 2014)", "uid": "p0000193", "west": null}, {"awards": "0632282 Jacobs, Stanley", "bounds_geometry": "POLYGON((-129.6 -54.2,-124.44 -54.2,-119.28 -54.2,-114.12 -54.2,-108.96 -54.2,-103.8 -54.2,-98.64 -54.2,-93.48 -54.2,-88.32 -54.2,-83.16 -54.2,-78 -54.2,-78 -56.29,-78 -58.38,-78 -60.47,-78 -62.56,-78 -64.65,-78 -66.74,-78 -68.83,-78 -70.92,-78 -73.01,-78 -75.1,-83.16 -75.1,-88.32 -75.1,-93.48 -75.1,-98.64 -75.1,-103.8 -75.1,-108.96 -75.1,-114.12 -75.1,-119.28 -75.1,-124.44 -75.1,-129.6 -75.1,-129.6 -73.01,-129.6 -70.92,-129.6 -68.83,-129.6 -66.74,-129.6 -64.65,-129.6 -62.56,-129.6 -60.47,-129.6 -58.38,-129.6 -56.29,-129.6 -54.2))", "dataset_titles": "Amundsen Sea Continental Shelf Mooring Data (2006-2007); Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901; NBP07-09 cruise data; NBP07-09 processed CTD data; NBP09-01 cruise data; NBP09-01 processed CTD data; Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "datasets": [{"dataset_uid": "000128", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP07-09 processed CTD data", "url": "http://accession.nodc.noaa.gov/0120761"}, {"dataset_uid": "601350", "doi": null, "keywords": "Amundsen Sea; Antarctic; Antarctica; CTD; CTD Data; Current Measurements; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; Pine Island Glacier; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Huber, Bruce; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Processed Temperature, Salinity, and Current Measurement Data from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601350"}, {"dataset_uid": "000127", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP07-09 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0709"}, {"dataset_uid": "000130", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "NBP09-01 processed CTD data", "url": "http://accession.nodc.noaa.gov/0071179"}, {"dataset_uid": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Giulivi, Claudia F.; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}, {"dataset_uid": "000129", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "NBP09-01 cruise data", "url": "https://www.rvdata.us/search/cruise/NBP0901"}, {"dataset_uid": "601349", "doi": null, "keywords": "Amundsen Sea; Antarctica; Current Measurements; LADCP; NBP0901; Oceans; Physical Oceanography; Pine Island Bay; R/v Nathaniel B. Palmer; Southern Ocean", "people": "Thurnherr, Andreas", "repository": "USAP-DC", "science_program": null, "title": "Calibrated Hydrographic Data acquired with a LADCP from the Amundsen Sea acquired during the Nathaniel B. Palmer expedition NBP0901", "url": "https://www.usap-dc.org/view/dataset/601349"}], "date_created": "Fri, 25 Sep 2015 00:00:00 GMT", "description": "The Office of Polar Programs, Antarctic Science Division, Ocean \u0026 Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. \u003cbr/\u003eThe region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. \u003cbr/\u003eBroader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house.", "east": -78.0, "geometry": "POINT(-103.8 -64.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": true, "keywords": "Not provided; R/V NBP", "locations": null, "north": -54.2, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian", "platforms": "Not provided; WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "NCEI", "repositories": "NCEI; R2R; USAP-DC", "science_programs": null, "south": -75.1, "title": "Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise - IPY/ASEP", "uid": "p0000332", "west": -129.6}, {"awards": "0944727 Arrigo, Kevin", "bounds_geometry": "POLYGON((-118.3 -71.6,-117.57 -71.6,-116.84 -71.6,-116.11 -71.6,-115.38 -71.6,-114.65 -71.6,-113.92 -71.6,-113.19 -71.6,-112.46 -71.6,-111.73 -71.6,-111 -71.6,-111 -71.86,-111 -72.12,-111 -72.38,-111 -72.64,-111 -72.9,-111 -73.16,-111 -73.42,-111 -73.68,-111 -73.94,-111 -74.2,-111.73 -74.2,-112.46 -74.2,-113.19 -74.2,-113.92 -74.2,-114.65 -74.2,-115.38 -74.2,-116.11 -74.2,-116.84 -74.2,-117.57 -74.2,-118.3 -74.2,-118.3 -73.94,-118.3 -73.68,-118.3 -73.42,-118.3 -73.16,-118.3 -72.9,-118.3 -72.64,-118.3 -72.38,-118.3 -72.12,-118.3 -71.86,-118.3 -71.6))", "dataset_titles": "Dataset: Chlorophyll a", "datasets": [{"dataset_uid": "000172", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Dataset: Chlorophyll a", "url": "http://www.bco-dmo.org/dataset/546372"}], "date_created": "Fri, 30 Jan 2015 00:00:00 GMT", "description": "ASPIRE is an NSF-funded project that will examine the ecology of the Amundsen Sea during the Austral summer of 2010. ASPIRE includes an international team of trace metal and carbon chemists, phytoplankton physiologists, microbial and zooplankton ecologists, and physical oceanographers, that will investigate why and how the Amundsen Sea Polynya is so much more productive than other polynyas and whether interannual variability can provide insight to climate-sensitive mechanisms driving carbon fluxes. This project will compliment the existing ASPIRE effort by using 1) experimental manipulations to understand photoacclimation of the dominant phytoplankton taxa under conditions of varying light and trace metal abundance, 2) nutrient addition bioassays to determine the importance of trace metal versus nitrogen limitation of phytoplankton growth, and 3) a numerical ecosystem model to understand the importance of differences in mixing regime, flow field, and Fe sources in controlling phytoplankton bloom dynamics and community composition in this unusually productive polynya system. The research strategy will integrate satellite remote sensing, field-based experimental manipulations, and numerical modeling. Outreach and education include participation in Stanford\u0027s Summer Program for Professional Development for Science Teachers, Stanford\u0027s School of Earth Sciences high school internship program, and development of curriculum for local science training centers, including the Chabot Space and Science Center. Undergraduate participation and training will include support for both graduate students and undergraduate assistants.", "east": -111.0, "geometry": "POINT(-114.65 -72.9)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -71.6, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Arrigo, Kevin", "platforms": "Not provided", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": -74.2, "title": "ASPIRE: Amundsen Sea Polynya International Research Expedition", "uid": "p0000348", "west": -118.3}, {"awards": "0732906 Nowicki, Sophie; 0732730 Truffer, Martin; 0732869 Holland, David; 0732804 McPhee, Miles", "bounds_geometry": "POINT(-100.728 -75.0427)", "dataset_titles": "Automatic Weather Station Pine Island Glacier; Borehole Temperatures at Pine Island Glacier, Antarctica; Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "datasets": [{"dataset_uid": "600072", "doi": "10.15784/600072", "keywords": "Antarctica; Atmosphere; McMurdo; Meteorology; Oceans; Ross Island; Southern Ocean", "people": "McPhee, Miles G.", "repository": "USAP-DC", "science_program": null, "title": "Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica", "url": "https://www.usap-dc.org/view/dataset/600072"}, {"dataset_uid": "601216", "doi": "10.15784/601216", "keywords": "Antarctica; Atmosphere; Automated Weather Station; Flux; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Meteorology; Pine Island Glacier; Weather Station Data", "people": "Mojica Moncada, Jhon F.; Holland, David", "repository": "USAP-DC", "science_program": "Thwaites (ITGC)", "title": "Automatic Weather Station Pine Island Glacier", "url": "https://www.usap-dc.org/view/dataset/601216"}, {"dataset_uid": "609627", "doi": "10.7265/N5T151MV", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Pine Island Glacier; Temperature", "people": "Truffer, Martin; Stanton, Timothy", "repository": "USAP-DC", "science_program": null, "title": "Borehole Temperatures at Pine Island Glacier, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609627"}], "date_created": "Tue, 30 Dec 2014 00:00:00 GMT", "description": "Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 \u003cbr/\u003eTitle: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica\u003cbr/\u003e\u003cbr/\u003eThe Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. \u003cbr/\u003e\u003cbr/\u003eBroader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the \"Multidisciplinary Study of the Amundsen Sea Embayment\" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded \"Polar Palooza\" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project.", "east": -100.728, "geometry": "POINT(-100.728 -75.0427)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": true, "keywords": "West Antarctica; Seismic; LABORATORY; Amundsen Sea; Ocean-Ice Interaction; Remote Sensing; COMPUTERS; FIELD SURVEYS; LANDSAT-8; FIELD INVESTIGATION; Ocean Profiling; AUVS; Sea Level Rise; Stability; Not provided; Deformation; SATELLITES; Ice Movement; GROUND-BASED OBSERVATIONS; Ice Temperature; International Polar Year; Borehole", "locations": "West Antarctica; Amundsen Sea", "north": -75.0427, "nsf_funding_programs": "Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science; Antarctic Integrated System Science", "paleo_time": null, "persons": "Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-8; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES; WATER-BASED PLATFORMS \u003e UNCREWED VEHICLES \u003e SUBSURFACE \u003e AUVS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -75.0427, "title": "Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica", "uid": "p0000043", "west": -100.728}, {"awards": "0087345 Conway, Howard", "bounds_geometry": "POINT(112 79)", "dataset_titles": null, "datasets": null, "date_created": "Fri, 15 Aug 2014 00:00:00 GMT", "description": "This award supports a program of ground-based geophysical measurements to map in detail the spatial variations of ice flow, accumulation rate, internal layering and ice thickness at the sites which have been identified as promising locations to drill the next deep ice core in West Antarctica. The main investigative tools are a high- and low-frequency ice penetrating radar to image the topography of internal layers and the bed, repeat GPS surveys to calculate the present day surface velocity field, synthetic aperture radar (SAR) interferometry to calculate the regional velocity field, and short firn cores to calculate present day accumulation rates. The data which will be collected will be used to as input to time-dependent ice flow and temperature models that will predict depth variation of age, layer thickness, and temperature. As well as yielding an estimate of expected conditions before drilling, the mismatch between the model prediction and data eventually recovered from the core will help infer thinning and climate (accumulation and temperature) histories for the region. The Western Divide, between the Ross Sea Embayment and the Amundsen Sea, has been identified as the region which best satisfies the criteria which have been established for a deep drilling site. Preliminary site selection using airborne geophysical methods has identified several potential drill sites on the Western Divide where the climate record should be best preserved. This work will contribute in a major way to the final site selection for the next deep ice core in West Antarctica.", "east": -112.0, "geometry": "POINT(-112 -79)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": false, "keywords": "FIELD SURVEYS; Internal Layering; Radar; Accumulation Rate; FIELD INVESTIGATION; LABORATORY; Not provided; Internal Layers; Antarctica; Ice Flow; Interferometry; Ice Thickness", "locations": "Antarctica", "north": -79.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Waddington, Edwin D.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.0, "title": "Collaborative Research: Western Divide West Antarctic Ice Cores (WAISCORES) Site Selection", "uid": "p0000557", "west": -112.0}, {"awards": "0632198 Anandakrishnan, Sridhar", "bounds_geometry": "POINT(110 -74)", "dataset_titles": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Dupont, Todd K.; Holt, John W.; Parizek, Byron R.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}], "date_created": "Wed, 29 Aug 2012 00:00:00 GMT", "description": "This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this \"pulse of activity\" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands.", "east": -110.0, "geometry": "POINT(-110 -74)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e SEISMIC REFLECTION PROFILERS", "is_usap_dc": false, "keywords": "Pine Island Glacier; Bed Reflectivity; Tidal Forcing; FIELD INVESTIGATION; Not provided; Position; Thwaites; Thickness; Amundsen Sea; LABORATORY; FIELD SURVEYS; Subglacial; Ice Dynamic; Ice Sheet Modeling", "locations": "Thwaites; Pine Island Glacier; Amundsen Sea", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anandakrishnan, Sridhar", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -74.0, "title": "IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.", "uid": "p0000699", "west": -110.0}, {"awards": "0739654 Catania, Ginny; 0739372 Conway, Howard", "bounds_geometry": null, "dataset_titles": "Coastal and Terminus History of the Eastern Amundsen Sea Embayment, West Antarctica, 1972 - 2011; Ice Flow History of the Thwaites Glacier, West Antarctica", "datasets": [{"dataset_uid": "609463", "doi": "10.7265/N5RR1W6X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Flow Lines; Thwaites Glacier", "people": "Fudge, T. J.; Conway, Howard; Catania, Ginny", "repository": "USAP-DC", "science_program": null, "title": "Ice Flow History of the Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609463"}, {"dataset_uid": "609522", "doi": "10.7265/N5CC0XNK", "keywords": "Amundsen Sea; Antarctica; Climate Change; Coastline; GIS Data; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Satellite Data Interpretation", "people": "Macgregor, Joseph A.; Catania, Ginny; Markowski, Michael; Andrews, Alan G.", "repository": "USAP-DC", "science_program": null, "title": "Coastal and Terminus History of the Eastern Amundsen Sea Embayment, West Antarctica, 1972 - 2011", "url": "https://www.usap-dc.org/view/dataset/609522"}], "date_created": "Wed, 30 May 2012 00:00:00 GMT", "description": "Catania 0739654\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to study the Amundsen Sea drainage system and improve understanding of the impact of recent glaciological changes as an aid to predicting how this region will change in the future. The intellectual merit of the work is that the Amundsen Sea drainage system has been a recent focus for glaciological research because of rapid changes occurring there as a result of grounding line retreat. The work will focus on the regions of flow transition and will map the internal stratigraphy of the ice sheet across the Thwaites Glacier shear margins and use the age and geometry of radar-detected internal layers to interpret ice flow history. Thwaites Glacier (one of the main pathways for ice drainage in the region) has recently widened and may continue to do so in the near future. Thwaites Glacier may be particularly vulnerable to grounding line retreat because it lacks a well-defined subglacial channel. The subglacial environment exerts strong control on ice flow and flow history will be mapped in the context of bed topography and bed reflectivity. The plan is to use existing ice-penetrating radar data and coordinate with planned upcoming surveys to reduce logistical costs. The work proposed here will take three years to complete but no additional fieldwork in Antarctica is required. More detailed ground-based geophysical (radar and seismic) experiments will be needed at key locations to achieve our overall goal and the work proposed here will aid in identifying those regions. The broader impacts of the project are that it will initiate a new collaboration among radar communities within the US including those that are on the forefront of radar systems engineering and those that are actively involved in radar-derived internal layer and bed analysis. The project will also provide support for a postdoctoral researcher and a graduate student, thus giving them exposure to a variety of methodologies and scientific issues. Finally, there are plans to further develop the \"Wired Antarctica\" website designed by Ginny Catania with the help of a student-teacher. This will allow for the existing lesson plans to be updated to Texas State standards so that they can be used more broadly within state middle and high schools.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e TM; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR", "is_usap_dc": true, "keywords": "ERS-1; Coastal; Terminus; LABORATORY; Subglacial; Glacier; Not provided; Thwaites Glacier; Antarctica; LANDSAT; Internal Stratigraphy; West Antarctica; Internal Layers; Amundsen Sea; FIELD INVESTIGATION; FIELD SURVEYS; Glaciers; LANDSAT-5; Radar; Seismic", "locations": "Coastal; Antarctica; Thwaites Glacier; Amundsen Sea; West Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Conway, Howard; Catania, Ginny; Markowski, Michael; Macgregor, Joseph A.; Andrews, Alan G.; Fudge, T. J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e EUROPEAN REMOTE SENSING SATELLITE (ERS) \u003e ERS-1; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e LANDSAT \u003e LANDSAT-5", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica", "uid": "p0000143", "west": null}, {"awards": "0758274 Parizek, Byron; 0636724 Blankenship, Donald", "bounds_geometry": "POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548))", "dataset_titles": "Access to data; AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica; Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica; ICECAP Basal Interface Specularity Content Profiles: IPY and OIB; Subglacial water flow paths under Thwaites Glacier, West Antarctica; Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "datasets": [{"dataset_uid": "002536", "doi": "", "keywords": null, "people": null, "repository": "NASA", "science_program": null, "title": "Access to data", "url": "http://www.giss.nasa.gov/tools/panoply/"}, {"dataset_uid": "601371", "doi": "10.15784/601371", "keywords": "Antarctica; East Antarctica; ICECAP; Ice Penetrating Radar; Radar Echo Sounder; Radar Echo Sounding; Subglacial Hydrology", "people": "Young, Duncan A.; Schroeder, Dustin; Greenbaum, Jamin; Blankenship, Donald D.; van Ommen, Tas; Siegert, Martin; Roberts, Jason", "repository": "USAP-DC", "science_program": null, "title": "ICECAP Basal Interface Specularity Content Profiles: IPY and OIB", "url": "https://www.usap-dc.org/view/dataset/601371"}, {"dataset_uid": "609334", "doi": "10.7265/N5HD7SK8", "keywords": "AGASEA; Airborne Altimetry; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Blankenship, Donald D.; Holt, John W.; Morse, David L.; Young, Duncan A.; Kempf, Scott D.", "repository": "USAP-DC", "science_program": null, "title": "Airborne Laser Altimetry of the Thwaites Glacier Catchment, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609334"}, {"dataset_uid": "609619", "doi": "10.7265/N58913TN", "keywords": "Amundsen Sea; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet Model; Thwaites Glacier", "people": "Dupont, Todd K.; Holt, John W.; Parizek, Byron R.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "url": "https://www.usap-dc.org/view/dataset/609619"}, {"dataset_uid": "000248", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access to data", "url": "http://nsidc.org/data/netcdf/tools.html"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Jackson, Charles; Blankenship, Donald D.; Muldoon, Gail R.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}, {"dataset_uid": "609518", "doi": "10.7265/N5RJ4GC8", "keywords": "AGASEA; Airborne Radar; Antarctica; Elevation; Flow Paths; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Thwaites Glacier", "people": "Carter, Sasha P.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial water flow paths under Thwaites Glacier, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609518"}, {"dataset_uid": "609517", "doi": "10.7265/N5W95730", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Thickness", "people": "Holt, John W.; Kempf, Scott D.; Young, Duncan A.; Blankenship, Donald D.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA Ice Thickness Profile Data from the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609517"}], "date_created": "Tue, 15 May 2012 00:00:00 GMT", "description": "This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program\u0027s emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: \"investigation of the physics of fast glacier flow with emphasis on processes at glacier beds\"; \"investigation of ice-shelf stability\"; and \"identification and quantification of the feedback between ice dynamics and climate change\". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations.", "east": -105.2773, "geometry": "POINT(-107.66765 -75.34995)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e RADIO \u003e INS", "is_usap_dc": true, "keywords": "Ice Sheet Thickness; Ice Sheet Elevation; Glacier Dynamics; Ice Stream; Numerical Model; West Antarctic; Surface Elevation; Basal Rheology; Ice Surface Velocity; Embayment Geometry; Amundsen Sea; Hydrology; FIELD SURVEYS; Antarctic Ice Sheet; Glacier; Subglacial; DHC-6; West Antarctic Ice Sheet; Model Output; Surface Climate; Glaciers; Basal Topography; Grounding Zone; Model Input Data; Airborne Laser Altimeters; FIELD INVESTIGATION; Thwaites Glacier; Airborne Laser Altimetry; Diagnostic; Ice-Shelf Buttressing; Ice Sheet; Prognostic; Glacier Surface; Airborne Radar Sounding; Digital Elevation Model; Ice Dynamic; Antarctica; Altimetry; Antarctica (agasea); Bed Elevation; Basal Stress; LABORATORY", "locations": "Antarctica; Thwaites Glacier; West Antarctic Ice Sheet; Antarctic Ice Sheet; West Antarctic; Amundsen Sea", "north": -74.0548, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "NASA", "repositories": "NASA; NSIDC; USAP-DC", "science_programs": null, "south": -76.6451, "title": "Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System", "uid": "p0000174", "west": -110.058}, {"awards": "0440847 Raymond, Charles", "bounds_geometry": null, "dataset_titles": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica; Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "datasets": [{"dataset_uid": "609503", "doi": "10.7265/N5222RQ8", "keywords": "Antarctica; Geology/Geophysics - Other; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPS; Ice Flow Velocity; Ross-Amundsen Divide; Strain", "people": "Matsuoka, Kenichi; Power, Donovan; Rasmussen, Al", "repository": "USAP-DC", "science_program": null, "title": "GPS-Measured Ice Velocities and Strain Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609503"}, {"dataset_uid": "609496", "doi": "10.7265/N5TH8JNG", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; GPR; Radar; Ross-Amundsen Divide", "people": "Raymond, Charles; Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji", "repository": "USAP-DC", "science_program": null, "title": "Polarimetric Radar Data from the Ross and Amundsen Sea Ice Flow Divide, West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609496"}], "date_created": "Mon, 29 Aug 2011 00:00:00 GMT", "description": "This award supports a project to investigate fabrics with ground-based radar measurements near the Ross/Amundsen Sea ice-flow divide where a deep ice core will be drilled. The alignment of crystals in ice (crystal-orientation fabric) has an important effect on ice deformation. As ice deforms, anisotropic fabrics are produced, which, in turn, influence further deformation. Measurement of ice fabric variations can help reveal the deformation history of the ice and indicate how the ice will deform in the future. Ice cores provide opportunities to determine a vertical fabric profile, but horizontal variations of fabrics remain unknown. Remote sensing with ice-penetrating radar is the only way to do that over large areas. Preliminary results show that well-established polarimetric methods can detect the degree of horizontal anisotropy of fabrics and their orientation, even when they are nearly vertical-symmetric fabrics. In conjunction with ice deformation history, our first mapping of ice fabrics will contribute to modeling ice flow near the future ice core site. The project will train a graduate student and provide research experiences for two under graduate students both in field and laboratory. The project will contribute to ongoing West Antarctic ice sheet program efforts to better understand the impact of the ice sheet on global sea level rise. This project also supports an international collaboration between US and Japanese scientists.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": true, "keywords": "GPS; FIELD SURVEYS; Antarctic; Radar; Antarctica; FIELD INVESTIGATION; Ice Sheet; Not provided; Ross-Amundsen Divide; West Antarctica; West Antarctic Ice Sheet", "locations": "Antarctica; Ross-Amundsen Divide; West Antarctica; Antarctic; West Antarctic Ice Sheet", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji; Raymond, Charles; Rasmussen, Al", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods", "uid": "p0000024", "west": null}, {"awards": "0836112 Smith, Walker; 0836144 Yager, Patricia; 0836061 Dennett, Mark", "bounds_geometry": "POLYGON((100 -69,107 -69,114 -69,121 -69,128 -69,135 -69,142 -69,149 -69,156 -69,163 -69,170 -69,170 -70,170 -71,170 -72,170 -73,170 -74,170 -75,170 -76,170 -77,170 -78,170 -79,163 -79,156 -79,149 -79,142 -79,135 -79,128 -79,121 -79,114 -79,107 -79,100 -79,100 -78,100 -77,100 -76,100 -75,100 -74,100 -73,100 -72,100 -71,100 -70,100 -69))", "dataset_titles": "Amundsen Sea Polynya International Research Expedition (ASPIRE) data; Controls on Climate-Active Gases by Amundsen Sea Ice Biota", "datasets": [{"dataset_uid": "600091", "doi": "10.15784/600091", "keywords": "Amundsen Sea; Antarctica; Biota; Oceans; Oden; Oden2008; Plankton; Sea Ice; Southern Ocean", "people": "Dennett, Mark", "repository": "USAP-DC", "science_program": null, "title": "Controls on Climate-Active Gases by Amundsen Sea Ice Biota", "url": "https://www.usap-dc.org/view/dataset/600091"}, {"dataset_uid": "600092", "doi": "10.15784/600092", "keywords": "Amundsen Sea; Antarctica; Chemistry:fluid; Chemistry:Fluid; CTD Data; Oceans; Oden; Oden2008; Sea Ice; Sea Surface; Southern Ocean", "people": "Smith, Walker", "repository": "USAP-DC", "science_program": null, "title": "Controls on Climate-Active Gases by Amundsen Sea Ice Biota", "url": "https://www.usap-dc.org/view/dataset/600092"}, {"dataset_uid": "000146", "doi": "", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Amundsen Sea Polynya International Research Expedition (ASPIRE) data", "url": "https://www.bco-dmo.org/project/2132"}], "date_created": "Sun, 24 Apr 2011 00:00:00 GMT", "description": "Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher.", "east": 170.0, "geometry": "POINT(135 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -69.