[{"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": "2317263 Cross, Andrew", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 14 Aug 2023 00:00:00 GMT", "description": "The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding below, and internal viscous flow within, ice masses. The latter of these\u2014viscous flow\u2014is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a crystal orientation fabric (COF). Historically, ice flow has been modeled using a constitutive equation, termed \u201cGlen\u2019s law\u201d, that describes ice flow rate as a function of temperature and stress. Glen\u2019s law was constrained under relatively high-stress conditions, and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, \u201csuperplastic\u201d conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. In this project, the PI primarily seeks to measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models.\r\n\r\nPolycrystalline ice samples with grain sizes ranging from 5 \u00b5m to 1000 \u00b5m will be fabricated and deformed in the PI\u2019s laboratory at WHOI, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of \u221230\u00b0C to \u221210\u00b0C, and at a constant uniaxial strain rate of 10-7 s-1. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student within the MIT-WHOI Joint Program, one or more undergraduate summer students, and a junior faculty member (the PI). In addition, the PI will host a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "United States Of America; Rheology; ROCKS/MINERALS/CRYSTALS; GLACIERS/ICE SHEETS", "locations": "United States Of America", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cross, Andrew", "platforms": null, "repositories": null, "science_programs": null, "south": null, "title": "Microstructural Evolution during Superplastic Ice Creep", "uid": "p0010430", "west": null}, {"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": "2149518 Fudge, Tyler", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Sun, 07 Aug 2022 00:00:00 GMT", "description": "Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and in ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements (ECM), hyperspectral imaging, laser ablation ICPMS measurements of impurities, and ice physical properties to investigate sub-cm chemical and physical variations in polar ice. This work will establish to what extent annual layer interpretations of polar ice with sub-cm layering is possible. Critical to resolving thin ice layers is understanding the across-core variations which may obscure or distort the vertical layering. Analyses will be focused on samples from WAIS Divide, SPICEcore, and GISP2, which have well established seasonal cycles that yielded benchmark timescales, as well a large diameter ice core from a blue ice area.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "ICE CORE RECORDS; Ice Core", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Fudge, T. J.; Fegyveresi, John M", "platforms": null, "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Testing Next Generation Measurement Techniques for Reconstruction of Paleoclimate Archives from Thin or Disturbed Ice Cores Sections", "uid": "p0010365", "west": -180.0}, {"awards": "2139497 Balco, Gregory", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 21 Jun 2022 00:00:00 GMT", "description": "This project will conduct basic research into geological dating techniques that are useful for determining the age of glacial deposits in polar regions, Antarctica in particular. These techniques are necessary for determining how large the polar ice sheets were in the geologic past, including during past periods of warm climate that likely resemble present and near-future conditions. Thus, they represent an important technical capability needed for estimating the response of polar ice sheets to climate warming. Because changes in the size of polar ice sheets are the largest potential contribution to future global sea-level change, this capability is also relevant to understanding likely sea-level impacts of future climate change. The research in this project comprises several observational and experimental approaches to improving the speed, efficiency, cost, and accuracy of these techniques, as well as a scientific outreach program aimed at making the resulting capabilities more broadly available to other researchers. The project supports a postdoctoral scholar and contributes to human resources development in polar and climate science.\r\n\r\nThe project focuses on several areas of cosmogenic-nuclide geochemistry, which is a geochemical dating method that relies on the production and decay of cosmic-ray-produced radionuclides in surface rocks. Measurements of these nuclides can be used to quantify the duration of surface exposure and ice cover at locations in Antarctica that are covered and uncovered by changes in the size of the Antarctic ice sheets, thus providing a means of reconstructing past ice-sheet change. The first proposed set of experiments are aimed at implementing a \u0027\u0027virtual mineral separation\u0027\u0027 approach to cosmogenic noble gas analysis that may allow measurement of nuclide concentrations in certain minerals without physically separating the minerals from the host rock. If feasible, this would realize significant speed and cost improvements for this type of analysis. A second set of experiments will focus on means of identifying and quantifying non-cosmogenic background inventories of some relevant nuclides, which is intended to improve the measurement sensitivity and precision for cosmic-ray-produced inventories of these nuclides. A third focus area aims to improve capabilities to measure multiple cosmic-ray-produced nuclides in the same sample, which has the potential to improve the accuracy of dating methods based on these nuclides and to expand the situations in which these methods can be applied. If successful, these experiments are likely to improve a number of applications of cosmogenic-nuclide geochemistry relevant to Antarctic research, including subglacial bedrock exposure dating, dating of multimillion-year-old glacial deposits, and surface-process studies useful in understanding landform evolution and ecosystem dynamics.\r\n\r\nThis award reflects NSF\u0027\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "California; LABORATORY; AMD; GEOCHEMISTRY; Amd/Us; USAP-DC; USA/NSF", "locations": "California", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": null, "persons": "Balco, Gregory", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -90.0, "title": "Targeted Basic Research to Enable Antarctic Science Applications of Cosmogenic-Nuclide Geochemistry", "uid": "p0010343", "west": -180.0}, {"awards": "1945127 Moffat, Carlos", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Fri, 03 Jun 2022 00:00:00 GMT", "description": "Freshwater discharges from melting high-latitude continental ice glacial reserves strongly control salt budgets, circulation and associated ocean water mass formation arising from polar ice shelves. These are different in nature than freshwater inputs associated with riverine coastal inputs. The PI proposes an observational deployment to measure a specific, previously-identified example of a coastal freshwater-driven current, the Antarctic Peninsula Coastal Current (APCC). \u003cbr/\u003e \u003cbr/\u003eThe research component of this CAREER project aims to improve understanding of the dynamics of freshwater discharge around the Antarctic continent. Associated research questions pertain to the i) controls on the cross- and along-shelf spreading of fresh, buoyant coastal currents, ii) the role of distributed coastal freshwater sources (as opposed to \u0027point\u0027 source river outflow sources typical of lower latitudes), and iii) the contribution of these coastal currents to water mass transformation and heat transfer on the continental shelf. An educational CAREER program component leverages a series of field experiences and research outputs including data, model outputs, and theory, to bring polar science to the classroom and the general public, as well as training a new polar scientist. This combined strategy will allow the investigator to lay the foundation for a successful academic career as a researcher and teacher at the University of Delaware. The project will also provide the opportunity to train a PhD student. Informal outreach efforts will include giving public lectures at University of Deleware\u0027s sponsored events, including Coast Day, a summer event that attracts 8000-10000 people, and remote lectures from the field using an existing outreach network. This proposal requires fieldwork in the Antarctic.\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": "Amd/Us; R/V LMG; TURBULENCE; USAP-DC; OCEAN CURRENTS; Antarctic Peninsula; AMD; USA/NSF; HEAT FLUX", "locations": "Antarctic Peninsula", "north": null, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Moffat, Carlos", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repositories": null, "science_programs": null, "south": null, "title": "CAREER: The Transformation, Cross-shore Export, and along-shore Transport of Freshwater on Antarctic Shelves", "uid": "p0010330", "west": null}, {"awards": "2019719 Brook, Edward J.", "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": "2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report; Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland", "datasets": [{"dataset_uid": "601697", "doi": "10.15784/601697", "keywords": "Allan Hills; Antarctica; Apres; Ice Core; Ice Penetrating Radar; Temperature Profiles", "people": "Conway, Howard; Brook, Edward", "repository": "USAP-DC", "science_program": "COLDEX", "title": "2022-23 Allan Hills Intermediate Ice Core Site Selection Field Report", "url": "https://www.usap-dc.org/view/dataset/601697"}, {"dataset_uid": "601659", "doi": "10.15784/601659", "keywords": "Antarctica; Continuous Flow; Glaciology; Greenland; Ice Core Data; Laser Spectroscopy; Oxygen Isotope; Triple Oxygen Isotopes", "people": "Davidge, Lindsey", "repository": "USAP-DC", "science_program": "Hercules Dome Ice Core", "title": "Replicate O-17-excess by continuous flow laser spectroscopy for an ice core section at Summit, Greenland", "url": "https://www.usap-dc.org/view/dataset/601659"}], "date_created": "Sat, 21 May 2022 00:00:00 GMT", "description": "Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth\u2019s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth\u2019s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community.\r\n\r\nKnowledge of Earth\u2019s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth\u2019s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "USA/NSF; AMD; Antarctica; Amd/Us; Coldex; USAP-DC; FIELD SURVEYS; ICE DEPTH/THICKNESS", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Neff, P.; Brook, Edward J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "COLDEX", "south": -90.0, "title": "Center for Oldest Ice Exploration", "uid": "p0010321", "west": -180.0}, {"awards": "0342484 Harwood, David", "bounds_geometry": "POINT(167.083333 -77.888889)", "dataset_titles": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "datasets": [{"dataset_uid": "601451", "doi": "10.15784/601451", "keywords": "Andrill; Antarctica; Continental Shelf; Diamict; Mcmurdo Sound; Miocene; Paleoclimate; Particle Size", "people": "Passchier, Sandra; Candice, Falk", "repository": "USAP-DC", "science_program": "ANDRILL", "title": "Particle-size measurements at 3-m intervals for AND-2A sediment core, McMurdo Sound", "url": "https://www.usap-dc.org/view/dataset/601451"}], "date_created": "Fri, 04 Feb 2022 00:00:00 GMT", "description": "ANDRILL is a scientific drilling program to investigate Antarctica\u0027s role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica\u0027s climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth\u0027s ocean-climate system. \u003cbr/\u003e\u003cbr/\u003eThis award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica\u0027s major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.\u003cbr/\u003e\u003cbr/\u003eThe South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area\u0027s complex tectonic history.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society\u0027s understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. \u003cbr/\u003e\u003cbr/\u003eAs key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica\u0027s ice sheets are important to society\u0027s understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth\u0027s climatic future.", "east": 167.083333, "geometry": "POINT(167.083333 -77.888889)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; USAP-DC; FIELD SURVEYS; ICE SHEETS; USA/NSF; Amd/Us; PALEOCLIMATE RECONSTRUCTIONS; Ross Ice Shelf; SEDIMENTS", "locations": "Ross Ice Shelf", "north": -77.888889, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Harwood, David; Levy, Richard", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "ANDRILL", "south": -77.888889, "title": "Collaborative Research: ANDRILL - - Investigating Antarcticas Role in Cenozoic Global Environmental Change", "uid": "p0010297", "west": 167.083333}, {"awards": "2032473 Kurbatov, Andrei; 2032463 Talghader, Joseph", "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": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "datasets": [{"dataset_uid": "601753", "doi": "10.15784/601753", "keywords": "Antarctica; Sampling", "people": "Mah, Merlin; Kurbatov, Andrei V.; Talghader, Joseph", "repository": "USAP-DC", "science_program": null, "title": "Visual, thermal, chemical, and stable isotope effects of near-infrared laser cutting on freezer ice", "url": "https://www.usap-dc.org/view/dataset/601753"}], "date_created": "Wed, 30 Jun 2021 00:00:00 GMT", "description": "Overview\u003c/br\u003e\nIt is proposed that laser cutting technology can be used to rapidly extract high quality ice samples from borehole walls. The technology applies to both existing boreholes and newly drilled ones, even enabling scientists to obtain samples using non\u2010coring mechanical drills. Since the instrumentation is highly portable, a field team of three persons might take no longer than a few days in the field to extract ice, and samples from a critical time period could be extracted from multiple locations in a single field season.\n\nThis pilot program will investigate and validate the technology of laser sampling. It is beneficial to use fiber optics to convey light in borehole instrumentation rather than attempting to package a complete laser system for travel down a borehole, so the cutting laser and wavelength (1.07Pm) are chosen with such engineering in mind. The primary scientific goals of the program are to: 1) determine optimum cutting conditions in terms of laser power and operating conditions, 2) quantifying the effects of residual meltwater that remain in the cut slot after a cut so that re-cutting needs can be predicted or mitigated, 3) designing and testing mechanical structures to retract samples from blocks of ice once cut, and 4) analyzing the composition and crystal structure of ice near a cut slot to determine the impacted volume (if any) of ice and temperatures where scientific readings might be affected by the sampling process.\n\u003c/br\u003e\u003c/br\u003e\nIntellectual Merits\u003c/br\u003e\nThe collection of deep ice from the Polar Ice Sheets involves large amounts of time, effort, and expense. Often, the most important information is held in very small volumes of core, and while replicate coring can supplement this core, there is often a need to retrieve additional ice samples based on recent scientific findings or borehole logging at a site. In addition, there is currently no easy method of extracting ice from boreholes drilled by non\u2010coring mechanical drills, which are often much faster, lighter, and less expensive to operate. There are numerous specific projects that could immediately benefit from laser sampling including sampling ice overlaying buried impact craters and bolides, filling critical gaps in the chemical record in damaged core sections from Siple Dome, obtaining oldest ice cores from brittle sections near the surface of the Allan Hills blue ice area, where coring drills apply stresses that may fracture the ice, and replacing core whose value has degraded due to time and depressurization. This program builds on a prior engineering advances in optical fiber\u2010based logging technology, developed previously for Siple Dome borehole logging.\n\u003c/br\u003e\u003c/br\u003e\nBroader Impact\u003c/br\u003e\nLaser sampling would advance numerous fields interfaced with glaciology and ice core studies. These include climate and paleoenvironmental science, volcanology, and human history where large volumes of ice are crucial to extract ultra\u2010high resolution records of natural and anthropogenic emissions. Potentially the principle of laser sampling could be used to directly sample and study ice on other planets or their satellites.\nThis program encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training postdoctoral scientists, graduate students, and advanced undergraduates. The program will include a research opportunity for one or more middle school teachers through a Research Experience for Teachers program with one of the local school districts of the Twin Cities area. The teacher(s) will assist the investigators in the analysis of scattered laser light in glacier ice, and will set up a small experiment at various visible wavelengths to measure scattering constants. These experiments have been chosen because they can easily translate into classroom demonstrations and hands\u2010on activities using eye-safe visible- light LED sources and large samples of artificial ice. The teacher(s) will also produce a lesson plan on basic optics, glacial ice, or polar science as a deliverable.\nThis proposal does not involve field work.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Amd/Us; Laser Cutting; Ice Core; USA/NSF; AMD; SULFATE; FIELD SURVEYS; OXYGEN COMPOUNDS; USAP-DC; LABORATORY; Sulfate", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Instrumentation and Facilities", "paleo_time": null, "persons": "Talghader, Joseph; Kurbatov, Andrei V.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative Research: Laser Cutting Technology for Borehole Sampling", "uid": "p0010218", "west": -180.0}, {"awards": "1851022 Fudge, Tyler; 1851094 Baker, Ian", "bounds_geometry": null, "dataset_titles": "EPICA Dome C Sulfate Data 7-3190m", "datasets": [{"dataset_uid": "601759", "doi": "10.15784/601759", "keywords": "Antarctica", "people": "Severi, Mirko; Fudge, T. J.", "repository": "USAP-DC", "science_program": "COLDEX", "title": "EPICA Dome C Sulfate Data 7-3190m", "url": "https://www.usap-dc.org/view/dataset/601759"}], "date_created": "Mon, 28 Jun 2021 00:00:00 GMT", "description": "An accurate constitutive relationship for ice is fundamental to ice-flow models and ice-core interpretations. While Glen\u2019s flow law describes well the overall deformation of ice when subjected to stress, many details remain poorly constrained. In particular, the effect of impurities on the strain rate both directly and through the development of ice fabric is not well understood. Variations in impurity concentrations are associated with variations in deformation rates as observed in both Greenland and Antarctica. The impact of uncertainties on the deformation of ice is most acutely observed in the interpretation of ice cores where the inference of past accumulation rate depends on the cumulative vertical thinning. Thus, many ice-core climate reconstructions, such as the gas-age ice-age difference, surface temperature histories, and aerosol fluxes, are also affected. Given the complexities of the possible impacts of sulfuric acid on the flow of ice and the interaction between these impacts, it seems almost impossible to examine an ice core and understand the impacts of impurities on the microstructural evolution and creep behavior. Our research seeks to understand the effects of sulfuric acid at concentrations applicable to polar ice sheets and relate these results to the flow of polar ice both through experiments and through modeling. Our results have shown that the presence of sulfuric acid in the grain boundaries of polar ice increases its strength in shear, while sulfuric acid in the whole matrix of polar ice reduces its strength. We have also found that sulfuric acid causes an initial increase in average grain sizes and then a subsequent decrease, a trend that differs from the continuous increase in average grain sizes observed in freshwater ice. We are also determining the role of stress state, i.e. simple compression versus shear, on the microstructural evolution and how sulfuric acid impacts this.