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker; Yager, Patricia; Dennett, Mark", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "BCO-DMO; USAP-DC", "science_programs": null, "south": -79.0, "title": "Collaborative Research: Controls on climate-active gases by Amundsen Sea ice biota", "uid": "p0000137", "west": 100.0}, {"awards": "0839069 Yager, Patricia", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP1005", "datasets": [{"dataset_uid": "002654", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP1005", "url": "https://www.rvdata.us/search/cruise/NBP1005"}], "date_created": "Thu, 03 Mar 2011 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThe Amundsen Sea Polynya is areally the most productive Antarctic polynya, exhibits higher chlorophyll levels during peak bloom and greater interannual variability than the better-studied Ross Sea Polynya ecosystem. Polynyas may be the key to understanding the future of polar regions as their extent is expected to increase with anthropogenic warming. The project will examine 1) sources of iron to the Amundsen Sea Polynya as a function of climate forcing, 2) phytoplankton community structure in relation to iron supply and mixed-layer depths, 3) the efficiency of the biological pump of carbon to depth and 4) the net flux of carbon as a function of climate and micronutrient forcing. The research also will compare results for the Amundsen Sea to existing data synthesis and modeling efforts for the Palmer LTER and Ross Sea. The project will 1) build close scientific collaborations between US and Swedish researchers; 2) investigate climate change implications with broad societal relevance; 3) train new researchers; 4) encourage participation in research science by underrepresented groups, and 5) involve broad dissemination of results via scientific literature and public outreach, including close interactions with NSF-supported PolarTrec and COSEE K-12 teachers.", "east": null, "geometry": null, "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Yager, Patricia", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Collaborative research aboard Icebreaker Oden: ASPIRE (Amundsen Sea Polynya International Research Expedition)", "uid": "p0000844", "west": null}, {"awards": "0632325 Seals, Cheryl; 0632161 Johnson, Jesse; 0632168 Hulbe, Christina; 0632346 Tulaczyk, Slawek", "bounds_geometry": "POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05))", "dataset_titles": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields; Wiki containing the data and provenance.", "datasets": [{"dataset_uid": "609396", "doi": "10.7265/N5K64G1S", "keywords": "Antarctica; Community Ice Sheet Model; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Hulbe, Christina; Daescu, Dacian N.", "repository": "USAP-DC", "science_program": null, "title": "Singular Value Decomposition Analysis of Ice Sheet Model Output Fields", "url": "https://www.usap-dc.org/view/dataset/609396"}, {"dataset_uid": "001499", "doi": "", "keywords": null, "people": null, "repository": "PI website", "science_program": null, "title": "Wiki containing the data and provenance.", "url": "http://websrv.cs.umt.edu/isis/index.php/Present_Day_Antarctica"}], "date_created": "Fri, 02 Jul 2010 00:00:00 GMT", "description": "Johnson/0632161\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to create a \"Community Ice Sheet Model (CISM)\". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating \"a new generation\" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "MODELS; International Polar Year; Derived Basal Temperature Evolution; Ice Sheet; Community Ice Sheet Model; Ice Sheet Model; LABORATORY; Amundsen Sea; Eismint; Modeling; Basal Temperature; Numerical Model; Antarctic Ice Sheet; Environmental Modeling; IPY; Antarctica; Model; Not provided; Ice Dynamic", "locations": "Antarctic Ice Sheet; Antarctica; Amundsen Sea", "north": -50.05, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e PLEISTOCENE", "persons": "Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N.", "platforms": "Not provided; OTHER \u003e MODELS \u003e MODELS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "PI website; USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region", "uid": "p0000756", "west": -180.0}, {"awards": "0338151 Raymond, Charles", "bounds_geometry": "POINT(-112.086 -79.468)", "dataset_titles": "Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica; Surface Elevation and Ice Thickness, Western Marie Byrd Land, Antarctica", "datasets": [{"dataset_uid": "609119", "doi": "10.7265/N5BZ63ZH", "keywords": "Airborne Radar; Airplane; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Marie Byrd Land", "people": "Wilson, Douglas S.; Luyendyk, Bruce P.", "repository": "USAP-DC", "science_program": null, "title": "Surface Elevation and Ice Thickness, Western Marie Byrd Land, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609119"}, {"dataset_uid": "609470", "doi": "10.7265/N5416V0W", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar; WAIS Divide", "people": "Raymond, Charles; Matsuoka, Kenichi", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Englacial Layers and Attenuation Rates across the Ross and Amundsen Sea Ice-Flow Divide (WAIS Divide), West Antarctica", "url": "https://www.usap-dc.org/view/dataset/609470"}], "date_created": "Tue, 11 May 2010 00:00:00 GMT", "description": "This award supports an investigation of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. Besides geometry of reflection layers the focus will be on intensities of radar echoes from within ice deeper than several hundred meters and will also examine echoes from the bed. Preliminary studies on theory and comparison with Japanese radar data from East Antarctica suggest that large spatial variations of the vertical gradient of radar echoes from within ice exist and are caused primarily by ice temperature and secondarily by crystal-orientation fabric. The hypothesis that the vertical gradient is a proxy of ice temperature will be tested. The project will utilize an existing data set from the Support Office for Aerogeophysical Research in Antarctica (SOAR) and will complement work already underway at University of Texas to analyze the radar data. The project will provide undergraduate research experience with an emphasis on computer analysis of time series and large data sets as well as development of web-based resource of results and methods and will support an international collaboration between US and Japan through discussions on the preliminary results from their study sites. Practical procedures developed through this study will be downloadable from the project\u0027s web site in the third year and will allow investigation of other ice sheets using existing radar data sets. This project will contribute to the interpretation of the future inland West Antarctic ice core and will help in the understanding of ice sheet history and climate change.", "east": -112.086, "geometry": "POINT(-112.086 -79.468)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e LIDAR/LASER SOUNDERS \u003e LASERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR", "is_usap_dc": true, "keywords": "SOAR; Ice Sheet Elevation; Antarctic Ice Sheet; Layers; USAP-DC; West Antarctic; FIELD INVESTIGATION; Amundsen; Ice Sheet; Airborne Laser Altimetry; Ice Surface; Not provided; Ice Penetrating Radar; Ice Sheet Thickness; Ice Extent; Ice Surface Elevation; Ice Cover; Ice Deformation; FIELD SURVEYS; Antarctica; Ground Ice; Subglacial; Reflection Layers; West Antarctic Ice Sheet; Ice Surface Temperature; LABORATORY; Amundsen Flow Divide; Radar Echo Sounding; Internal Layering; Radar Altimetry; Ice; Radar Echoes; Englacial; Crystal Orientation Fabric; Ice Thickness; Altimetry; Ice Temperature; Radar Echo Sounder; Ice Thickness Distribution", "locations": "Antarctic Ice Sheet; Antarctica; West Antarctic; Amundsen; Amundsen Flow Divide; West Antarctic Ice Sheet", "north": -79.468, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Raymond, Charles; Matsuoka, Kenichi; Luyendyk, Bruce P.; Wilson, Douglas S.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.468, "title": "Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data", "uid": "p0000017", "west": -112.086}, {"awards": "0440775 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Amundsen Sea Continental Shelf Mooring Data (2006-2007); Expedition data of NBP0702; NBP0702 surface sediment sample information and images", "datasets": [{"dataset_uid": "002645", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0702", "url": "https://www.rvdata.us/search/cruise/NBP0702"}, {"dataset_uid": "601473", "doi": "10.15784/601473", "keywords": "Amundsen Sea; Antarctica; Marine Geoscience; Marine Sediments; NBP0702; Photo; R/v Nathaniel B. Palmer; Seafloor Sampling; Sediment Description; Smith-Mcintyre Grab", "people": "Jacobs, Stanley; Leventer, Amy", "repository": "USAP-DC", "science_program": null, "title": "NBP0702 surface sediment sample information and images", "url": "https://www.usap-dc.org/view/dataset/601473"}, {"dataset_uid": "601809", "doi": "10.15784/601809", "keywords": "Amundsen Sea; Antarctica; Cryosphere; Mooring; Ocean Currents; Pressure; Salinity; Temperature", "people": "Giulivi, Claudia F.; Jacobs, Stanley", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Continental Shelf Mooring Data (2006-2007)", "url": "https://www.usap-dc.org/view/dataset/601809"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "AMD; Amd/Us; R/V NBP; NSF/USA; Amundsen Sea; USAP-DC", "locations": "Amundsen Sea", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "The Amundsen Continental Shelf and the Antarctic Ice Sheet", "uid": "p0000836", "west": null}, {"awards": "9815961 Bengtson, John", "bounds_geometry": "POLYGON((-179.99905 -43.56728,-143.99915 -43.56728,-107.99925 -43.56728,-71.99935 -43.56728,-35.99945 -43.56728,0.000450000000001 -43.56728,36.00035 -43.56728,72.00025 -43.56728,108.00015 -43.56728,144.00005 -43.56728,179.99995 -43.56728,179.99995 -47.058498,179.99995 -50.549716,179.99995 -54.040934,179.99995 -57.532152,179.99995 -61.02337,179.99995 -64.514588,179.99995 -68.005806,179.99995 -71.497024,179.99995 -74.988242,179.99995 -78.47946,144.00005 -78.47946,108.00015 -78.47946,72.00025 -78.47946,36.00035 -78.47946,0.000450000000001 -78.47946,-35.99945 -78.47946,-71.99935 -78.47946,-107.99925 -78.47946,-143.99915 -78.47946,-179.99905 -78.47946,-179.99905 -74.988242,-179.99905 -71.497024,-179.99905 -68.005806,-179.99905 -64.514588,-179.99905 -61.02337,-179.99905 -57.532152,-179.99905 -54.040934,-179.99905 -50.549716,-179.99905 -47.058498,-179.99905 -43.56728))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001997", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9909"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "9815961 \u003cbr/\u003eBENGTSON\u003cbr/\u003eThe pack ice region surrounding Antarctica contains at least fifty percent of the world\u0027s population of seals, comprising about eighty percent of the world\u0027s total pinniped biomass. As a group, these seals are among the dominant top predators in Southern Ocean ecosystems, and the fluctuation in their abundance, growth patterns, life histories, and behavior provide a potential source of information about environmental variability integrated over a wide range of spatial and temporal scales. This proposal was developed as part of the international Antarctic Pack Ice Seals (APIS) program, which is aimed to better understand the ecological relationships between the distribution of pack ice seals and their environment. During January-February, 2000, a research cruise through the pack ice zone of the eastern Ross Sea and western Amundsen Sea will be conducted to survey and sample along six transects perpendicular to the continental shelf. Each of these transects will pass through five environmental sampling strata: continental shelf zone, Antarctic slope front, pelagic zone, the ice edge front, and the open water outside the pack ice zone. All zones but open water will be ice-covered to some degree. Surveys along each transect will gather data on bathymetry, hydrography, sea ice dynamics and characteristics, phytoplankton and ice algae stocks, prey species (e.g., fish, cephalopods and euphausiids), and seal distribution, abundance and diet. This physical and trophic approach to investigating ecological interactions among pack ice seals, prey and the physical environment will allow the interdisciplinary research team to test the hypothesis that there are measurable physical and biological features in the Southern Ocean that result in area of high biological activity by upper trophic level predators. Better insight into the interplay among pack ice seals and biological and physical features of Antarctic marine ecosystems will allow for a better prediction of fluctuation in seal population in the context of environmental change.", "east": 179.99995, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -43.56728, "nsf_funding_programs": null, "paleo_time": null, "persons": "Bengtson, John", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.47946, "title": "Antarctic Pack Ice Seals: Ecological Interactions with Prey and the Environment", "uid": "p0000614", "west": -179.99905}, {"awards": "0538516 Ackley, Stephen", "bounds_geometry": null, "dataset_titles": "Expedition data of NBP0709", "datasets": [{"dataset_uid": "002648", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0709", "url": "https://www.rvdata.us/search/cruise/NBP0709"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project is a study of the evolution of the sea ice cover, and the mass balance of ice in the Amundsen Sea and the Bellingshausen Sea in the internationally collaborative context of the International Polar Year (2007-2008). In its simplest terms, the mass balance is the net freezing and melting that occurs over an annual cycle at a given location. If the ice were stationary and were completely to melt every year, the mass balance would be zero. While non-zero balances have significance in questions of climate and environmental change, the process itself has global consequences since the seasonal freeze-melt cycle has the effect of distilling the surface water. Oceanic salt is concentrated into brine and rejected from the ice into deeper layers in the freezing process, while during melt, the newly released and relatively fresh water stabilizes the surface layers. The observation program will be carried out during a drift program of the Nathaniel B. Palmer, and through a buoy network established on the sea ice that will make year-long measurements of ice thickness, and temperature profile, large-scale deformation, and other characteristics. The project is a component of the Antarctic Sea Ice Program, endorsed internationally by the Joint Committee for IPY. Additionally, the buoys to be deployed have been endorsed as an IPY contribution to the World Climate Research Program/Scientific Committee on Antarctic Research (WCRP/SCAR) International Programme on Antarctic Buoys (IPAB). While prior survey information has been obtained in this region, seasonal and time-series measurements on sea ice mass balance are crucial data in interpreting the mechanisms of air-ice-ocean interaction. \u003cbr/\u003e The network will consist of an array of twelve buoys capable of GPS positioning. Three buoys will be equipped with thermister strings and ice and snow thickness measurement gauges, as well as a barometer. Two buoys will be equipped with meteorological sensors including wind speed and direction, atmospheric pressure, and incoming radiation. Seven additional buoys will have GPS positioning only, and will be deployed approximately 100 km from the central site. These outer buoys will be critical in capturing high frequency motion complementary to satellite-derived ice motion products. Additional buoys have been committed internationally through IPAB and will be deployed in the region as part of this program.\u003cbr/\u003e This project will complement similar projects to be carried out in the Weddell Sea by the German Antarctic Program, and around East Antarctica by the Australian Antarctic Program. The combined buoy and satellite deformation measurements, together with the mass balance measurements, will provide a comprehensive annual data set on sea ice thermodynamics and dynamics for comparison with both coupled and high-resolution sea ice models.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e PRESSURE SENSORS; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e TURBIDITY METERS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Ackley, Stephen", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": null, "title": "Sea Ice Mass Balance in the Antarctic-SIMBA Drift Station", "uid": "p0000839", "west": null}, {"awards": "9725024 Jacobs, Stanley", "bounds_geometry": null, "dataset_titles": "Expedition Data; Expedition data of NBP0001; Expedition data of NBP0008; Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "datasets": [{"dataset_uid": "002598", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0001", "url": "https://www.rvdata.us/search/cruise/NBP0001"}, {"dataset_uid": "601161", "doi": "10.15784/601161 ", "keywords": "Antarctica; CTD; CTD Data; Mertz Polynya; NBP0008; Oceans; Oxygen; Physical Oceanography; R/v Nathaniel B. Palmer; Salinity; Southern Ocean; Temperature", "people": "Mortlock, R. A.; Smethie, William M; Jacobs, Stanley; Mele, Phil", "repository": "USAP-DC", "science_program": null, "title": "Summer Oceanographic Measurements near the Mertz Polynya NBP0008", "url": "https://www.usap-dc.org/view/dataset/601161"}, {"dataset_uid": "002599", "doi": null, "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition data of NBP0008", "url": "https://www.rvdata.us/search/cruise/NBP0008"}, {"dataset_uid": "001885", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0008"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. ***", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R; USAP-DC", "science_programs": null, "south": null, "title": "Circumpolar Deep Water and the West Antarctic Ice Sheet", "uid": "p0000815", "west": null}, {"awards": "9814692 Kellogg, Thomas", "bounds_geometry": "POLYGON((-179.99342 -58.74225,-143.994734 -58.74225,-107.996048 -58.74225,-71.997362 -58.74225,-35.998676 -58.74225,0.000010000000003 -58.74225,35.998696 -58.74225,71.997382 -58.74225,107.996068 -58.74225,143.994754 -58.74225,179.99344 -58.74225,179.99344 -60.716231,179.99344 -62.690212,179.99344 -64.664193,179.99344 -66.638174,179.99344 -68.612155,179.99344 -70.586136,179.99344 -72.560117,179.99344 -74.534098,179.99344 -76.508079,179.99344 -78.48206,143.994754 -78.48206,107.996068 -78.48206,71.997382 -78.48206,35.998696 -78.48206,0.000010000000003 -78.48206,-35.998676 -78.48206,-71.997362 -78.48206,-107.996048 -78.48206,-143.994734 -78.48206,-179.99342 -78.48206,-179.99342 -76.508079,-179.99342 -74.534098,-179.99342 -72.560117,-179.99342 -70.586136,-179.99342 -68.612155,-179.99342 -66.638174,-179.99342 -64.664193,-179.99342 -62.690212,-179.99342 -60.716231,-179.99342 -58.74225))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001992", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP0001"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a marine geological investigation of the Amundsen Sea region toward a better understanding of the deglaciation history of the West Antarctic Ice Sheet (WAIS). The WAIS may be inherently unstable because it is the last marine-based ice sheet in the world. Unlike other embayments in West Antarctica, major ice streams draining into the Amundsen Sea from the interior of the WAIS lack buttressing ice shelves. Mass balance data for the distal portions of these ice streams (Pine Island and Thwaites glaciers) appear to be in balance or may be becoming negative. Because both ice streams have beds that slope downward toward the center of the ice sheet, grounding-line recession resulting from either continued thinning or sea-level rise could trigger irreversible grounding-line retreat, leading to ice-sheet disintegration and consequent global sea-level rise. The limited marine geological and geophysical data available from the Amundsen Sea suggest that grounded ice or an ice shelf occupied the inner Amundsen Sea embayment until perhaps as recently as 1000 to 2000 years ago, and this ice may have retreated rapidly in historic time.\u003cbr/\u003e\u003cbr/\u003eThis project, a study of the marine geology and geophysics of the Amundsen Sea continental shelf from 100 degrees W to 130 degrees W, is designed to address the Amundsen Sea part of WAIS Science Plan Priority Goal H2: \"What is the deglaciation history in the eastern Ross, the Bellingshausen and Amundsen Seas?\" This project will examine bathymetric data of the Amundsen Sea continental shelf to determine the positions of former ice-steam channels, and to aid in choosing sites for sediment coring. Single-channel seismic reflection studies will be conducted in order to determine sediment-thickness patterns, to aid in choice of coring sites, and to locate and identify morphologic features indicative of former grounded ice (e.g., moraines, scours, flutes, striations, till wedges and deltas, etc.). Coring will be concentrated along former ice flow-lines. Core samples will be analyzed in the laboratory for sedimentology, to determine whether of not basal tills are present (indicating former grounded ice and its former extent), and for calcareous and siliceous microfossils. The chronology of grounding-line and ice-shelf retreat from a presumed Last Glacial Maximum position near the shelf break will be established using accelerator mass spectrometry (AMS) carbon-14 dates of acid-insoluble particulate organic carbon.\u003cbr/\u003e\u003cbr/\u003eThis project will share ship time in the Amundsen Sea with a physical oceanographic project. Marine geologic data and samples collected will be integrated with findings of other investigators toward developing a comprehensive interpretation of the history of the WAIS.", "east": 179.99344, "geometry": "POINT(0.000010000000003 -68.612155)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e MSBS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -58.74225, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Kellogg, Thomas; Jacobs, Stanley", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -78.48206, "title": "Glacial History of the Amundsen Sea Shelf", "uid": "p0000620", "west": -179.99342}, {"awards": "9316767 Jeffries, Martin", "bounds_geometry": "POLYGON((-180 -43.56571,-144 -43.56571,-108 -43.56571,-72 -43.56571,-36 -43.56571,0 -43.56571,36 -43.56571,72 -43.56571,108 -43.56571,144 -43.56571,180 -43.56571,180 -46.304308,180 -49.042906,180 -51.781504,180 -54.520102,180 -57.2587,180 -59.997298,180 -62.735896,180 -65.474494,180 -68.213092,180 -70.95169,144 -70.95169,108 -70.95169,72 -70.95169,36 -70.95169,0 -70.95169,-36 -70.95169,-72 -70.95169,-108 -70.95169,-144 -70.95169,-180 -70.95169,-180 -68.213092,-180 -65.474494,-180 -62.735896,-180 -59.997298,-180 -57.2587,-180 -54.520102,-180 -51.781504,-180 -49.042906,-180 -46.304308,-180 -43.56571))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "002234", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9503"}, {"dataset_uid": "002231", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/NBP9505"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "The goal of this investigation is to understand the role of snow in sea ice development processes and air-ice-ocean heat exchange interactions in the seasonal and perennial sea ice zones of the Ross Sea, the Amundsen Sea, and the Bellingshausen Sea. Observations and measurements of the characteristics of sea ice and snow will be combined with numerical models of sea-ice flooding and the entrainment of snow into the ice cover in order to gain an understanding of the sea-ice heat and mass balance, and to quantify the energy exchange within the antarctic sea-ice cover. The snow measurement program, using the RVIB Nathaniel B. Palmer, will include depth, grain size and morphology, density, temperature, thermal conductivity, water content, and stable isotope ratio. The ice measurement program will include thickness, salinity, temperature, density, brine content, and included gas volume, as well as such structural properties as the fraction of frazil, platelet, and congelation ice in the seasonal antarctic pack ice. Differences in ice types are the result of differences in the environment in which the ice forms: frazil ice is formed in supercooled sea water, normally through wind or wave-induced turbulence, while platelet and congelation ice is formed under quiescent conditions. The fraction of frazil ice is an important variable in the energy budget of the upper ocean, and contributes significantly to the stabilization of the surface layers. The numerical models will involve the thermodynamics of phase changes from liquid water to ice, along with the resulting energy transfer, brine expulsion, and the modulating effect of a snow cover. The results are expected to have broad relevance and application to understanding the effects of sea-ice processes in global change, and atmospheric, oceanographic, and remote sensing investigations of the Southern Ocean.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e GRAVIMETERS \u003e GRAVIMETERS", "is_usap_dc": false, "keywords": "R/V NBP", "locations": null, "north": -43.56571, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Jeffries, Martin", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V NBP", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -70.95169, "title": "The Role of Snow in Antarctic Sea Ice Development and Ocean-Atmosphere Energy Exchange", "uid": "p0000642", "west": -180.0}, {"awards": "0741510 Yuan, Xiaojun", "bounds_geometry": "POLYGON((-180 -69,-172 -69,-164 -69,-156 -69,-148 -69,-140 -69,-132 -69,-124 -69,-116 -69,-108 -69,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-100 -77,-100 -78,-100 -79,-108 -79,-116 -79,-124 -79,-132 -79,-140 -79,-148 -79,-156 -79,-164 -79,-172 -79,180 -79,178.5 -79,177 -79,175.5 -79,174 -79,172.5 -79,171 -79,169.5 -79,168 -79,166.5 -79,165 -79,165 -78,165 -77,165 -76,165 -75,165 -74,165 -73,165 -72,165 -71,165 -70,165 -69,166.5 -69,168 -69,169.5 -69,171 -69,172.5 -69,174 -69,175.5 -69,177 -69,178.5 -69,-180 -69))", "dataset_titles": "Temperature and salinity measurements collected using XBT, XCTD from the Oden and other platforms in the Southern Oceans from 2003-2008 (NODC Accession 0053045)", "datasets": [{"dataset_uid": "000214", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Temperature and salinity measurements collected using XBT, XCTD from the Oden and other platforms in the Southern Oceans from 2003-2008 (NODC Accession 0053045)", "url": "https://data.nodc.noaa.gov/cgi-bin/iso?id=gov.noaa.nodc:0053045"}], "date_created": "Sat, 20 Feb 2010 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThe project goal is to investigate the ocean-atmosphere-ice (OAI) interactions in the Amundsen and Ross Seas during the austral summer of 2007-08 using hydrographic measurements (CTD and XBT) in conjunction with (1) ship-based observations and satellite-derived estimates of sea ice concentration, and (2) ship-based observations and re-analyses of meteorological variables. The major scientific objectives are as follows: (1) to examine upper ocean characteristics along three transects in the Amundsen Sea and two transects in the Ross Sea within the context of ice-atmosphere variability over the preceding winter-spring season and as compared to other years where data are available; (2) to determine if there is additional evidence of increased upwelling of warm Circumpolar Deep Water onto the shelf in the Amundsen Sea and/or increased freshening in the Ross Sea as has been inferred by previous, but limited, ocean surveys in these regions; and (3) to examine the spatial variability in ocean thermal structure along the ship\u0027s track (outside the transects) to provide greater regional context and to compare with ocean XBT data collected during Oden 2006-07. A repeated temperature survey between the Amundsen and Ross Sea is particularly invaluable, given that this sector is the regional center of the high latitude OAI response to ENSO, thus providing opportunity for examining and linking regional oceanic temporal variability to global climate variability. The research will improve our understanding of the high latitude OAI response to climate change, and provide the physical context for the observed biology and geochemistry (investigated by our colleagues. Our results will be made widely available through research publications and internet-available databases, and through the strong public outreach efforts of Lamont-Doherty Earth Observatory. The outreach efforts will help increase awareness and understanding of anthropogenic climate change, melting ice, and ecosystem alteration in the highly sensitive Antarctic.", "east": -100.0, "geometry": "POINT(-147.5 -74)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -69.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Yuan, Xiaojun; Stammerjohn, Sharon", "platforms": "Not provided", "repo": "NCEI", "repositories": "NCEI", "science_programs": null, "south": -79.0, "title": "SGER: Science-of-Opportunity Aboard Icebreaker Oden: Ocean-Atmosphere-Ice Interactions and Changes", "uid": "p0000562", "west": 165.0}, {"awards": "0741380 Smith, Walker", "bounds_geometry": "POLYGON((100 -65,106 -65,112 -65,118 -65,124 -65,130 -65,136 -65,142 -65,148 -65,154 -65,160 -65,160 -66.5,160 -68,160 -69.5,160 -71,160 -72.5,160 -74,160 -75.5,160 -77,160 -78.5,160 -80,154 -80,148 -80,142 -80,136 -80,130 -80,124 -80,118 -80,112 -80,106 -80,100 -80,100 -78.5,100 -77,100 -75.5,100 -74,100 -72.5,100 -71,100 -69.5,100 -68,100 -66.5,100 -65))", "dataset_titles": "Small Grants for Exploratory Research - Oceanographic Research in the Amundsen and Ross Seas", "datasets": [{"dataset_uid": "600085", "doi": "10.15784/600085", "keywords": "Amundsen Sea; Chemistry:fluid; Chemistry:Fluid; CTD Data; Geochemistry; Oceans; Oden; OSO2007; Sea Surface; Southern Ocean", "people": "Smith, Walker", "repository": "USAP-DC", "science_program": null, "title": "Small Grants for Exploratory Research - Oceanographic Research in the Amundsen and Ross Seas", "url": "https://www.usap-dc.org/view/dataset/600085"}], "date_created": "Mon, 22 Jun 2009 00:00:00 GMT", "description": "The research will examine the relative importance of the physical and chemical controls on phytoplankton dynamics and carbon flux in continental margin regions of the Southern Ocean, and elucidate mechanisms by which plankton populations and carbon export might be altered by climate change. We specifically will address (1) how the phytoplankton on the continental margins of the southern Ocean respond to spatial and temporal changes in temperature, light, iron supply, and carbon dioxide levels, (2) how these factors initiate changes in phytoplankton assemblage structure, and (3) how carbon export and the efficiency of the biological pump are impacted by the biomass and composition of the phytoplankton. Two regions of study (the Amundsen and Ross Seas) will be investigated, one well studied (Ross Sea) and one poorly described (Amundsen Sea). It is hypothesized that each region will have markedly different physical forcing, giving rise to distinct chemical conditions and therefore biological responses. As such, the comparison of the two may give us insights into the mechanisms of how Antarctic continental margins will respond under changing environmental conditions. Broader impacts include participation by an international graduate student from Brazil, outreach via seminars to the general public, collaboration with the teachers-in-residence on the cruise, development of a cruise web site and interactive email exchanges with local middle school students while at sea", "east": 160.0, "geometry": "POINT(130 -72.5)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -65.0, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Smith, Walker", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -80.0, "title": "Small Grants for Exploratory Research - Oceanographic Research in the Amundsen and Ross Seas:", "uid": "p0000217", "west": 100.0}, {"awards": "0742057 Gallager, Scott", "bounds_geometry": "POLYGON((-168.291 -64.846,-165.018 -64.846,-161.745 -64.846,-158.472 -64.846,-155.199 -64.846,-151.926 -64.846,-148.653 -64.846,-145.38 -64.846,-142.107 -64.846,-138.834 -64.846,-135.561 -64.846,-135.561 -66.0269,-135.561 -67.2078,-135.561 -68.3887,-135.561 -69.5696,-135.561 -70.7505,-135.561 -71.9314,-135.561 -73.1123,-135.561 -74.2932,-135.561 -75.4741,-135.561 -76.655,-138.834 -76.655,-142.107 -76.655,-145.38 -76.655,-148.653 -76.655,-151.926 -76.655,-155.199 -76.655,-158.472 -76.655,-161.745 -76.655,-165.018 -76.655,-168.291 -76.655,-168.291 -75.4741,-168.291 -74.2932,-168.291 -73.1123,-168.291 -71.9314,-168.291 -70.7505,-168.291 -69.5696,-168.291 -68.3887,-168.291 -67.2078,-168.291 -66.0269,-168.291 -64.846))", "dataset_titles": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "datasets": [{"dataset_uid": "600086", "doi": "10.15784/600086", "keywords": "Amundsen Sea; Biota; Microbiology; Navigation; Oceans; Oden; OSO2007; Sample/collection Description; Sample/Collection Description; Southern Ocean", "people": "Gallager, Scott; Dennett, Mark", "repository": "USAP-DC", "science_program": null, "title": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "url": "https://www.usap-dc.org/view/dataset/600086"}], "date_created": "Mon, 16 Mar 2009 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThe research will continue and extend the study in the Southern Ocean that was initiated during the Oden Southern Ocean 2006 expedition in collaboration with Swedish scientist Mellissa Chierici. We will quantify carbon flux through the food web in the marginal ice zone (MIZ) by measuring size fractionated primary and secondary production, grazing and carbon flux through nanoplankton (2-20 um), microplankton (20-200um), and mesoplankton (200-2000 um). Community structure, species abundance and size specific grazing rates will be quantified using a variety of techniques both underway and at ice stations along the MIZ. The proposed cruise track extends across the Drake Passage to the Western Antarctic Peninsula (WAP) with three station transects along a gradient from the open ocean through the marginal ice zone (MIZ) in the Bellinghausen and Amundsen Seas and into the Ross Sea Polynya. Ice stations along each transect will provide material to characterize production associated with annual ice. Underway measurements of primary and secondary production (chlorophyll, CDOM, microplankton, and mesoplankton) and hydrography (temperature, salinity, pH, DO, turbidity) will establish a baseline for future cruises and as support for other projects such as biogeochemical studies on carbon dioxide drawdown and trace metal work on primary production. The outcome of these measurements will be a description of nano to mesoplankton standing stocks, community structure, and carbon flux along the MIZ in the Bellinghausen and Amundsen Seas and the Ross Sea Polynya.", "east": -135.561, "geometry": "POINT(-151.926 -70.7505)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -64.846, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Gallager, Scott; Dennett, Mark", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.655, "title": "SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions", "uid": "p0000563", "west": -168.291}, {"awards": "0741428 Hutchins, David", "bounds_geometry": "POINT(-106 -73)", "dataset_titles": null, "datasets": null, "date_created": "Sun, 23 Nov 2008 00:00:00 GMT", "description": "Abstract\u003cbr/\u003e\u003cbr/\u003eThis Small Grants for Exploratory Research (SGER) proposal describes global change-related experimental research designed to take full advantage of a unique science opportunity on short notice, the leasing of the Oden to conduct ice-breaking operations in McMurdo Sound. \u003cbr/\u003e\u003cbr/\u003eOur emphasis will be on using this opportunistic research platform to ask two questions about present day and future controls on Antarctic margin phytoplankton communities. These are: 1. How will expected alterations in pCO2, pH, and Fe availability in the Southern Ocean, due to future anthropogenic climate change affect phytoplankton species assemblages, carbon and nutrient biogeochemistry, and remineralization processes? 2. What is the current role of organic co-factors (vitamins) in limiting or co-limiting (along with iron ) phytoplankton growth and production in the Antarctic margin? The research approach includes experimental incubations with variation in iron enrichment, carbon dioxide concentration, and temperature. A second suite of experiments will examine co-limitation effects between vitamin B12 and Fe and B12 uptake kinetics. Changes in phytoplankton community structure, and carbon and nutrient cycling will be determined, in collaboration with many of the participating U.S. and Swedish investigators. Together, these two main objectives should allow us to obtain novel insights into the current and future controls on Antarctic margin phytoplankton growth, productivity, and carbon and nutrient biogeochemistry. In particular, the experiments in the Amundsen Sea represent a one-of-a-kind opportunity to understand algal dynamics and potential future responses to climate change in this little-studied ecosystem, and compare these results to those from the better-known Ross Sea. An important result of this study will be to build strong international collaborations with the Swedish marine science community. Additional broader impacts include participatin of an Hispanic Ph.D. student in cruise work and post-cruise analyses, and integration of results into graduate courses at the USC Catalina Lab facility. Public outreach will include presentations on global change impacts on the ocean targeted at audiences ranging from legislators and policymakers to the general public.", "east": -106.0, "geometry": "POINT(-106 -73)", "instruments": null, "is_usap_dc": true, "keywords": "SHIPS", "locations": null, "north": -73.0, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Hutchins, David", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e SHIPS", "repositories": null, "science_programs": null, "south": -73.0, "title": "SGER: Science-of-Opportunity Aboard Icebreaker Oden - Phytoplankton Global Change Experiments and Vitamin/Iron Co-Limitation in the Amundsen and Ross Seas", "uid": "p0000224", "west": -106.0}, {"awards": "0230197 Holt, John", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment; Amundsen Sea Sector Data Set; Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "datasets": [{"dataset_uid": "609292", "doi": "10.7265/N59W0CDC", "keywords": "AGASEA; Airborne Radar; Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Solid Earth", "people": "Morse, David L.; Holt, John W.; Blankenship, Donald D.; Vaughan, David G.; Young, Duncan A.; Corr, Hugh F. J.", "repository": "USAP-DC", "science_program": null, "title": "Subglacial Topography: Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609292"}, {"dataset_uid": "609312", "doi": "10.7265/N5J9649Q", "keywords": "Amundsen Sea; Antarctica; Elevation; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology", "people": "Fastook, James L.", "repository": "USAP-DC", "science_program": null, "title": "Amundsen Sea Sector Data Set", "url": "https://www.usap-dc.org/view/dataset/609312"}, {"dataset_uid": "601673", "doi": "10.15784/601673", "keywords": "Antarchitecture; Antarctica; Ice Penetrating Radar; Isochron; Layers; Radar; Radioglaciology; Thwaites Glacier", "people": "Jackson, Charles; Blankenship, Donald D.; Muldoon, Gail R.; Young, Duncan A.", "repository": "USAP-DC", "science_program": null, "title": "AGASEA 4.7 ka Englacial Isochron over the Thwaites Glacier Catchment", "url": "https://www.usap-dc.org/view/dataset/601673"}], "date_created": "Mon, 01 Jan 2007 00:00:00 GMT", "description": "This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical\u003cbr/\u003edata will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.\u003cbr/\u003eThe West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea\u003cbr/\u003elevel rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical\u003cbr/\u003ecenters. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.\u003cbr/\u003eThe results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.\u003cbr/\u003eThrough its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e RADAR ALTIMETERS \u003e RADAR ALTIMETERS", "is_usap_dc": true, "keywords": "Thwaites Glacier; Ice Velocity; Ablation; Amundsen Sea; Pine Island Glacier; Elevation; Antarctica (agasea); Ice Sheet Elevation; West Antarctic Ice Sheet; Ice Temperature; Amundsen Basin; Subglacial Topography; Ice Melt; West Antarctica; Velocity Measurements; Snow Accumulation; Antarctica; Bedrock Elevation; Modeling", "locations": "Antarctica; West Antarctica; Amundsen Basin; Pine Island Glacier; Thwaites Glacier; West Antarctic Ice Sheet; Amundsen Sea", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A.", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)", "uid": "p0000243", "west": -180.0}]
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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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Benthic Iron Fluxes and Cycling in the Amundsen Sea
|
None | 2024-06-13 | None | No dataset link provided | The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron, which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide iron to the Amundsen Sea ecosystem. However, sediment sources of iron have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment iron fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through the website CryoConnect.org. <br/><br/>This project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment iron (Fe) cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the ?Accelerating Thwaites Ecosystem Impacts for the Southern Ocean? (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography and beyond.<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. | None | None | false | false | |||||||||
Collaborative Research: Testing the Linchpin of WAIS Collapse with Diatoms and IRD in Pleistocene and Late Pliocene Strata of the Resolution Drift, Amundsen Sea, Antarctica
|
1939146 1939139 |
2024-02-20 | Scherer, Reed Paul; Siddoway, Christine | Part I, Non-technical Abstract <br/>Concerns that the West Antarctic Ice Sheet (WAIS) might be susceptible to releasing its ice as giant icebergs into the Southern Ocean due to a warming climate, raising global sea level, were first expressed more than 40 years ago. To best-assess this threat, scientists need to know whether such events occurred in the geologically recent past, during warm intervals of past glacial-interglacial cycles. Ocean drilling near the most vulnerable sector of the WAIS, in 2019, yielded seafloor geologic records demonstrating times when icebergs dropped large volumes of sands and pebbles, called ice-rafted detritus (IRD) in deep water of the Amundsen Sea. Occurring together with IRD that was eroded from bedrock beneath the ice sheets, there are abundant microfossils of diatoms (algal plankton), which indicate high biological productivity in the open ocean. The new sediment cores provide a complete, uninterrupted record of a time of dramatic fluctuations of ice sheet extent that occurred over the last 3 million years. Therefore, they provide the means to obtain clear answers to the question whether ice sheet collapse occurred in the past and offering clues to its potential future. This project will investigate sediment intervals where IRD coincides with evidence of high diatom production, to test whether these two criteria indicate rapid ice sheet collapse. Geochemical analysis of IRD pebbles will help trace the source of the icebergs to likely on-land sites. By analyzing conditions of high diatom and IRD accumulation in deep ocean sediment, where local coastal influences can be avoided, we will assess oceanographic and climatic conditions associated with past ice sheet collapse events. Diatoms provide powerful evidence of temperature and ocean productivity changes in the past, that, when linked to time, can translate into rates of ice sheet drawdown. These results will provide critical data for designing, constraining and testing the next suite computer models that can determine the likelihood and timing of future ice sheet collapse in a warming world. The project will include training of undergraduate and graduate students from diverse backgrounds, and the public will be introduced to Antarctic science and engaged through several different outreach efforts.<br/><br/>Part 2, Technical Abstract<br/><br/>New drillcores from the Amundsen Sea, Antarctica (IODP Expedition 379) contain a continuous record of oceanographic changes and iceberg rafted debris (IRD) spanning the last 5 million years. This study aims to identify the signature of retreat/collapse of the West Antarctic Ice Sheet (WAIS) in these continental margin, deep-sea sediments by quantitatively analyzing, in detail, diatom and IRD records across glacial-interglacial lithostratigraphic transitions to establish the timing and frequency of Late Pliocene and Pleistocene WAIS collapse events. The investigators will secure age constraints and diagnostic observations of marine paleoenvironmental conditions for selected interglacial intervals of cores from sites U1532 and U1533, using high resolution micropaleontology of diatom assemblages coupled with microstratigraphic analysis of IRD depositional events, while petrography, geochronology and thermochronology of iceberg rafted clasts will provide evidence of iceberg sources and pathways. Depositional paleotemperatures will be assessed via a new paleotemperature proxy based on quantitative assessment of morphologic changes in the dominant Southern Ocean diatom Fragilariopsis kerguelensis. Their results will contribute to parameterization of new ice sheet models that seek to reconstruct and forecast West Antarctic Ice Sheet behavior. This project will directly contribute to undergraduate education at an undergraduate-only college and at a public university that serves a demographic typified by first generation university students and underrepresented groups. Spanning geology, geochemistry, sedimentology, paleontology and paleoceanography, the proposed work will allow undergraduate students to develop diverse skills through hands-on research within a collaborative team that is dedicated to societally relevant research. The two graduate students will conduct original research and work alongside/mentor undergraduates, making for a well-rounded research experience that prepares them for success in future academic or employment sectors. The discoveries that come from this deep-sea record from West Antarctica will be communicated by students and investigators at national and international conferences and an array of public science outreach events.<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((-120 -66,-117.5 -66,-115 -66,-112.5 -66,-110 -66,-107.5 -66,-105 -66,-102.5 -66,-100 -66,-97.5 -66,-95 -66,-95 -67.1,-95 -68.2,-95 -69.3,-95 -70.4,-95 -71.5,-95 -72.6,-95 -73.7,-95 -74.8,-95 -75.9,-95 -77,-97.5 -77,-100 -77,-102.5 -77,-105 -77,-107.5 -77,-110 -77,-112.5 -77,-115 -77,-117.5 -77,-120 -77,-120 -75.9,-120 -74.8,-120 -73.7,-120 -72.6,-120 -71.5,-120 -70.4,-120 -69.3,-120 -68.2,-120 -67.1,-120 -66)) | POINT(-107.5 -71.5) | false | false | ||||||||||
Investigating Effects of Transient and Non-Newtonian Mantle Viscosity on Glacial Isostatic Adjustment Process and their Implications for GPS Observations in Antarctica
|
2333940 |
2024-01-08 | Zhong, Shijie | No dataset link provided | Satellite observations of Earth?s surface gravity and elevation changes indicate rapid melting of ice sheets in recent decades in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica. This rapid melting may lead to significant global sea level rise which is a major societal concern. Measurements from the Global Positioning System (GPS) show rapid land uplift in these regions as the ice sheets melt. When an ice sheet melts, the melt water flows to oceans, causing global sea level to rise. However, the sea level change at a given geographic location is also influenced by two other factors associated with the ice melting process: 1) the vertical motion of the land and 2) gravitational attraction. The vertical motion of the land is caused by the change of pressure force on the surface of the solid Earth. For example, the removal of ice mass reduces the pressure force on the land, leading to uplift of the land below the ice sheet, while the addition of water in oceans increases the pressure force on the seafloor, causing it to subside. The sea level always follows the equipotential surface of the gravity which changes as the mass on the Earth?s surface (e.g., the ice and water) or/and in its interiors (e.g., at the crust-mantle boundary) is redistributed. Additionally, the vertical motion of the land below an ice sheet has important effects on the evolution and stability of the ice sheet and may determine whether the ice sheet will rapidly collapse or gradually stabilize. The main goal of this project is to build an accurate and efficient computer model to study the displacement and deformation of the Antarctic crust and mantle in response to recent ice melting. The project will significantly improve existing and publicly available computer code, CitcomSVE. The horizontal and vertical components of the Earth?s surface displacement depends on mantle viscosity and elastic properties of the Earth. Although seismic imaging studies demonstrate that the Antarctica mantle is heterogeneous, most studies on the ice-melting induced deformation in Antarctica have assumed that mantle viscosity and elastic properties only vary with the depth due to computational limitations. In this project, the new computational method in CitcomSVE avoids such assumptions and makes it possible to include realistic 3-D mantle viscosity and elastic properties in computing the Antarctica crustal and mantle displacement. This project will interpret the GPS measurements of the surface displacements in northern Antarctica Peninsula and Amundsen Sea Embayment of West Antarctica and use the observations to place constraints on mantle viscosity and deformation mechanisms. The project will also seek to predict the future land displacement Antarctica, which will lead to a better understand of Antarctica ice sheets. Finally, the project has direct implications for the study of global sea level change and the dynamics of the Greenland ice sheet. Technical Description Glacial isostatic adjustment (GIA) is important for understanding not only fundamental science questions including mantle viscosity, mantle convection and lithospheric deformation but also societally important questions of global sea-level change, polar ice melting, climate change, and groundwater hydrology. Studies of rock deformation in laboratory experiments, post-seismic deformation, and mantle dynamics indicate that mantle viscosity is temperature- and stress-dependent. Although the effects of stress-dependent (i.e., non-Newtonian) viscosity and transient creep rheology on GIA process have been studied, observational evidence remains elusive. There has been significant ice mass loss in recent decades in northern Antarctica Peninsula (NAP) and Amundsen Sea Embayment (ASE) of West Antarctica. The ice mass loss has caused rapid bedrock uplift as measured by GPS techniques which require surprisingly small upper mantle viscosity of ~1018 Pas. The rapid uplifts may have important feedback effects on ongoing ice melting because of their influence on grounding line migration, and the inferred small viscosity may have implications for mantle rheology and deformation on decadal time scales. The main objective of the project is to test hypotheses that the GPS observations in NAP and ASE regions are controlled by 3-D non-Newtonian or/and transient creep viscosity by developing new GIA modeling capability based on finite element package CitcomSVE. The project will carry out the following three tasks: Task 1 is to build GIA models for the NAP and ASE regions to examine the effects of 3-D temperature-dependent mantle viscosity on the surface displacements and to test hypothesis that the 3-D mantle viscosity improves the fit to the GPS observations. Task 2 is to test the hypothesis that non-Newtonian or/and transient creep rheology controls GIA process on decadal time scales by computing GIA models and comparing model predictions with GPS observations for the NAP and ASE regions. Task 3 is to implement transient creep (i.e., Burgers model) rheology into finite element package CitcomSVE for modeling the GIA process on global and regional scales and to make the package publicly available to the scientific community. The project will develop the first numerical GIA model with Burgers transient rheology and use the models to examine the effects of 3-D temperature-dependent viscosity, non-Newtonian viscosity and transient rheology on GIA-induced surface displacements in Antarctica. The project will model the unique GPS observations of unusually large displacement rates in the NAP and ASE regions to place constraints on mantle rheology and to distinguish between 3-D temperature-dependent, non-Newtonian and transient mantle viscosity. The project will expand the capability of the publicly available software package CitcomSVE for modeling viscoelastic deformation and tidal deformation on global and regional scales. The project will advance our understanding in lithospheric deformation and mantle rheology on decadal time scales, which helps predict grounding line migration and understand ice sheet stability in West Antarctica. The project will strengthen the open science practice by improving the publicly available code CitcomSVE at github. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
NSF-NERC: PROcesses, drivers, Predictions: Modeling the response of Thwaites Glacier over the next Century using Ice/Ocean Coupled Models (PROPHET)
|
2152622 |
2022-12-20 | Morlighem, Mathieu; Das, Indrani |
|
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites Glacier has been accelerating and widening over the past three decades. How fast Thwaites will disintegrate or how quickly it will find a new stable state have become some of the most important questions of the future of the West Antarctic Ice Sheet and its contribution to sea-level rise over the next decades to centuries and beyond. This project will rely on three independent numerical models of ice flow, coupled to an ocean circulation model to (1) improve our understanding of the interactions between the ice and the underlying bedrock, (2) analyze how sensitive the glacier is to external changes, (3) assess the processes that may lead to a collapse of Thwaites, and, most importantly, (4) forecast future ice loss of Thwaites. By providing predictions based on a suite of coupled ice-ocean models, this project will also assess the uncertainty in model projections. The project will use three independent ice-sheet models: Ice Sheet System Model, Ua, and STREAMICE, coupled to the ocean circulation model of the MIT General Circulation Model. The team will first focus on the representation of key physical processes of calving, ice damage, and basal slipperiness that have either not been included, or are poorly represented, in previous ice-flow modelling work. The team will then quantify the relative role of different proposed external drivers of change (e.g., ocean-induced ice-shelf thinning, loss of ice-shelf pinning points) and explore the stability regime of Thwaites Glacier with the aim of identifying internal thresholds separating stable and unstable grounding-line retreat. Using inverse methodology, the project will produce new physically consistent high-resolution (300-m) data sets on ice-thicknesses from available radar measurements. Furthermore, the team will generate new remote sensing data sets on ice velocities and rates of elevation change. These will be used to constrain and validate the numerical models, and will also be valuable stand-alone data sets. This process will allow the numerical models to be constrained more tightly by data than has previously been possible. The resultant more robust model predictions of near-future impact of Thwaites Glacier on global sea levels can inform policy-relevant decision-making. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POLYGON((-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-103 -74,-102 -74,-101 -74,-100 -74,-100 -74.3,-100 -74.6,-100 -74.9,-100 -75.2,-100 -75.5,-100 -75.8,-100 -76.1,-100 -76.4,-100 -76.7,-100 -77,-101 -77,-102 -77,-103 -77,-104 -77,-105 -77,-106 -77,-107 -77,-108 -77,-109 -77,-110 -77,-110 -76.7,-110 -76.4,-110 -76.1,-110 -75.8,-110 -75.5,-110 -75.2,-110 -74.9,-110 -74.6,-110 -74.3,-110 -74)) | POINT(-105 -75.5) | false | false | |||||||||