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "AMD; Polycrystalline Ice; LABORATORY; Epica Dome C; SNOW/ICE; USA/NSF; USAP-DC; Ice Core; Amd/Us", "locations": "Epica Dome C", "north": null, "nsf_funding_programs": "Antarctic Science and Technology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: The Impact of Impurities and Stress State on Polycrystalline Ice Deformation", "uid": "p0010211", "west": null}, {"awards": "2042495 Blackburn, Terrence; 2045611 Rasbury, Emma", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": null, "datasets": null, "date_created": "Fri, 18 Jun 2021 00:00:00 GMT", "description": "Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth\u2019s past warm periods. Large uncertainties, however, in reconstructions of past and future sea levels, result from the poorly constrained climate sensitivity of the Antarctic Ice sheet (AIS). This research project aims to develop the use of subglacial precipitates as an archive the Antarctic ice sheet (AIS) past response to climate change. The subglacial precipitates from East Antarctica form in water bodies beneath Antarctic ice and in doing so provide an entirely new and unique measure of how the AIS responds to climate change. In preliminary examination of these precipitates, we identified multiple samples consisting of cyclic opal and calcite that spans hundreds of thousands of years in duration. Our preliminary geochemical characterization of these samples indicates that the observed mineralogic changes result from a cyclic change in subglacial water compositions between isotopically and chemically distinct waters. Opal-forming waters are reduced (Ce* \u003c1 and high Fe/Mn) and exhibit elevated 234U/238U compositions similar to the saline groundwater brines found at the periphery of the AIS. Calcite-forming waters, are rather, oxidized and exhibit \u03b418O compositions consistent with derivation from the depleted polar plateau (\u003c -50 \u2030). 234U-230Th dates permit construction of a robust timeseries describing these mineralogic and compositional changes through time. Comparisons of these time series with other Antarctic climate records (e.g., ice core records) reveal that calcite forming events align with millennial scale changes in local temperature or \u201cAntarctic isotopic maximums\u201d, which represent Southern Hemisphere warm periods during low Atlantic Meridional overturning circulation. Ultimately, this project seeks to develop a comprehensive model as to how changes in the thermohaline cycle induce a glaciologic response which in turn induces a change in the composition of subglacial waters and the mineralogic phase recorded within the precipitate archive. ", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "GLACIERS/ICE SHEETS; FIELD INVESTIGATION; AMD; USA/NSF; Amd/Us; USAP-DC; East Antarctica", "locations": "East Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences", "paleo_time": null, "persons": "Blackburn, Terrence; Tulaczyk, Slawek; Hain, Mathis; Rasbury, Troy", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repositories": null, "science_programs": null, "south": -90.0, "title": "Collaborative Research: Reconstructing East Antarctica\u2019s Past Response to Climate using Subglacial Precipitates", "uid": "p0010192", "west": -180.0}, {"awards": "1443525 Schwartz, Susan", "bounds_geometry": "POLYGON((-165 -83.8,-163 -83.8,-161 -83.8,-159 -83.8,-157 -83.8,-155 -83.8,-153 -83.8,-151 -83.8,-149 -83.8,-147 -83.8,-145 -83.8,-145 -83.92,-145 -84.04,-145 -84.16,-145 -84.28,-145 -84.4,-145 -84.52,-145 -84.64,-145 -84.76,-145 -84.88,-145 -85,-147 -85,-149 -85,-151 -85,-153 -85,-155 -85,-157 -85,-159 -85,-161 -85,-163 -85,-165 -85,-165 -84.88,-165 -84.76,-165 -84.64,-165 -84.52,-165 -84.4,-165 -84.28,-165 -84.16,-165 -84.04,-165 -83.92,-165 -83.8))", "dataset_titles": "YD (2012-2017): Whillians Ice Stream Subglacial Access Research Drilling", "datasets": [{"dataset_uid": "200201", "doi": "https://doi.org/10.7914/SN/YD_2012", "keywords": null, "people": null, "repository": "IRIS", "science_program": null, "title": "YD (2012-2017): Whillians Ice Stream Subglacial Access Research Drilling", "url": "http://www.fdsn.org/networks/detail/YD_2012/"}], "date_created": "Fri, 12 Feb 2021 00:00:00 GMT", "description": "Ice fracturing plays a crucial role in mechanical processes that influence the contribution of glaciers and ice sheets to the global sea-level rise. Such processes include, among others, ice shelf disintegration, iceberg calving, and fast ice sliding. Over the last century, seismology developed highly sensitive instrumentation and sophisticated data processing techniques to study earthquakes. This interdisciplinary project used seismological research methods to investigate fracturing beneath and within ice on a fast-moving ice stream in West Antarctica that is experiencing rapid sliding and flexure driven by ocean tides. Data were collected from two strategically located clusters of seismometers. One was located in the epicenter zone where tidally triggered rapid sliding events of the ice stream start. The other was placed in the grounding zone, where the ice stream flexes with tides where it goes afloat and becomes an ice shelf.\r\n\r\n Seismometers in the epicenter cluster recorded many thousands of microearthquakes coming from beneath ice during ice stream sliding events. Analyses of these microearthquakes suggest that the geologic materials beneath the ice stream are fracturing. The spatial pattern of fracturing is not random but forms elongated stripes that resemble well-known glacial landforms called megascale glacial lineations. These findings indicate that the frictional resistance to ice sliding may change through time due to these landforms changing as a result of erosion and sedimentation beneath ice. This may have implications for the rate of ice loss from Antarctic ice streams that drain about 90% of all ice discharged into the Southern Ocean. In addition to microearthquakes, the epicenter cluster of seismometers also recorded vibrations (tremors) from beneath the ice stream. These may be caused by the rapid repetition of many microearthquakes coming from the same source.\r\n\r\n The grounding zone cluster of seismometers recorded many thousands of microearthquakes as well. However, they are caused by ice fracturing near the ice stream\u0027s surface rather than at its base. These microearthquakes originate when the grounding zone experiences strong tension caused by ice flexure during dropping ocean tide. This tension causes the opening of near-surface fractures (crevasses) just before the lowest tide, rather than at the lowest tide as expected from elasticity of solids. This unexpected timing of ice fracturing indicates that ice in the grounding zone behaves like a viscoelastic material, i.e., partly like a solid and partly like a fluid. This is an important general finding that will be useful to other scientists who are modeling interactions of ice with ocean water in the Antarctic grounding zones. Overall, the observed pervasive fracturing in the grounding zone, where an ice stream becomes an ice shelf, may make ice shelves potentially vulnerable to catastrophic collapses. It also may weaken ice shelves and make it easier for large icebergs to break off at their fronts.\r\n\r\n In addition to Antarctic research, this award supported education and outreach activities, including presentations and field trips during several summer schools at UCSC for talented and diverse high school students. The students were exposed to glaciological and seismological concepts and performed hands-on scientific exercises. The field trips focused on the marine terrace landscape around Santa Cruz. This landscape resulted from interactions between the uplift of rocks along the San Andreas fault with global-sea level changes caused by the waxing and waning of polar ice sheets in response to Ice Age climate cycles.\r\n\r\n", "east": -145.0, "geometry": "POINT(-155 -84.4)", "instruments": null, "is_usap_dc": true, "keywords": "Whillans Ice Stream; GLACIERS/ICE SHEETS; FIELD INVESTIGATION", "locations": "Whillans Ice Stream", "north": -83.8, "nsf_funding_programs": "Antarctic Integrated System Science", "paleo_time": null, "persons": "Tulaczyk, Slawek; Schwartz, Susan", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION", "repo": "IRIS", "repositories": "IRIS", "science_programs": "WISSARD", "south": -85.0, "title": "High Resolution Heterogeneity at the Base of Whillans Ice Stream and its Control on Ice Dynamics", "uid": "p0010159", "west": -165.0}, {"awards": "1907974 Saltzman, Eric", "bounds_geometry": "POLYGON((129.26 -89.86,130.261 -89.86,131.262 -89.86,132.263 -89.86,133.264 -89.86,134.265 -89.86,135.266 -89.86,136.267 -89.86,137.268 -89.86,138.269 -89.86,139.27 -89.86,139.27 -89.861,139.27 -89.862,139.27 -89.863,139.27 -89.864,139.27 -89.865,139.27 -89.866,139.27 -89.867,139.27 -89.868,139.27 -89.869,139.27 -89.87,138.269 -89.87,137.268 -89.87,136.267 -89.87,135.266 -89.87,134.265 -89.87,133.264 -89.87,132.263 -89.87,131.262 -89.87,130.261 -89.87,129.26 -89.87,129.26 -89.869,129.26 -89.868,129.26 -89.867,129.26 -89.866,129.26 -89.865,129.26 -89.864,129.26 -89.863,129.26 -89.862,129.26 -89.861,129.26 -89.86))", "dataset_titles": "H2 in South Pole firn air", "datasets": [{"dataset_uid": "601332", "doi": "10.15784/601332", "keywords": "Antarctica; Firn; Glaciology; Hydrogen; Ice Core Records; Snow/ice; Snow/Ice; South Pole", "people": "Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "H2 in South Pole firn air", "url": "https://www.usap-dc.org/view/dataset/601332"}], "date_created": "Tue, 09 Jun 2020 00:00:00 GMT", "description": "Hydrogen (H2) is one of the most abundant trace gases in the atmosphere, with a mean level of 500 ppb and an atmospheric lifetime of about two years. Hydrogen has an impact on both air quality and climate, due to its role as a precursor for tropospheric ozone and stratospheric water vapor. Projections indicate that a future \"hydrogen economy\" would increase hydrogen emissions. Understanding of the atmospheric hydrogen budget is largely based on a 30-year record of surface air measurements, but there are no long-term records with which to assess either: 1) the influence of climate change on atmospheric hydrogen, or 2) the extent to which humans have impacted the hydrogen budget. Polar ice core records of hydrogen will advance our understanding of the atmospheric hydrogen cycle and provide a stronger basis for projecting future changes to atmospheric levels of hydrogen and their impacts. \u003cbr/\u003e\u003cbr/\u003eThe research will involve laboratory work to enable the collection and analysis of hydrogen in polar ice cores. Hydrogen is a highly diffusive molecule and, unlike most other atmospheric gases, diffusion of hydrogen in ice is so rapid that ice samples must be stored in impermeable containers immediately upon drilling and recovery. This project will: 1) construct a laboratory system for extracting and analyzing hydrogen in polar ice, 2) develop and test materials and construction designs for vessels to store ice core samples in the field, and 3) test the method on samples of opportunity previously stored in the field. The goal of this project is a proven, cost-effective design for storage flasks to be fabricated for use on future polar ice coring projects. This project will support the dissertation research of a graduate student in the UC Irvine Department of Earth System Science.\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": 139.27, "geometry": "POINT(134.265 -89.865)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY; Firn; TRACE GASES/TRACE SPECIES; South Pole; FIELD INVESTIGATION; USAP-DC", "locations": "South Pole", "north": -89.86, "nsf_funding_programs": "Antarctic Instrumentation and Facilities; Antarctic Glaciology; Antarctic Instrumentation and Support", "paleo_time": null, "persons": "Saltzman, Eric", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -89.87, "title": "EAGER: Feasibility of Reconstructing the Atmospheric History of Molecular Hydrogen from Antarctic Ice", "uid": "p0010106", "west": 129.26}, {"awards": "1807522 Jones, Tyler", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "datasets": [{"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601326", "doi": "10.15784/601326", "keywords": "Antarctica; Delta 18O; Delta Deuterium; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Snow/ice; Snow/Ice; WAIS Divide Ice Core; Water Isotopes; West Antarctic Ice Sheet", "people": "White, James; Morris, Valerie; Jones, Tyler R.; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Mid-Holocene high-resolution water isotope time series for the WAIS Divide ice core", "url": "https://www.usap-dc.org/view/dataset/601326"}, {"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Price, Michael; Garland, Joshua; Bradley, Elizabeth; Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Ice cores contain detailed accounts of Earth\u0027s climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process.This award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "AMD; West Antarctic Ice Sheet; ISOTOPES; Amd/Us; USAP-DC; USA/NSF; Water Isotopes; WAIS Divide Ice Core; Deuterium; LABORATORY", "locations": "West Antarctic Ice Sheet", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Garland, Joshua; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Targeted resampling of deep polar ice cores using information theory", "uid": "p0010100", "west": -112.085}, {"awards": "1743643 Passchier, Sandra", "bounds_geometry": null, "dataset_titles": "Major and trace element analyses of Eocene-Oligocene marine sediments from ODP Site 696, South Orkney Microcontinent; Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "datasets": [{"dataset_uid": "601582", "doi": "10.15784/601582", "keywords": "Antarctica; Glaciation; IODP 650; IODP 696; Paleoceanography; Provenance; Sediment Core Data; Weathering; Weddell Sea", "people": "Passchier, Sandra; States, Abbey; Li, Xiaona; Hojnacki, Victoria; Lepp, Allison", "repository": "USAP-DC", "science_program": null, "title": "Major and trace element analyses of Eocene-Oligocene marine sediments from ODP Site 696, South Orkney Microcontinent", "url": "https://www.usap-dc.org/view/dataset/601582"}, {"dataset_uid": "601581", "doi": "10.15784/601581", "keywords": "Antarctica; Glaciation; IODP 696; Marine Geoscience; Marine Sediments; Paleoceanography; Sediment Core Data; Weddell Sea", "people": "Horowitz Castaldo, Josie; Light, Jennifer; Passchier, Sandra; Lepp, Allison", "repository": "USAP-DC", "science_program": null, "title": "Particle-size distributions of Eocene-Oligocene sediment from ODP Site 696, South Orkney Microcontinent", "url": "https://www.usap-dc.org/view/dataset/601581"}], "date_created": "Tue, 26 May 2020 00:00:00 GMT", "description": "Abstract (non-technical)\u003cbr/\u003eSea level rise is a problem of global importance and it is increasingly affecting the tens of millions of Americans living along coastlines. The melting of glaciers in mountain areas worldwide in response to global warming is a major cause of sea level rise and increases in nuisance coastal flooding. However, the world\u0027s largest land-based ice sheets are situated in the Polar Regions and their response under continued warming is very difficult to predict. One reason for this uncertainty is a lack of observations of ice behavior and melt under conditions of warming, as it is a relatively new global climate state lasting only a few generations so far. Researchers will investigate ice growth on Antarctica under past warm conditions using geological archives embedded in the layers of sand and mud under the sea floor near Antarctica. By peeling back at the layers beneath the seafloor investigators can read the history book of past events affecting the ice sheet. The Antarctic continent on the South Pole, carries the largest ice mass in the world. The investigator\u0027s findings will substantially improve scientists understanding of the response of ice sheets to global warming and its effect on sea level rise.\u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eAbstract (technical)\u003cbr/\u003eThe melt of land based ice is raising global sea levels with at present only minor contributions from polar ice sheets. However, the future role of polar ice sheets in climate change is one of the most critical uncertainties in predictions of sea level rise around the globe. The respective roles of oceanic and atmospheric greenhouse forcing on ice sheets are poorly addressed with recent measurements of polar climatology, because of the extreme rise in greenhouse forcing the earth is experiencing at this time. Data on the evolution of the West Antarctic ice sheet is particularly sparse. To address the data gap, researchers will reconstruct the timing and spatial distribution of Antarctic ice growth through the last greenhouse to icehouse climate transition around 37 to 33 Ma. They will collect sedimentological and geochemical data on core samples from a high-latitude paleoarchive to trace the shutdown of the chemical weathering system, the onset of glacial erosion, ice rafting, and sea ice development, as East and West Antarctic ice sheets coalesced in the Weddell Sea sector. Their findings will lead to profound increases in the understanding of the role of greenhouse forcing in ice sheet development and its effect on the global climate system.\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": "Amd/Us; AMD; SEDIMENTS; LABORATORY; USA/NSF; USAP-DC; Weddell Sea", "locations": "Weddell Sea", "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Passchier, Sandra", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Timing and Spatial Distribution of Antarctic Ice Sheet Growth and Sea-ice Formation across the Eocene-Oligocene Transition", "uid": "p0010101", "west": null}, {"awards": "1443470 Aydin, Murat", "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": "South Pole ice core (SPC14) discrete methane data; SP19 Gas Chronology; SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "datasets": [{"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601270", "doi": "10.15784/601270", "keywords": "Antarctica", "people": "Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPC14 carbonyl sulfide, methyl chloride, and methyl bromide measurements from South Pole, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601270"}], "date_created": "Thu, 26 Mar 2020 00:00:00 GMT", "description": "In the past, Earth\u0027s climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth\u0027s atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth\u0027s climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record.\u003cbr/\u003e\u003cbr/\u003eThe primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; CARBONYL SULFIDE; HALOCARBONS AND HALOGENS; TRACE GASES/TRACE SPECIES; Antarctic; USAP-DC", "locations": "Antarctic", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Carbonyl Sulfide, Methyl Chloride, and Methyl Bromide Measurements in the New Intermediate-depth South Pole Ice Core", "uid": "p0010089", "west": -180.0}, {"awards": "1443566 Bay, Ryan", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "Laser Dust Logging of the South Pole Ice Core (SPICE)", "datasets": [{"dataset_uid": "601222", "doi": "10.15784/601222", "keywords": "Antarctica; Dust; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; SPICEcore", "people": "Bay, Ryan", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Laser Dust Logging of the South Pole Ice Core (SPICE)", "url": "https://www.usap-dc.org/view/dataset/601222"}], "date_created": "Thu, 31 Oct 2019 00:00:00 GMT", "description": "This award supports the deployment and analysis of data from an oriented laser dust logger in the South Pole ice core borehole to complement study of the ice core record. Before the core is even processed, data from the borehole probe will immediately determine the depth-age relationship, augment 3D mapping of South Pole stratigraphy, aid in searches for the oldest ice in Antarctica, and reveal layers of volcanic or extraterrestrial fallout. Regarding the intellectual merit, the oriented borehole log will be essential for investigating features in the ice sheet that may have implications for ice core chronology, ice flow, ice sheet physical properties and stability in response to climate change. The tools and techniques developed in this program have applications in glaciology, biogeoscience and exploration of other planetary bodies. The program aims for a deeper understanding of the consequences and causes of abrupt climate change. The broader impacts of the project are that it will include outreach and education, providing a broad training ground for students and post-docs. Data and metadata will be made available through data centers and repositories such as the National Snow and Ice Data Center web portal. \u003cbr/\u003e\u003cbr/\u003eThe laser dust logger detects reproducible paleoclimate features at sub-centimeter depth scale. Dust logger data are being used for synchronizing records and dating any site on the continent, revealing accumulation anomalies and episodes of rapid ice sheet thinning, and discovering particulate horizons of special interest. In this project we will deploy a laser dust logger equipped with a magnetic compass to find direct evidence of preferentially oriented dust. Using optical scattering measurements from IceCube calibration studies at South Pole and borehole logs at WAIS Divide, we have detected a persistent anisotropy correlated with flow and crystal fabric which suggests that the majority of insoluble particulates must be located within ice grains. With typical concentrations of parts-per-billion, little is known about the location of impurities within the polycrystalline structure of polar ice. While soluble impurities are generally thought to concentrate at inter-grain boundaries and determine electrical conductivity, the fate of insoluble particulates is much less clear, and microscopic examinations are extremely challenging. These in situ borehole measurements will help to unravel intimate relationships between impurities, flow, and crystal fabric. Data from this project will further develop a unique record of South Pole surface roughness as a proxy for paleowind and provide new insights for understanding glacial radar propagation. This project has field work in Antarctica.