Estimation of Antarctic Ice Melt using Stable Isotopic Analyses of Seawater
|
1644118 |
2022-09-21 | Dunbar, Robert |
|
Estimating Antarctic ice sheet growth or loss is important to predicting future sea level rise. Such estimates rely on field measurements or remotely sensed based observations of the ice sheet surface, ice margins, and or ice shelves. This work examines the introduction of freshwater into the ocean to surrounding Antarctica to track meltwater from continental ice. Polar ice is depleted in two stable isotopes, 18O and D, deuterium, relative to Southern Ocean seawater and precipitation. Measurements of seawater isotopic composition in conjunction with precise observations of seawater temperature and salinity, will permit discrimination of freshwater derived from melting glacial ice from that derived from regional precipitation or sea ice melt.<br/><br/>This research describes an accepted method for determining rates and locations of meltwater entering the oceans from polar ice sheets. As isotopic and salinity perturbations are cumulative in many Antarctic coastal seas, the method allows for the detection of any marked acceleration in meltwater introduction in specific regions, using samples collected and analyzed over a period of years to decades. Impact of the project derives from use of an independent method capable of constraining knowledge about current ice sheet melt rates, their stability and potential impact on sea level rise. The project allows for sample collection taken from foreign vessels of opportunity sailing in Antarctic waters, and subsequent sharing and interpretation of data. Research partners include the U.S., Korea, China, New Zealand, the United Kingdom, and Germany. Participating collaborators will collect seawater samples for isotopic and salinity analysis at Stanford University. USAP cruises will concentrate on sampling the Ross Sea, and the West Antarctic. The work plan includes interpretation of isotopic data using box model and mixing curve analyses as well as using isotope enabled ROMS (Regional Ocean Modeling System) models. The broader impacts of the research will include development of an educational module that illustrates the scientific method and how ocean observations help society understand how Earth is changing. | POLYGON((-108 -73,-107.3 -73,-106.6 -73,-105.9 -73,-105.2 -73,-104.5 -73,-103.8 -73,-103.1 -73,-102.4 -73,-101.7 -73,-101 -73,-101 -73.3,-101 -73.6,-101 -73.9,-101 -74.2,-101 -74.5,-101 -74.8,-101 -75.1,-101 -75.4,-101 -75.7,-101 -76,-101.7 -76,-102.4 -76,-103.1 -76,-103.8 -76,-104.5 -76,-105.2 -76,-105.9 -76,-106.6 -76,-107.3 -76,-108 -76,-108 -75.7,-108 -75.4,-108 -75.1,-108 -74.8,-108 -74.5,-108 -74.2,-108 -73.9,-108 -73.6,-108 -73.3,-108 -73)) | POINT(-104.5 -74.5) | false | false | |||||||||
Collaborative Research: US GEOTRACES GP17-ANT: Dissolved concentrations, isotopes, and colloids of the bioactive trace metals
|
2123491 2123333 2123354 |
2022-09-08 | Conway, Timothy; Fitzsimmons, Jessica; John, Seth | No dataset link provided | The goal of the international GEOTRACES program is to understand the distributions of trace chemical elements and their isotopes (TEIs) in the oceans. Many trace metals such as iron are essential for life and thus considered nutrients for phytoplankton growth, with trace metal cycling being especially important for influencing carbon cycling in the iron-limited Southern Ocean, where episodic supply of iron from a range of different external sources is important. The primary goal of this project is to measure the dissolved concentrations, size partitioning, and dissolved isotope signature of Fe on a transect of water-column stations throughout the Amundsen Sea and surrounding region of the Antarctic Margin, as part of the GP17-ANT Expedition. The secondary goal of this project is to analyze the concentrations and size partitioning of the trace metals manganese, zinc, copper, cadmium, nickel, and lead in all water-column samples, measure the isotope ratios of zinc, cadmium, nickel, and copper in a subset of water column samples, and measure the Fe isotopic signature of aerosols, porewaters, and particles. Observations from this project will be incorporated into regional and global biogeochemistry models to assess TEI cycling within the Amundsen Sea and implications for the wider Southern Ocean. This project spans three institutions, four graduate students, undergraduate students, and will provide ultrafiltered samples and data to other PIs as service. The US GEOTRACES GP17 ANT expedition, planned for austral summer 2023/2024 aims to determine the distribution and cycling of trace elements and their isotopes in the Amundsen Sea Sector (100-135°W) of the Antarctic Margin. The cruise will follow the Amundsen Sea ‘conveyor belt’ by sampling waters coming from the Antarctic Circumpolar Current onto the continental shelf, including near the Dotson and Pine Island ice shelves, the productive Amundsen Sea Polynya (ASP), and outflowing waters. Episodic addition of dissolved Fe and other TEIs from dust, ice-shelves, melting ice, and sediments drive seasonal primary productivity and carbon export over the Antarctic shelf and offshore into Southern Ocean. Seasonal coastal polynyas such as the highly productive ASP thus act as key levers on global carbon cycling. However, field observations of TEIs in such regions remain scarce, and biogeochemical cycling processes are poorly captured in models of ocean biogeochemistry. The investigators will use their combined analytical toolbox, in collaboration with the diagnostic chemical tracers and regional models of other funded groups to address four main objectives: 1) What is the relative importance of different sources in supplying Fe and other TEIs to the ASP? 2) What is the physiochemical speciation of this Fe, and its potential for transport? 3) How do biological uptake, scavenging and regeneration in the ASP influence TEI distributions, stoichiometry, and nutrient limitation? 4) What is the flux and signature of TEIs transported offshore to the ACC and Southern Ocean? | POLYGON((-135 -66,-131.5 -66,-128 -66,-124.5 -66,-121 -66,-117.5 -66,-114 -66,-110.5 -66,-107 -66,-103.5 -66,-100 -66,-100 -67,-100 -68,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-103.5 -76,-107 -76,-110.5 -76,-114 -76,-117.5 -76,-121 -76,-124.5 -76,-128 -76,-131.5 -76,-135 -76,-135 -75,-135 -74,-135 -73,-135 -72,-135 -71,-135 -70,-135 -69,-135 -68,-135 -67,-135 -66)) | POINT(-117.5 -71) | false | false | |||||||||
OPP-PRF: Benthic Iron Fluxes and Cycling in the Amundsen Sea
|
2212904 |
2022-08-07 | Herbert, Lisa | No dataset link provided | The Amundsen Sea, near the fastest melting Antarctic glaciers, hosts one of the most productive polar ecosystems in the world. Phytoplankton serve as the base of the food chain, and their growth also removes carbon dioxide from the atmosphere. Phytoplankton growth is fertilized in this area by nutrient iron (Fe), which is only present at low concentrations in seawater. Prior studies have shown the seabed sediments may provide Fe to the Amundsen Sea ecosystem. However, sediment sources of Fe have never been studied here directly. This project fills this gap by analyzing sediments from the Amundsen Sea and investigating whether sediment Fe fertilizes plankton growth. The results will help scientists understand the basic ecosystem drivers and predict the effects of climate change on this vibrant, vulnerable region. This project also emphasizes inclusivity and openness to the public. The researchers will establish a mentoring network for diverse polar scientists through the Polar Impact Network and communicate their results to the public through CryoConnect.org. This project leverages samples already collected from the Amundsen Sea (NBP22-02) to investigate sediment Fe cycling and fluxes. The broad questions driving this research are 1) does benthic Fe fertilize Antarctic coastal primary productivity, and 2) what are the feedbacks between benthic Fe release and carbon cycling in the coastal Antarctic? To answer these questions, the researchers will analyze pore water Fe content and speciation and calculate fluxes of Fe across the sediment-water interface. These results will be compared to sediment characteristics (e.g., organic carbon content, reactive Fe content, proximity to glacial sources) to identify controls on benthic Fe release. This research dovetails with and expands on the science goals of the “Accelerating Thwaites Ecosystem Impacts for the Southern Ocean” (ARTEMIS) project through which the field samples were collected. In turn, the findings of ARTEMIS regarding modeled and observed trace metal dynamics, surface water productivity, and carbon cycling will inform the conclusions of this project, allowing insight into the impact of benthic Fe in the whole system. This project represents a unique opportunity for combined study of the water column and sediment biogeochemistry which will be of great value to the marine biogeochemistry community and will inform future sediment-ocean studies in polar oceanography and beyond. | 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 | |||||||||
Collaborative Research: Do Ocean Wave Impacts Pose a Hazard to the Stability of West Antarctic Ice Shelves?
|
1744759 1246151 1744856 1744958 |
2022-05-16 | Dunham, Eric; Bromirski, Peter; Wei, Yong | Understanding and being able to more reliably forecast ice mass loss from Antarctica is a critical research priority for Antarctic Science. Massive ice shelves buttress marine terminating glaciers, slowing the rate that land ice reaches the sea and, in turn, restraining the rate of sea level rise. To date, most work has focused on the destabilizing impacts of warmer air and water temperatures, resulting in melting that thins and weakens ice shelves. However, recent findings indicate that sea ice does not protect ice shelves from wave impacts as much as previously thought, which has raised the possibility that tsunamis and other ocean waves could affect shelf stability. This project will assess the potential for increased shelf fracturing from the impact of tsunamis and from heightened wave activity due to climate-driven changes in storm patterns and reduced sea-ice extent by developing models to investigate how wave impacts damage ice shelves. The modeling effort will allow for regional comparisons between large and small ice shelves, and provide an evaluation of the impacts of changing climate and storm patterns on ice shelves, ice sheets, glaciers, and, ultimately, sea level rise. This project will train graduate students in mathematical modeling and interdisciplinary approaches to Earth and ocean sciences.<br/><br/>This project takes a four-pronged approach to estimating the impact of vibrations on ice shelves at the grounding zone due to tsunamis, very long period, infragravity, and storm-driven waves. First, the team will use high-resolution tsunami modeling to investigate the response of ice shelves along the West Antarctic coast to waves originating in different regions of the Pacific Ocean. Second, it will compare the response to wave impacts on grounding zones of narrow and wide ice shelves. Third, it will assess the exposure risk due to storm forcing through a reanalysis of weather and wave model data; and, finally, the team will model the propagation of ocean-wave-induced vibrations in the ice from the shelf front to and across the grounding zone. In combination, this project aims to identify locations along the Antarctic coast that are subject to enhanced, bathymetrically-focused, long-period ocean-wave impacts. Linkages between wave impacts and climate arise from potential changes in sea-ice extent in front of shelves, and changes in the magnitude, frequency, and tracks of storms. Understanding the effects of ocean waves and climate on ice-shelf integrity is critical to anticipate their contribution to the amplitude and timing of sea-level rise. Wave-driven reductions in ice-shelf stability may enhance shelf fragmentation and iceberg calving, reducing ice shelf buttressing and eventually accelerating sea-level rise.<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. | None | None | false | false | ||||||||||
Collaborative Research: Modeling ice-ocean interaction for the rapidly evolving ice shelf cavities of Pine Island and Thwaites glaciers, Antarctica
|
1643285 1643174 |
2022-05-13 | Joughin, Ian; Dutrieux, Pierre; Padman, Laurence; Springer, Scott |
|
Overview: Several recent studies indicate continuing and increasing ice loss from the Amundsen Sea region of West Antarctica (chiefly Pine Island and Thwaites glaciers). This loss is initiated by thinning of the floating ice shelves by basal melting driven by circulation of relatively warm ocean water under the ice shelves. This thinning triggers ice-dynamics related feedbacks, which leads to loss of ice from the grounded ice sheet. Models suggest that, even though long-term committed ice loss might be governed by ice dynamics, the magnitude of ocean-driven melting at the base of the ice shelves plays a critical role in controlling the rate of ice loss. These conclusions, however, are based on simple parameterized models for melt rate that do not take into account how ocean circulation will change in future as large-scale climate forcing changes, and as the ice shelves thin and retreat through both excess melting and accelerated ice flow. Given that present global climate models struggle to resolve the modern ocean state close to the ice shelves around Antarctica, their projections of future impacts on basal melting and time scale of ice loss have large uncertainties. This project is aimed at reducing these uncertainties though two approaches: (i) assessing, for a given ocean state, how the melt rates will change as ice-shelf cavities evolve through melting and grounding-line retreat, and (ii) improving understanding of the sensitivity of melt rates beneath the Pine Island and Thwaites ice shelves to changes in ocean state on the Amundsen Sea continental shelf. These studies will provide more realistic bounds on ice loss and sea level rise, and lay the groundwork for development of future fully-coupled ice sheet-ocean simulations. Intellectual Merit: Rather than pursue a strategy of using fully coupled models, this project adopts a simpler semi-coupled approach to understand the sensitivity of ice-shelf melting to future forcing. Specifically, the project focuses on using regional ocean circulation models to understand current and future patterns of melting in ice-shelf cavities. The project’s preliminary stage will focus on developing high-resolution ice-shelf cavity-circulation models driven by modern observed regional ocean state and validated with current patterns of melt inferred from satellite observations. Next, an ice-flow model will be used to estimate the future grounding line at various stages of retreat. Using these results, an iterative process with the ocean-circulation and ice-flow models will be applied to determine melt rates at each stage of grounding line retreat. These results will help assess whether more physically constrained melt-rate estimates substantially alter the hypothesis that unstable collapse of the Amundsen Sea sector of West Antarctica is underway. Further, by multiple simulations with modified open-ocean boundary conditions, this study will provide a better understanding of the sensitivity of melt to future changes in regional forcing. For example, what is the sensitivity of melt to changes in Circumpolar Deep Water temperature and to changes in the thermocline height driven be changes in wind forcing? Finally, several semi-coupled ice-ocean simulations will be used to investigate the influence of the ocean-circulation driven distribution of melt over the next several decades. These simulations will provide a much-improved understanding of the linkages between far-field ocean forcing, cavity circulation and melting, and ice-sheet response. Broader Impacts: Planning within the current large range of uncertainty in future sea level change leads to high social and economic costs for governments and businesses worldwide. Thus, our project to reduce sea-level rise uncertainty has strong societal as well as scientific interest. The findings and methods will be applicable to ice shelf cavities in other parts of Antarctica and northern Greenland, and will set the stage for future studies with fully coupled models as computational resources improve. This interdisciplinary work combines expertise of glaciologists and oceanographers, and will contribute to the education of new researchers in this field, with participation of graduate students and postdocs. Through several outreach activities, team members will help make the public aware of the dramatic changes occurring in Antarctica along with the likely consequences. This proposal does not require fieldwork in the Antarctic. | POLYGON((-104 -73,-102.2 -73,-100.4 -73,-98.6 -73,-96.8 -73,-95 -73,-93.2 -73,-91.4 -73,-89.6 -73,-87.8 -73,-86 -73,-86 -73.8,-86 -74.6,-86 -75.4,-86 -76.2,-86 -77,-86 -77.8,-86 -78.6,-86 -79.4,-86 -80.2,-86 -81,-87.8 -81,-89.6 -81,-91.4 -81,-93.2 -81,-95 -81,-96.8 -81,-98.6 -81,-100.4 -81,-102.2 -81,-104 -81,-104 -80.2,-104 -79.4,-104 -78.6,-104 -77.8,-104 -77,-104 -76.2,-104 -75.4,-104 -74.6,-104 -73.8,-104 -73)) | POINT(-95 -77) | false | false | |||||||||
Collaborative Research: Topographic controls on Antarctic Ice Sheet grounding line retreat - integrating models and observations
|
1745055 1745043 |
2021-09-28 | Simkins, Lauren; Stearns, Leigh; Anderson, John; van der Veen, Cornelis |
|
The goals of this collaborative project are to merge empirical observations from the deglaciated Antarctic continental shelf and 1-D and 3-D numerical model experiments to test the sensitivity of marine-based ice sheets to subglacial topography with collaborators at the University of Kansas (L. Stearns, C. van der Veen). We focus on five glacial systems (i.e., flowlines) across the Amundsen Sea, Ross Sea, and George V Coast of Wilkes Land that extended to/near the continental shelf break at the Last Glacial Maximum – with a range of bed characteristics, topographic features, oceanographic and climatic conditions, and patterns of past ice flow and grounding line retreat. Specifically, at the University of Virginia, we (L. Simkins, S. Munevar Garcia) are: (ongoing) exploring bed roughness across the flowlines to determine the sensitivity of ice flow and grounding line behavior to different scales and wavelengths of bed topography/roughness; (upcoming) developing an empirical relationship between ice-marginal landform sediment volume and grounding line occupation time, and combining this with sedimentological analyses and new absolute age constraints to produce more comprehensive timelines of grounding line retreat, influential boundary conditions and processes, and determine the presence/absence of ice shelves; (ongoing) integrating quantitative and qualitative paleo- and offshore data to be incorporated into and/or validate 1-D and 3-D model experiments further testing the sensitivity of the five glacial systems to bed topography; and (completed) co-developing community engagement and education materials that focus on merging paleo-observations and model information of the Antarctic Ice Sheet from the LGM to the present | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
Continuing Operations Proposal:
The Polar Rock Repository as a Resource for Earth Systems Science
|
9910267 2137467 0739480 1643713 1141906 0440695 |
2021-09-09 | Grunow, Anne |
|
The Polar Rock Repository (PRR) was established to curate and loan geologic samples from polar regions to researchers and educators. OPP established the PRR in part to avoid redundant sample collection and thus reduce the environmental impact of polar research. The PRR also provides the research community with an important resource for developing new research projects. The PRR acquires rock collections through donations from institutions and scientists and makes these samples available as no-cost loans for research, education and museum exhibits. Sample metadata are available in an on-line database. The database also includes rock property information useful for geophysical studies. Researchers may request samples for analysis using an online request form. The PRR fulfills several data management directives, including the Scientific Committee on Antarctic Research, Antarctic Data Management directive of providing free, full and open access to both metadata and the samples. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
West Antarctic Ice-sheet Change and Paleoceanography in the Amundsen Sea Across the Pliocene Climatic Optimum
|
2114839 |
2021-08-25 | Passchier, Sandra | No dataset link provided | The project targets the long-term variability of the West Antarctic Ice Sheet over several glacial-interglacial cycles in the early Pliocene sedimentary record drilled by the International Ocean Discovery Program (IODP) Expedition 379 in the Amundsen Sea. Data collection includes 1) the sand provenance of ice-rafted debris and shelf diamictites and its sources within the Amundsen Sea and Antarctic Peninsula region; 2) sedimentary structures and sortable silt calculations from particle size records and reconstructions of current intensities and interactions; and 3) the bulk provenance of continental rise sediments compared to existing data from the Amundsen Sea shelf with investigations into downslope currents as pathways for Antarctic Bottom Water formation. The results are analyzed within a cyclostratigraphic framework of reflectance spectroscopy and colorimetry (RSC) and X-ray fluorescence scanner (XRF) data to gain insight into orbital forcing of the high-latitude processes. The early Pliocene Climatic Optimum (PCO) ~4.5-4.1 Ma spans a major warm period recognized in deep-sea stable isotope and sea-surface temperature records. This period also coincides with a global mean sea level highstand of > 20 m requiring contributions in ice mass loss from Antarctica. The following hypotheses will be tested: 1) that the West Antarctic Ice Sheet retreated from the continental shelf break through an increase in sub iceshelf melt and iceberg calving at the onset of the PCO ~4.5 Ma, and 2) that dense shelf water cascaded down through slope channels after ~4.5 Ma as the continental shelf became exposed during glacial terminations. The project will reveal for the first time how the West Antarctic Ice Sheet operated in a warmer climate state prior to the onset of the current “icehouse” period ~3.3 Ma. | None | None | false | false | |||||||||
NSFGEO-NERC: Collaborative Research: Accelerating Thwaites Ecosystem Impacts for the Southern Ocean (ARTEMIS)
|
1941292 1941327 1941308 1941304 1941483 |
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: The Antarctic Circumpolar Current: A Conduit or Blender of Antarctic Bottom Waters?
|
2023259 2023244 2023303 |
2021-07-01 | Stewart, Andrew; Thompson, Andrew; Purkey, Sarah |
|
The formation of dense Antarctic Bottom Water (AABW) and its export northward from the Antarctic continent is one of the key components of the global ocean overturning circulation, and plays a critical role in regulating Earth's climate on multi-decadal-to-millennial time scales. Recent studies of the global ocean overturning circulation have increasingly emphasized its three-dimensional structure: AABW is produced in a handful of distinct sites around the Antarctic continent, and there is a pronounced asymmetry in the allocation of AABW transports into the Atlantic, Indian and Pacific basins. The connectivity of AABW between the Antarctic continental shelf and the northern basins is mediated by the Antarctic Circumpolar Current (ACC), a circumpolar eastward flow that also serves as the primary route for inter-basin exchange. The mapping from different shelf AABW sources to the northern basins dictates the response of the global MOC to localized variability or shifts in the state of the Antarctic shelf, for example due to major glacier calving events or modified inputs of freshwater from the Antarctic ice sheet. At present this mapping is not well constrained, with conflicting conclusions drawn in previous studies: at one extreme the ACC has been suggested to be a ``conduit'' that simply allows each variety of AABW to transit directly northward; at the other extreme, it has been suggested that the ACC ``blends'' all shelf AABW sources together before they reach the northern basins. Such conflicts arise, in part, because little is understood about the physics that determines AABW's pathways across the ACC. To close this gap in understanding, this collaborative project draws on three complementary analytical tools: process-oriented modeling of AABW export across the ACC, a high-resolution global ocean model, and an observationally-constrained estimate of the global circulation. The PIs will first identify and quantify the pathways of AABW across the ACC by using these tools to propagate passive tracers that identify each of the four major AABW formation sites. They will then use a suite of process model sensitivity experiments to develop a theory for what controls meridional versus inter-basin transport of AABW in the ACC, and transfer this theory to interpret the AABW pathways simulated in the global model. Finally, they will combine the process model, global model and the observationally-constrained circulation product to map the rates at which AABW is transformed into lighter waters, and relate these transformation rates to the diagnosed pathways of AABW across the ACC. This combination of approaches allow the PIs to not only constrain the three-dimensional circulation of AABW from Antarctica to the northern basins, but also provides a mechanistic understanding of the circulation that can be transferred to past or future climates. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
Antarctic Submarine Melt Variability from Remote Sensing of Icebergs
|
1933764 1643455 |
2021-06-28 | Enderlin, Ellyn |
|
The project uses repeat, very high-resolution (~0.5 m pixel width and length) satellite images acquired by the WorldView satellites, to estimate rates of iceberg melting in key coastal regions around Antarctica. The satellite images are used to construct maps of iceberg surface elevation change over time, which are converted to estimates of area-averaged submarine melt rates. Where ocean temperature observations are available, the melt rates are compared to these data to determine if variations in ocean temperature can explain observed iceberg melt variability. The iceberg melt rates are also compared to glacier frontal ablation rates (flow towards the terminus minus changes in terminus position over time) and integrated into a numerical ice flow model in order to assess the importance of submarine melting on recent changes in terminus position, ice flow, and dynamic mass loss. Overall, the analysis will yield insights into the effects of changes in ocean forcing on the submarine melting of Antarctic ice shelves and icebergs. The project does not require field work in Antarctica. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
ANT LIA Collaborative Research: Interrogating Molecular and Physiological Adaptations in Antarctic Marine Animals.