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; Antarctica; ICE CORE RECORDS; USAP-DC", "locations": "Antarctica", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Bay, Ryan", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Laser Dust Logging of a South Pole Ice Core", "uid": "p0010061", "west": 90.0}, {"awards": "1141839 Steig, Eric; 1142646 Twickler, Mark; 1142517 Aydin, Murat", "bounds_geometry": "POINT(90 -90)", "dataset_titles": "South Pole Ice Core Holocene Major Ion Dataset; South Pole ice core (SPC14) discrete methane data; South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth; SP19 Gas Chronology; Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "datasets": [{"dataset_uid": "601396", "doi": "10.15784/601396", "keywords": "Accumulation; Antarctica; Diffusion Length; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Dynamic; Layer Thinning; Oxygen Isotope; South Pole; SPICEcore; Temperature", "people": "Vaughn, Bruce; White, James; Epifanio, Jenna; Buizert, Christo; Waddington, Edwin D.; Conway, Howard; Stevens, Max; Schauer, Andrew; Morris, Valerie; Koutnik, Michelle; Fudge, T. J.; Jones, Tyler R.; Steig, Eric J.; Kahle, Emma", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)", "url": "https://www.usap-dc.org/view/dataset/601396"}, {"dataset_uid": "601380", "doi": "10.15784/601380", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Ice Core Stratigraphy; Methane; South Pole; SPICEcore", "people": "Epifanio, Jenna", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SP19 Gas Chronology", "url": "https://www.usap-dc.org/view/dataset/601380"}, {"dataset_uid": "601381", "doi": "10.15784/601381", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Ice Core Records; Methane; South Pole; SPICEcore", "people": "Kreutz, Karl; Buizert, Christo; Brook, Edward J.; Epifanio, Jenna; Severinghaus, Jeffrey P.; Kennedy, Joshua A.; Ferris, David G.; Kalk, Michael; Hood, Ekaterina; Fudge, T. J.; Osterberg, Erich; Winski, Dominic A.; Steig, Eric J.; Kahle, Emma; Sowers, Todd A.; Edwards, Jon S.; Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole ice core (SPC14) discrete methane data", "url": "https://www.usap-dc.org/view/dataset/601381"}, {"dataset_uid": "601399", "doi": "10.15784/601399", "keywords": "Antarctica; Glaciology; Ice Core; Ice Core Chemistry; Ice Core Records; Major Ion; Sea Ice; Sea Salt; Sodium; South Pole; SPICEcore", "people": "Winski, Dominic A.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core Holocene Major Ion Dataset", "url": "https://www.usap-dc.org/view/dataset/601399"}, {"dataset_uid": "601221", "doi": "10.15784/601221", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice; Ice Core Data; Ice Core Depth; Ice Core Records; Snow/ice; Snow/Ice; SPICEcore", "people": "Souney, Joseph Jr.; Twickler, Mark; Kahle, Emma; Nicewonger, Melinda R.; Fudge, T. J.; Hargreaves, Geoff; Nunn, Richard; Steig, Eric J.; Aydin, Murat; Casey, Kimberly A.; Fegyveresi, John", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "South Pole Ice Core (SPICEcore) SPC14 Core Quality Versus Depth", "url": "https://www.usap-dc.org/view/dataset/601221"}], "date_created": "Wed, 30 Oct 2019 00:00:00 GMT", "description": "This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.", "east": 90.0, "geometry": "POINT(90 -90)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "USAP-DC; Amd/Us; Antarctica; ANALYTICAL LAB; USA/NSF; AMD; South Pole; ICE CORE RECORDS; FIELD INVESTIGATION; Ice Core", "locations": "Antarctica; South Pole", "north": -90.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Twickler, Mark; Souney, Joseph Jr.; Aydin, Murat; Steig, Eric J.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e ANALYTICAL LAB", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Collaborative Research: A 1500m Ice Core from South Pole", "uid": "p0010060", "west": 90.0}, {"awards": "1443550 Brook, Edward", "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": "Polar Ice Cores 3,000 Year Nitrous Oxide d15N and d18O Data; SPICEcore Holocene CO2 and N2O data", "datasets": [{"dataset_uid": "601197", "doi": "10.15784/601197", "keywords": "Antarctica; Carbon Dioxide; Ice Core Gas Records; Nitrous Oxide; South Pole; SPICEcore", "people": "Brook, Edward J.", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "SPICEcore Holocene CO2 and N2O data", "url": "https://www.usap-dc.org/view/dataset/601197"}, {"dataset_uid": "200055", "doi": "", "keywords": null, "people": null, "repository": "NCEI", "science_program": null, "title": "Polar Ice Cores 3,000 Year Nitrous Oxide d15N and d18O Data", "url": "https://www.ncdc.noaa.gov/paleo-search/study/25530"}], "date_created": "Tue, 06 Aug 2019 00:00:00 GMT", "description": "The temperature of the earth is controlled, in part, by heat trapping gases that include carbon dioxide, methane, and nitrous oxide. Despite their importance to climate, direct measurements of these gases in the atmosphere are limited to the last 50 years at best. Air trapped in ice cores extends those data back hundreds of millennia, and measurements of greenhouse gases in ice cores underpin much of our understanding of global chemical cycles relevant to modern climate change. Existing records vary in quality and detail. The proposed work fills gaps in our knowledge of nitrous oxide and carbon dioxide over the last 10,000 years. New measurements from an ice core from the South Pole will be used to determine what role changes in ocean and land based processes played in controlling these gases, which decreased during the first 2,000 years of this time period, then gradually increased toward the present. The work will address a major controversy over whether early human activities could have impacted the atmosphere, and provide data to improve mathematical models of the land-ocean-atmosphere system that predict how future climate change will impact the composition of the atmosphere and climate. \u003cbr/\u003e\u003cbr/\u003eFor nitrous oxide the work will improve on existing concentration records It will also develop measurement of the isotopomers of nitrous oxide and explore their utility for understanding aspects of the Holocene nitrous oxide budget. The primary goal is to determine if marine and/or terrestrial emissions of nitrous oxide change in response to changes in Holocene climate. A new Holocene isotopic record for carbon dioxide (stable carbon and oxygen isotopes), will improve the precision of existing records by a factor 5 and increase the temporal resolution. These data will be used to evaluate controversial hypotheses about why carbon dioxide concentrations changed in the Holocene and provide insight into millennial scale processes in the carbon cycle, which are not resolved by current isotopic data. A graduate student and post doc will receive advanced training during and the student and principle investigator will conduct outreach efforts targeted at local middle school students. The proposed work will also contribute to teaching efforts by the PI and to public lectures on climate and climate change. The results will be disseminated through publications, data archive, and the OSU Ice Core Lab web site. New analytical methods of wide utility will also be developed and documented.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "Antarctica; ICE CORE RECORDS; CARBON DIOXIDE; NOT APPLICABLE; USAP-DC; TRACE GASES/TRACE SPECIES; NITROUS OXIDE", "locations": "Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "NCEI; USAP-DC", "science_programs": "SPICEcore", "south": -90.0, "title": "Controls on Variations in Atmospheric Carbon Dioxide and Nitrous Oxide During the Last 10,000 years", "uid": "p0010043", "west": -180.0}, {"awards": "1644245 Aydin, Murat", "bounds_geometry": null, "dataset_titles": "Ice Core Air Ethane and Acetylene Measurements - South Pole SPC14 Ice Core (SPICEcore project); Ice core ethane measurements, Greenland and Antarctica, 1000-1900 CE.", "datasets": [{"dataset_uid": "601367", "doi": "10.15784/601367", "keywords": "Antarctica; Ethane", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Ice Core Air Ethane and Acetylene Measurements - South Pole SPC14 Ice Core (SPICEcore project)", "url": "https://www.usap-dc.org/view/dataset/601367"}, {"dataset_uid": "002574", "doi": "", "keywords": null, "people": null, "repository": "Arctic Data Center", "science_program": null, "title": "Ice core ethane measurements, Greenland and Antarctica, 1000-1900 CE.", "url": "https://arcticdata.io/catalog/view/doi:10.18739/A2CR5NC1B"}], "date_created": "Tue, 13 Nov 2018 00:00:00 GMT", "description": "Aydin/1644245\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to measure ethane in ice core air extracted from the recently drilled intermediate depth South Pole ice core (SPICECORE). Ethane is an abundant hydrocarbon in the atmosphere. The ice core samples that will be used in this analysis will span about 150 years before present to about 55,000 years before present and therefore, ethane emissions linked to human activities are not a subject of this study. The study will focus on quantifying the variability in the natural sources of ethane and the processes that govern its removal from the atmosphere. A long-term ice core ethane record will provide new knowledge on the chemistry of Earth?s atmosphere during time periods when human influence was either much smaller than present day or non-existent. The broader impacts of this work include education and training of students and a contribution to a better understanding of the chemistry of the atmosphere in the past and how it has been impacted by past changes in climate.\u003cbr/\u003e\u003cbr/\u003eNatural sources that emit ethane are both geologic (e.g. seeps, vents, mud volcanoes etc.) and pyrogenic (wild fires) which is commonly called biomass burning. Ethane is removed from the atmosphere via oxidation reactions. The ice core ethane measurements have great potential as a proxy for gaseous emissions from biomass burning. This is especially true for time periods preceding the industrial revolution when atmospheric variability of trace gases was largely controlled by natural processes. Another objective of this study is to improve understanding of the causes of atmospheric methane variability apparent which are in the existing ice core records. Methane is a simpler hydrocarbon than ethane and more abundant in the atmosphere. Even though the project does not include any methane measurements; the commonalities between the sources and removal of atmospheric ethane and methane mean that ethane measurements can be used to gain insight into the causes of changes in atmospheric methane levels. The broader impacts of the project include partial support for one Ph.D. student and support for undergraduate researchers at UC Irvine. The PIs group currently has 4 undergraduate researchers. The PI and the graduate students in the UCI ice core laboratory regularly participate in on- and off-campus activities such as laboratory tours and lectures directed towards educating high-school students and science teachers, and the local community at large about the scientific value of polar ice cores as an environmental record of our planet\u0027s past. The results of this research will be disseminated via peer-review publications and will contribute to policy-relevant activities such as the IPCC Climate Assessment. Data resulting from this project will be archived in a national data repository. This award does not have field work in Antarctica.", "east": null, "geometry": null, "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USAP-DC; NOT APPLICABLE", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "USAP-DC", "repositories": "Arctic Data Center; USAP-DC", "science_programs": "SPICEcore", "south": null, "title": "Ethane Measurements in the Intermediate Depth South Pole Ice Core (SPICECORE)", "uid": "p0000762", "west": null}, {"awards": "1246045 Waddington, Edwin", "bounds_geometry": "POLYGON((-180 -70,-144 -70,-108 -70,-72 -70,-36 -70,0 -70,36 -70,72 -70,108 -70,144 -70,180 -70,180 -72,180 -74,180 -76,180 -78,180 -80,180 -82,180 -84,180 -86,180 -88,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -88,-180 -86,-180 -84,-180 -82,-180 -80,-180 -78,-180 -76,-180 -74,-180 -72,-180 -70))", "dataset_titles": "Code for inference of fabric from sonic velocity and thin-section measurements.; Code for models involving stochastic treatment of ice fabric", "datasets": [{"dataset_uid": "000244", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for models involving stochastic treatment of ice fabric", "url": "https://github.com/mjhay/stochastic_fabric"}, {"dataset_uid": "000243", "doi": "", "keywords": null, "people": null, "repository": "GitHub", "science_program": null, "title": "Code for inference of fabric from sonic velocity and thin-section measurements.", "url": "https://github.com/mjhay/neem_sonic_model"}], "date_created": "Mon, 02 Apr 2018 00:00:00 GMT", "description": "Waddington/1246045 \u003cbr/\u003e\u003cbr/\u003eThis award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "NOT APPLICABLE; USAP-DC", "locations": null, "north": -70.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Waddington, Edwin D.", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "GitHub", "repositories": "GitHub", "science_programs": null, "south": -90.0, "title": "Anisotropic Ice and Stratigraphic Disturbances", "uid": "p0000073", "west": -180.0}, {"awards": "1043167 White, James; 1043092 Steig, Eric", "bounds_geometry": "POINT(-112.08 -79.47)", "dataset_titles": "Resampling of Deep Polar Ice Cores using Information Theory; Seasonal temperatures in West Antarctica during the Holocene ; Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core; WAIS Divide Ice Core Discrete CH4 (80-3403m)", "datasets": [{"dataset_uid": "600169", "doi": "10.15784/600169", "keywords": "Antarctica; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Paleoclimate; Snow Accumulation; WAIS Divide; WAIS Divide Ice Core", "people": "Jones, Tyler R.; Morris, Valerie; Vaughn, Bruce; White, James", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/600169"}, {"dataset_uid": "601741", "doi": "10.15784/601741", "keywords": "Antarctica; Ch4; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Methane; WAIS", "people": "Sowers, Todd A.; Brook, Edward", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide Ice Core Discrete CH4 (80-3403m)", "url": "https://www.usap-dc.org/view/dataset/601741"}, {"dataset_uid": "601365", "doi": "10.15784/601365", "keywords": "Antarctica; Delta 18O; Isotope; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "White, James; Jones, Tyler R.; Garland, Joshua; Vaughn, Bruce; Morris, Valerie", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Resampling of Deep Polar Ice Cores using Information Theory", "url": "https://www.usap-dc.org/view/dataset/601365"}, {"dataset_uid": "601603", "doi": "10.15784/601603", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Seasonality; Seasonal Temperatures; Temperature; Water Isotopes; West Antarctic Ice Sheet", "people": "Jones, Tyler R.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Seasonal temperatures in West Antarctica during the Holocene ", "url": "https://www.usap-dc.org/view/dataset/601603"}, {"dataset_uid": "601274", "doi": "10.15784/601274", "keywords": "Antarctica; Delta 18O; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Isotope; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Price, Michael; Garland, Joshua; Bradley, Elizabeth; Morris, Valerie; Jones, Tyler R.; White, James; Vaughn, Bruce", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "url": "https://www.usap-dc.org/view/dataset/601274"}], "date_created": "Thu, 15 Sep 2016 00:00:00 GMT", "description": "Steig/1043092\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.", "east": -112.08, "geometry": "POINT(-112.08 -79.47)", "instruments": null, "is_usap_dc": true, "keywords": "LABORATORY", "locations": null, "north": -79.47, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "White, James; Vaughn, Bruce; Jones, Tyler R.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.47, "title": "Collaborative Research: Stable Isotopes of Ice in the Transition and Glacial Sections of the WAIS Divide Deep Ice Core", "uid": "p0000078", "west": -112.08}, {"awards": "0934534 Sergienko, Olga", "bounds_geometry": "POLYGON((-106 -70,-105.4 -70,-104.8 -70,-104.2 -70,-103.6 -70,-103 -70,-102.4 -70,-101.8 -70,-101.2 -70,-100.6 -70,-100 -70,-100 -70.6,-100 -71.2,-100 -71.8,-100 -72.4,-100 -73,-100 -73.6,-100 -74.2,-100 -74.8,-100 -75.4,-100 -76,-100.6 -76,-101.2 -76,-101.8 -76,-102.4 -76,-103 -76,-103.6 -76,-104.2 -76,-104.8 -76,-105.4 -76,-106 -76,-106 -75.4,-106 -74.8,-106 -74.2,-106 -73.6,-106 -73,-106 -72.4,-106 -71.8,-106 -71.2,-106 -70.6,-106 -70))", "dataset_titles": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "datasets": [{"dataset_uid": "609626", "doi": "10.7265/N5XS5SBW", "keywords": "Antarctica; Arctic; Bindschadler Ice Stream; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland; Lambert Ice Stream; Macayeal Ice Stream; Pine Island Glacier; Thwaites Glacier", "people": "Sergienko, Olga", "repository": "USAP-DC", "science_program": null, "title": "Inverted Basal Shear Stress of Antarctic and Greenland Ice Streams and Glaciers", "url": "https://www.usap-dc.org/view/dataset/609626"}], "date_created": "Thu, 06 Feb 2014 00:00:00 GMT", "description": "Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.", "east": -100.0, "geometry": "POINT(-103 -73)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e VISUAL OBSERVATIONS", "is_usap_dc": true, "keywords": "Not provided; Inverse Modeling; GROUND-BASED OBSERVATIONS; Basal Shear Stress", "locations": null, "north": -70.0, "nsf_funding_programs": "Arctic Natural Sciences", "paleo_time": null, "persons": "Sergienko, Olga", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -76.0, "title": "COLLABORATIVE RESEARCH: Enabling ice sheet sensitivity and stability analysis with a large-scale higher-order ice sheet model\u0027s adjoint to support sea level change assessment", "uid": "p0000048", "west": -106.0}, {"awards": "0839078 Brook, Edward", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Thu, 31 Oct 2013 00:00:00 GMT", "description": "This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a robust analytical technique for measuring the stable isotopes of CO2 in air trapped in polar ice, and to reconstruct the \u00e413C of CO2 over the last glacial to interglacial transition (20,000 to 10,000 years BP) and through the Holocene. The bulk of these measurements will be made on newly cored ice from the WAIS Divide Ice Core. A robust record \u00e413C of CO2 will be a valuable addition to the rich data produced from this project. The intellectual merit of the proposed work relates to the fact that explaining glacial-interglacial changes in atmospheric CO2 remains a major challenge for paleoclimatology. The lack of a coherent, widely accepted explanation underscores uncertainties in the basic mechanisms that control the carbon cycle, and that lack of understanding limits our ability to confidently predict how the carbon cycle will change in the future, in the face of a potentially major perturbation of both global temperature and the CO2 content of the atmosphere. A widely accepted record of this parameter could transform our understanding of how the carbon cycle and climate change are linked. The broader impacts of the work include training of graduate student at OSU who will conduct much of the lab work and will also participate in fieldwork at the WAIS Divide Core site. The student will also participate in a number of organized outreach efforts and will develop his own outreach effort, through weblogs and other communication of his research. The PIs will communicate the results from this project to a variety of audiences through academic courses and public talks. The proposed work addresses a major topic in biogeochemistry, the origin of glacial-interglacial CO2 cycles. The results are relevant to understanding changes in the carbon cycle due to human activities because the lack of clear understanding of past variations contributes to public uncertainty about the importance of modern climate change. The proposed funding will also contribute to analytical infrastructure at OSU and develop an analytical capability for an ice core measurement currently not available in the United States.