|
1935672 1935635 |
2021-06-28 | Ryan, Joseph; Santagata, Scott | No dataset link provided | Understanding the genomic changes underlying adaptations to polar environments is critical for predicting how ecological changes will affect life in these fragile environments. Accomplishing these goals requires looking in detail at genome-scale data across a wide array of organisms in a phylogenetic framework. This study combines multifaceted computational and functional approaches that involves analyzing in the genic evolution of invertebrate organisms, known as the bryozoans or ectoprocts. In addition, the commonality of our results in other taxa will be tested by comparing the results to those produced from the previous and newly proposed workshops. Specific aims of this study include: 1) identifying genes involved in adaptation to Antarctic marine environments using transcriptomic and genomic data from bryozoans to test for positively selected genes in a phylogenetic framework, 2) experimentally testing identified candidate enzymes (especially those involved in calcium signaling, glycolysis, the citric acid cycle, and the cytoskeleton) for evidence of cold adaption, and 3) conducting computational workshops aimed at training scientists in techniques for the identification of genetic adaptations to polar and other disparate environments. The proposed work provides critical insights into the molecular rules of life in rapidly changing Antarctic environments, and provides important information for understanding how Antarctic taxa will respond to future environmental conditions. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
West Antarctic Ice Shelf- Ocean Interactions
|
1644159 |
2021-06-25 | Jacobs, Stanley |
|
This project extended and combined historical and recent ocean data sets to investigate ice-ocean-interactions along the Pacific continental margin of the West Antarctic Ice Sheet. The synthesis focused on the strikingly different environments on and near the cold Ross Sea and warm Amundsen Sea continental shelves, where available measurements reach back to 1911 and 1994, respectively. On the more extensively covered Ross Sea continental shelf, multiple reoccupations of ocean stations and transects since the 1950s were used to extend our knowledge of ocean thermohaline change and variability. The more rugged Amundsen Sea continental shelf contains the earth's fastest melting ice shelves, which Holland et al (2019) show can be linked to decadal-scale variability in the tropical Pacific, and Jacobs et al. (2021) document as being the primary influence on freshening downstream in the Ross Sea. Recent and potential future rates of sea level rise are the primary broad-scale impacts revealed by the observations of ice and ocean changes in these study areas. More regionally, freshening also influences the properties of slope front and coastal currents, and abyssal water mass formation. The overriding question in such work is whether their contributions to global and regional sea levels will continue to increase ~linearly, perhaps allowing greenhouse gas reductions to head off the worst consequences, or accelerate and contribute to major social and economic upheavals. The compiled ocean station profile data has been derived from measurements made from 16 ships operated by 6 countries, from 5 projects using holes through fast and glacier ice, and from 3 studies using drifting floats. We are grateful to the many individuals who have acquired, processed and provided the data, along with their supporting agencies, and welcome corrections and updates to this archive. | POLYGON((-180 -72.5,-177 -72.5,-174 -72.5,-171 -72.5,-168 -72.5,-165 -72.5,-162 -72.5,-159 -72.5,-156 -72.5,-153 -72.5,-150 -72.5,-150 -73.15,-150 -73.8,-150 -74.45,-150 -75.1,-150 -75.75,-150 -76.4,-150 -77.05,-150 -77.7,-150 -78.35,-150 -79,-153 -79,-156 -79,-159 -79,-162 -79,-165 -79,-168 -79,-171 -79,-174 -79,-177 -79,180 -79,178.2 -79,176.4 -79,174.6 -79,172.8 -79,171 -79,169.2 -79,167.4 -79,165.6 -79,163.8 -79,162 -79,162 -78.35,162 -77.7,162 -77.05,162 -76.4,162 -75.75,162 -75.1,162 -74.45,162 -73.8,162 -73.15,162 -72.5,163.8 -72.5,165.6 -72.5,167.4 -72.5,169.2 -72.5,171 -72.5,172.8 -72.5,174.6 -72.5,176.4 -72.5,178.2 -72.5,-180 -72.5)) | POINT(-174 -75.75) | false | false | |||||||||
NSF-NERC: Geological History Constraints on the Magnitude of Grounding Line Retreat in the Thwaites Glacier System
|
1738989 2317097 |
2021-03-16 | Goehring, Brent; Hall, Brenda; Campbell, Seth; Venturelli, Ryan A; Balco, Gregory | This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Thwaites Glacier system dominates the contribution to sea-level rise from Antarctica. Predicting how this system will evolve in coming decades, and thereby its likely contribution to sea level, requires detailed understanding of how it has responded to changes in climate and oceanographic conditions in the past. This project will provide a record of regional sea-level change by establishing chronologies for raised marine beaches as well as the timing and duration of periods of retreat of Thwaites Glacier during the past 10,000 years by sampling and dating bedrock presently covered by Thwaites Glacier via subglacial drilling. Together with climatic and oceanographic conditions from other records, these will provide boundary conditions for past-to-present model simulations as well as those used to predict future glacier changes under a range of climate scenarios. Specifically, the project will test the hypothesis--implied by existing geological evidence from the region--that present rapid retreat of the Thwaites Glacier system is reversible. The team aims to utilize two approaches: 1. To reconstruct relative sea level during the Holocene, it will map and date raised marine and shoreline deposits throughout Pine Island Bay. Chronological constraints on sea-level change will be provided by radiocarbon dating of organic material in landforms and sediments that are genetically related to past sea level, such as shell fragments, bones of marine fauna, and penguin guano. 2. To obtain geological evidence for past episodes of grounding-line retreat, the team will apply cosmogenic-nuclide exposure-dating of subglacial bedrock. Using drill systems recently developed for subglacial bedrock recovery, the team will obtain subglacial bedrock from sites where ice thickness is dynamically linked to grounding-line position in the Thwaites system (specifically in the Hudson Mountains, and near Mount Murphy). Observation of significant cosmogenic-nuclide concentrations--the team will primarily measure Beryllium-10 and in situ Carbon-14--in these samples would provide direct, unambiguous evidence for past episodes of thinning linked to grounding-line retreat as well as constraints on their timing and duration. | POLYGON((-114 -74,-112.2 -74,-110.4 -74,-108.6 -74,-106.8 -74,-105 -74,-103.2 -74,-101.4 -74,-99.6 -74,-97.8 -74,-96 -74,-96 -74.2,-96 -74.4,-96 -74.6,-96 -74.8,-96 -75,-96 -75.2,-96 -75.4,-96 -75.6,-96 -75.8,-96 -76,-97.8 -76,-99.6 -76,-101.4 -76,-103.2 -76,-105 -76,-106.8 -76,-108.6 -76,-110.4 -76,-112.2 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74)) | POINT(-105 -75) | false | false | ||||||||||
Collaborative Research: Building Geologically Informed Bed Classes to Improve Projections of Ice Sheet Change
|
2001714 2002346 |
2021-03-02 | Tinto, Kirsty; Bell, Robin; Porter, David; Muto, Atsu | No dataset link provided | Predictions of future changes of the Antarctic ice sheet are essential for understanding changes in the global sea level expected for the coming centuries. These predictions rely on models of ice-sheet flow that in turn rely on knowledge of the physical conditions of the Antarctic continent beneath the ice. Exploration of Antarctica by land, sea, and air has advanced our understanding of the geological material under the Antarctic ice sheet, but this information has not yet been fully integrated into ice-sheet models. This project will take advantage of existing data from decades of US and international investment in geophysical surveys to create a new understanding of the geology underlying the Amundsen Sea and the adjacent areas of the West Antarctic Ice Sheet?a portion of Antarctica that is considered particularly vulnerable to collapse. A series of new datasets called ?Bed Classes? will be developed that will translate the geological properties of the Antarctic continent in ways that can be incorporated into ice-sheet models. <br/><br/>This project will develop a new regional geologic/tectonic framework for the Amundsen Sea Embayment and its ice catchments using extensive marine and airborne geophysical data together with ground-based onshore geophysical and geological constraints to delineate sedimentary basins, bedrock ridges, faults, and volcanic structures. Using this new geologic interpretation of the region, several key issues regarding the geologic influence on ice-sheet stability will be addressed: whether the regional heat flow is dominated by localization along the faults or lithology; the role of geology on the sources, sinks, and flow-paths of subglacial water; the distribution of sediments that determine bed-character variability; and the extent of geologic control on the current Thwaites Glacier grounding line. The impact of improved geological knowledge on ice-sheet models will be tested with the development of a set of ?Bed Class? grids to capture these new insights for use in the models. Bed Classes will be tested within the Parallel Ice Sheet Model framework with initial experiments to identify the sensitivity of model simulations to geological parameterizations. Through a series of workshops with ice-sheet modelers, the Bed Classes will be refined and made accessible to the broader modelling community. This work aims to ensure that the Bed-Class concept can be applied more broadly to ice-sheet models working in different geographic areas and on different timescales.<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((-115 -70,-113 -70,-111 -70,-109 -70,-107 -70,-105 -70,-103 -70,-101 -70,-99 -70,-97 -70,-95 -70,-95 -70.8,-95 -71.6,-95 -72.4,-95 -73.2,-95 -74,-95 -74.8,-95 -75.6,-95 -76.4,-95 -77.2,-95 -78,-97 -78,-99 -78,-101 -78,-103 -78,-105 -78,-107 -78,-109 -78,-111 -78,-113 -78,-115 -78,-115 -77.2,-115 -76.4,-115 -75.6,-115 -74.8,-115 -74,-115 -73.2,-115 -72.4,-115 -71.6,-115 -70.8,-115 -70)) | POINT(-105 -74) | false | false | |||||||||
NSF-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN) Integrating Atmosphere-Ice-Ocean Processes affecting the Sub-Ice-Shelf Environment
|
1929991 1738992 |
2021-02-22 | Truffer, Martin; Scambos, Ted; Muto, Atsu; Heywood, Karen; Boehme, Lars; Hall, Robert; Wahlin, Anna; Lenaerts, Jan; Pettit, Erin | This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Thwaites and neighboring glaciers in the Amundsen Sea Embayment are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Mass loss from the Amundsen Sea Embayment could lead to the eventual collapse of the West Antarctic Ice Sheet, raising the global sea level by up to 2.5 meters (8 feet) in as short as 500 years. The processes driving the loss appear to be warmer ocean circulation and changes in the width and flow speed of the glacier, but a better understanding of these changes is needed to refine predictions of how the glacier will evolve. One highly sensitive process is the transitional flow of glacier ice from land onto the ocean to become a floating ice shelf. This flow of ice from grounded to floating is affected by changes in air temperature and snowfall at the surface; the speed and thickness of ice feeding it from upstream; and the ocean temperature, salinity, bathymetry, and currents that the ice flows into. The project team will gather new measurements of each of these local environmental conditions so that it can better predict how future changes in air, ocean, or the ice will affect the loss of ice to the ocean in this region. <br/> <br/>Current and anticipated near-future mass loss from Thwaites Glacier and nearby Amundsen Sea Embayment region is mainly attributed to reduction in ice-shelf buttressing due to sub-ice-shelf melting by intrusion of relatively warm Circumpolar Deep Water into sub-ice-shelf cavities. Such predictions for mass loss, however, still lack understanding of the dominant processes at and near grounding zones, especially their spatial and temporal variability, as well as atmospheric and oceanic drivers of these processes. This project aims to constrain and compare these processes for the Thwaites and the Dotson Ice Shelves, which are connected through upstream ice dynamics, but influenced by different submarine troughs. The team's specific objectives are to: 1) install atmosphere-ice-ocean multi-sensor remote autonomous stations on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to ice-shelf fronts (using seal tagging, glider-based and ship-based surveys, and existing moored and conductivity-temperature-depth-cast data), 3) measure ocean properties into sub-ice-shelf cavities (using autonomous underwater vehicles) to detail ocean transports and heat fluxes; and 4) constrain current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the ice-shelves (using radar, active-source seismic, and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change. The team will also engage the public and bring awareness to this rapidly changing component of the cryosphere through a "Live from the Ice" social media campaign in which the public can follow the action and data collection from the perspective of tagged seals and autonomous stations.<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((-114 -74,-113 -74,-112 -74,-111 -74,-110 -74,-109 -74,-108 -74,-107 -74,-106 -74,-105 -74,-104 -74,-104 -74.2,-104 -74.4,-104 -74.6,-104 -74.8,-104 -75,-104 -75.2,-104 -75.4,-104 -75.6,-104 -75.8,-104 -76,-105 -76,-106 -76,-107 -76,-108 -76,-109 -76,-110 -76,-111 -76,-112 -76,-113 -76,-114 -76,-114 -75.8,-114 -75.6,-114 -75.4,-114 -75.2,-114 -75,-114 -74.8,-114 -74.6,-114 -74.4,-114 -74.2,-114 -74)) | POINT(-109 -75) | false | false | ||||||||||
Air-Sea Fluxes of Momentum, Heat, and Carbon Dioxide at High Wind Speeds in the Southern Ocean
|
1043623 |
2020-10-09 | Miller, Scott | Accurate parameterizations of the air-sea fluxes of CO2 into the Southern Ocean, in particular at high wind velocity, are needed to better assess how projections of global climate warming in a windier world could affect the ocean carbon uptake, and alter the ocean heat budget at high latitudes. <br/><br/>Air-sea fluxes of momentum, sensible and latent heat (water vapor) and carbon dioxide (CO2) are to be measured continuously underway on cruises using micrometeorological eddy covariance techniques adapted to ship-board use. The measured gas transfer velocity (K) is then to be related to other parameters known to affect air-sea-fluxes.<br/><br/>A stated goal of this work is the collection of a set of direct air-sea flux measurements at high wind speeds, conditions where parameterization of the relationship of gas exchange to wind-speed remains contentious. The studies will be carried out at sites in the Southern Ocean using the USAP RV Nathaniel B Palmer as measurment platform. Co-located pCO2 data, to be used in the overall analysis and enabling internal consistency checks, are being collected from existing underway systems aboard the USAP research vessel under other NSF awards. | POLYGON((117.5 -47,120.35 -47,123.2 -47,126.05 -47,128.9 -47,131.75 -47,134.6 -47,137.45 -47,140.3 -47,143.15 -47,146 -47,146 -49.04,146 -51.08,146 -53.12,146 -55.16,146 -57.2,146 -59.24,146 -61.28,146 -63.32,146 -65.36,146 -67.4,143.15 -67.4,140.3 -67.4,137.45 -67.4,134.6 -67.4,131.75 -67.4,128.9 -67.4,126.05 -67.4,123.2 -67.4,120.35 -67.4,117.5 -67.4,117.5 -65.36,117.5 -63.32,117.5 -61.28,117.5 -59.24,117.5 -57.2,117.5 -55.16,117.5 -53.12,117.5 -51.08,117.5 -49.04,117.5 -47)) | POINT(131.75 -57.2) | false | false | ||||||||||
NSF-NERC The Future of Thwaites Glacier and its Contribution to Sea-level Rise Science Coordination Office
|
1738913 |
2020-09-09 | Scambos, Ted; Vaughan, David G. |
|
This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. The Science Coordination Office will facilitate planning and coordination of the science and broader impacts of several international research projects studying Thwaites Glacier--one of the largest glaciers in Antarctica. The glacier is located on the Pacific coast of the Antarctic continent. It is flowing almost twice as fast now as in the 1970s, and is one of the largest likely contributors to sea-level rise over the coming decades to centuries. Many of the factors that will affect the speed and retreat of Thwaites Glacier will be addressed by the set of projects funded by the Thwaites initiative. The Science Coordination Office comprises a US-UK science and communications team that will work with each project's scientists and students, logistics planners, and NSF and NERC to ensure the overall success of the project. The Office will maintain an informative website, and will produce content to explain the activities of the scientists and highlight the results of the work. <br/><br/>The role of the Science Coordination Office will be to enhance integration and coordination among the science projects selected for the joint NSF-NERC Thwaites initiative to achieve maximum collective scientific and societal impact. The Office will facilitate scientific and logistical planning; facilitate data management, sharing, and discovery; and facilitate and support web content, outreach, and education for this high-profile research endeavor. The Office's role will be key to enabling the program to achieve its scientific goals and for the program to be broadly recognized and valued by scientists, the public, and policymakers.<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((-118 -70,-116 -70,-114 -70,-112 -70,-110 -70,-108 -70,-106 -70,-104 -70,-102 -70,-100 -70,-98 -70,-98 -71,-98 -72,-98 -73,-98 -74,-98 -75,-98 -76,-98 -77,-98 -78,-98 -79,-98 -80,-100 -80,-102 -80,-104 -80,-106 -80,-108 -80,-110 -80,-112 -80,-114 -80,-116 -80,-118 -80,-118 -79,-118 -78,-118 -77,-118 -76,-118 -75,-118 -74,-118 -73,-118 -72,-118 -71,-118 -70)) | POINT(-108 -75) | false | false | |||||||||
Collaborative Research: Pathways of Circumpolar Deep Water to West Antarctica from Profiling Float and Satellite Measurements
|
1341496 |
2019-12-10 | Girton, James; Rynearson, Tatiana |
|
Current oceanographic interest in the interaction of relatively warm water of the Southern Ocean Circumpolar Deep Water (CDW) as it moves southward to the frigid waters of the Antarctic continental shelves is based on the potential importance of heat transport from the global ocean to the base of continental ice shelves. This is needed to understand the longer term mass balance of the continent, the stability of the vast Antarctic ice sheets and the rate at which sea-level will rise in a warming world. Improved observational knowledge of the mechanisms of how warming CDW moves across the Antarctic Circumpolar Current (ACC) is needed. Understanding this dynamical transport, believed to take place through the eddy flux of time-varying mesoscale circulation features, will improve coupled ocean-atmospheric climate models. The development of the next generation of coupled ocean-ice-climate models help us understand future changes in atmospheric heat fluxes, glacial and sea-ice balance, and changes in the Antarctic ecosystems. A recurring obstacle to our understanding is the lack of data in this distant region. In this project, a total of 10 subsurface profiling EM-APEX floats adapted to operate under sea ice were launched in 12 missions (and 2 recoveries) from 4 cruises of opportunity to the Amundsen Sea sector of the Antarctic continental margin during Austral summer. The floats were launched south of the Polar Front and measured shear, turbulence, temperature, and salinity to 2000m depth for 1-2 year missions while drifting with the CDW layer between profiles. | POLYGON((-142 -66,-135.3 -66,-128.6 -66,-121.9 -66,-115.2 -66,-108.5 -66,-101.8 -66,-95.1 -66,-88.4 -66,-81.7 -66,-75 -66,-75 -66.8,-75 -67.6,-75 -68.4,-75 -69.2,-75 -70,-75 -70.8,-75 -71.6,-75 -72.4,-75 -73.2,-75 -74,-81.7 -74,-88.4 -74,-95.1 -74,-101.8 -74,-108.5 -74,-115.2 -74,-121.9 -74,-128.6 -74,-135.3 -74,-142 -74,-142 -73.2,-142 -72.4,-142 -71.6,-142 -70.8,-142 -70,-142 -69.2,-142 -68.4,-142 -67.6,-142 -66.8,-142 -66)) | POINT(-108.5 -70) | false | false | |||||||||
NSF-NERC: THwaites Offshore Research (THOR)
|
1738942 |
2019-11-01 | Wellner, Julia; Larter, Robert; Minzoni, Rebecca; Hogan, Kelly; Anderson, John; Graham, Alastair; Hillenbrand, Claus-Dieter; Nitsche, Frank O.; Simkins, Lauren; Smith, James A. | This project contributes to the joint initiative launched by the U.S. National Science Foundation (NSF) and the U.K. Natural Environment Research Council (NERC) to substantially improve decadal and longer-term projections of ice loss and sea-level rise originating from Thwaites Glacier in West Antarctica. Satellite observations extending over the last 25 years show that Thwaites Glacier is rapidly thinning and accelerating. Over this same period, the Thwaites grounding line, the point at which the glacier transitions from sitting on the seabed to floating, has retreated. Oceanographic studies demonstrate that the main driver of these changes is incursion of warm water from the deep ocean that flows beneath the floating ice shelf and causes basal melting. The period of satellite observation is not long enough to determine how a large glacier, such as Thwaites, responds to long-term and near-term changes in the ocean or the atmosphere. As a result, records of glacier change from the pre-satellite era are required to build a holistic understanding of glacier behavior. Ocean-floor sediments deposited at the retreating grounding line and further offshore contain these longer-term records of changes in the glacier and the adjacent ocean. An additional large unknown is the topography of the seafloor and how it influences interactions of landward-flowing warm water with Thwaites Glacier and affects its stability. Consequently, this project focuses on the seafloor offshore from Thwaites Glacier and the records of past glacial and ocean change contained in the sediments deposited by the glacier and surrounding ocean.<br/><br/>Uncertainty in model projections of the future of Thwaites Glacier will be significantly reduced by cross-disciplinary investigations seaward of the current grounding line, including extracting the record of decadal to millennial variations in warm water incursion, determining the pre-satellite era history of grounding-line migration, and constraining the bathymetric pathways that control flow of warm water to the grounding line. Sedimentary records and glacial landforms preserved on the seafloor will allow reconstruction of changes in drivers and the glacial response to them over a range of timescales, thus providing reference data that can be used to initiate and evaluate the reliability of models. Such data will further provide insights on the influence of poorly understood processes on marine ice sheet dynamics. This project will include an integrated suite of marine and sub-ice shelf research activities aimed at establishing boundary conditions seaward of the Thwaites Glacier grounding line, obtaining records of the external drivers of change, improving knowledge of processes leading to collapse of Thwaites Glacier, and determining the history of past change in grounding line migration and conditions at the glacier base. These objectives will be achieved through high-resolution geophysical surveys of the seafloor and analysis of sediments collected in cores from the inner shelf seaward of the Thwaites Glacier grounding line using ship-based equipment, and from beneath the ice shelf using a corer deployed through the ice shelf via hot water drill holes.<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((-120 -71,-118 -71,-116 -71,-114 -71,-112 -71,-110 -71,-108 -71,-106 -71,-104 -71,-102 -71,-100 -71,-100 -71.5,-100 -72,-100 -72.5,-100 -73,-100 -73.5,-100 -74,-100 -74.5,-100 -75,-100 -75.5,-100 -76,-102 -76,-104 -76,-106 -76,-108 -76,-110 -76,-112 -76,-114 -76,-116 -76,-118 -76,-120 -76,-120 -75.5,-120 -75,-120 -74.5,-120 -74,-120 -73.5,-120 -73,-120 -72.5,-120 -72,-120 -71.5,-120 -71)) | POINT(-110 -73.5) | false | false | ||||||||||
CAREER: Cross-Instrument Synthesis of Antarctic Radar Sounding Observations
|
1745137 |
2019-10-12 | Schroeder, Dustin; MacKie, Emma |
|
Earth's geologic record shows that the great ice sheets have contributed to rates of sea-level rise that have been much higher than those observed today. That said, some sectors of the current Antarctic ice sheet are losing mass at large and accelerating rates. One of the primary challenges for placing these recent and ongoing changes in the context of geologically historic rates, and for making projections decades to centuries into the future, is the difficulty of observing conditions and processes beneath the ice sheet. Whereas satellite observations allow tracking of the ice-surface velocity and elevation on the scale of glacier catchments to ice sheets, airborne ice-penetrating radar has been the only approach for assessing conditions on this scale beneath the ice. These radar observations have been made since the late 1960s, but, because many different instruments have been used, it is difficult to track change in subglacial conditions through time. This project will develop the technical tools and approaches required to cross-compare among these measurements and thus open up opportunities for tracking and understanding changes in the critical subglacial environment. Intertwined with the research and student training on this project will be an outreach education effort to provide middle school and high school students with improved resources and enhanced exposure to geophysical, glaciological, and remote-sensing topics through partnership with the National Science Olympiad.<br/><br/>The radar sounding of ice sheets is a powerful tool for glaciological science with broad applicability across a wide range of cryosphere problems and processes. Radar sounding data have been collected with extensive spatial and temporal coverage across the West Antarctic Ice Sheet, including areas where multiple surveys provide observations that span decades in time or entire cross-catchment ice-sheet sectors. However, one major obstacle to realizing the scientific potential of existing radar sounding observations in Antarctica is the lack of analysis approaches specifically developed for cross-instrument interpretation. Radar is also spatially limited and often has gaps of many tens of kilometers between data points. Further work is needed to investigate ways of extrapolating radar information beyond the flight lines. This project aims to directly address these barriers to full utilization of the collective Antarctic radar sounding record by developing a suite of processing and interpretation techniques to enable the synthesis of radar sounding data sets collected with systems that range from incoherent to coherent, single-channel to swath-imaging, and digital to optically-recorded radar sounders. This includes a geostatistical analysis of ice sheet and radar datasets to make probabilistic predictions of conditions at the bed. The approaches will be assessed for two target regions: the Amundsen Sea Embayment and the Siple Coast. All pre- and post-processed sounding data produced by this project will be publically hosted for use by the wider research community.<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((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
Collaborative Research: Evaluating Retreat in the Amundsen Sea Embayment: Assessing Controlling Processes, Uncertainties, and Projections
|
1443190 |
2019-09-16 | Pollard, David; Parizek, Byron R. | No dataset link provided | Accurate reconstructions and predictions of glacier movement on timescales of human interest require a better understanding of available observations and the ability to model the key processes that govern ice flow. The fact that many of these processes are interconnected, are loosely constrained by data, and involve not only the ice, but also the atmosphere, ocean, and solid Earth, makes this a challenging endeavor, but one that is essential for Earth-system modeling and the resulting climate and sea-level forecasts that are provided to policymakers worldwide. Based on the amount of ice present in the West Antarctic Ice Sheet and its ability to flow and/or melt into the ocean, its complete collapse would result in a global sea-level rise of 3.3 to 5 meters, making its stability and rate of change scientific questions of global societal significance. Whether or not a collapse eventually occurs, a better understanding of the potential West Antarctic contribution to sea level over the coming decades and centuries is necessary when considering the fate of coastal population centers. Recent observations of the Amundsen Sea Embayment of West Antarctica indicate that it is experiencing faster mass loss than any other region of the continent. At present, the long-term stability of this embayment is unknown, with both theory and observations suggesting that collapse is possible. This study is focused on this critical region as well as processes governing changes in outlet glacier flow. To this end, we will test an ice-sheet model against existing observations and improve treatment of key processes within ice sheet models. This is a four-year (one year of no-cost extension) modeling study using the open-source Ice Sheet System Model in coordination with other models to help improve projections of future sea-level change. Overall project goals, which are distributed across the collaborating institutions, are to: 1. hindcast the past two-to-three decades of evolution of the Amundsen Sea Embayment sector to determine controlling processes, incorporate and test parameterizations, and assess and improve model initialization, spinup, and performance; 2. utilize observations from glacial settings and efficient process-oriented models to develop a better understanding of key processes associated with outlet glacier dynamics and to create numerically efficient parameterizations for these often sub-grid-scale processes; 3. project a range of evolutions of the Amundsen Sea Embayment sector in the next several centuries given various forcings and inclusion or omission of physical processes in the model. | POLYGON((-130 -73,-125.5 -73,-121 -73,-116.5 -73,-112 -73,-107.5 -73,-103 -73,-98.5 -73,-94 -73,-89.5 -73,-85 -73,-85 -73.9,-85 -74.8,-85 -75.7,-85 -76.6,-85 -77.5,-85 -78.4,-85 -79.3,-85 -80.2,-85 -81.1,-85 -82,-89.5 -82,-94 -82,-98.5 -82,-103 -82,-107.5 -82,-112 -82,-116.5 -82,-121 -82,-125.5 -82,-130 -82,-130 -81.1,-130 -80.2,-130 -79.3,-130 -78.4,-130 -77.5,-130 -76.6,-130 -75.7,-130 -74.8,-130 -73.9,-130 -73)) | POINT(-107.5 -77.5) | false | false | |||||||||