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.; Mix, Alan", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Developing a glacial-interglacial record of delta-13C of atmospheric CO2", "uid": "p0000260", "west": null}, {"awards": "1240707 Fahnestock, Mark; 0632292 Bell, Robin", "bounds_geometry": "POLYGON((65 -77.5,67.4 -77.5,69.8 -77.5,72.2 -77.5,74.6 -77.5,77 -77.5,79.4 -77.5,81.8 -77.5,84.2 -77.5,86.6 -77.5,89 -77.5,89 -78.25,89 -79,89 -79.75,89 -80.5,89 -81.25,89 -82,89 -82.75,89 -83.5,89 -84.25,89 -85,86.6 -85,84.2 -85,81.8 -85,79.4 -85,77 -85,74.6 -85,72.2 -85,69.8 -85,67.4 -85,65 -85,65 -84.25,65 -83.5,65 -82.75,65 -82,65 -81.25,65 -80.5,65 -79.75,65 -79,65 -78.25,65 -77.5))", "dataset_titles": "Data Access Tool; Processed Ice Penetrating Radar Altimeter data (SEGY format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT; Processed Ice Penetrating Radar Data (jpeg images) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ; Processed Ice Penetrating Radar Data (Matlab format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ; Processed Ice Penetrating Radar Data (Netcdf format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "datasets": [{"dataset_uid": "601286", "doi": "10.15784/601286", "keywords": "AGAP; Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar; Radar Echo Sounder", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Data (jpeg images) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "url": "https://www.usap-dc.org/view/dataset/601286"}, {"dataset_uid": "601285", "doi": null, "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar Echo Sounder", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Data (Netcdf format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "url": "https://www.usap-dc.org/view/dataset/601285"}, {"dataset_uid": "001489", "doi": "", "keywords": null, "people": null, "repository": "MGDS", "science_program": null, "title": "Data Access Tool", "url": "http://www.marine-geo.org/tools/search/entry.php?id=AGAP_GAMBIT"}, {"dataset_uid": "601283", "doi": "10.1594/IEDA/318208", "keywords": "Aerogeophysics; AGAP; Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar; Radar Echo Sounder", "people": "Bell, Robin", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Altimeter data (SEGY format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT", "url": "https://www.usap-dc.org/view/dataset/601283"}, {"dataset_uid": "601284", "doi": null, "keywords": "Airborne Radar; Airplane; Antarctica; East Antarctica; Gamburtsev Mountains; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Sheet; Radar; Radar Echo Sounder", "people": "Bell, Robin; Studinger, Michael S.", "repository": "USAP-DC", "science_program": null, "title": "Processed Ice Penetrating Radar Data (Matlab format) from the Gamburtsev Mountains in Antarctica acquired during GAMBIT ", "url": "https://www.usap-dc.org/view/dataset/601284"}], "date_created": "Sun, 29 Sep 2013 00:00:00 GMT", "description": "This award supports an aerogeophysical study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project would perform a combined gravity, magnetics, and radar study to achieve a range of goals including: advancing our understanding of the origin and evolution of the polar ice sheets and subglacial lakes; defining the crustal architecture of East Antarctica, a key question in the earth\u0027s history; and locating the oldest ice in East Antarctica, which may ultimately help find ancient climate records. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. \u003cbr/\u003eBecause of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this study, NSF is also supporting a seismological survey of the GSM under award number 0537371. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach including a focus on groups underrepresented in the earth sciences.", "east": 89.0, "geometry": "POINT(77 -81.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e ALTIMETERS \u003e LIDAR/LASER ALTIMETERS \u003e AIRBORNE LASER SCANNER; 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 ECHO SOUNDERS", "is_usap_dc": false, "keywords": "GRAVITY; East Antarctica; GLACIERS/ICE SHEETS; ICE SHEETS; DHC-6; MAGNETIC FIELD; Not provided; Gamburtsev Mountains", "locations": "East Antarctica; Gamburtsev Mountains", "north": -77.5, "nsf_funding_programs": "Antarctic Earth Sciences; Antarctic Earth Sciences; Antarctic Glaciology", "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.; Fahnestock, Mark", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "MGDS; USAP-DC", "science_programs": null, "south": -85.0, "title": "Collaborative Research: IPY: GAMBIT: Gamburtsev Aerogeophysical Mapping of Bedrock and Ice Targets", "uid": "p0000114", "west": 65.0}, {"awards": "0838810 Hulbe, Christina", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Mon, 01 Jul 2013 00:00:00 GMT", "description": "Hulbe/0838810 \u003cbr/\u003e\u003cbr/\u003eThis award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).\u003cbr/\u003e\u003cbr/\u003eThis award supports a modeling study of the processes in West Antarctic grounding zones, the transition from ice resting on bedrock to ice floating on the ocean surface with an eye toward understanding the interrelated causes of rapid change in grounding line configuration and outlet flow. A combination of satellite remote sensing and numerical modeling will be used to investigate both past and ongoing patterns of change. New high-resolution surface elevation maps made from a novel combination of satellite laser altimetry and remotely observed surface shape provide a unique view of grounding zones. These data will be used to diagnose events associated with the shutdown of Kamb Ice Stream, to investigate a recent discharge event on Institute Ice Stream and to investigate ongoing change at the outlet of Whillans Ice Stream, along with other modern processes around the West Antarctic. An existing numerical model of coupled ice sheet, ice stream, and ice shelf flow will be used and improved as part of the research project. The broader impacts of the project relate to the importance of understanding the role of polar ice sheets in global sea level rise. The work will contribute to the next round of deliberations for the Intergovernmental Panel on Climate Change (IPCC). Improved views, interpretations, and insights into the physical processes that govern variability in ice sheet outlet streams will help correct the shortcomings of the last IPCC report that didn?t include the role of ice sheets in sea level rise. The PIs have a strong record of public outreach, involvement in the professional community, and student training.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "LABORATORY; Kamb Ice Stream; Grounding Line; FIELD INVESTIGATION; SATELLITES; Transition Zone; Ice Shelf Flow; Outlet Flow; Ice Sheet; Modeling; COMPUTERS; Antarctica", "locations": "Antarctica; Kamb Ice Stream", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hulbe, Christina; Fahnestock, Mark", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e SATELLITES", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Mass Transit: Controls on Grounding and Ungrounding at Marine Ice Sheet Outlets", "uid": "p0000371", "west": null}, {"awards": "0738975 Baker, Ian", "bounds_geometry": null, "dataset_titles": "Siple Dome A (SDMA) Grain Orientation 640 - 790 Meters", "datasets": [{"dataset_uid": "609526", "doi": "10.7265/N53T9F5X", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Sample/collection Description; Sample/Collection Description; Siple Dome; Siple Dome Ice Core; South Pole; WAISCORES", "people": "Obbard, Rachel; Sieg, Katherine; Baker, Ian", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Siple Dome A (SDMA) Grain Orientation 640 - 790 Meters", "url": "https://www.usap-dc.org/view/dataset/609526"}], "date_created": "Mon, 26 Nov 2012 00:00:00 GMT", "description": "This award supports a project to fully characterize the microstructure in ice cores, in particular the microstructural locations of impurities, grain orientations and strain gradients. This work will complement the optical observations, electrical conductivity measurement, and precise, detailed measurements of the soluble ion and gas contents that are performed by others. Linking the concentrations of soluble ions and gases, measured to a few parts per billion, to the optically determined annual layer structure and the stable isotope data in ice cores has enabled a great deal to be established about the concentrations and depth/age distributions of particles, trace gases and impurities for several polar ice cores. Ice core studies carried out by several groups contribute immensely to our understanding of paleoclimate and, to our ability to predict future climate change. The work will build on previous measurements and technique development in this area, as well as focusing on new techniques to characterize ice cores. The work will use both scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDS) and confocal scanning optical microscopy coupled with Raman spectroscopy (RS) to determine the microstructural locations of impurities and correlate this information with depth/age, and impurity type and concentration for several polar ice cores. The Broader Impacts of the proposed work are that knowledge of the location of impurities coupled with the grain orientation (both c- and a-axis) and grain misorientation information will allow paleoclimatologists to better interpret ice core data and other scientists to understand and model the physical and mechanical properties of natural ice sheets. Other Broader Impacts of the work are that the work will be performed and lead to the education of a Ph.D. student. At the end of the project, as well as the knowledge gained from coursework, the graduate student will have experience in ice core specimen preparation and characterization using scanning electron microscopy, x-ray microanalysis, confocal scanning microscopy, Raman spectroscopy and ion chromatography. Results from the research will be published in refereed journals, presented at conferences, and placed on a web page.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": true, "keywords": "FEI Xl30 Environmental Scanning Electron Microscope - Field Emission Gun (esem - Feg); LABORATORY; Electron Backscatter Diffraction", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Baker, Ian; Obbard, Rachel; Sieg, Katherine", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Advanced Microstructural Characterization of Polar Ice Cores", "uid": "p0000178", "west": null}, {"awards": "0739684 Hatcher, Patrick", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 26 Sep 2012 00:00:00 GMT", "description": "This award supports a project to fully develop the analytical protocols needed to exploit a relatively new technique for the analysis of soluble organic matter in ice core samples. The technique couples Electrospray ionization to high resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). Sample volume will be reduced and pre-concentration steps will be eliminated. Following method optimization a suite of ice core samples will be studied from several Antarctic and Greenland locations to address several hypothesis driven research questions. Preliminary results show that a vast record of relatively high molecular weight organic material exists in ice core samples and intriguing results from a few samples warrant further investigation. Several important questions related to developing a better understanding of the nature and paleo record of organic matter in ice cores will be addressed. These include developing a better understanding of the origin of nitrogen and sulfur isotopes in pre-industrial vs. modern samples, developing the methods to apply molecular biomarker techniques, routinely used by organic geochemists for sediment analyses, to the analysis of organic matter in ice cores, tracking the level of oxidation of homologous series of compounds and using them as a proxy for atmospheric oxidant levels in the past and determining whether or not high resolution FTICR mass spectral analysis can provide the ice core community with a robust method to analyze organic materials at the molecular level. The intellectual merit of this work is that this analytical method will provide a new understanding of the nature of organic matter in ice, possibly leading to the discovery of multitudes of molecular species indicative of global change processes whose abundances can be compared with other change proxies. The proposed studies are of an exploratory nature and potentially transformative for the field of ice core research and cryobiology. The broader impacts of these studies are that they should provide compelling evidence regarding organic matter sources, atmospheric processing and anthropogenic inputs to polar ice and how these have varied over time. The collaborative work proposed here will partner atmospheric chemistry/polar ice chemistry expertise with organic geochemistry expertise, resulting in significant contributions to both fields of study and significant advances in ice core analysis. Training of both graduate and undergraduate students will be a key component of the project and students will be involved in collaborative research using advanced analytical instrumentation, presentation of research results at national meetings, and will participate in manuscript preparation.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": false, "keywords": "Ice Core; Isotope; Organic Matter; Nitrogen; Sulfur; Not provided; LABORATORY; Mass Spectrometry; COMPUTERS; Molecular", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Hatcher, Patrick; Grannas, Amanda", "platforms": "Not provided; OTHER \u003e MODELS \u003e COMPUTERS; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Molecular Level Characterization of Organic Matter in Ice Cores using High-resolution FTICR mass spectrometry", "uid": "p0000707", "west": null}, {"awards": "0828786 Barletta, Robert", "bounds_geometry": "POINT(38.466667 72.583336)", "dataset_titles": null, "datasets": null, "date_created": "Tue, 06 Sep 2011 00:00:00 GMT", "description": "Barletta \u003cbr/\u003e0828786\u003cbr/\u003e\u003cbr/\u003eThis award supports a Small Grant for Exploratory Research (SGER) for a project to conduct a limited scope, proof-of-concept study of the application of Raman spectroscopy to the analysis of ice cores. As a non-destructive analytical tool with high spatial resolution, Raman spectroscopy has found widespread application in situations where water is a major constituent in the sample, including marine science and the analysis of clathrates in ice-cores themselves. Raman can provide information at high enough sensitivity (ppm to ppb) to make its use as a non-destructive survey tool for ice core samples attractive. Laser-based techniques such as Raman can be used to obtain chemical information at near diffraction-limited resolution allowing particulates on the order of 1micron or less to be characterized. Preliminary work has demonstrated the selectivity of Raman spectroscopy for determining related polyatomic species (ions and compounds), and the ability to discern oxidation state from such analysis. In spite of the potential of this technique, instrumentation necessary to analyze ice core samples using micro-Raman spectroscopy with UV excitation is not readily available. Even with visible excitation, libraries of Raman spectra necessary for mixture de-convolution are not available. The proposed effort is a novel extension of Raman into the area of polar and climatic research, providing data on chemical speciation hitherto unavailable, of critical importance to the understanding of the biology present in glacial ice as well as the sources of particulate material found in ice cores. Since the availability of ice-core material at critical horizons is limited, this non-destructive technique will help to maximize the information obtained from these samples. The broader impacts of the work are that it will bring a new researcher into the field of polar ice core analysis and it has the potential to also bring a new non-destructive technique into the field. Finally, the research will take place at a predominately undergraduate institution in South Alabama with a large proportion (24% of undergraduates) of minority students. The proposed effort is high-risk because, although based upon established principles of vibrational spectroscopy, the application to the analytical problems of trace environmental analysis are unique, and the precision requirements are stringent. Moreover, this work will demonstrate the feasibility of an integrated approach to ice core analysis, while addressing specific problems in glaciology.", "east": 38.466667, "geometry": "POINT(38.466667 -72.583336)", "instruments": null, "is_usap_dc": false, "keywords": "Particulates; Spectroscopy; Antarctic; LABORATORY; Ice Core; FIELD INVESTIGATION; Not provided; Ions; Raman Spectra", "locations": "Antarctic", "north": -72.583336, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Barletta, Robert", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -72.583336, "title": "SGER - ?Raman Analysis of Ice-Core Samples", "uid": "p0000285", "west": 38.466667}, {"awards": "0424589 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-137 -74,-132.1 -74,-127.2 -74,-122.3 -74,-117.4 -74,-112.5 -74,-107.6 -74,-102.7 -74,-97.8 -74,-92.9 -74,-88 -74,-88 -74.65,-88 -75.3,-88 -75.95,-88 -76.6,-88 -77.25,-88 -77.9,-88 -78.55,-88 -79.2,-88 -79.85,-88 -80.5,-92.9 -80.5,-97.8 -80.5,-102.7 -80.5,-107.6 -80.5,-112.5 -80.5,-117.4 -80.5,-122.3 -80.5,-127.2 -80.5,-132.1 -80.5,-137 -80.5,-137 -79.85,-137 -79.2,-137 -78.55,-137 -77.9,-137 -77.25,-137 -76.6,-137 -75.95,-137 -75.3,-137 -74.65,-137 -74))", "dataset_titles": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams; Archive of data; Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau; Ku-band Radar Echograms; Radar Depth Sounder Echograms and Ice Thickness; Snow Radar Echograms", "datasets": [{"dataset_uid": "601411", "doi": "10.15784/601411", "keywords": "Antarctica; East Antarctic Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; ICECAP; Ice Penetrating Radar; Internal Reflecting Horizons", "people": "Cavitte, Marie G. P; Blankenship, Donald D.; Schroeder, Dustin; Tozer, Carly; Roberts, Jason; Frezzotti, Massimo; Paden, John; Muldoon, Gail R.; Quartini, Enrica; Kempf, Scott D.; Young, Duncan A.; Mulvaney, Robert; Ritz, Catherine; Greenbaum, Jamin; Ng, Gregory", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Ice-penetrating radar internal stratigraphy over Dome C and the wider East Antarctic Plateau", "url": "https://www.usap-dc.org/view/dataset/601411"}, {"dataset_uid": "601049", "doi": "10.15784/601049", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Navigation; Radar; Snow", "people": "Gogineni, Prasad; Leuschen, Carl; Allen, Chris; Li, Jilu; Rodriguez, Fernando; Paden, John", "repository": "USAP-DC", "science_program": null, "title": "Snow Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601049"}, {"dataset_uid": "002497", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "Archive of data", "url": "https://www.cresis.ku.edu/data/accumulation"}, {"dataset_uid": "601048", "doi": "10.15784/601048", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ku-Band; Navigation; Radar", "people": "Li, Jilu; Paden, John; Leuschen, Carl; Rodriguez, Fernando; Gogineni, Prasad; Allen, Chris", "repository": "USAP-DC", "science_program": null, "title": "Ku-band Radar Echograms", "url": "https://www.usap-dc.org/view/dataset/601048"}, {"dataset_uid": "601047", "doi": "10.15784/601047", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; MCoRDS; Navigation; Radar", "people": "Li, Jilu; Leuschen, Carl; Allen, Chris; Rodriguez, Fernando; Paden, John; Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Radar Depth Sounder Echograms and Ice Thickness", "url": "https://www.usap-dc.org/view/dataset/601047"}, {"dataset_uid": "600384", "doi": "10.15784/600384", "keywords": "Airborne Radar; Antarctica; Basler; Glaciers/ice Sheet; Glaciers/Ice Sheet; Kamb Ice Stream; Radar; Siple Coast; Whillans Ice Stream", "people": "Paden, John; Hale, Richard", "repository": "USAP-DC", "science_program": null, "title": "Airborne radar profiles of the Whillans, Bindschadler, and Kamb Ice Streams", "url": "https://www.usap-dc.org/view/dataset/600384"}], "date_created": "Wed, 01 Jun 2011 00:00:00 GMT", "description": "This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbr\u00e6. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.\u003cbr/\u003e\u003cbr/\u003eThe intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. \u003cbr/\u003e\u003cbr/\u003eAs lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.", "east": -88.0, "geometry": "POINT(-112.5 -77.25)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS", "is_usap_dc": true, "keywords": "Remote Sensing; Not provided; Pine Island; Ice Sheet; DHC-6; Antarctic; Thwaites Region; Antarctica; Mass Balance; Accumulation; Velocity; Insar", "locations": "Antarctica; Antarctic; Pine Island; Thwaites Region", "north": -74.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Braaten, David; Joughin, Ian; Steig, Eric J.; Das, Sarah; Paden, John; Gogineni, Prasad", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; Not provided", "repo": "USAP-DC", "repositories": "Project website; USAP-DC", "science_programs": null, "south": -80.5, "title": "Center for Remote Sensing of Ice Sheets (CReSIS)", "uid": "p0000102", "west": -137.0}, {"awards": "0739780 Taylor, Kendrick", "bounds_geometry": "POINT(-112.117 -79.666)", "dataset_titles": "WAIS DIVIDE - High Temporal Resolution Black Carbon Record of Southern Hemisphere Biomass Burning", "datasets": [{"dataset_uid": "600142", "doi": "10.15784/600142", "keywords": "Antarctica; Atmosphere; Black Carbon; Chemistry:ice; Chemistry:Ice; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; WAIS Divide; WAIS Divide Ice Core", "people": "Taylor, Kendrick C.