Collaborative Research: Cobalamin and Iron Co-Limitation Of Phytoplankton Species in Terra Nova Bay
|
1643684 1644073 |
2019-08-08 | DiTullio, Giacomo; Lee, Peter |
|
Phytoplankton blooms in the coastal waters of the Ross Sea, Antarctica are typically dominated by either diatoms or Phaeocystis Antarctica (a flagellated algae that often can form large colonies in a gelatinous matrix). The project seeks to determine if an association of bacterial populations with Phaeocystis antarctica colonies can directly supply Phaeocystis with Vitamin B12, which can be an important co-limiting micronutrient in the Ross Sea. The supply of an essential vitamin coupled with the ability to grow at lower iron concentrations may put Phaeocystis at a competitive advantage over diatoms. Because Phaeocystis cells can fix more carbon than diatoms and Phaeocystis are not grazed as efficiently as diatoms, the project will help in refining understanding of carbon dynamics in the region as well as the basis of the food web webs. Such understanding also has the potential to help refine predictive ecological models for the region. The project will conduct public outreach activities and will contribute to undergraduate and graduate research. Engagement of underrepresented students will occur during summer student internships. A collaboration with Italian Antarctic researchers, who have been studying the Terra Nova Bay ecosystem since the 1980s, aims to enhance the project and promote international scientific collaborations. <br/><br/>The study will test whether a mutualistic symbioses between attached bacteria and Phaeocystis provides colonial cells a mechanism for alleviating chronic Vitamin B12 co-limitation effects thereby conferring them with a competitive advantage over diatom communities. The use of drifters in a time series study will provide the opportunity to track in both space and time a developing algal bloom in Terra Nova Bay and to determine community structure and the physiological nutrient status of microbial populations. A combination of flow cytometry, proteomics, metatranscriptomics, radioisotopic and stable isotopic labeling experiments will determine carbon and nutrient uptake rates and the role of bacteria in mitigating potential vitamin B12 and iron limitation. Membrane inlet and proton transfer reaction mass spectrometry will also be used to estimate net community production and release of volatile organic carbon compounds that are climatically active. Understanding how environmental parameters can influence microbial community dynamics in Antarctic coastal waters will advance an understanding of how changes in ocean stratification and chemistry could impact the biogeochemistry and food web dynamics of Southern Ocean ecosystems. | POLYGON((-180 -72,-173.6 -72,-167.2 -72,-160.8 -72,-154.4 -72,-148 -72,-141.6 -72,-135.2 -72,-128.8 -72,-122.4 -72,-116 -72,-116 -72.7,-116 -73.4,-116 -74.1,-116 -74.8,-116 -75.5,-116 -76.2,-116 -76.9,-116 -77.6,-116 -78.3,-116 -79,-122.4 -79,-128.8 -79,-135.2 -79,-141.6 -79,-148 -79,-154.4 -79,-160.8 -79,-167.2 -79,-173.6 -79,180 -79,178 -79,176 -79,174 -79,172 -79,170 -79,168 -79,166 -79,164 -79,162 -79,160 -79,160 -78.3,160 -77.6,160 -76.9,160 -76.2,160 -75.5,160 -74.8,160 -74.1,160 -73.4,160 -72.7,160 -72,162 -72,164 -72,166 -72,168 -72,170 -72,172 -72,174 -72,176 -72,178 -72,-180 -72)) | POINT(-158 -75.5) | false | false | |||||||||
Collaborative Research: Grounding Line Dynamics: Crary Ice Rise Revisited
|
1443356 1443552 |
2019-05-06 | Conway, Howard; Koutnik, Michelle; Winberry, Paul |
|
Recent observations and model results suggest that collapse of the Amundsen Sea sector of West Antarctica may already be underway. However, the timeline of collapse and the effects of ongoing climatic and oceanographic changes are key unanswered questions. Complete disintegration of the ice sheet would raise global sea level by more than 3 m, which would have significant societal impacts. Improved understanding of the controls on ice-sheet evolution is needed to make better predictions of ice-sheet behavior. Results from numerical models show that buttressing from surrounding ice shelves and/or from small-scale grounded ice rises should act to slow the retreat and discharge of ice from the interior ice sheet. However, there are very few field observations with which to develop and validate models. Field observations conducted in the early 1980s on Crary Ice Rise in the Ross Sea Embayment are a notable exception. This project will revisit Crary Ice Rise with new tools to make a suite of measurements designed to address questions about how the ice rise affects ice discharge from the Ross Sea sector of West Antarctica. The team will include a graduate and undergraduate student, and will participate in a range of outreach activities.<br/><br/>New tools including radar, seismic, and GPS instruments will be used to conduct targeted geophysical measurements both on Crary Ice Rise and across its grounding line. The project will use these new measurements, together with available ancillary data to inform a numerical model of grounding line dynamics. The model and measurements will be used to address the (1) How has the ice rise evolved over timescales ranging from: the past few decades; the past millennia after freeze-on; and through the deglaciation? (2) What history of ice dynamics is preserved in the radar-detected internal stratigraphy? (3) What dynamical effect does the presence/absence of the ice rise have on discharge of the Ross Ice Streams today? (4) How is it contributing to the slow-down of the proximal Whillans and Mercer ice streams? (5) What dynamical response will the ice rise have under future environmental change? | POLYGON((-175 -82.7,-173.9 -82.7,-172.8 -82.7,-171.7 -82.7,-170.6 -82.7,-169.5 -82.7,-168.4 -82.7,-167.3 -82.7,-166.2 -82.7,-165.1 -82.7,-164 -82.7,-164 -82.77,-164 -82.84,-164 -82.91,-164 -82.98,-164 -83.05,-164 -83.12,-164 -83.19,-164 -83.26,-164 -83.33,-164 -83.4,-165.1 -83.4,-166.2 -83.4,-167.3 -83.4,-168.4 -83.4,-169.5 -83.4,-170.6 -83.4,-171.7 -83.4,-172.8 -83.4,-173.9 -83.4,-175 -83.4,-175 -83.33,-175 -83.26,-175 -83.19,-175 -83.12,-175 -83.05,-175 -82.98,-175 -82.91,-175 -82.84,-175 -82.77,-175 -82.7)) | POINT(-169.5 -83.05) | false | false | |||||||||
Circumpolar Deep Water and the West Antarctic Ice Sheet
|
9725024 |
2019-03-11 | Jacobs, Stanley; Visbeck, Martin |
|
This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. | POLYGON((140 -65,141 -65,142 -65,143 -65,144 -65,145 -65,146 -65,147 -65,148 -65,149 -65,150 -65,150 -65.3,150 -65.6,150 -65.9,150 -66.2,150 -66.5,150 -66.8,150 -67.1,150 -67.4,150 -67.7,150 -68,149 -68,148 -68,147 -68,146 -68,145 -68,144 -68,143 -68,142 -68,141 -68,140 -68,140 -67.7,140 -67.4,140 -67.1,140 -66.8,140 -66.5,140 -66.2,140 -65.9,140 -65.6,140 -65.3,140 -65)) | POINT(145 -66.5) | false | false | |||||||||
None
|
1644159 |
2018-07-12 | Dutrieux, Pierre; Stammerjohn, Sharon; Jenkins, Adrian; Jacobs, Stanley |
|
None | None | None | false | false | |||||||||
Ice sheet Dynamics and Processes along the West Antarctic Continental Shelf
|
0838735 |
2018-01-26 | Nitsche, Frank O. |
|
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5). The West Antarctic Ice Sheet is believed to be vulnerable to climate change as it is grounded below sea level, is drained by rapidly flowing ice streams and is fringed by floating ice shelves subject to melting by incursions of relatively warm Antarctic circumpolar water. Currently, the most rapidly thinning glaciers in Antarctica occur in the Amundsen and Bellingshausen Sea sectors. This study seeks to place the present day observations into a longer-term geological context over a broad scale by high-resolution swath bathymetric mapping of continental shelf sea floor features that indicate past ice presence and behavior. Gaps in existing survey coverage of glacial lineations and troughs indicating ice flow direction and paleo-grounding zone wedges over the Ross, Amundsen and Bellingshausen Sea sectors are targeted. The surveys will be conducted as part of the 2010 Icebreaker Oden science opportunity and will take advantage of the vessel?s state-of-the-art swath mapping system.<br/><br/>Broader impacts:<br/>This activity will supplement and complement more focused regional studies by US, Swedish, UK, French, Japanese and Polish collaborators also sailing on the Oden. The PI will compile bathymetric data to be acquired by the Oden and other ships in the region over the duration of the project into the existing bathymetric data base. The compiled data set will be made publically available through the NSF founded Antarctic Multibeam Bathymetry and Geophysical Data Synthesis (AMBS) site. It will also be integrated into the GEBCO International Bathymetric Chart of the Southern Ocean (IBCSO) and so significantly improve the basis for ship navigation in the Pacific sector of the Southern Ocean. Undergraduate students will be involved in the research under supervision of the PI via the Lamont summer internship program. The PI is a young investigator and this will be his first NSF grant as a PI. | POLYGON((-140 -68,-136 -68,-132 -68,-128 -68,-124 -68,-120 -68,-116 -68,-112 -68,-108 -68,-104 -68,-100 -68,-100 -68.75,-100 -69.5,-100 -70.25,-100 -71,-100 -71.75,-100 -72.5,-100 -73.25,-100 -74,-100 -74.75,-100 -75.5,-104 -75.5,-108 -75.5,-112 -75.5,-116 -75.5,-120 -75.5,-124 -75.5,-128 -75.5,-132 -75.5,-136 -75.5,-140 -75.5,-140 -74.75,-140 -74,-140 -73.25,-140 -72.5,-140 -71.75,-140 -71,-140 -70.25,-140 -69.5,-140 -68.75,-140 -68)) | POINT(-120 -71.75) | false | false | |||||||||
Collaborative Research: Long-Term and Interannual Variability of Antarctic Ice Sheet Mass Balance From Satellite Gravimetry and Other Geodetic Measurements
|
1043750 |
2016-05-13 | Chen, Jianli; Wilson, Clark; Blankenship, Donald D.; Tapley, Byron |
|
1043750/Chen<br/><br/>This award supports a project to improve the estimate of long-term and inter-annual variability of Antarctic ice sheet mass balance at continental, regional, and catchment scales, using satellite gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) and other geodetic measurements. The work will improve the quantification of long-term mass change rates over Antarctica using GRACE gravity data with a longer record and newer generation(s) of products and will develop advanced numerical forward modeling techniques that can accurately correct leakage effects associated with GRACE data processing, and significantly improve spatial resolution of GRACE mass rate estimates over Antarctica. The work will also contribute to a better understanding of crustal uplift rates due to postglacial rebound (PGR) and present day ice load change over Antarctica via PGR models, GPS measurements, and combined analysis of GRACE and ICESat elevation changes. Inter-annual variations of ice mass over Antarctica will be investigated at continental and catchment scales and connections to regional climate change will be studied. The major deliverables from this study will be improved assessments of ice mass balance for the entire Antarctic ice sheet and potential contribution to global mean sea level rise. The work will also provide estimates of regional ice mass change rates over Antarctica, with a focus along the coast in the Amundsen Sea Embayment, the Peninsula in West Antarctica, and in Wilkes Land and Victoria Land in East Antarctica. Estimates of inter-annual ice mass change over Antarctica at various spatial scales, and assessments of uncertainty of GRACE ice rate estimates and PGR models errors over Antarctica will also be made. The intellectual merits of the proposed investigation include 1) providing improved assessments of Antarctic ice mass balance at different temporal and spatial scales with unprecedented accuracy, an important contribution to broad areas of polar science research; 2) combining high accuracy GPS vertical uplift measurements and PGR models to better quantify long-term crust uplift effects that are not distinguishable from ice mass changes by GRACE; and 3) unifying the work of several investigations at the forefront of quantifying ice sheet and glacier mass balance and crustal uplift based on a variety of modern space geodetic observations. The broader impacts include the fact that the project will actively involve student participation and training, through the support of two graduate students. In addition the project will contribute to general education and public outreach (E/PO) activities and the results from this investigation will help inspire future geoscientists and promote public awareness of significant manifestations of climate change. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||||||||
Pre and post molt biology of emperor penguins - Oden trans - Ross / Amundsen Sea cruise
|
1043454 |
2015-12-12 | Kooyman, Gerald |
|
The emperor penguin dives deeper and longer, fasts longer, and endures the harshest weather conditions of all diving birds. It spends about four and half months per annum deep in Antarctic pack ice away from shore and stations, and thus is largely unavailable for study. This time includes preparation for the molt, and travel to the colony to breed, a time period in which great swings in body weight occur. This study will fill an important gap in what we know about the biology of the annual cycle of the emperor by examining the molt-post molt period. The P.I. proposes to traverse the Amundsen and Bellingshausen seas on the Oden, to locate and tag emperor penguins during the molt season. The objectives are to (1) Place satellite tags on 20 adult post molt birds to determine their route, rate of travel, and diving behavior as they return back to their breeding colonies, (2) Obtain an index of body condition, (3) Collect guano to determine the type of food consumed by emperor penguins in the region, (4) Conduct shipboard surveys to sight and plot the location and abundance of adult and juvenile birds on the ship's track. The PI hypothesizes that bird dives will be shallow during the initial post-molt phase, and that food will consist primarily of krill; that there will be differential dispersal of birds from the Ross Sea vs. Marie Byrd Land, with Ross Sea birds traveling farther; and that the greatest adult mortality occurs during the molt and early post molt period. Broader impacts include training of a post doc, a graduate student, and an aquarium volunteer. The P.I. also will present findings through a website, through public lectures, and in collaboration with the Birch aquarium. | POLYGON((-172.642 -72.55,-170.9074 -72.55,-169.1728 -72.55,-167.4382 -72.55,-165.7036 -72.55,-163.969 -72.55,-162.2344 -72.55,-160.4998 -72.55,-158.7652 -72.55,-157.0306 -72.55,-155.296 -72.55,-155.296 -73.0743,-155.296 -73.5986,-155.296 -74.1229,-155.296 -74.6472,-155.296 -75.1715,-155.296 -75.6958,-155.296 -76.2201,-155.296 -76.7444,-155.296 -77.2687,-155.296 -77.793,-157.0306 -77.793,-158.7652 -77.793,-160.4998 -77.793,-162.2344 -77.793,-163.969 -77.793,-165.7036 -77.793,-167.4382 -77.793,-169.1728 -77.793,-170.9074 -77.793,-172.642 -77.793,-172.642 -77.2687,-172.642 -76.7444,-172.642 -76.2201,-172.642 -75.6958,-172.642 -75.1715,-172.642 -74.6472,-172.642 -74.1229,-172.642 -73.5986,-172.642 -73.0743,-172.642 -72.55)) | POINT(-163.969 -75.1715) | false | false | |||||||||
Roosevelt Island Climate Evolution Project (RICE): US Deep Ice Core Glaciochemistry Contribution (2011- 2014)
|
1042883 |
2015-10-27 | Haines, Skylar; Kurbatov, Andrei V.; Mayewski, Paul A.; Beers, Thomas M. |
|
1042883/Mayewski<br/><br/>This award supports a project to analyze a deep ice core which will be drilled by a New Zealand research team at Roosevelt Island. The objectives are to process the ice core at very high resolution to (a) better understand phasing sequences in Arctic/Antarctic abrupt climate change, even at the level of individual storm events; (b) determine the impact of changes in the Westerlies and the Amundsen Sea Low on past/present/future climate change; (c) determine how sea ice extent has varied in the area; (d) compare the response of West Antarctica climate to other regions during glacial/interglacial cycles; and (e) determine how climate of the Ross Sea Embayment changed during the transition from Ross Ice Sheet to Ross Ice Shelf. The intellectual merit of the RICE deep ice core project is that it is expected to provide a 30kyr long (and possibly 150kyr long) extremely high-resolution view of climate change in the Ross Sea Embayment Region and data essential to test and understand critical questions that have emerged as a consequence of the recent synthesis of Antarctic and Southern Ocean climate change presented in the Scientific Commission for Antarctic Research document: Antarctic Climate Change and the Environment (ACCE, 2009). Ice core processing and analysis will be performed jointly by University of Maine and the collaborators from New Zealand. Co-registered sampling for all chemical analyses will be accomplished by a joint laboratory effort at the IGNS NZ ice core facility using a continuous melter system developed by the University of Maine. The RICE deep ice core record will provide information necessary in unraveling the significance of multi-millennial underpinning for climate change and in the understanding of observed and projected climate change in light of current dramatic human impact on Antarctica and the Southern Ocean. The broader impacts of the project include the fact that two CCI graduate students will be funded through the project, and will be involved in all aspects of field research, core sampling, sample processing, analytical and numerical analyses, data interpretation, writing of manuscripts, and presentation of results at national and international conferences. Data and ideas developed in this project and associated work will be used in several courses taught at the University of Maine. Innovative cyberinfrastructure will be incorporated into this work and ground breaking analytical technologies, and data access/storage tools will be used. | None | None | false | false | |||||||||
Collaborative International Research: Amundsen Sea Influence on West Antarctic Ice Sheet Stability and Sea Level Rise - IPY/ASEP
|
0632282 |
2015-09-25 | Jacobs, Stanley; Hellmer, Hartmut; Jenkins, Adrian | The Office of Polar Programs, Antarctic Science Division, Ocean & Climate Systems Program has made this award to support a multidisciplinary effort to study the upwelling of relatively warm deep water onto the Amundsen Sea continental shelf and how it relates to atmospheric forcing and bottom bathymetry and how the warm waters interact with both glacial and sea ice. This study constitutes a contribution of a coordinated research effort in the region known as the Amundsen Sea Embayment Project or ASEP. Previous work by the PI and others has shown that the West Antarctic Ice Sheet has been found to be melting faster, perhaps by orders of magnitude, than ice sheets elsewhere around Antarctica, excluding those on the Peninsula. Submarine channels that incise the continental shelf are thought to provide fairly direct access of relatively warm circum polar deep water to the cavity under the floating extension of the ice shelf. Interactions with sea ice en route can modify the upwelled waters. The proposed investigations build on previous efforts by the PI and colleagues to use hydrographic measurements to put quantitative bounds on the rate of glacial ice melt by relatively warm seawater. <br/>The region can be quite difficult to access due to sea ice conditions and previous hydrographic measurements have been restricted to the austral summer time frame. In this project it was proposed to obtain the first austral spring hydrographic data via CTD casts and XBT drops (September-October 2007) as part of a separately funded cruise (PI Steve Ackley) the primary focus of which is sea-ice conditions to be studied while the RV Nathanial B Palmer (RV NBP) drifts in the ice pack. This includes opportunistic sampling for pCO2 and TCO2. A dedicated cruise in austral summer 2009 will follow this opportunity. The principal objectives of the dedicated field program are to deploy a set of moorings with which to characterize temporal variability in warm water intrusions onto the shelf and to conduct repeat hydrographic surveying and swath mapping in targeted areas, ice conditions permitting. Automatic weather stations are to be deployed in concert with the program, sea-ice observations will be undertaken from the vessel and the marine cavity beneath the Pine Island may be explored pending availability of the British autonomous underwater vehicle Autosub 3. These combined ocean-sea ice-atmosphere observations are aimed at a range of model validations. A well-defined plan for making data available as well as archiving in a timely fashion should facilitate a variety of modeling efforts and so extend the value of the spatially limited observations. <br/>Broader impacts: This project is relevant to an International Polar Year research emphasis on ice sheet dynamics focusing in particular on the seaward ocean-ice sheet interactions. Such interactions must be clarified for understanding the potential for sea level rise by melt of the West Antarctic ice Sheet. The project entails substantive international partnerships (British Antarctic Survey and Alfred Wegner Institute) and complements other Amundsen Sea Embayment Project proposals covering other elements of ice sheet dynamics. The proposal includes partial support for 2 graduate students and 2 post docs. Participants from the Antarctic Artists and Writers program are to take part in the cruise and so aid in outreach. In addition, the project is to be represented in the Lamont-Doherty annual open house. | POLYGON((-129.6 -54.2,-124.44 -54.2,-119.28 -54.2,-114.12 -54.2,-108.96 -54.2,-103.8 -54.2,-98.64 -54.2,-93.48 -54.2,-88.32 -54.2,-83.16 -54.2,-78 -54.2,-78 -56.29,-78 -58.38,-78 -60.47,-78 -62.56,-78 -64.65,-78 -66.74,-78 -68.83,-78 -70.92,-78 -73.01,-78 -75.1,-83.16 -75.1,-88.32 -75.1,-93.48 -75.1,-98.64 -75.1,-103.8 -75.1,-108.96 -75.1,-114.12 -75.1,-119.28 -75.1,-124.44 -75.1,-129.6 -75.1,-129.6 -73.01,-129.6 -70.92,-129.6 -68.83,-129.6 -66.74,-129.6 -64.65,-129.6 -62.56,-129.6 -60.47,-129.6 -58.38,-129.6 -56.29,-129.6 -54.2)) | POINT(-103.8 -64.65) | false | false | ||||||||||
ASPIRE: Amundsen Sea Polynya International Research Expedition
|
0944727 |
2015-01-30 | Arrigo, Kevin |
|
ASPIRE is an NSF-funded project that will examine the ecology of the Amundsen Sea during the Austral summer of 2010. ASPIRE includes an international team of trace metal and carbon chemists, phytoplankton physiologists, microbial and zooplankton ecologists, and physical oceanographers, that will investigate why and how the Amundsen Sea Polynya is so much more productive than other polynyas and whether interannual variability can provide insight to climate-sensitive mechanisms driving carbon fluxes. This project will compliment the existing ASPIRE effort by using 1) experimental manipulations to understand photoacclimation of the dominant phytoplankton taxa under conditions of varying light and trace metal abundance, 2) nutrient addition bioassays to determine the importance of trace metal versus nitrogen limitation of phytoplankton growth, and 3) a numerical ecosystem model to understand the importance of differences in mixing regime, flow field, and Fe sources in controlling phytoplankton bloom dynamics and community composition in this unusually productive polynya system. The research strategy will integrate satellite remote sensing, field-based experimental manipulations, and numerical modeling. Outreach and education include participation in Stanford's Summer Program for Professional Development for Science Teachers, Stanford's School of Earth Sciences high school internship program, and development of curriculum for local science training centers, including the Chabot Space and Science Center. Undergraduate participation and training will include support for both graduate students and undergraduate assistants. | POLYGON((-118.3 -71.6,-117.57 -71.6,-116.84 -71.6,-116.11 -71.6,-115.38 -71.6,-114.65 -71.6,-113.92 -71.6,-113.19 -71.6,-112.46 -71.6,-111.73 -71.6,-111 -71.6,-111 -71.86,-111 -72.12,-111 -72.38,-111 -72.64,-111 -72.9,-111 -73.16,-111 -73.42,-111 -73.68,-111 -73.94,-111 -74.2,-111.73 -74.2,-112.46 -74.2,-113.19 -74.2,-113.92 -74.2,-114.65 -74.2,-115.38 -74.2,-116.11 -74.2,-116.84 -74.2,-117.57 -74.2,-118.3 -74.2,-118.3 -73.94,-118.3 -73.68,-118.3 -73.42,-118.3 -73.16,-118.3 -72.9,-118.3 -72.64,-118.3 -72.38,-118.3 -72.12,-118.3 -71.86,-118.3 -71.6)) | POINT(-114.65 -72.9) | false | false | |||||||||
Collaborative Research; IPY: Ocean-Ice Interaction in the Amundsen Sea sector of West Antarctica
|
0732906 0732730 0732869 0732804 |
2014-12-30 | Truffer, Martin; Stanton, Timothy; Bindschadler, Robert; Behar, Alberto; Nowicki, Sophie; Anandakrishnan, Sridhar; Holland, David; McPhee, Miles G. |
|
Collaborative With: McPhee 0732804, Holland 0732869, Truffer 0732730, Stanton 0732926, Anandakrishnan 0732844 <br/>Title: Collaborative Research: IPY: Ocean-Ice Interaction in the Amundsen Sea Sector of West Antarctica<br/><br/>The Office of Polar Programs, Antarctic Integrated and System Science Program has made this award to support an interdisciplinary study of the effects of the ocean on the stability of glacial ice in the most dynamic region the West Antarctic Ice Sheet, namely the Pine Island Glacier in the Amundsen Sea Embayment. The collaborative project builds on the knowledge gained by the highly successful West Antarctic Ice Sheet program and is being jointly sponsored with NASA. Recent observations indicate a significant ice loss, equivalent to 10% of the ongoing increase in sea-level rise, in this region. These changes are largest along the coast and propagate rapidly inland, indicating the critical impact of the ocean on ice sheet stability in the region. While a broad range of remote sensing and ground-based instrumentation is available to characterize changes of the ice surface and internal structure (deformation, ice motion, melt) and the shape of the underlying sediment and rock bed, instrumentation has yet to be successfully deployed for observing boundary layer processes of the ocean cavity which underlies the floating ice shelf and where rapid melting is apparently occurring. Innovative, mini ocean sensors that can be lowered through boreholes in the ice shelf (about 500 m thick) will be developed and deployed to automatically provide ocean profiling information over at least three years. Their data will be transmitted through a conducting cable frozen in the borehole to the surface where it will be further transmitted via satellite to a laboratory in the US. Geophysical and remote sensing methods (seismic, GPS, altimetry, stereo imaging, radar profiling) will be applied to map the geometry of the ice shelf, the shape of the sub ice-shelf cavity, the ice surface geometry and deformations within the glacial ice. To integrate the seismic, glaciological and oceanographic observations, a new 3-dimensional coupled ice-ocean model is being developed which will be the first of its kind. NASA is supporting satellite based research and the deployment of a robotic-camera system to explore the environment in the ocean cavity underlying the ice shelf and NSF is supporting all other aspects of this study. <br/><br/>Broader impacts: This project is motivated by the potential societal impacts of rapid sea level rise and should result in critically needed improvements in characterizing and predicting the behavior of coupled ocean-ice systems. It is a contribution to the International Polar Year and was endorsed by the International Council for Science as a component of the "Multidisciplinary Study of the Amundsen Sea Embayment" proposal #258 of the honeycomb of endorsed IPY activities. The research involves substantial international partnerships with the British Antarctic Survey and the University of Bristol in the UK. The investigators will partner with the previously funded "Polar Palooza" education and outreach program in addition to undertaking a diverse set of outreach activities of their own. Eight graduate students and one undergraduate as well as one post doc will be integrated into this research project. | POINT(-100.728 -75.0427) | POINT(-100.728 -75.0427) | false | false | |||||||||
Collaborative Research: Western Divide West Antarctic Ice Cores (WAISCORES) Site Selection
|
0087345 |
2014-08-15 | Conway, Howard; Waddington, Edwin D. | No dataset link provided | This award supports a program of ground-based geophysical measurements to map in detail the spatial variations of ice flow, accumulation rate, internal layering and ice thickness at the sites which have been identified as promising locations to drill the next deep ice core in West Antarctica. The main investigative tools are a high- and low-frequency ice penetrating radar to image the topography of internal layers and the bed, repeat GPS surveys to calculate the present day surface velocity field, synthetic aperture radar (SAR) interferometry to calculate the regional velocity field, and short firn cores to calculate present day accumulation rates. The data which will be collected will be used to as input to time-dependent ice flow and temperature models that will predict depth variation of age, layer thickness, and temperature. As well as yielding an estimate of expected conditions before drilling, the mismatch between the model prediction and data eventually recovered from the core will help infer thinning and climate (accumulation and temperature) histories for the region. The Western Divide, between the Ross Sea Embayment and the Amundsen Sea, has been identified as the region which best satisfies the criteria which have been established for a deep drilling site. Preliminary site selection using airborne geophysical methods has identified several potential drill sites on the Western Divide where the climate record should be best preserved. This work will contribute in a major way to the final site selection for the next deep ice core in West Antarctica. | POINT(112 79) | POINT(-112 -79) | false | false | |||||||||
IPY: Flow Dynamics of the Amundsen Sea Glaciers: Thwaites and Pine Island.