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS DIVIDE - High Temporal Resolution Black Carbon Record of Southern Hemisphere Biomass Burning", "url": "https://www.usap-dc.org/view/dataset/600142"}], "date_created": "Thu, 28 Apr 2011 00:00:00 GMT", "description": "Edwards/0739780\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to develop a 2,000-year high-temporal resolution record of biomass burning from the analysis of black carbon in the WAIS Divide bedrock ice core. Pilot data for the WAIS WD05A core demonstrates that we now have the ability to reconstruct this record with minimal impact on the amount of ice available for other projects. The intellectual merit of this project is that black carbon (BC) aerosols result solely from combustion and play a critical but poorly quantified role in global climate forcing and the carbon cycle. When incorporated into snow and ice, BC increases absorption of solar radiation making seasonal snow packs, mountain glaciers, polar ice sheets, and sea ice much more vulnerable to climate warming. BC emissions in the Southern Hemisphere are dominated by biomass burning in the tropical regions of Southern Africa, South America and South Asia. Biomass burning, which results from both climate and human activities, alters the atmospheric composition of greenhouse gases, aerosols and perturbs key biogeochemical cycles. A long-term record of biomass burning is needed to aid in the interpretation of ice core gas composition and will provide important information regarding human impacts on the environment and climate before instrumental records. The broader impacts of the project are that it represents a paradigm shift in our ability to reconstruct the history of fire from ice core records and to understand its impact on atmospheric chemistry and climate over millennial time scales. This type of data is especially needed to drive global circulation model simulations of black carbon aerosols, which have been found to be an important component of global warming and which may be perturbing the hydrologic cycle. The project will also employ undergraduate students and is committed to attracting underrepresented groups to the physical sciences. The project?s outreach component will be conducted as part of the WAIS project outreach program and will reach a wide audience.", "east": -112.117, "geometry": "POINT(-112.117 -79.666)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; Not provided; Gas Record; Ice Core; Gas Measurement; Ice Core Gas Composition; Antarctica; LABORATORY; Bedrock Ice Core; Ice Core Gas Records; Wais Project; Greenhouse Gas; Atmospheric Chemistry; FIELD INVESTIGATION; Black Carbon; Biomass Burning; WAIS Divide; FIELD SURVEYS; West Antarctica; Methane", "locations": "Antarctica; West Antarctica; WAIS Divide", "north": -79.666, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward J.; McConnell, Joseph; Mitchell, Logan E; Sowers, Todd A.; Taylor, Kendrick C.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.666, "title": "WAIS DIVIDE - High Temporal Resolution Black Carbon Record of Southern Hemisphere Biomass Burning", "uid": "p0000022", "west": -112.117}, {"awards": "0538494 Meese, Debra", "bounds_geometry": null, "dataset_titles": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "datasets": [{"dataset_uid": "609436", "doi": "10.7265/N5DF6P5P", "keywords": "Antarctica; Arctic; Byrd Glacier; Byrd Ice Core; Chemistry:ice; Chemistry:Ice; Geochemistry; GISP2; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Lake Vostok; Paleoclimate; Vostok Ice Core", "people": "Baker, Ian; Obbard, Rachel", "repository": "USAP-DC", "science_program": null, "title": "Microstructural Location and Composition of Impurities in Polar Ice Cores", "url": "https://www.usap-dc.org/view/dataset/609436"}], "date_created": "Thu, 03 Jun 2010 00:00:00 GMT", "description": "0538494\u003cbr/\u003eMeese\u003cbr/\u003eThis award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e MICROSCOPES; IN SITU/LABORATORY INSTRUMENTS \u003e PHOTON/OPTICAL DETECTORS \u003e SCANNING ELECTRON MICROSCOPES", "is_usap_dc": false, "keywords": "LABORATORY; Grain Growth; FIELD SURVEYS; Accumulation Rate; Firn Core; FIELD INVESTIGATION; Chemistry; Snow Pit; Depth Hoar; Firn Density; Ice Core; Not provided; Stratigraphic Analysis; Firn; US ITASE; Annual Layers", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Meese, Deb; MEESE, DEBRA", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "The Physical Properties of the US ITASE Firn and Ice Cores from South Pole to Taylor Dome", "uid": "p0000289", "west": null}, {"awards": "0335330 Waddington, Edwin", "bounds_geometry": "POLYGON((-60 83,-55.8 83,-51.6 83,-47.4 83,-43.2 83,-39 83,-34.8 83,-30.6 83,-26.4 83,-22.2 83,-18 83,-18 80.5,-18 78,-18 75.5,-18 73,-18 70.5,-18 68,-18 65.5,-18 63,-18 60.5,-18 58,-22.2 58,-26.4 58,-30.6 58,-34.8 58,-39 58,-43.2 58,-47.4 58,-51.6 58,-55.8 58,-60 58,-60 60.5,-60 63,-60 65.5,-60 68,-60 70.5,-60 73,-60 75.5,-60 78,-60 80.5,-60 83))", "dataset_titles": "Borehole Optical Stratigraphy Modeling, Antarctica", "datasets": [{"dataset_uid": "609468", "doi": "10.7265/N5H70CR5", "keywords": "Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Modeling Code", "people": "Hawley, Robert L.; Waddington, Edwin D.; Smith, Ben; Fudge, T. J.", "repository": "USAP-DC", "science_program": null, "title": "Borehole Optical Stratigraphy Modeling, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609468"}], "date_created": "Thu, 01 Apr 2010 00:00:00 GMT", "description": "This award supports a study of the physical nature and environmental origin of optical features (light and dark zones) observed by video in boreholes in polar ice. These features appear to include an annual signal, as well as longer period signals. Borehole logs exist from a previous project, and in this lab-based project the interpretation of these logs will be improved. The origin of the features is of broad interest to the ice-core community. If some components relate to changes in the depositional environment beyond seasonality, important climatic cycles may be seen. If some components relate to post-depositional reworking, insights will be gained into the physical processes that change snow and firn, and the implications for interpretation of the chemical record in terms of paleoclimate. In order to exploit these features to best advantage in future ice-core and climate-change research, the two principal objectives of this project are to determine what physically causes the optical differences that we see and to determine the environmental processes that give rise to these physical differences. In the laboratory at NICL the conditions of a log of a borehole wall will be re-created as closely as possible by running the borehole video camera along sections of ice core, making an optical log of light reflected from the core. Combinations of physical variables that are correlated with optical features will be identified. A radiative-transfer model will be used to aid in the interpretation of these measurements, and to determine the optimum configuration for an improved future logging tool. An attempt will be made to determine the origin of the features. Two broad possibilities exist: 1) temporal changes in the depositional environment, and 2) post-depositional reworking. This project represents an important step toward a new way of learning about paleoclimate with borehole optical methods. Broader impacts include enhancing the infrastructure for research and education, since this instrument will complement high-resolution continuous-melter chemistry techniques and provide a rapid way to log physical variables using optical features as a proxy for climate signals. Since no core is required for this method, it can be used in rapidly drilled access holes or where core quality is poor. This project will support a graduate student who will carry out this project under the direction of the Principal Investigator. K-12 education will be enhanced through an ongoing collaboration with a science and math teacher from a local middle school. International collaboration will be expanded through work on this project with colleagues at the Norwegian Polar Institute and broad dissemination of results will occur through a project website for the general public.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e OPTICAL DUST LOGGERS", "is_usap_dc": true, "keywords": "Ice; Stratigraphy; Optical; Glaciers; Polar Ice; Ice Microphysics; Snow; Firn; Climate Change; LABORATORY; Snow Stratigraphy; Borehole", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Smith, Ben; Waddington, Edwin D.; Hawley, Robert L.; Fudge, T. J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Borehole Optical Stratigraphy: Ice Microphysics, Climate Change, and the Optical Properties of Firn", "uid": "p0000016", "west": -180.0}, {"awards": "0619457 Bell, Robin", "bounds_geometry": "POLYGON((-51 72.5,-49.5 72.5,-48 72.5,-46.5 72.5,-45 72.5,-43.5 72.5,-42 72.5,-40.5 72.5,-39 72.5,-37.5 72.5,-36 72.5,-36 71.85,-36 71.2,-36 70.55,-36 69.9,-36 69.25,-36 68.6,-36 67.95,-36 67.3,-36 66.65,-36 66,-37.5 66,-39 66,-40.5 66,-42 66,-43.5 66,-45 66,-46.5 66,-48 66,-49.5 66,-51 66,-51 66.65,-51 67.3,-51 67.95,-51 68.6,-51 69.25,-51 69.9,-51 70.55,-51 71.2,-51 71.85,-51 72.5))", "dataset_titles": null, "datasets": null, "date_created": "Mon, 20 Jul 2009 00:00:00 GMT", "description": "This project develops a system of airborne instruments to explore the polar ice sheets and their underlying environments. The instrument suite includes an ice-penetrating radar, laser altimeter, gravimeter and magnetometer. Airborne geophysical measurements are key to understanding the 99% of Antarctica and 85% of Greenland covered by ice, which have thus far been studied at the postage stamp level. Projects linking ice sheet behavior to underlying geology will immediately benefit from this system, but even more exciting are the system\u0027s potential uses for work at the frontiers of polar science, such as: 1) exploring subglacial lakes, recently discovered and potentially the most unique sites on Earth for understanding life in extreme environments; 2) locating the deepest, oldest ice, which would offer million year and older samples of the atmosphere and 3) interpreting Antarctica\u0027s subglacial geology, which contains unique and unstudied volcanoes, mountains, and tectonic provinces. In terms of broader impacts, this project constructs research infrastructure critical to society\u0027s understanding of sea level rise, and supports a project involving domestic, international, and private sector collaborations.", "east": -36.0, "geometry": "POINT(-43.5 69.25)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": 72.5, "nsf_funding_programs": null, "paleo_time": null, "persons": "Bell, Robin; Studinger, Michael S.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": 66.0, "title": "Development of a Polar Multidisciplinary Airborne Imaging System for the International Polar Year 2007-2009", "uid": "p0000205", "west": -51.0}, {"awards": "0122520 Gogineni, S. Prasad", "bounds_geometry": "POLYGON((-110 -62,-105 -62,-100 -62,-95 -62,-90 -62,-85 -62,-80 -62,-75 -62,-70 -62,-65 -62,-60 -62,-60 -63.5,-60 -65,-60 -66.5,-60 -68,-60 -69.5,-60 -71,-60 -72.5,-60 -74,-60 -75.5,-60 -77,-65 -77,-70 -77,-75 -77,-80 -77,-85 -77,-90 -77,-95 -77,-100 -77,-105 -77,-110 -77,-110 -75.5,-110 -74,-110 -72.5,-110 -71,-110 -69.5,-110 -68,-110 -66.5,-110 -65,-110 -63.5,-110 -62))", "dataset_titles": "Antarctic Radar Echograms and Derived Ice Thickness Data from CReSIS", "datasets": [{"dataset_uid": "609414", "doi": "", "keywords": "Airborne Radar; Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Radar", "people": "Gogineni, Prasad", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Radar Echograms and Derived Ice Thickness Data from CReSIS", "url": "https://www.usap-dc.org/view/dataset/609414"}], "date_created": "Wed, 01 Jul 2009 00:00:00 GMT", "description": "0122520\u003cbr/\u003eGogineni\u003cbr/\u003e\u003cbr/\u003eSea level has been rising over the last century. Although the immediate impact of sea level rise may be less severe than other effects of global climate change, the long-term consequences can be much more devastating since nearly 60% of the world population lives in coastal regions. Scientists have postulated that excess water is being released from polar ice sheets due to long-term, global climate change, but there are insufficient data to confirm these theories. Understanding the interactions between the ice sheets, oceans and atmosphere is essential to quantifying the role of ice sheets in sea level rise. Toward that end, this research project involves the innovative application of information technology in the development and deployment of intelligent radar sensors for measuring key glaciological parameters. \u003cbr/\u003e\u003cbr/\u003eRadar instrumentation will consist of a synthetic aperture radar (SAR) that can operate in bistatic or monostatic mode. One important application of the SAR will be in the determination of basal conditions, particularly the presence and distribution of basal water. Basal water lubricates the ice/bed interface, enhancing flow, and increasing the amount of ice discharged into the ocean. Another application of the SAR will be to measure ice thickness and map internal layers in both shallow and deep ice. Information on near-surface internal layers will be used to estimate the average, recent accumulation rate, while the deeper layers provide a history of past accumulation and flow rates. A tracked vehicle and an automated snowmobile will be used to test and demonstrate the utility of an intelligent radar in glaciological investigations.\u003cbr/\u003e\u003cbr/\u003eThe system will be developed to collect, process and analyze data in real time and in conjunction with a priori information derived from archived sources. The combined real time and archived information will be used onboard the vehicles to select and generate an optimum sensor configuration. This project thus involves innovative research in intelligent systems, sounding radars and ice sheet modeling. In addition it has a very strong public outreach and education program, which include near-real-time image broadcasts via the world wide web", "east": -60.0, "geometry": "POINT(-85 -69.5)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e AIRSAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e IMAGING RADAR SYSTEMS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e RADAR ECHO SOUNDERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e IMAGING RADARS \u003e SAR", "is_usap_dc": true, "keywords": "Radar Echo Sounding; Not provided; FIELD SURVEYS; Airborne Radar Sounding; Radar Echo Sounder; Antarctic Ice Sheet; LABORATORY; Antarctica; Ice Sheet Thickness; Antarctic; Ice Sheet; Synthetic Aperture Radar Imagery; Radar Altimetry; Ice Sheet Elevation; FIELD INVESTIGATION; Radar", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet", "north": -62.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Gogineni, Prasad", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -77.0, "title": "ITR/SI+AP: A Mobile Sensor Web for Polar Ice Sheet Measurements", "uid": "p0000583", "west": -110.0}, {"awards": "0538630 Severinghaus, Jeffrey", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 01 Apr 2009 00:00:00 GMT", "description": "0538630\u003cbr/\u003eSeveringhaus\u003cbr/\u003eThis award supports a project to produce the first record of Kr/N2 in the paleo-atmosphere as measured in air bubbles trapped in ice cores. These measurements may be indicative of past variations in mean ocean temperature. Knowing the mean ocean temperature in the past will give insight into past variations in deep ocean temperature, which remain poorly understood. Deep ocean temperature variations are important for understanding the mechanisms of climate change. Krypton is highly soluble in water, and its solubility varies with temperature, with higher solubilities at colder water temperatures. A colder ocean during the last glacial period would therefore hold more krypton than today\u0027s ocean. Because the total amount of krypton in the ocean-atmosphere system is constant, the increase in the krypton inventory in the glacial ocean should cause a resultant decrease in the atmospheric inventory of krypton. The primary goal of this work is to develop the use of Kr/N2 as an indicator of paleo-oceanic mean temperature. This will involve improving the analytical technique for the Kr/N2 measurement itself, and measuring the Kr/N2 in air bubbles in ice from the last glacial maximum (LGM) and the late Holocene in the Vostok and GISP2 ice cores. This provides an estimate of LGM mean ocean temperature change, and allows for a comparison between previous estimates of deep ocean temperature during the LGM. The Vostok ice core is ideal for this purpose because of the absence of melt layers, which compromise the krypton and xenon signal. Another goal is to improve precision on the Xe/N2 measurement, which could serve as a second, independent proxy of ocean temperature change. A mean ocean temperature time series during this transition may help to explain these observations. Additionally, the proposed work will measure the Kr/N2 from marine isotope stage (MIS) 3 in the GISP2 ice core. Knowing the past ocean temperature during MIS 3 will help to constrain sea level estimates during this time period. The broader impacts of the proposed work: are that it will provide the first estimate of the extent and timing of mean ocean temperature change in the past. This will help to constrain previously proposed mechanisms of climate change involving large changes in deep ocean temperature. This project will also support the education of a graduate student. The PI gives interviews and talks to the media and public about climate change, and the work will enhance these outreach activities. Finally, the work will occur during the International Polar Year (IPY), and will underscore the unique importance of the polar regions for understanding the global atmosphere and ocean system.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Paleoatmospheric Krypton and Xenon Abundances from Trapped Air in Polar Ice as Indicators of Past Mean Ocean Temperature", "uid": "p0000553", "west": null}, {"awards": "0538683 Lal, Devendra", "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": "Solar activity during the last millennium, estimated from cosmogenic in-situ C14 in South Pole and GISP2 ice cores", "datasets": [{"dataset_uid": "600058", "doi": "10.15784/600058", "keywords": "Antarctica; Carbon-14; Cosmos; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Solar Activity; South Pole", "people": "Lal, Devendra", "repository": "USAP-DC", "science_program": null, "title": "Solar activity during the last millennium, estimated from cosmogenic in-situ C14 in South Pole and GISP2 ice cores", "url": "https://www.usap-dc.org/view/dataset/600058"}], "date_created": "Fri, 20 Feb 2009 00:00:00 GMT", "description": "0538683\u003cbr/\u003eLal\u003cbr/\u003eThis award supports a project to continue development of a new method for estimating solar activity in the past. It is based on measurements of the concentrations of in-situ produced C-14 in polar ice by cosmic rays, which depend only on (i) the cosmic ray flux, and (ii) ice accumulation rate. This is the only direct method available to date polar ice, since it does not involve any uncertain climatic transfer functions as are encountered in the applications of cosmogenic C-14 data in tree rings, or of Be-10 in ice and sediments. An important task is to improve on the temporal resolution during identified periods of high/low solar activity in the past 32 Kyr. The plan is to undertake a study of changes in the cosmic ray flux during the last millennium (1100-1825 A.D.), during which time 4 low and 1 high solar activity epoch has been identified from historical records. Sunspot data during most of these periods are sparse. Adequate ice samples are available from ice cores from the South Pole and from Summit, Greenland and a careful high resolution study of past solar activity levels during this period will be undertaken. The intellectual merit of the work includes providing independent verification of estimated solar activity levels from the two polar ice records of cosmic ray flux and greatly improve our understanding of solar-terrestrial relationships. \u003cbr/\u003eThe broader impacts include collaboration with other scientists who are experts in the application of the atmospheric cosmogenic C-14 and student training. Both undergraduates and a graduate student will be involved in the proposed research. Various forms of outreach will also be used to disseminate the results of this project, including public presentations and interactions with the media.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Not provided", "locations": null, "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lal, Devendra", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Solar Activity during the Last Millennium, Estimated from Cosmogenic in-situ 14C in South Pole and GISP2 Ice Cores", "uid": "p0000555", "west": -180.0}, {"awards": "0636953 Saltzman, Eric", "bounds_geometry": "POINT(-148.82 -81.66)", "dataset_titles": "Carbonyl Sulfide Measurements in the Taylor Dome M3C1 Ice Core; Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core; Methyl Bromide Measurements in the Taylor Dome M3C1 Ice Core; Methyl Chloride Measurements from the Siple Dome A Deep Core, Antarctica; Methyl Chloride Measurements in the Taylor Dome M3C1 Ice Core", "datasets": [{"dataset_uid": "601361", "doi": "10.15784/601361", "keywords": "Antarctica; Carbonyl Sulfide; Trace Gases", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/601361"}, {"dataset_uid": "609598", "doi": "10.7265/N5X0650D", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Methyl Bromide Measurements in the Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/609598"}, {"dataset_uid": "609599", "doi": "10.7265/N5S75D8P", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Carbonyl Sulfide Measurements in the Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/609599"}, {"dataset_uid": "609600", "doi": "10.7265/N5PG1PPB", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Taylor Dome; Taylor Dome Ice Core", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Methyl Chloride Measurements in the Taylor Dome M3C1 Ice Core", "url": "https://www.usap-dc.org/view/dataset/609600"}, {"dataset_uid": "609356", "doi": "10.7265/N56W9807", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Williams, Margaret; Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Methyl Chloride Measurements from the Siple Dome A Deep Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609356"}], "date_created": "Wed, 22 Oct 2008 00:00:00 GMT", "description": "Saltzman/0636953\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to measure methyl chloride, methyl bromide, and carbonyl sulfide in air extracted from Antarctic ice cores. Previous measurements in firn air and shallow ice cores suggest that the ice archive contains paleo-atmospheric signals for these gases. The goal of this study is to extend these records throughout the Holocene and into the last Glacial period to examine the behavior of these trace gases over longer time scales and a wider range of climatic conditions. These studies are exploratory, and both the stability of these trace gases and the extent to which they may be impacted by in situ processes will be assessed. This project will involve sampling and analyzing archived ice core samples from the Siple Dome, Taylor Dome, Byrd, and Vostok ice cores. The ice core samples will be analyzed by dry extraction, with gas chromatography/mass spectrometry with isotope dilution. The ice core measurements will generate new information about the range of natural variability of these trace gases in the atmosphere. The intellectual merit of this project is that this work will provide an improved basis for assessing the impact of anthropogenic activities on biogeochemical cycles, and new insight into the climatic sensitivity of the biogeochemical processes controlling atmospheric composition. The broader impact of this project is that there is a strong societal interest in understanding how man\u0027s activities impact the atmosphere, and how atmospheric chemistry may be altered by future climate change. The results of this study will contribute to the development of scenarios used for future projections of stratospheric ozone and climate change. In terms of human development, this project will support the doctoral dissertation of a graduate student in Earth System Science, and undergraduate research on polar ice core chemistry. This project will also contribute to the development of an Earth Sciences teacher training curriculum for high school teachers in the Orange County school system in collaboration with an established, NSF-sponsored Math and Science Partnership program (FOCUS).", "east": -148.82, "geometry": "POINT(-148.82 -81.66)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Antarctica; Methyl Bromide; Antarctic; Ice Core Gas Records; Ice Core Data; Carbonyl Sulfide; Methyl Chloride; Antarctic Ice Sheet; Siple Dome; Trace Gases; Ice Core Chemistry; Biogeochemical; Atmospheric Chemistry; West Antarctic Ice Sheet; LABORATORY; Ice Core; West Antarctica", "locations": "Antarctic; Antarctica; Antarctic Ice Sheet; Siple Dome; West Antarctica; West Antarctic Ice Sheet", "north": -81.66, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Saltzman, Eric; Aydin, Murat; Williams, Margaret", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core; Siple Dome Ice Core", "south": -81.66, "title": "Methyl Chloride, Methyl Bromide, and Carbonyl Sulfide in Deep Antarctic Ice Cores", "uid": "p0000042", "west": -148.82}, {"awards": "0230338 Hallet, Bernard; 0233823 Fountain, Andrew", "bounds_geometry": "POLYGON((162.132 -77.73,162.1495 -77.73,162.167 -77.73,162.1845 -77.73,162.202 -77.73,162.2195 -77.73,162.237 -77.73,162.2545 -77.73,162.272 -77.73,162.2895 -77.73,162.307 -77.73,162.307 -77.7303,162.307 -77.7306,162.307 -77.7309,162.307 -77.7312,162.307 -77.7315,162.307 -77.7318,162.307 -77.7321,162.307 -77.7324,162.307 -77.7327,162.307 -77.733,162.2895 -77.733,162.272 -77.733,162.2545 -77.733,162.237 -77.733,162.2195 -77.733,162.202 -77.733,162.1845 -77.733,162.167 -77.733,162.1495 -77.733,162.132 -77.733,162.132 -77.7327,162.132 -77.7324,162.132 -77.7321,162.132 -77.7318,162.132 -77.7315,162.132 -77.7312,162.132 -77.7309,162.132 -77.7306,162.132 -77.7303,162.132 -77.73))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 02 Jul 2008 00:00:00 GMT", "description": "This award supports a comprehensive study of land-based polar ice cliffs. Through field measurements, modeling, and remote sensing, the physics underlying the formation of ice cliffs at the margin of Taylor Glacier in the McMurdo Dry Valleys will be investigated. At three sites, measurements of ice deformation and temperature fields near the cliff face will be combined with existing energy balance data to quantify ice-cliff evolution over one full seasonal cycle. In addition, a small seismic network will monitor local \"ice quakes\" associated with calving events. Numerical modeling, validated by the field data, will enable determination of the sensitivity of ice cliff evolution to environmental variables. There are both local and global motivations for studying the ice cliffs of Taylor Glacier. On a global scale, this work will provide insight into the fundamental processes of calving and glacier terminus A better grasp of ice cliff processes will also improve boundary conditions required for predicting glaciers\u0027 response to climate change. Locally, the Taylor Glacier is an important component of the McMurdo Dry Valleys landscape and the results of this study will aid in defining ecologically-important sources of glacial meltwater and will lead to a better understanding of moraine formation at polar ice cliffs. This study will help launch the career of a female scientist, will support one graduate student, and provide experiential learning experiences for two undergraduates. The post-doctoral researcher will also use this research in the curriculum of a wilderness science experiential education program for high school girls.", "east": 162.307, "geometry": "POINT(162.2195 -77.7315)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOCOUPLES \u003e THERMOCOUPLES; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e MAGNETIC/MOTION SENSORS \u003e SEISMOMETERS \u003e SEISMOMETERS; EARTH REMOTE SENSING INSTRUMENTS \u003e ACTIVE REMOTE SENSING \u003e PROFILERS/SOUNDERS \u003e RADAR SOUNDERS \u003e GPR; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e AWS; IN SITU/LABORATORY INSTRUMENTS \u003e PRESSURE/HEIGHT METERS \u003e SURVEYING TOOLS", "is_usap_dc": false, "keywords": "SEISMOLOGICAL STATIONS; Ice Quakes; Ice Cliffs; Not provided; Taylor Glacier; FIELD SURVEYS; Remote Sensing; GROUND-BASED OBSERVATIONS; Modeling; Mcmurdo Dry Valleys; Ice Deformation; Glacial Meltwater; FIELD INVESTIGATION", "locations": "Mcmurdo Dry Valleys; Taylor Glacier", "north": -77.73, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Pettit, Erin; Hallet, Bernard; Fountain, Andrew", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e SEISMOLOGICAL STATIONS; Not provided", "repositories": null, "science_programs": null, "south": -77.733, "title": "Collaborative Research: Mechanics of Dry-Land Calving of Ice Cliffs", "uid": "p0000721", "west": 162.132}, {"awards": "0540915 Scambos, Ted", "bounds_geometry": "POLYGON((-57.9857 -48.444,-55.95557 -48.444,-53.92544 -48.444,-51.89531 -48.444,-49.86518 -48.444,-47.83505 -48.444,-45.80492 -48.444,-43.77479 -48.444,-41.74466 -48.444,-39.71453 -48.444,-37.6844 -48.444,-37.6844 -50.12802,-37.6844 -51.81204,-37.6844 -53.49606,-37.6844 -55.18008,-37.6844 -56.8641,-37.6844 -58.54812,-37.6844 -60.23214,-37.6844 -61.91616,-37.6844 -63.60018,-37.6844 -65.2842,-39.71453 -65.2842,-41.74466 -65.2842,-43.77479 -65.2842,-45.80492 -65.2842,-47.83505 -65.2842,-49.86518 -65.2842,-51.89531 -65.2842,-53.92544 -65.2842,-55.95557 -65.2842,-57.9857 -65.2842,-57.9857 -63.60018,-57.9857 -61.91616,-57.9857 -60.23214,-57.9857 -58.54812,-57.9857 -56.8641,-57.9857 -55.18008,-57.9857 -53.49606,-57.9857 -51.81204,-57.9857 -50.12802,-57.9857 -48.444))", "dataset_titles": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.; Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007; MODIS Mosaic of Antarctica (MOA)", "datasets": [{"dataset_uid": "000189", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Atlas of the Cryosphere - View dynamic maps of snow, sea ice, glaciers, ice sheets, permafrost, and more.", "url": "http://nsidc.org/MMS/atlas/cryosphere_atlas_north.html"}, {"dataset_uid": "609466", "doi": "10.7265/N5N014GW", "keywords": "Ablation; Atmosphere; Glaciology; GPS; Meteorology; Oceans; Photo/video; Photo/Video; Sea Ice; Southern Ocean; Temperature", "people": "Yermolin, Yevgeny; Bauer, Rob; Scambos, Ted; Thom, Jonathan; Bohlander, Jennifer", "repository": "USAP-DC", "science_program": null, "title": "Climate, Drift, and Image Data from Antarctic Icebergs A22A and UK211, 2006-2007", "url": "https://www.usap-dc.org/view/dataset/609466"}, {"dataset_uid": "000190", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "MODIS Mosaic of Antarctica (MOA)", "url": "http://nsidc.org/data/nsidc-0280.html"}], "date_created": "Thu, 16 Aug 2007 00:00:00 GMT", "description": "This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.", "east": -37.6844, "geometry": "POINT(-47.83505 -56.8641)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e ICE AUGERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e SNOW DENSITY CUTTER; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e IMAGING SPECTROMETERS/RADIOMETERS \u003e MODIS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e CAMERAS \u003e CAMERAS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e RECORDERS/LOGGERS \u003e MMS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Air Temperature; Weddell Sea; Edge-Wasting; Ice Shelf Meltwater; TERRA; Antarctic; GPS; Iceberg; Ice Breakup; South Atlantic Ocean; AQUA; Tabular; Photo; Not provided; Icetrek; HELICOPTER; Antarctica", "locations": "Antarctic; Weddell Sea; Antarctica; South Atlantic Ocean", "north": -48.444, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Scambos, Ted; Bohlander, Jennifer; Bauer, Rob; Yermolin, Yevgeny; Thom, Jonathan", "platforms": "AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER; Not provided; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e AQUA; SPACE-BASED PLATFORMS \u003e EARTH OBSERVATION SATELLITES \u003e TERRA; SPACE-BASED PLATFORMS \u003e NAVIGATION SATELLITES \u003e GLOBAL POSITIONING SYSTEM (GPS) \u003e GPS", "repo": "NSIDC", "repositories": "NSIDC; USAP-DC", "science_programs": null, "south": -65.2842, "title": "Investigating Iceberg Evolution During Drift and Break-Up: A Proxy for Climate-Related Changes in Antarctic Ice Shelves", "uid": "p0000003", "west": -57.9857}, {"awards": "9909436 Farley, Kenneth", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 11 Jul 2007 00:00:00 GMT", "description": "9909436 \u003cbr/\u003eFarley\u003cbr/\u003e\u003cbr/\u003eThis award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an investigation of the uplift history of the Dry Valleys segment of the Transantarctic Mountains. The overall goal is to further constrain the exhumation history of the Transantarctic Mountains by using the newly developed apatite (U-Th)/He dating method on samples collected in vertical profiles. This approach, combined with existing apatite fission track information will constrain the rate and patterns of exhumation across the Transantarctic Mountains since their inception as a rift-flank uplift in the early Cenozoic.\u003cbr/\u003e\u003cbr/\u003eThis project will complement other projects and build on previous interpretations of the exhumation and tectonic history determined using apatite fission track thermochronology. It will bridge the gap between information on erosion rates determined from fission track thermochronology and from cosmogenic surface exposure dating and integrate the exhumation history of the mountains with their landscape evolution. As such, the results from this project will address an outstanding problem in Antarctic science; namely the stability of the East Antarctic Ice Sheet, and the timing of the transition from a \"warm\" dynamic ice sheet to a cold polar ice sheet. Highly relevant to this issue is the landscape evolution of the Transantarctic Mountains because many diverse lines of evidence for the rate of landscape evolution have been used to argue for a dynamic ice sheet up until either the Pliocene (the \"dynamic\" ice sheet model) or the middle Miocene (the \"stable\" ice sheet model). Understanding the past stability or dynamic fluctuations of the East Antarctic ice sheet with respect to the climate record is, of course, important for understanding how the present ice sheet may respond to global warming.\u003cbr/\u003e\u003cbr/\u003eThe specific objective of this project is to determine apatite (U-Th)/He age versus elevation trends for a number of vertical profiles from locations within the Transantarctic Mountain front and across the structural grain of the range. Fission track data already exist for all of these profiles, with apatite fission track ages ranging from 150-30 Ma. The greater precision of the (U-Th)/He technique and the fact it records information at lower temperatures (closure temperature of ~70 degrees Celsius; limits of 40-85 degrees Celsius for the He partial retention zone) will allow examination of the exhumation history of the TAM in more detail from ca 130 Ma to ~20 Ma. Another facet is to examine areas where Cretaceous exhumation is recorded and areas where the fission track profiles indicate periods of thermal and tectonic stability and minimal erosion throughout the Cretaceous. The variation of timing of the onset of more rapid exhumation accompanying uplift and formation of the Transantarctic Mountains in the early Cenozoic will also be examined.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Earth Sciences", "paleo_time": null, "persons": "Farley, Kenneth", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": null, "title": "Collaborative Research: Exhumation of the Transantarctic Mountains: Constraints from (U-Th)/He Dating of Apatites", "uid": "p0000281", "west": null}, {"awards": "0229292 Cressie, Noel", "bounds_geometry": null, "dataset_titles": null, "datasets": null, "date_created": "Wed, 28 Feb 2007 00:00:00 GMT", "description": "Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice\u003cbr/\u003esheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": false, "keywords": "Surface Elevation; Stress Field; Basal Elevation; DHC-6", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cressie, Noel; Jezek, Kenneth; Berliner, L.", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6", "repositories": null, "science_programs": null, "south": null, "title": "Dynamics of Ice Streams: A Physical Statistical Approach", "uid": "p0000711", "west": null}, {"awards": "0126194 Harder, Susan", "bounds_geometry": null, "dataset_titles": "Access to data", "datasets": [{"dataset_uid": "001336", "doi": "", "keywords": null, "people": null, "repository": "NSIDC", "science_program": null, "title": "Access to data", "url": "http://nsidc.org/data/agdc_investigators.html"}], "date_created": "Tue, 20 Feb 2007 00:00:00 GMT", "description": "This award supports a two-year project to continue work developing the techniques to make carbon monoxide (CO) measurements in ice core samples. Carbon monoxide is an important atmospheric chemical constituent as it is a primary sink for hydroxyl radical (OH) (and therefore influences the oxidizing capacity of the atmosphere) and because the concentrations of three major greenhouses gases , carbon dioxide (CO2), methane (CH4) and ozone (O3) are directly tied to the concentration of CO. In light of recent anthropogenic increases in the emissions of CO, CO2, CH4 and NOx, it is desirable to understand this complex chemical system and the changes in the greenhouse forcing resulting from perturbation. Because it is difficult to test the accuracy of models for past and future conditions for which no direct atmospheric measurements of trace gas concentrations are available these measurements must be obtained in other ways. Polar ice cores provide a means to make these measurements. Further work is necessary to refine the analytical technique and additional measurements are necessary to investigate the accuracy of these results and to establish the nature of temporal trends in CO. It is anticipated that the CO record, combined with existing or new data for CO2, CH4 , N2O and other paleoclimate variables, will provide further constraints on model studies of the effect of changing atmospheric chemistry on greenhouse forcing.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS", "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Harder, Susan", "platforms": "Not provided", "repo": "NSIDC", "repositories": "NSIDC", "science_programs": null, "south": null, "title": "Ice Core Records of Atmospheric Carbon Monoxide", "uid": "p0000706", "west": null}, {"awards": "0230378 Kanagaratnam, Pannirselvam", "bounds_geometry": "POLYGON((-112.224 -79.3385,-112.1245 -79.3385,-112.025 -79.3385,-111.9255 -79.3385,-111.826 -79.3385,-111.7265 -79.3385,-111.627 -79.3385,-111.5275 -79.3385,-111.428 -79.3385,-111.3285 -79.3385,-111.229 -79.3385,-111.229 -79.35475,-111.229 -79.371,-111.229 -79.38725,-111.229 -79.4035,-111.229 -79.41975,-111.229 -79.436,-111.229 -79.45225,-111.229 -79.4685,-111.229 -79.48475,-111.229 -79.501,-111.3285 -79.501,-111.428 -79.501,-111.5275 -79.501,-111.627 -79.501,-111.7265 -79.501,-111.826 -79.501,-111.9255 -79.501,-112.025 -79.501,-112.1245 -79.501,-112.224 -79.501,-112.224 -79.48475,-112.224 -79.4685,-112.224 -79.45225,-112.224 -79.436,-112.224 -79.41975,-112.224 -79.4035,-112.224 -79.38725,-112.224 -79.371,-112.224 -79.35475,-112.224 -79.3385))", "dataset_titles": null, "datasets": null, "date_created": "Wed, 18 Oct 2006 00:00:00 GMT", "description": "This award supports a project to build and test a 12-18 GHz radar system with a plane wave antenna. This is a wideband radar operating over a frequency range of 12 to 18 GHz to detect near-surface internal firn layers of the ice sheet with better than 10 cm resolution to a depth of approximately 7 m. These measurements will allow determination of spatially continuous snow accumulation rate in the firn, which would be useful along a traverse and is of critical importance to the validation of CryoSat and ICESAT satellite missions aimed at assessing the current state of mass balance of the polar ice sheets. The antenna system planned for the radar is relatively compact, and will be located on the sledge carrying the radar systems. The broad scientific focus of this project will be to investigate important glacial processes relevant to ice sheet mass balance. The new radar will allow the characterization (with high depth resolution) of the spatial variability of snow accumulation rate along a traverse route for interpreting data from CryoSat and ICESAT missions. As part of this project, we will institute a strong outreach program involving K-12 education and a minority institution of higher education. We currently work closely with the Advanced Learning Technology Program (ALTec) at the University of Kansas to develop interactive, resource-based lessons for use on-line by students of all grade levels, and we will develop new resources related to this project. We currently have an active research and education collaboration with faculty and undergraduate students at neighboring Haskell Indian Nations University, in Lawrence, Kansas, and we will expand our collaboration to include this project.", "east": -111.229, "geometry": "POINT(-111.7265 -79.41975)", "instruments": "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 GPR", "is_usap_dc": false, "keywords": "Firn; Cryosat; Plane Wave Antenna; Glacial Processes; GROUND-BASED OBSERVATIONS; Not provided; Icesat; FIELD INVESTIGATION; Radar; LABORATORY; Snow Accumulation; Mass Balance; FIELD SURVEYS", "locations": null, "north": -79.3385, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Kanagaratnam, Pannirselvam; Braaten, David; Bauer, Rob", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repositories": null, "science_programs": null, "south": -79.501, "title": "High Resolution Ice Thickness and Plane Wave Mapping of Near-Surface Layers", "uid": "p0000731", "west": -112.224}, {"awards": "0126343 Nishiizumi, Kunihiko", "bounds_geometry": "POINT(-148.812 -81.6588)", "dataset_titles": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "datasets": [{"dataset_uid": "609307", "doi": "10.7265/N5XK8CGS", "keywords": "Antarctica; Geochemistry; Geochronology; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Nishiizumi, Kunihiko; Finkel, R. C.