|
0632198 |
2012-08-29 | Anandakrishnan, Sridhar |
|
This award supports a project to study ice sheet history and dynamics on the Thwaites Glacier and Pine Island Glacier in the Amundsen Sea sector of the West Antarctic Ice Sheet. The international collaboration that has been established with the British Antarctic Survey will enable a fuller suite of geophysical experiments with more-efficient use of people and logistics than we could achieve individually. This project is one of a number of projects to characterize the Amundsen Sea Embayment, which has been identified in numerous planning documents as perhaps the most important target for ice-dynamical research. Taken together, this "pulse of activity" will result in a better understanding of this important part of the global system. Field work will measure the subglacial environment of Thwaites and Pine Island Glaciers using three powerful, but relatively simple tools: reflection seismic imaging, GPS motion monitoring of the tidal forcing, and passive seismic monitoring of the seismicity associated with motion. The results of the field work will feed into ice-sheet modeling efforts that are tuned to the case of an ocean-terminating glacier and will assess the influence of these glaciers on current sea level and project into the future. The broader impacts of the project involve the inclusion of a film- and audio-professional to document the work for informal outreach (public radio and TV; museums). In addition, we will train graduate students in polar geophysical and glaciological research and in numerical modeling techniques. The ultimate goal of this project, of assessing the role of Thwaites Glacier in global sea level change, has broad societal impact in coastal regions and small islands. | POINT(110 -74) | POINT(-110 -74) | false | false | |||||||||
Collaborative Research: Ice-flow history of the Thwaites Glacier, West Antarctica
|
0739654 0739372 |
2012-05-30 | Conway, Howard; Catania, Ginny; Markowski, Michael; Macgregor, Joseph A.; Andrews, Alan G.; Fudge, T. J. |
|
Catania 0739654<br/><br/>This award supports a project to study the Amundsen Sea drainage system and improve understanding of the impact of recent glaciological changes as an aid to predicting how this region will change in the future. The intellectual merit of the work is that the Amundsen Sea drainage system has been a recent focus for glaciological research because of rapid changes occurring there as a result of grounding line retreat. The work will focus on the regions of flow transition and will map the internal stratigraphy of the ice sheet across the Thwaites Glacier shear margins and use the age and geometry of radar-detected internal layers to interpret ice flow history. Thwaites Glacier (one of the main pathways for ice drainage in the region) has recently widened and may continue to do so in the near future. Thwaites Glacier may be particularly vulnerable to grounding line retreat because it lacks a well-defined subglacial channel. The subglacial environment exerts strong control on ice flow and flow history will be mapped in the context of bed topography and bed reflectivity. The plan is to use existing ice-penetrating radar data and coordinate with planned upcoming surveys to reduce logistical costs. The work proposed here will take three years to complete but no additional fieldwork in Antarctica is required. More detailed ground-based geophysical (radar and seismic) experiments will be needed at key locations to achieve our overall goal and the work proposed here will aid in identifying those regions. The broader impacts of the project are that it will initiate a new collaboration among radar communities within the US including those that are on the forefront of radar systems engineering and those that are actively involved in radar-derived internal layer and bed analysis. The project will also provide support for a postdoctoral researcher and a graduate student, thus giving them exposure to a variety of methodologies and scientific issues. Finally, there are plans to further develop the "Wired Antarctica" website designed by Ginny Catania with the help of a student-teacher. This will allow for the existing lesson plans to be updated to Texas State standards so that they can be used more broadly within state middle and high schools. | None | None | false | false | |||||||||
Collaborative Research: Synthesis of Thwaites Glacier Dynamics: Diagnostic and Prognostic Sensitivity Studies of a West Antarctic Outlet System
|
0758274 0636724 |
2012-05-15 | Carter, Sasha P.; Dupont, Todd K.; Holt, John W.; Morse, David L.; Parizek, Byron R.; Young, Duncan A.; Kempf, Scott D.; Blankenship, Donald D. | This award supports a three-year study to isolate essential physical processes affecting Thwaites Glacier (TG) in the Amundsen Sea Embayment (ASE) of West Antarctica using a suite of existing numerical models in conjunction with existing and International Polar Year (IPY)-proposed data sets. Four different models will be utilized to explore the effects of embayment geometry, ice-shelf buttressing, basal-stress distribution, surface mass balance, surface climate, and inland dynamic perturbations on the present and future dynamics of TG. This particular collection of models is ideally suited for the broad nature of this investigation, as they incorporate efficient and complementary simplifications of the stress field (shallow-ice and shelf-stream), system geometry (1-d and 2-d plan-view and flowline; depth-integrated and depth-dependent), and mass-momentum energy coupling (mechanical and thermo-mechanical). The models will be constrained and validated by data sets (including regional maps of ice thickness, surface elevation, basal topography, ice surface velocity, and potential fields) and geophysical data analyses (including increasing the spatial resolution of surface elevations, improving regional estimates of geothermal flux, and characterizing the sub-glacial interface of grounded ice as well as the grounding-zone transition between grounded and floating ice). The intellectual merit of the research focuses on several of the NSF Glaciology program's emphases, including: ice dynamics, numerical modeling, and remote sensing of ice sheets. In addition, the research directly addresses the following specific NSF objectives: "investigation of the physics of fast glacier flow with emphasis on processes at glacier beds"; "investigation of ice-shelf stability"; and "identification and quantification of the feedback between ice dynamics and climate change". The broader impacts of this research effort will help answer societally relevant questions of future ice sheet stability and sea-level change. The research also will aid in the early career development of two young investigators and will contribute to the education of both graduate and undergraduate students directly involved in the research, and results will be incorporated into courses and informal presentations. | POLYGON((-110.058 -74.0548,-109.57993 -74.0548,-109.10186 -74.0548,-108.62379 -74.0548,-108.14572 -74.0548,-107.66765 -74.0548,-107.18958 -74.0548,-106.71151 -74.0548,-106.23344 -74.0548,-105.75537 -74.0548,-105.2773 -74.0548,-105.2773 -74.31383,-105.2773 -74.57286,-105.2773 -74.83189,-105.2773 -75.09092,-105.2773 -75.34995,-105.2773 -75.60898,-105.2773 -75.86801,-105.2773 -76.12704,-105.2773 -76.38607,-105.2773 -76.6451,-105.75537 -76.6451,-106.23344 -76.6451,-106.71151 -76.6451,-107.18958 -76.6451,-107.66765 -76.6451,-108.14572 -76.6451,-108.62379 -76.6451,-109.10186 -76.6451,-109.57993 -76.6451,-110.058 -76.6451,-110.058 -76.38607,-110.058 -76.12704,-110.058 -75.86801,-110.058 -75.60898,-110.058 -75.34995,-110.058 -75.09092,-110.058 -74.83189,-110.058 -74.57286,-110.058 -74.31383,-110.058 -74.0548)) | POINT(-107.66765 -75.34995) | false | false | ||||||||||
Detection of Crystal Orientation Fabrics near the Ross/Amundsen Sea Ice-flow Divide and at the Siple Dome Ice Core Site using Polarimetric Radar Methods
|
0440847 |
2011-08-29 | Matsuoka, Kenichi; Power, Donovan; Fujita, Shuji; Raymond, Charles; Rasmussen, Al | This award supports a project to investigate fabrics with ground-based radar measurements near the Ross/Amundsen Sea ice-flow divide where a deep ice core will be drilled. The alignment of crystals in ice (crystal-orientation fabric) has an important effect on ice deformation. As ice deforms, anisotropic fabrics are produced, which, in turn, influence further deformation. Measurement of ice fabric variations can help reveal the deformation history of the ice and indicate how the ice will deform in the future. Ice cores provide opportunities to determine a vertical fabric profile, but horizontal variations of fabrics remain unknown. Remote sensing with ice-penetrating radar is the only way to do that over large areas. Preliminary results show that well-established polarimetric methods can detect the degree of horizontal anisotropy of fabrics and their orientation, even when they are nearly vertical-symmetric fabrics. In conjunction with ice deformation history, our first mapping of ice fabrics will contribute to modeling ice flow near the future ice core site. The project will train a graduate student and provide research experiences for two under graduate students both in field and laboratory. The project will contribute to ongoing West Antarctic ice sheet program efforts to better understand the impact of the ice sheet on global sea level rise. This project also supports an international collaboration between US and Japanese scientists. | None | None | false | false | ||||||||||
Collaborative Research: Controls on climate-active gases by Amundsen Sea ice biota
|
0836112 0836144 0836061 |
2011-04-24 | Smith, Walker; Yager, Patricia; Dennett, Mark | Convincing evidence now confirms that polar regions are changing rapidly in response to human activities. Changes in sea ice extent and thickness will have profound implications for productivity, food webs and carbon fluxes at high latitudes, since sea ice biota are a significant source of biogenic matter for the ecosystem. While sea ice is often thought to be a barrier to gas exchange between the ocean and the atmosphere, it more likely functions as a source or sink for climate-active gases such as carbon dioxide and ozone-depleting organohalogens, due in part to activities of microbes embedded in the sea ice matrix. This project brings together experienced US and Swedish investigators to examine the controls by sea-ice biota on the production and degradation of key climate-active gases in the Pacific sector of the Southern Ocean. We hypothesize that 1) the physical properties of the sea-ice environment will determine the community structure and activities of the sea ice biota; 2) the productivity, biomass, physiological state and species composition of ice algae will determine the production of specific classes of organic carbon, including organohalogens; 3) heterotrophic co-metabolism within the ice will break down these compounds to some extent, depending on the microbial community structure and productivity, and 4) the sea ice to atmosphere fluxes of CO2 and organohalogens will be inversely related. This project will build close scientific collaborations between US and Swedish researchers and also train young scientists, including members of underrepresented groups. Dissemination of results will include the scientific literature, and public outreach venues including interactions with a PolarTrec teacher. | POLYGON((100 -69,107 -69,114 -69,121 -69,128 -69,135 -69,142 -69,149 -69,156 -69,163 -69,170 -69,170 -70,170 -71,170 -72,170 -73,170 -74,170 -75,170 -76,170 -77,170 -78,170 -79,163 -79,156 -79,149 -79,142 -79,135 -79,128 -79,121 -79,114 -79,107 -79,100 -79,100 -78,100 -77,100 -76,100 -75,100 -74,100 -73,100 -72,100 -71,100 -70,100 -69)) | POINT(135 -74) | false | false | ||||||||||
Collaborative research aboard Icebreaker Oden: ASPIRE (Amundsen Sea Polynya International Research Expedition)
|
0839069 |
2011-03-03 | Yager, Patricia |
|
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>The Amundsen Sea Polynya is areally the most productive Antarctic polynya, exhibits higher chlorophyll levels during peak bloom and greater interannual variability than the better-studied Ross Sea Polynya ecosystem. Polynyas may be the key to understanding the future of polar regions as their extent is expected to increase with anthropogenic warming. The project will examine 1) sources of iron to the Amundsen Sea Polynya as a function of climate forcing, 2) phytoplankton community structure in relation to iron supply and mixed-layer depths, 3) the efficiency of the biological pump of carbon to depth and 4) the net flux of carbon as a function of climate and micronutrient forcing. The research also will compare results for the Amundsen Sea to existing data synthesis and modeling efforts for the Palmer LTER and Ross Sea. The project will 1) build close scientific collaborations between US and Swedish researchers; 2) investigate climate change implications with broad societal relevance; 3) train new researchers; 4) encourage participation in research science by underrepresented groups, and 5) involve broad dissemination of results via scientific literature and public outreach, including close interactions with NSF-supported PolarTrec and COSEE K-12 teachers. | None | None | false | false | |||||||||
Collaborative Research: IPY, The Next Generation: A Community Ice Sheet Model for Scientists and Educators With Demonstration Experiments in Amundsen Sea Embayment Region
|
0632325 0632161 0632168 0632346 |
2010-07-02 | Hulbe, Christina; Seals, Cheryl; Johnson, Jesse; Daescu, Dacian N. |
|
Johnson/0632161<br/><br/>This award supports a project to create a "Community Ice Sheet Model (CISM)". The intellectual merit of the proposed activity is that the development of such a model will aid in advancing the science of ice sheet modeling. The model will be developed with the goal of assuring that CISM is accurate, robust, well documented, intuitive, and computationally efficient. The development process will stress principles of software design. Two complementary efforts will occur. One will involve novel predictive modeling experiments on the Amundsen Sea Embayment region of Antarctica with the goal of understanding how interactions between basal processes and ice sheet dynamics can result in abrupt reconfigurations of ice-sheets, and how those reconfigurations impact other Earth systems. New modeling physics are to include the higher order stress terms that allow proper resolution of ice stream and shelf features, and the associated numerical methods that allow higher and lower order physics to be coexist in a single model. The broader impacts of the proposed activity involve education and public outreach. The model will be elevated to a high standard in terms of user interface and design, which will allow for the production of inquiry based, polar and climate science curriculum for K-12 education. The development of a CISM itself would represent a sea change in the way that glaciological research is conducted, eliminating numerous barriers to progress in polar research such as duplicated efforts, lack of transparency in publication, lack of a cryospheric model for others to link to and reference, and a common starting point from which to begin investigation. As the appropriate interfaces are developed, a curriculum to utilize CISM in education will be developed. Students participating in this grant will be required to be involved in public outreach through various mechanisms including local and state science fairs. The model will also serve as a basis for educating "a new generation" of climate scientists. This project is relevant to the International Polar Year (IPY) as the research team is multi-institutional and multi-disciplinary, will bring new groups and new specialties into the realm of polar research and is part of a larger group of proposals whose research focuses on research in the Amundsen Sea Embayment Plan region of Antarctica. The project is international in scope and the nature of software development is quite international, with firm commitments from the United Kingdom and Belgium to collaborate. In addition there will be an international external advisory board that will be used to guide development, and serve as a link to other IPY activities. | POLYGON((-180 -50.05,-144 -50.05,-108 -50.05,-72 -50.05,-36 -50.05,0 -50.05,36 -50.05,72 -50.05,108 -50.05,144 -50.05,180 -50.05,180 -54.045,180 -58.04,180 -62.035,180 -66.03,180 -70.025,180 -74.02,180 -78.015,180 -82.01,180 -86.005,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -86.005,-180 -82.01,-180 -78.015,-180 -74.02,-180 -70.025,-180 -66.03,-180 -62.035,-180 -58.04,-180 -54.045,-180 -50.05)) | POINT(0 -89.999) | false | false | |||||||||
Glaciological Characteristics of the Ross/Amundsen Sea Ice-flow Divide Deduced by a New Analysis of Ice-penetrating Radar Data
|
0338151 |
2010-05-11 | Raymond, Charles; Matsuoka, Kenichi; Luyendyk, Bruce P.; Wilson, Douglas S. | This award supports an investigation of spatial variations of ice temperature and subglacial conditions using available ice-penetrating radar data around a future deep ice coring site near the Ross and Amundsen flow divide of West Antarctic Ice Sheet. Besides geometry of reflection layers the focus will be on intensities of radar echoes from within ice deeper than several hundred meters and will also examine echoes from the bed. Preliminary studies on theory and comparison with Japanese radar data from East Antarctica suggest that large spatial variations of the vertical gradient of radar echoes from within ice exist and are caused primarily by ice temperature and secondarily by crystal-orientation fabric. The hypothesis that the vertical gradient is a proxy of ice temperature will be tested. The project will utilize an existing data set from the Support Office for Aerogeophysical Research in Antarctica (SOAR) and will complement work already underway at University of Texas to analyze the radar data. The project will provide undergraduate research experience with an emphasis on computer analysis of time series and large data sets as well as development of web-based resource of results and methods and will support an international collaboration between US and Japan through discussions on the preliminary results from their study sites. Practical procedures developed through this study will be downloadable from the project's web site in the third year and will allow investigation of other ice sheets using existing radar data sets. This project will contribute to the interpretation of the future inland West Antarctic ice core and will help in the understanding of ice sheet history and climate change. | POINT(-112.086 -79.468) | POINT(-112.086 -79.468) | false | false | ||||||||||
The Amundsen Continental Shelf and the Antarctic Ice Sheet
|
0440775 |
2010-05-04 | Jacobs, Stanley |
|
This collaborative study between Columbia University and the Southampton Oceanography Centre will investigate the dynamics of warm water intrusions under antarctic floating ice shelves. The study will focus on the Amundsen Sea and Pine Island Glacier, and will document how this water gains access to the continental shelf, transports heat into the ice shelf cavities via deep, glacially-scoured troughs, and rises beneath the ice to drive basal melting. The resulting seawater-meltwater mixtures upwell near the ice fronts, contributing to the formation of atypical coastal polynyas with strong geochemical signatures. Multidecadal freshening downstream is consistent with thinning ice shelves, which may be triggering changes inland, increasing the flow of grounded ice into the sea. This work will be carried out in combination with parallel modeling, remote sensing and data based projects, in an effort to narrow uncertainties about the response of West Antarctic Ice Sheet to climate change. Using state-of-the-art facilities and instruments, this work will enhance knowledge of water mass production and modification, and the understanding of interactions between the ocean circulation, sea floor and ice shelves. The data and findings will be reported to publicly accessible archives and submitted for publication in the scientific literature. The information obtained should prove invaluable for the development and validation of general circulation models, needed to predict the future role of the Antarctic Ice Sheet in sea level change. | None | None | false | false | |||||||||
Antarctic Pack Ice Seals: Ecological Interactions with Prey and the Environment
|
9815961 |
2010-05-04 | Bengtson, John |
|
9815961 <br/>BENGTSON<br/>The pack ice region surrounding Antarctica contains at least fifty percent of the world's population of seals, comprising about eighty percent of the world's total pinniped biomass. As a group, these seals are among the dominant top predators in Southern Ocean ecosystems, and the fluctuation in their abundance, growth patterns, life histories, and behavior provide a potential source of information about environmental variability integrated over a wide range of spatial and temporal scales. This proposal was developed as part of the international Antarctic Pack Ice Seals (APIS) program, which is aimed to better understand the ecological relationships between the distribution of pack ice seals and their environment. During January-February, 2000, a research cruise through the pack ice zone of the eastern Ross Sea and western Amundsen Sea will be conducted to survey and sample along six transects perpendicular to the continental shelf. Each of these transects will pass through five environmental sampling strata: continental shelf zone, Antarctic slope front, pelagic zone, the ice edge front, and the open water outside the pack ice zone. All zones but open water will be ice-covered to some degree. Surveys along each transect will gather data on bathymetry, hydrography, sea ice dynamics and characteristics, phytoplankton and ice algae stocks, prey species (e.g., fish, cephalopods and euphausiids), and seal distribution, abundance and diet. This physical and trophic approach to investigating ecological interactions among pack ice seals, prey and the physical environment will allow the interdisciplinary research team to test the hypothesis that there are measurable physical and biological features in the Southern Ocean that result in area of high biological activity by upper trophic level predators. Better insight into the interplay among pack ice seals and biological and physical features of Antarctic marine ecosystems will allow for a better prediction of fluctuation in seal population in the context of environmental change. | POLYGON((-179.99905 -43.56728,-143.99915 -43.56728,-107.99925 -43.56728,-71.99935 -43.56728,-35.99945 -43.56728,0.000450000000001 -43.56728,36.00035 -43.56728,72.00025 -43.56728,108.00015 -43.56728,144.00005 -43.56728,179.99995 -43.56728,179.99995 -47.058498,179.99995 -50.549716,179.99995 -54.040934,179.99995 -57.532152,179.99995 -61.02337,179.99995 -64.514588,179.99995 -68.005806,179.99995 -71.497024,179.99995 -74.988242,179.99995 -78.47946,144.00005 -78.47946,108.00015 -78.47946,72.00025 -78.47946,36.00035 -78.47946,0.000450000000001 -78.47946,-35.99945 -78.47946,-71.99935 -78.47946,-107.99925 -78.47946,-143.99915 -78.47946,-179.99905 -78.47946,-179.99905 -74.988242,-179.99905 -71.497024,-179.99905 -68.005806,-179.99905 -64.514588,-179.99905 -61.02337,-179.99905 -57.532152,-179.99905 -54.040934,-179.99905 -50.549716,-179.99905 -47.058498,-179.99905 -43.56728)) | POINT(0 -89.999) | false | false | |||||||||
Sea Ice Mass Balance in the Antarctic-SIMBA Drift Station
|
0538516 |
2010-05-04 | Ackley, Stephen |
|