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Cosmogenic Radionuclides in the Siple Dome A Ice Core", "url": "https://www.usap-dc.org/view/dataset/609307"}], "date_created": "Mon, 12 Jun 2006 00:00:00 GMT", "description": "This award supports a three-year renewal project to complete measurement of cosmogenic nuclides in the Siple Dome ice core as part of the West Antarctic ice core program. The investigators will continue to measure profiles of Beryllium-10 (half-life = 1.5x10 6 years) and Chlorine-36 (half-life = 3.0x10 5 years) in the entire ice core which spans the time period from the present to about 100 kyr. It will be particularly instructive to compare the Antarctic record with the detailed Arctic record that was measured by these investigators as part of the GISP2 project. This comparison will help separate global from local effects at the different drill sites. Cosmogenic radionuclides in polar ice cores have been used to study the long-term variations in several important geophysical variables, including solar activity, geomagnetic field strength, atmospheric circulation, snow accumulation rates, and others. The time series of nuclide concentrations resulting from this work will be applied to several problem areas: perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. Comparison of Beryllium-10 and Chlorine-36 profiles in different cores will allow us to improve the ice core chronology and directly compare ice cores from different regions of the globe. Additional comparison with the Carbon-14 record will allow correlation of the ice core paleoenvironment record to other, Carbon-14 dated, paleoclimate records.", "east": -148.812, "geometry": "POINT(-148.812 -81.6588)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e AMS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; Antarctica; Ice Core; Cosmogenic Radionuclides; Chlorine-36; GROUND STATIONS; Beryllium-10; Siple Dome; West Antarctica", "locations": "Antarctica; Siple Dome; West Antarctica", "north": -81.6588, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Finkel, R. C.; Nishiizumi, Kunihiko", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.6588, "title": "Cosmogenic Radionuclides in the Siple Dome Ice Core", "uid": "p0000358", "west": -148.812}, {"awards": "0232042 Finn, Carol", "bounds_geometry": "POLYGON((139.27539 -82.35733,142.369695 -82.35733,145.464 -82.35733,148.558305 -82.35733,151.65261 -82.35733,154.746915 -82.35733,157.84122 -82.35733,160.935525 -82.35733,164.02983 -82.35733,167.124135 -82.35733,170.21844 -82.35733,170.21844 -82.516831,170.21844 -82.676332,170.21844 -82.835833,170.21844 -82.995334,170.21844 -83.154835,170.21844 -83.314336,170.21844 -83.473837,170.21844 -83.633338,170.21844 -83.792839,170.21844 -83.95234,167.124135 -83.95234,164.02983 -83.95234,160.935525 -83.95234,157.84122 -83.95234,154.746915 -83.95234,151.65261 -83.95234,148.558305 -83.95234,145.464 -83.95234,142.369695 -83.95234,139.27539 -83.95234,139.27539 -83.792839,139.27539 -83.633338,139.27539 -83.473837,139.27539 -83.314336,139.27539 -83.154835,139.27539 -82.995334,139.27539 -82.835833,139.27539 -82.676332,139.27539 -82.516831,139.27539 -82.35733))", "dataset_titles": null, "datasets": null, "date_created": "Tue, 16 Aug 2005 00:00:00 GMT", "description": "This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the Transantarctic Mountains and an adjacent region of East Antarctica. The East Antarctic shield is one of Earth\u0027s oldest and largest cratonic assemblies, with a long-lived Archean to early Paleozoic history. Long-standing interest in the geologic evolution of this shield has been rekindled over the past decade by tectonic models linking East Antarctica with other Precambrian crustal elements in the Rodinia and Gondwanaland supercontinents. It is postulated that the Pacific margin of East Antarctica was rifted from Laurentia during late Neoproterozoic breakup of Rodinia, and it then developed as an active plate boundary during subsequent amalgamation of Gondwanaland in the earliest Paleozoic. If true, the East Antarctic shield played a key role in supercontinent transformation at a time of global changes in plate configuration, terrestrial surficial process, sea level, and marine geochemistry and biota. A better understanding of the geological evolution of the East Antarctic shield is therefore critical for studying Precambrian crustal evolution in general, as well as resource distribution, biosphere evolution, and glacial and climate history during later periods of Earth history. Because of nearly complete coverage by the polar ice cap, however, Antarctica remains the single most geologically unexplored continent. Exposures of cratonic basement are largely limited to coastal outcrops in George V Land and Terre Adelie (Australian sector), the Prince Charles Mountains and Enderby Land (Indian sector), and Queen Maud Land (African sector), where the geology is reasonably well-known. By contrast, little is known about the composition and structure of the shield interior. Given the extensive ice cover, collection of airborne geophysical data is the most cost-effective method to characterize broad areas of sub-ice basement and expand our knowledge of the East Antarctic shield interior. \u003cbr/\u003e\u003cbr/\u003eThis project will conduct an airborne magnetic survey (coupled with ground-based gravity measurements) across an important window into the shield where it is exposed in the Nimrod Glacier area of the central Transantarctic Mountains. Specific goals are to:\u003cbr/\u003e1. Characterize the magnetic and gravity signature of East Antarctic crustal basement exposed at the Ross margin (Nimrod Group),\u003cbr/\u003e2. Extend the magnetic data westward along a corridor across the polar ice cap in order to image the crust in ice-covered areas,\u003cbr/\u003e3. Obtain magnetic data over the Ross Orogen in order to image the ice-covered boundary between basement and supracrustal rocks, allowing us to better constrain the geometry of fundamental Ross structures, and\u003cbr/\u003e4. Use the shape, trends, wavelengths, and amplitudes of magnetic anomalies to define magnetic domains in the shield, common building blocks for continent-scale studies of Precambrian geologic structure and evolution.\u003cbr/\u003e\u003cbr/\u003eHigh-resolution airborne magnetic data will be collected along a transect extending from exposed rocks of the Nimrod Group across the adjacent polar ice cap. The Nimrod Group represents the only bona fide Archean-Proterozoic shield basement exposed for over 2500 km of the Pacific margin of Antarctica. This survey will characterize the geologically well-known shield terrain in this sector using geophysical methods for the first time. This baseline over the exposed shield will allow for better interpretation of geophysical patterns in other ice-covered regions and can be used to target future investigations. In collaboration with colleagues from the BGR (Germany), a tightly-spaced, \"draped\" helicopter magnetic survey will be flown during the 2003-04 austral summer, to be complemented by ground measurements of gravity over the exposed basement. Data reduction, interpretation and geological correlation will be completed in the second year. This project will enhance the education of students, the advancement of under-represented groups, the research instrumentation of the U.S. Antarctic Program, partnerships between the federal government and institutions of higher education, and cooperation between national research programs. It will benefit society through the creation of new basic knowledge about the Antarctic continent, which in turn may help with applied research in other fields such as the glacial history of Antarctica.", "east": 170.21844, "geometry": "POINT(154.746915 -83.154835)", "instruments": "SOLAR/SPACE OBSERVING INSTRUMENTS \u003e MAGNETIC FIELD/ELECTRIC FIELD INSTRUMENTS \u003e MAM", "is_usap_dc": false, "keywords": "Central Transantarctic Mountains; Aeromagnetic Data; HELICOPTER; DHC-6; Not provided", "locations": "Central Transantarctic Mountains", "north": -82.35733, "nsf_funding_programs": null, "paleo_time": null, "persons": "Finn, C. A.; FINN, CAROL", "platforms": "AIR-BASED PLATFORMS \u003e PROPELLER \u003e DHC-6; AIR-BASED PLATFORMS \u003e ROTORCRAFT/HELICOPTER \u003e HELICOPTER; Not provided", "repositories": null, "science_programs": null, "south": -83.95234, "title": "Collaborative Research: Geophysical Mapping of the East Antarctic Shield Adjacent to the Transantarctic Mountains", "uid": "p0000249", "west": 139.27539}, {"awards": "9017827 Lal, Devendra", "bounds_geometry": null, "dataset_titles": "Dome C Ice Core Chemistry and Depth and Age Scale Data", "datasets": [{"dataset_uid": "609243", "doi": "", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Depth-Age-Model; Dome C Ice Core; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate", "people": "Lorius, Claude; Lal, Devendra", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Dome C Ice Core Chemistry and Depth and Age Scale Data", "url": "https://www.usap-dc.org/view/dataset/609243"}], "date_created": "Thu, 26 Aug 2004 00:00:00 GMT", "description": "This award is for support of a study to establish a quantitative nuclear method for determination of Antarctic ablation and accumulation rates and to provide correction factors for the carbon 14 ages of ice samples dated using trapped carbon 14. Recent studies have established the presence of cosmogenic in-situ produced carbon 14 in polar ice. In conjunction with estimated carbon 14 production rates, measured concentrations of carbon 14 per gram of ice yield, ablation rates which are in good agreement with the values determined from stake measurements. Similar studies to determine accumulation rates have been tested and the estimates are consistent with previous studies. This study will expand the preliminary work done to date in order to improve the 14CO and 14CO2 vacuum extraction techniques, by lowering blank levels and by obtaining more complete separation of 14CO and 14CO2.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "GROUND STATIONS", "locations": null, "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Lal, Devendra; Lorius, Claude; Lal, Devendra", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": null, "title": "Nuclear Studies of Accumulating and Ablation Ice Using Cosmogenic 14c", "uid": "p0000152", "west": null}, {"awards": "0087151 Cole-Dai, Jihong", "bounds_geometry": null, "dataset_titles": "Sulfate-Based Volcanic Record from South Pole Ice Core", "datasets": [{"dataset_uid": "609215", "doi": "10.7265/N5CR5R88", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Solid Earth; South Pole", "people": "Cole-Dai, Jihong", "repository": "USAP-DC", "science_program": null, "title": "Sulfate-Based Volcanic Record from South Pole Ice Core", "url": "https://www.usap-dc.org/view/dataset/609215"}], "date_created": "Fri, 09 Apr 2004 00:00:00 GMT", "description": "This award supports a two year project to analyze shallow (~150 m) ice cores from South Pole in order to construct an annually resolved, sulfate-based volcanic record covering the last 1400 years. Two shallow ice cores will be recovered at the South Pole during the 00/01 field season and will be used for this work. Volcanic records from polar ice cores provide valuable information for studies of the connection between volcanism and climate. The new records are expected to be continuous and to cover at least the last 1400 years. The information from these records will verify the volcanic events found in the few existing Antarctic records and resolve discrepancies in the timing and magnitude of major explosive eruptions \u003cbr/\u003edetermined from those earlier records. In order to achieve the objectives of the proposed research, funds are provided to assist with the construction of an analytical laboratory for ice core and environmental \u003cbr/\u003echemistry research.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Ice Core; Snow Chemistry; West Antarctica; GROUND-BASED OBSERVATIONS; Antarctica; Ice Core Gas Records; Ion Chemistry; Ice Core Data", "locations": "West Antarctica; Antarctica", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Cole-Dai, Jihong", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "A Sulfate-based Volcanic Record from South Pole Ice Cores", "uid": "p0000167", "west": null}, {"awards": "9526601 Albert, Mary", "bounds_geometry": null, "dataset_titles": "Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609100", "doi": "10.7265/N5S46PVZ", "keywords": "Antarctica; Glaciology; Permeability; Siple Dome; Siple Dome Ice Core; Snow/ice; Snow/Ice; Temperature", "people": "Albert, Mary R.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Snow and Firn Temperature and Permeability Measurements from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609100"}], "date_created": "Sat, 01 Dec 2001 00:00:00 GMT", "description": "This award supports a project to examine the physical processes that affect the manner in which heat, vapor and chemical species in air are incorporated into snow and polar firn. The processes include advection, diffusion, and the effects of solar radiation penetration into the snow. An understanding of these processes is important because they control the rate at which reactive and non-reactive chemical species in the atmosphere become incorporated into the snow, firn, and polar ice, and thus will affect interpretation of polar ice core data. Currently, the interpretation of polar ice core data assumes that diffusion controls the rate at which chemical species are incorporated into firn. This project will determine whether ventilation, or advection of the species by air movement in the firn, and radiation penetration processes have a significant effect. Field studies at the two West Antarctic ice sheet deep drilling sites will be conducted to determine the spatial and temporal extent for key parameters, and boundary conditions needed to model the advection, conduction, and radiation transmission/absorption processes. An existing multidimensional numerical model is being expanded to simulate the processes and to serve as the basis for ongoing and future work in transport and distribution of reactive chemical species.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e PROBES \u003e PERMEAMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMOMETERS \u003e THERMOMETERS", "is_usap_dc": true, "keywords": "Glaciology; Antarctica; Snow Permeability; Firn Permeability; USAP-DC; GROUND-BASED OBSERVATIONS; Not provided; GROUND STATIONS; Snow Properties; Snow Temperature; Siple Dome; Firn Temperature", "locations": "Antarctica; Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Albert, Mary R.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "Near-Surface Processes Affecting Gas Exchange: West Antarctic Ice Sheet", "uid": "p0000061", "west": null}]
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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.
The seaward motion of ice sheets and glaciers is primarily controlled by basal sliding below, and internal viscous flow within, ice masses. The latter of these—viscous flow—is dependent on various factors, including temperature, stress, grain size, and the alignment of ice crystals during flow to produce a crystal orientation fabric (COF). Historically, ice flow has been modeled using a constitutive equation, termed “Glen’s law”, that describes ice flow rate as a function of temperature and stress. Glen’s law was constrained under relatively high-stress conditions, and is often attributed to the motion of crystal defects within ice grains. More recently, however, grain boundary sliding (GBS) has been invoked as the rate-controlling process under low-stress, “superplastic” conditions. The grain boundary sliding hypothesis is contentious because GBS is not thought to produce a COF, whereas geophysical measurements and polar ice cores demonstrate strong COFs in polar ice masses. However, very few COF measurements have been conducted on ice samples subjected to superplastic flow conditions in the laboratory. In this project, the PI primarily seeks to measure the evolution of ice COF across the transition from superplastic to Glen-type creep. Results will be used to interrogate the role of superplastic GBS creep within polar ice masses, and thereby provide constraints on polar ice discharge models.
Polycrystalline ice samples with grain sizes ranging from 5 µm to 1000 µm will be fabricated and deformed in the PI’s laboratory at WHOI, using a 1-atm cryogenic axial-torsion apparatus. Experiments will be conducted at temperatures of −30°C to −10°C, and at a constant uniaxial strain rate of 10-7 s-1. Under these conditions, 5% to 99.99% of strain should be accommodated by superplastic, GBS-limited creep, depending on the sample grain size. The deformed samples will then be imaged using cryogenic electron backscatter diffraction (cryo-EBSD) and high-angular-resolution electron backscatter diffraction (HR-EBSD) to quantify COF, grain size, grain shape, and crystal defect (dislocation) densities, among other microstructural properties. These measurements will be used to decipher the rate-controlling mechanisms operating within different thermomechanical regimes, and resolve a long-standing debate over whether superplastic creep can produce a COF in ice. In addition to the polycrystal experiments, ice bicrystals will be fabricated and deformed to investigate the micromechanical behavior of individual grain boundaries under superplastic conditions. Ultimately, these results will be used to provide a microstructural toolbox for identifying superplastic creep using geophysical (e.g., seismic, radar) and glaciological (e.g., ice core) observations. This project will support one graduate student within the MIT-WHOI Joint Program, one or more undergraduate summer students, and a junior faculty member (the PI). In addition, the PI will host a workshop aimed at bringing together experimentalists, glaciologists, and ice modelers to facilitate cross-disciplinary knowledge sharing and collaborative problem solving.
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.
Interpreting highly compressed portions of ice cores is increasingly important as projects target climate records in basal ice, and in ice recovered from blue-ice areas. This project will integrate precisely co-registered electrical conductivity measurements (ECM), hyperspectral imaging, laser ablation ICPMS measurements of impurities, and ice physical properties to investigate sub-cm chemical and physical variations in polar ice. This work will establish to what extent annual layer interpretations of polar ice with sub-cm layering is possible. Critical to resolving thin ice layers is understanding the across-core variations which may obscure or distort the vertical layering. Analyses will be focused on samples from WAIS Divide, SPICEcore, and GISP2, which have well established seasonal cycles that yielded benchmark timescales, as well a large diameter ice core from a blue ice area.
This project will conduct basic research into geological dating techniques that are useful for determining the age of glacial deposits in polar regions, Antarctica in particular. These techniques are necessary for determining how large the polar ice sheets were in the geologic past, including during past periods of warm climate that likely resemble present and near-future conditions. Thus, they represent an important technical capability needed for estimating the response of polar ice sheets to climate warming. Because changes in the size of polar ice sheets are the largest potential contribution to future global sea-level change, this capability is also relevant to understanding likely sea-level impacts of future climate change. The research in this project comprises several observational and experimental approaches to improving the speed, efficiency, cost, and accuracy of these techniques, as well as a scientific outreach program aimed at making the resulting capabilities more broadly available to other researchers. The project supports a postdoctoral scholar and contributes to human resources development in polar and climate science.
The project focuses on several areas of cosmogenic-nuclide geochemistry, which is a geochemical dating method that relies on the production and decay of cosmic-ray-produced radionuclides in surface rocks. Measurements of these nuclides can be used to quantify the duration of surface exposure and ice cover at locations in Antarctica that are covered and uncovered by changes in the size of the Antarctic ice sheets, thus providing a means of reconstructing past ice-sheet change. The first proposed set of experiments are aimed at implementing a ''virtual mineral separation'' approach to cosmogenic noble gas analysis that may allow measurement of nuclide concentrations in certain minerals without physically separating the minerals from the host rock. If feasible, this would realize significant speed and cost improvements for this type of analysis. A second set of experiments will focus on means of identifying and quantifying non-cosmogenic background inventories of some relevant nuclides, which is intended to improve the measurement sensitivity and precision for cosmic-ray-produced inventories of these nuclides. A third focus area aims to improve capabilities to measure multiple cosmic-ray-produced nuclides in the same sample, which has the potential to improve the accuracy of dating methods based on these nuclides and to expand the situations in which these methods can be applied. If successful, these experiments are likely to improve a number of applications of cosmogenic-nuclide geochemistry relevant to Antarctic research, including subglacial bedrock exposure dating, dating of multimillion-year-old glacial deposits, and surface-process studies useful in understanding landform evolution and ecosystem dynamics.