This project is a study of the evolution of the sea ice cover, and the mass balance of ice in the Amundsen Sea and the Bellingshausen Sea in the internationally collaborative context of the International Polar Year (2007-2008). In its simplest terms, the mass balance is the net freezing and melting that occurs over an annual cycle at a given location. If the ice were stationary and were completely to melt every year, the mass balance would be zero. While non-zero balances have significance in questions of climate and environmental change, the process itself has global consequences since the seasonal freeze-melt cycle has the effect of distilling the surface water. Oceanic salt is concentrated into brine and rejected from the ice into deeper layers in the freezing process, while during melt, the newly released and relatively fresh water stabilizes the surface layers. The observation program will be carried out during a drift program of the Nathaniel B. Palmer, and through a buoy network established on the sea ice that will make year-long measurements of ice thickness, and temperature profile, large-scale deformation, and other characteristics. The project is a component of the Antarctic Sea Ice Program, endorsed internationally by the Joint Committee for IPY. Additionally, the buoys to be deployed have been endorsed as an IPY contribution to the World Climate Research Program/Scientific Committee on Antarctic Research (WCRP/SCAR) International Programme on Antarctic Buoys (IPAB). While prior survey information has been obtained in this region, seasonal and time-series measurements on sea ice mass balance are crucial data in interpreting the mechanisms of air-ice-ocean interaction. <br/> The network will consist of an array of twelve buoys capable of GPS positioning. Three buoys will be equipped with thermister strings and ice and snow thickness measurement gauges, as well as a barometer. Two buoys will be equipped with meteorological sensors including wind speed and direction, atmospheric pressure, and incoming radiation. Seven additional buoys will have GPS positioning only, and will be deployed approximately 100 km from the central site. These outer buoys will be critical in capturing high frequency motion complementary to satellite-derived ice motion products. Additional buoys have been committed internationally through IPAB and will be deployed in the region as part of this program.<br/> This project will complement similar projects to be carried out in the Weddell Sea by the German Antarctic Program, and around East Antarctica by the Australian Antarctic Program. The combined buoy and satellite deformation measurements, together with the mass balance measurements, will provide a comprehensive annual data set on sea ice thermodynamics and dynamics for comparison with both coupled and high-resolution sea ice models. | None | None | false | false | |||||||||
Circumpolar Deep Water and the West Antarctic Ice Sheet
|
9725024 |
2010-05-04 | Jacobs, Stanley |
|
This project will study the dynamics of Circumpolar Deep Water intruding on the continental shelf of the West Antarctic coast, and the effect of this intrusion on the production of cold, dense bottom water, and melting at the base of floating glaciers and ice tongues. It will concentrate on the Amundsen Sea shelf, specifically in the region of the Pine Island Glacier, the Thwaites Glacier, and the Getz Ice Shelf. Circumpolar Deep Water (CDW) is a relatively warm water mass (warmer than +1.0 deg Celsius) which is normally confined to the outer edge of the continental shelf by an oceanic front separating this water mass from colder and saltier shelf waters. In the Amundsen Sea however, the deeper parts of the continental shelf are filled with nearly undiluted CDW, which is mixed upward, delivering significant amounts of heat to the base of the floating glacier tongues and the ice shelf. The melt rate beneath the Pine Island Glacier averages ten meters of ice per year with local annual rates reaching twenty meters. By comparison, melt rates beneath the Ross Ice Shelf are typically twenty to forty centimeters of ice per year. In addition, both the Pine Island and the Thwaites Glacier are extremely fast-moving, and have a significant effect on the regional ice mass balance of West Antarctica. This project therefore has an important connection to antarctic glaciology, particularly in assessing the combined effect of global change on the antarctic environment. The particular objectives of the project are (1) to delineate the frontal structure on the continental shelf sufficiently to define quantitatively the major routes of CDW inflow, meltwater outflow, and the westward evolution of CDW influence; (2) to use the obtained data set to validate a three-dimensional model of sub-ice ocean circulation that is currently under construction, and (3) to refine the estiamtes of in situ melting on the mass balance of the antarctic ice sheet. The observational program will be carried out from the research vessel Nathaniel B. Palmer in February and March, 1999. *** | None | None | false | false | |||||||||
Glacial History of the Amundsen Sea Shelf
|
9814692 |
2010-05-04 | Kellogg, Thomas; Jacobs, Stanley |
|
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a marine geological investigation of the Amundsen Sea region toward a better understanding of the deglaciation history of the West Antarctic Ice Sheet (WAIS). The WAIS may be inherently unstable because it is the last marine-based ice sheet in the world. Unlike other embayments in West Antarctica, major ice streams draining into the Amundsen Sea from the interior of the WAIS lack buttressing ice shelves. Mass balance data for the distal portions of these ice streams (Pine Island and Thwaites glaciers) appear to be in balance or may be becoming negative. Because both ice streams have beds that slope downward toward the center of the ice sheet, grounding-line recession resulting from either continued thinning or sea-level rise could trigger irreversible grounding-line retreat, leading to ice-sheet disintegration and consequent global sea-level rise. The limited marine geological and geophysical data available from the Amundsen Sea suggest that grounded ice or an ice shelf occupied the inner Amundsen Sea embayment until perhaps as recently as 1000 to 2000 years ago, and this ice may have retreated rapidly in historic time.<br/><br/>This project, a study of the marine geology and geophysics of the Amundsen Sea continental shelf from 100 degrees W to 130 degrees W, is designed to address the Amundsen Sea part of WAIS Science Plan Priority Goal H2: "What is the deglaciation history in the eastern Ross, the Bellingshausen and Amundsen Seas?" This project will examine bathymetric data of the Amundsen Sea continental shelf to determine the positions of former ice-steam channels, and to aid in choosing sites for sediment coring. Single-channel seismic reflection studies will be conducted in order to determine sediment-thickness patterns, to aid in choice of coring sites, and to locate and identify morphologic features indicative of former grounded ice (e.g., moraines, scours, flutes, striations, till wedges and deltas, etc.). Coring will be concentrated along former ice flow-lines. Core samples will be analyzed in the laboratory for sedimentology, to determine whether of not basal tills are present (indicating former grounded ice and its former extent), and for calcareous and siliceous microfossils. The chronology of grounding-line and ice-shelf retreat from a presumed Last Glacial Maximum position near the shelf break will be established using accelerator mass spectrometry (AMS) carbon-14 dates of acid-insoluble particulate organic carbon.<br/><br/>This project will share ship time in the Amundsen Sea with a physical oceanographic project. Marine geologic data and samples collected will be integrated with findings of other investigators toward developing a comprehensive interpretation of the history of the WAIS. | POLYGON((-179.99342 -58.74225,-143.994734 -58.74225,-107.996048 -58.74225,-71.997362 -58.74225,-35.998676 -58.74225,0.000010000000003 -58.74225,35.998696 -58.74225,71.997382 -58.74225,107.996068 -58.74225,143.994754 -58.74225,179.99344 -58.74225,179.99344 -60.716231,179.99344 -62.690212,179.99344 -64.664193,179.99344 -66.638174,179.99344 -68.612155,179.99344 -70.586136,179.99344 -72.560117,179.99344 -74.534098,179.99344 -76.508079,179.99344 -78.48206,143.994754 -78.48206,107.996068 -78.48206,71.997382 -78.48206,35.998696 -78.48206,0.000010000000003 -78.48206,-35.998676 -78.48206,-71.997362 -78.48206,-107.996048 -78.48206,-143.994734 -78.48206,-179.99342 -78.48206,-179.99342 -76.508079,-179.99342 -74.534098,-179.99342 -72.560117,-179.99342 -70.586136,-179.99342 -68.612155,-179.99342 -66.638174,-179.99342 -64.664193,-179.99342 -62.690212,-179.99342 -60.716231,-179.99342 -58.74225)) | POINT(0.000010000000003 -68.612155) | false | false | |||||||||
The Role of Snow in Antarctic Sea Ice Development and Ocean-Atmosphere Energy Exchange
|
9316767 |
2010-05-04 | Jeffries, Martin |
|
The goal of this investigation is to understand the role of snow in sea ice development processes and air-ice-ocean heat exchange interactions in the seasonal and perennial sea ice zones of the Ross Sea, the Amundsen Sea, and the Bellingshausen Sea. Observations and measurements of the characteristics of sea ice and snow will be combined with numerical models of sea-ice flooding and the entrainment of snow into the ice cover in order to gain an understanding of the sea-ice heat and mass balance, and to quantify the energy exchange within the antarctic sea-ice cover. The snow measurement program, using the RVIB Nathaniel B. Palmer, will include depth, grain size and morphology, density, temperature, thermal conductivity, water content, and stable isotope ratio. The ice measurement program will include thickness, salinity, temperature, density, brine content, and included gas volume, as well as such structural properties as the fraction of frazil, platelet, and congelation ice in the seasonal antarctic pack ice. Differences in ice types are the result of differences in the environment in which the ice forms: frazil ice is formed in supercooled sea water, normally through wind or wave-induced turbulence, while platelet and congelation ice is formed under quiescent conditions. The fraction of frazil ice is an important variable in the energy budget of the upper ocean, and contributes significantly to the stabilization of the surface layers. The numerical models will involve the thermodynamics of phase changes from liquid water to ice, along with the resulting energy transfer, brine expulsion, and the modulating effect of a snow cover. The results are expected to have broad relevance and application to understanding the effects of sea-ice processes in global change, and atmospheric, oceanographic, and remote sensing investigations of the Southern Ocean. | POLYGON((-180 -43.56571,-144 -43.56571,-108 -43.56571,-72 -43.56571,-36 -43.56571,0 -43.56571,36 -43.56571,72 -43.56571,108 -43.56571,144 -43.56571,180 -43.56571,180 -46.304308,180 -49.042906,180 -51.781504,180 -54.520102,180 -57.2587,180 -59.997298,180 -62.735896,180 -65.474494,180 -68.213092,180 -70.95169,144 -70.95169,108 -70.95169,72 -70.95169,36 -70.95169,0 -70.95169,-36 -70.95169,-72 -70.95169,-108 -70.95169,-144 -70.95169,-180 -70.95169,-180 -68.213092,-180 -65.474494,-180 -62.735896,-180 -59.997298,-180 -57.2587,-180 -54.520102,-180 -51.781504,-180 -49.042906,-180 -46.304308,-180 -43.56571)) | POINT(0 -89.999) | false | false | |||||||||
SGER: Science-of-Opportunity Aboard Icebreaker Oden: Ocean-Atmosphere-Ice Interactions and Changes
|
0741510 |
2010-02-20 | Yuan, Xiaojun; Stammerjohn, Sharon |
|
Abstract<br/><br/>The project goal is to investigate the ocean-atmosphere-ice (OAI) interactions in the Amundsen and Ross Seas during the austral summer of 2007-08 using hydrographic measurements (CTD and XBT) in conjunction with (1) ship-based observations and satellite-derived estimates of sea ice concentration, and (2) ship-based observations and re-analyses of meteorological variables. The major scientific objectives are as follows: (1) to examine upper ocean characteristics along three transects in the Amundsen Sea and two transects in the Ross Sea within the context of ice-atmosphere variability over the preceding winter-spring season and as compared to other years where data are available; (2) to determine if there is additional evidence of increased upwelling of warm Circumpolar Deep Water onto the shelf in the Amundsen Sea and/or increased freshening in the Ross Sea as has been inferred by previous, but limited, ocean surveys in these regions; and (3) to examine the spatial variability in ocean thermal structure along the ship's track (outside the transects) to provide greater regional context and to compare with ocean XBT data collected during Oden 2006-07. A repeated temperature survey between the Amundsen and Ross Sea is particularly invaluable, given that this sector is the regional center of the high latitude OAI response to ENSO, thus providing opportunity for examining and linking regional oceanic temporal variability to global climate variability. The research will improve our understanding of the high latitude OAI response to climate change, and provide the physical context for the observed biology and geochemistry (investigated by our colleagues. Our results will be made widely available through research publications and internet-available databases, and through the strong public outreach efforts of Lamont-Doherty Earth Observatory. The outreach efforts will help increase awareness and understanding of anthropogenic climate change, melting ice, and ecosystem alteration in the highly sensitive Antarctic. | POLYGON((-180 -69,-172 -69,-164 -69,-156 -69,-148 -69,-140 -69,-132 -69,-124 -69,-116 -69,-108 -69,-100 -69,-100 -70,-100 -71,-100 -72,-100 -73,-100 -74,-100 -75,-100 -76,-100 -77,-100 -78,-100 -79,-108 -79,-116 -79,-124 -79,-132 -79,-140 -79,-148 -79,-156 -79,-164 -79,-172 -79,180 -79,178.5 -79,177 -79,175.5 -79,174 -79,172.5 -79,171 -79,169.5 -79,168 -79,166.5 -79,165 -79,165 -78,165 -77,165 -76,165 -75,165 -74,165 -73,165 -72,165 -71,165 -70,165 -69,166.5 -69,168 -69,169.5 -69,171 -69,172.5 -69,174 -69,175.5 -69,177 -69,178.5 -69,-180 -69)) | POINT(-147.5 -74) | false | false | |||||||||
Small Grants for Exploratory Research - Oceanographic Research in the Amundsen and Ross Seas:
|
0741380 |
2009-06-22 | Smith, Walker |
|
The research will examine the relative importance of the physical and chemical controls on phytoplankton dynamics and carbon flux in continental margin regions of the Southern Ocean, and elucidate mechanisms by which plankton populations and carbon export might be altered by climate change. We specifically will address (1) how the phytoplankton on the continental margins of the southern Ocean respond to spatial and temporal changes in temperature, light, iron supply, and carbon dioxide levels, (2) how these factors initiate changes in phytoplankton assemblage structure, and (3) how carbon export and the efficiency of the biological pump are impacted by the biomass and composition of the phytoplankton. Two regions of study (the Amundsen and Ross Seas) will be investigated, one well studied (Ross Sea) and one poorly described (Amundsen Sea). It is hypothesized that each region will have markedly different physical forcing, giving rise to distinct chemical conditions and therefore biological responses. As such, the comparison of the two may give us insights into the mechanisms of how Antarctic continental margins will respond under changing environmental conditions. Broader impacts include participation by an international graduate student from Brazil, outreach via seminars to the general public, collaboration with the teachers-in-residence on the cruise, development of a cruise web site and interactive email exchanges with local middle school students while at sea | POLYGON((100 -65,106 -65,112 -65,118 -65,124 -65,130 -65,136 -65,142 -65,148 -65,154 -65,160 -65,160 -66.5,160 -68,160 -69.5,160 -71,160 -72.5,160 -74,160 -75.5,160 -77,160 -78.5,160 -80,154 -80,148 -80,142 -80,136 -80,130 -80,124 -80,118 -80,112 -80,106 -80,100 -80,100 -78.5,100 -77,100 -75.5,100 -74,100 -72.5,100 -71,100 -69.5,100 -68,100 -66.5,100 -65)) | POINT(130 -72.5) | false | false | |||||||||
SGER: Primary and Secondary Production and Carbon Flux Through the Microbial Community Along the Western Antarctic Marginal Ice Zone on the Oden Southern Ocean 2007 Expeditions
|
0742057 |
2009-03-16 | Gallager, Scott; Dennett, Mark |
|
Abstract<br/><br/>The research will continue and extend the study in the Southern Ocean that was initiated during the Oden Southern Ocean 2006 expedition in collaboration with Swedish scientist Mellissa Chierici. We will quantify carbon flux through the food web in the marginal ice zone (MIZ) by measuring size fractionated primary and secondary production, grazing and carbon flux through nanoplankton (2-20 um), microplankton (20-200um), and mesoplankton (200-2000 um). Community structure, species abundance and size specific grazing rates will be quantified using a variety of techniques both underway and at ice stations along the MIZ. The proposed cruise track extends across the Drake Passage to the Western Antarctic Peninsula (WAP) with three station transects along a gradient from the open ocean through the marginal ice zone (MIZ) in the Bellinghausen and Amundsen Seas and into the Ross Sea Polynya. Ice stations along each transect will provide material to characterize production associated with annual ice. Underway measurements of primary and secondary production (chlorophyll, CDOM, microplankton, and mesoplankton) and hydrography (temperature, salinity, pH, DO, turbidity) will establish a baseline for future cruises and as support for other projects such as biogeochemical studies on carbon dioxide drawdown and trace metal work on primary production. The outcome of these measurements will be a description of nano to mesoplankton standing stocks, community structure, and carbon flux along the MIZ in the Bellinghausen and Amundsen Seas and the Ross Sea Polynya. | POLYGON((-168.291 -64.846,-165.018 -64.846,-161.745 -64.846,-158.472 -64.846,-155.199 -64.846,-151.926 -64.846,-148.653 -64.846,-145.38 -64.846,-142.107 -64.846,-138.834 -64.846,-135.561 -64.846,-135.561 -66.0269,-135.561 -67.2078,-135.561 -68.3887,-135.561 -69.5696,-135.561 -70.7505,-135.561 -71.9314,-135.561 -73.1123,-135.561 -74.2932,-135.561 -75.4741,-135.561 -76.655,-138.834 -76.655,-142.107 -76.655,-145.38 -76.655,-148.653 -76.655,-151.926 -76.655,-155.199 -76.655,-158.472 -76.655,-161.745 -76.655,-165.018 -76.655,-168.291 -76.655,-168.291 -75.4741,-168.291 -74.2932,-168.291 -73.1123,-168.291 -71.9314,-168.291 -70.7505,-168.291 -69.5696,-168.291 -68.3887,-168.291 -67.2078,-168.291 -66.0269,-168.291 -64.846)) | POINT(-151.926 -70.7505) | false | false | |||||||||
SGER: Science-of-Opportunity Aboard Icebreaker Oden - Phytoplankton Global Change Experiments and Vitamin/Iron Co-Limitation in the Amundsen and Ross Seas
|
0741428 |
2008-11-23 | Hutchins, David | No dataset link provided | Abstract<br/><br/>This Small Grants for Exploratory Research (SGER) proposal describes global change-related experimental research designed to take full advantage of a unique science opportunity on short notice, the leasing of the Oden to conduct ice-breaking operations in McMurdo Sound. <br/><br/>Our emphasis will be on using this opportunistic research platform to ask two questions about present day and future controls on Antarctic margin phytoplankton communities. These are: 1. How will expected alterations in pCO2, pH, and Fe availability in the Southern Ocean, due to future anthropogenic climate change affect phytoplankton species assemblages, carbon and nutrient biogeochemistry, and remineralization processes? 2. What is the current role of organic co-factors (vitamins) in limiting or co-limiting (along with iron ) phytoplankton growth and production in the Antarctic margin? The research approach includes experimental incubations with variation in iron enrichment, carbon dioxide concentration, and temperature. A second suite of experiments will examine co-limitation effects between vitamin B12 and Fe and B12 uptake kinetics. Changes in phytoplankton community structure, and carbon and nutrient cycling will be determined, in collaboration with many of the participating U.S. and Swedish investigators. Together, these two main objectives should allow us to obtain novel insights into the current and future controls on Antarctic margin phytoplankton growth, productivity, and carbon and nutrient biogeochemistry. In particular, the experiments in the Amundsen Sea represent a one-of-a-kind opportunity to understand algal dynamics and potential future responses to climate change in this little-studied ecosystem, and compare these results to those from the better-known Ross Sea. An important result of this study will be to build strong international collaborations with the Swedish marine science community. Additional broader impacts include participatin of an Hispanic Ph.D. student in cruise work and post-cruise analyses, and integration of results into graduate courses at the USC Catalina Lab facility. Public outreach will include presentations on global change impacts on the ocean targeted at audiences ranging from legislators and policymakers to the general public. | POINT(-106 -73) | POINT(-106 -73) | false | false | |||||||||
Airborne Geophysical Survey of the Amundsen Sea Embayment, Antarctica (AGASEA)
|
0230197 |
2007-01-01 | Blankenship, Donald D.; Fastook, James L.; Corr, Hugh F. J.; Holt, John W.; Morse, David L.; Vaughan, David G.; Young, Duncan A. | This award supports a comprehensive aerogeophysical survey of the Amundsen Sea Embayment (ASE) in West Antarctica. The University of Texas will join forces with the British Antarctic Survey to use both US and UK aircraft and instrumentation to achieve this survey. Analyses of the new aerogeophysical<br/>data will result in the generation of maps of ice sheet surface, volume and bottom-interface characteristics. These maps will support the efforts of a community of US and international researchers to assess the present and predict the future behavior of the ice sheet in the ASE.<br/>The West Antarctic ice sheet has been the subject of intensive interdisciplinary study by both the European and U.S. scientific communities since it was recognized to be a potential source for up to 5 meters of sea<br/>level rise, possibly on short timescales. In terms of ice discharge, the ASE is the largest drainage system in West Antarctica. Yet it has been comparatively unstudied, primarily due to its remoteness from logistical<br/>centers. The ASE is the only major drainage to exhibit significant elevation change over the period of available satellite observations. Present knowledge of the ice thickness and subglacial boundary conditions in the ASE are insufficient to understand its evolution or its sensitivity to climatic change.<br/>The results from our surveys are required to achieve the fundamental research objectives outlined by the US scientific community in an ASE Science Plan. The surveys and analyses will be achieved through international collaboration and will involve graduate students, undergraduates and high school apprentices.<br/>Through its potential for influencing sea level, the future behavior of the ASE is of primary societal importance. Given the substantial public and scientific interest that recent reports of change in West Antarctica have generated, we expect fundamental research in the Amundsen Sea Embayment, enabled by our surveys, will have widespread impact. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false |