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.
Freshwater discharges from melting high-latitude continental ice glacial reserves strongly control salt budgets, circulation and associated ocean water mass formation arising from polar ice shelves. These are different in nature than freshwater inputs associated with riverine coastal inputs. The PI proposes an observational deployment to measure a specific, previously-identified example of a coastal freshwater-driven current, the Antarctic Peninsula Coastal Current (APCC). <br/> <br/>The research component of this CAREER project aims to improve understanding of the dynamics of freshwater discharge around the Antarctic continent. Associated research questions pertain to the i) controls on the cross- and along-shelf spreading of fresh, buoyant coastal currents, ii) the role of distributed coastal freshwater sources (as opposed to 'point' source river outflow sources typical of lower latitudes), and iii) the contribution of these coastal currents to water mass transformation and heat transfer on the continental shelf. An educational CAREER program component leverages a series of field experiences and research outputs including data, model outputs, and theory, to bring polar science to the classroom and the general public, as well as training a new polar scientist. This combined strategy will allow the investigator to lay the foundation for a successful academic career as a researcher and teacher at the University of Delaware. The project will also provide the opportunity to train a PhD student. Informal outreach efforts will include giving public lectures at University of Deleware's sponsored events, including Coast Day, a summer event that attracts 8000-10000 people, and remote lectures from the field using an existing outreach network. This proposal requires fieldwork in the Antarctic.<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.
Cores drilled through the Antarctic ice sheet provide a remarkable window on the evolution of Earth’s climate and unique samples of the ancient atmosphere. The clear link between greenhouse gases and climate revealed by ice cores underpins much of the scientific understanding of climate change. Unfortunately, the existing data do not extend far enough back in time to reveal key features of climates warmer than today. COLDEX, the Center for Oldest Ice Exploration, will solve this problem by exploring Antarctica for sites to collect the oldest possible record of past climate recorded in the ice sheet. COLDEX will provide critical information for understanding how Earth’s near-future climate may evolve and why climate varies over geologic time. New technologies will be developed for exploration and analysis that will have a long legacy for future research. An archive of old ice will stimulate new research for the next generations of polar scientists. COLDEX programs will galvanize that next generation of polar researchers, bring new results to other scientific disciplines and the public, and help to create a more inclusive and diverse scientific community.
Knowledge of Earth’s climate history is grounded in the geologic record. This knowledge is gained by measuring chemical, biological and physical properties of geologic materials that reflect elements of climate. Ice cores retrieved from polar ice sheets play a central role in this science and provide the best evidence for a strong link between atmospheric carbon dioxide and climate on geologic timescales. The goal of COLDEX is to extend the ice-core record of past climate to at least 1.5 million years by drilling and analyzing a continuous ice core in East Antarctica, and to much older times using discontinuous ice sections at the base and margin of the ice sheet. COLDEX will develop and deploy novel radar and melt-probe tools to rapidly explore the ice, use ice-sheet models to constrain where old ice is preserved, conduct ice coring, develop new analytical systems, and produce novel paleoclimate records from locations across East Antarctica. The search for Earth’s oldest ice also provides a compelling narrative for disseminating information about past and future climate change and polar science to students, teachers, the media, policy makers and the public. COLDEX will engage and incorporate these groups through targeted professional development workshops, undergraduate research experiences, a comprehensive communication program, annual scientific meetings, scholarships, and broad collaboration nationally and internationally. COLDEX will provide a focal point for efforts to increase diversity in polar science by providing field, laboratory, mentoring and networking experiences for students and early career scientists from groups underrepresented in STEM, and by continuous engagement of the entire COLDEX community in developing a more inclusive scientific culture.
ANDRILL is a scientific drilling program to investigate Antarctica's role in global climate change over the last sixty million years. The approach integrates geophysical surveys, new drilling technology, multidisciplinary core analysis, and ice sheet modeling to address four scientific themes: (1) the history of Antarctica's climate and ice sheets; (2) the evolution of polar biota and ecosystems; (3) the timing and nature of major tectonic and volcanic episodes; and (4) the role of Antarctica in the Earth's ocean-climate system. <br/><br/>This award initiates what may become a long-term program with drilling of two previously inaccessible sediment records beneath the McMurdo Ice Shelf and in South McMurdo Sound. These stratigraphic records cover critical time periods in the development of Antarctica's major ice sheets. The McMurdo Ice Shelf site focuses on the Ross Ice Shelf, whose size is a sensitive indicator of global climate change. It has recently undergone major calving events, and there is evidence of a thousand-kilometer contraction since the last glacial maximum. As a generator of cold bottom water, the shelf may also play a key role in ocean circulation. The core obtained from this site will also offer insight into sub-ice shelf sedimentary, biologic, and oceanographic processes; the history of Ross Island volcanism; and the flexural response of the lithosphere to volcanic loading, which is important for geophysical and tectonic studies of the region.<br/><br/>The South McMurdo Sound site is located adjacent to the Dry Valleys, and focuses on the major ice sheet overlying East Antarctica. A debate persists regarding the stability of this ice sheet. Evidence from the Dry Valleys supports contradictory conclusions; a stable ice sheet for at least the last fifteen million years or an active ice sheet that cycled through expansions and contractions as recently as a few millions of years ago. Constraining this history is critical to deep-time models of global climate change. The sediment cores will be used to construct an overall glacial and interglacial history for the region; including documentation of sea-ice coverage, sea level, terrestrial vegetation, and melt-water discharge events. The core will also provide a general chronostratigraphic framework for regional seismic studies and help unravel the area's complex tectonic history.<br/><br/>The broader impacts of this project include formal and informal education, new research infrastructure, various forms of collaboration, and improving society's understanding of global climate change. Education is supported at the postdoctoral, graduate, undergraduate, and K-12 levels. Teachers and curriculum specialists are integrated into the research program, and a range of video resources will be produced, including a science documentary for television release. New research infrastructure includes equipment for core analysis and ice sheet modeling, as well as development of a unique drilling system to penetrate ice shelves. Drill development and the overall project are co-supported by international collaboration with scientists and the National Antarctic programs of New Zealand, Germany, and Italy. The program also forges new collaborations between research and primarily undergraduate institutions within the United States. <br/><br/>As key factors in sea-level rise and oceanic and atmospheric circulation, Antarctica's ice sheets are important to society's understanding of global climate change. ANDRILL offers new data on marine and terrestrial temperatures, and changes our understanding of extreme climate events like the formation of polar ice caps. Such data are critical to developing accurate models of the Earth's climatic future.
Overview</br>
It is proposed that laser cutting technology can be used to rapidly extract high quality ice samples from borehole walls. The technology applies to both existing boreholes and newly drilled ones, even enabling scientists to obtain samples using non‐coring mechanical drills. Since the instrumentation is highly portable, a field team of three persons might take no longer than a few days in the field to extract ice, and samples from a critical time period could be extracted from multiple locations in a single field season.
This pilot program will investigate and validate the technology of laser sampling. It is beneficial to use fiber optics to convey light in borehole instrumentation rather than attempting to package a complete laser system for travel down a borehole, so the cutting laser and wavelength (1.07Pm) are chosen with such engineering in mind. The primary scientific goals of the program are to: 1) determine optimum cutting conditions in terms of laser power and operating conditions, 2) quantifying the effects of residual meltwater that remain in the cut slot after a cut so that re-cutting needs can be predicted or mitigated, 3) designing and testing mechanical structures to retract samples from blocks of ice once cut, and 4) analyzing the composition and crystal structure of ice near a cut slot to determine the impacted volume (if any) of ice and temperatures where scientific readings might be affected by the sampling process.
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Intellectual Merits</br>
The collection of deep ice from the Polar Ice Sheets involves large amounts of time, effort, and expense. Often, the most important information is held in very small volumes of core, and while replicate coring can supplement this core, there is often a need to retrieve additional ice samples based on recent scientific findings or borehole logging at a site. In addition, there is currently no easy method of extracting ice from boreholes drilled by non‐coring mechanical drills, which are often much faster, lighter, and less expensive to operate. There are numerous specific projects that could immediately benefit from laser sampling including sampling ice overlaying buried impact craters and bolides, filling critical gaps in the chemical record in damaged core sections from Siple Dome, obtaining oldest ice cores from brittle sections near the surface of the Allan Hills blue ice area, where coring drills apply stresses that may fracture the ice, and replacing core whose value has degraded due to time and depressurization. This program builds on a prior engineering advances in optical fiber‐based logging technology, developed previously for Siple Dome borehole logging.
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Broader Impact</br>
Laser sampling would advance numerous fields interfaced with glaciology and ice core studies. These include climate and paleoenvironmental science, volcanology, and human history where large volumes of ice are crucial to extract ultra‐high resolution records of natural and anthropogenic emissions. Potentially the principle of laser sampling could be used to directly sample and study ice on other planets or their satellites.
This program encompasses a broad base of theoretical, experimental, and design work, which makes it ideal for training postdoctoral scientists, graduate students, and advanced undergraduates. The program will include a research opportunity for one or more middle school teachers through a Research Experience for Teachers program with one of the local school districts of the Twin Cities area. The teacher(s) will assist the investigators in the analysis of scattered laser light in glacier ice, and will set up a small experiment at various visible wavelengths to measure scattering constants. These experiments have been chosen because they can easily translate into classroom demonstrations and hands‐on activities using eye-safe visible- light LED sources and large samples of artificial ice. The teacher(s) will also produce a lesson plan on basic optics, glacial ice, or polar science as a deliverable.
This proposal does not involve field work.
An accurate constitutive relationship for ice is fundamental to ice-flow models and ice-core interpretations. While Glen’s flow law describes well the overall deformation of ice when subjected to stress, many details remain poorly constrained. In particular, the effect of impurities on the strain rate both directly and through the development of ice fabric is not well understood. Variations in impurity concentrations are associated with variations in deformation rates as observed in both Greenland and Antarctica. The impact of uncertainties on the deformation of ice is most acutely observed in the interpretation of ice cores where the inference of past accumulation rate depends on the cumulative vertical thinning. Thus, many ice-core climate reconstructions, such as the gas-age ice-age difference, surface temperature histories, and aerosol fluxes, are also affected. Given the complexities of the possible impacts of sulfuric acid on the flow of ice and the interaction between these impacts, it seems almost impossible to examine an ice core and understand the impacts of impurities on the microstructural evolution and creep behavior. Our research seeks to understand the effects of sulfuric acid at concentrations applicable to polar ice sheets and relate these results to the flow of polar ice both through experiments and through modeling. Our results have shown that the presence of sulfuric acid in the grain boundaries of polar ice increases its strength in shear, while sulfuric acid in the whole matrix of polar ice reduces its strength. We have also found that sulfuric acid causes an initial increase in average grain sizes and then a subsequent decrease, a trend that differs from the continuous increase in average grain sizes observed in freshwater ice. We are also determining the role of stress state, i.e. simple compression versus shear, on the microstructural evolution and how sulfuric acid impacts this.
Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth’s past warm periods. Large uncertainties, however, in reconstructions of past and future sea levels, result from the poorly constrained climate sensitivity of the Antarctic Ice sheet (AIS). This research project aims to develop the use of subglacial precipitates as an archive the Antarctic ice sheet (AIS) past response to climate change. The subglacial precipitates from East Antarctica form in water bodies beneath Antarctic ice and in doing so provide an entirely new and unique measure of how the AIS responds to climate change. In preliminary examination of these precipitates, we identified multiple samples consisting of cyclic opal and calcite that spans hundreds of thousands of years in duration. Our preliminary geochemical characterization of these samples indicates that the observed mineralogic changes result from a cyclic change in subglacial water compositions between isotopically and chemically distinct waters. Opal-forming waters are reduced (Ce* <1 and high Fe/Mn) and exhibit elevated 234U/238U compositions similar to the saline groundwater brines found at the periphery of the AIS. Calcite-forming waters, are rather, oxidized and exhibit δ18O compositions consistent with derivation from the depleted polar plateau (< -50 ‰). 234U-230Th dates permit construction of a robust timeseries describing these mineralogic and compositional changes through time. Comparisons of these time series with other Antarctic climate records (e.g., ice core records) reveal that calcite forming events align with millennial scale changes in local temperature or “Antarctic isotopic maximums”, which represent Southern Hemisphere warm periods during low Atlantic Meridional overturning circulation. Ultimately, this project seeks to develop a comprehensive model as to how changes in the thermohaline cycle induce a glaciologic response which in turn induces a change in the composition of subglacial waters and the mineralogic phase recorded within the precipitate archive.
Ice fracturing plays a crucial role in mechanical processes that influence the contribution of glaciers and ice sheets to the global sea-level rise. Such processes include, among others, ice shelf disintegration, iceberg calving, and fast ice sliding. Over the last century, seismology developed highly sensitive instrumentation and sophisticated data processing techniques to study earthquakes. This interdisciplinary project used seismological research methods to investigate fracturing beneath and within ice on a fast-moving ice stream in West Antarctica that is experiencing rapid sliding and flexure driven by ocean tides. Data were collected from two strategically located clusters of seismometers. One was located in the epicenter zone where tidally triggered rapid sliding events of the ice stream start. The other was placed in the grounding zone, where the ice stream flexes with tides where it goes afloat and becomes an ice shelf.
Seismometers in the epicenter cluster recorded many thousands of microearthquakes coming from beneath ice during ice stream sliding events. Analyses of these microearthquakes suggest that the geologic materials beneath the ice stream are fracturing. The spatial pattern of fracturing is not random but forms elongated stripes that resemble well-known glacial landforms called megascale glacial lineations. These findings indicate that the frictional resistance to ice sliding may change through time due to these landforms changing as a result of erosion and sedimentation beneath ice. This may have implications for the rate of ice loss from Antarctic ice streams that drain about 90% of all ice discharged into the Southern Ocean. In addition to microearthquakes, the epicenter cluster of seismometers also recorded vibrations (tremors) from beneath the ice stream. These may be caused by the rapid repetition of many microearthquakes coming from the same source.
The grounding zone cluster of seismometers recorded many thousands of microearthquakes as well. However, they are caused by ice fracturing near the ice stream's surface rather than at its base. These microearthquakes originate when the grounding zone experiences strong tension caused by ice flexure during dropping ocean tide. This tension causes the opening of near-surface fractures (crevasses) just before the lowest tide, rather than at the lowest tide as expected from elasticity of solids. This unexpected timing of ice fracturing indicates that ice in the grounding zone behaves like a viscoelastic material, i.e., partly like a solid and partly like a fluid. This is an important general finding that will be useful to other scientists who are modeling interactions of ice with ocean water in the Antarctic grounding zones. Overall, the observed pervasive fracturing in the grounding zone, where an ice stream becomes an ice shelf, may make ice shelves potentially vulnerable to catastrophic collapses. It also may weaken ice shelves and make it easier for large icebergs to break off at their fronts.
In addition to Antarctic research, this award supported education and outreach activities, including presentations and field trips during several summer schools at UCSC for talented and diverse high school students. The students were exposed to glaciological and seismological concepts and performed hands-on scientific exercises. The field trips focused on the marine terrace landscape around Santa Cruz. This landscape resulted from interactions between the uplift of rocks along the San Andreas fault with global-sea level changes caused by the waxing and waning of polar ice sheets in response to Ice Age climate cycles.
Hydrogen (H2) is one of the most abundant trace gases in the atmosphere, with a mean level of 500 ppb and an atmospheric lifetime of about two years. Hydrogen has an impact on both air quality and climate, due to its role as a precursor for tropospheric ozone and stratospheric water vapor. Projections indicate that a future "hydrogen economy" would increase hydrogen emissions. Understanding of the atmospheric hydrogen budget is largely based on a 30-year record of surface air measurements, but there are no long-term records with which to assess either: 1) the influence of climate change on atmospheric hydrogen, or 2) the extent to which humans have impacted the hydrogen budget. Polar ice core records of hydrogen will advance our understanding of the atmospheric hydrogen cycle and provide a stronger basis for projecting future changes to atmospheric levels of hydrogen and their impacts. <br/><br/>The research will involve laboratory work to enable the collection and analysis of hydrogen in polar ice cores. Hydrogen is a highly diffusive molecule and, unlike most other atmospheric gases, diffusion of hydrogen in ice is so rapid that ice samples must be stored in impermeable containers immediately upon drilling and recovery. This project will: 1) construct a laboratory system for extracting and analyzing hydrogen in polar ice, 2) develop and test materials and construction designs for vessels to store ice core samples in the field, and 3) test the method on samples of opportunity previously stored in the field. The goal of this project is a proven, cost-effective design for storage flasks to be fabricated for use on future polar ice coring projects. This project will support the dissertation research of a graduate student in the UC Irvine Department of Earth System Science.<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.
Ice cores contain detailed accounts of Earth's climate history. The collection of an ice core can be logistically challenging, and extraction of data from the core can be time-consuming as well as susceptible to both human and machine error. Furthermore, locked in measurements from ice cores is information that scientists have not yet found ways to recover. This project will apply techniques from information theory to ice-core data to unlock that information. The primary goal is to demonstrate that information theory can (a) identify regions of a specific ice-core record that are in need of further analysis and (b) provide some specific guidance for that analysis. A secondary goal is to demonstrate that information theory has practical and scientific utility for studies of past climate. This project aims to use information theory in two distinct ways: first, to identify regions of a core where information appears to be damaged or missing, perhaps due to human and/or machine error. In the segment of the West Antarctic Ice Sheet Divide core that is 5000-8000 years old, for instance, information-theoretic methods reveal significant levels of noise, probably due to a laboratory instrument, and something that was not visible in the raw data. This is a particularly important segment of the record, as it contains valuable clues about climatic shifts and the onset of the Holocene. Targeted re-sampling of this segment of the core and reanalysis with newer laboratory apparatus could resolve the data issues. The second way in which information theory can potentially aid in ice-core analysis is by extracting climate signals from the data--such as the accumulation rate at the core site over the period of its formation. This quantity usually requires significant time and effort to produce, but information theory could help to streamline that process.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.
Abstract (non-technical)<br/>Sea level rise is a problem of global importance and it is increasingly affecting the tens of millions of Americans living along coastlines. The melting of glaciers in mountain areas worldwide in response to global warming is a major cause of sea level rise and increases in nuisance coastal flooding. However, the world's largest land-based ice sheets are situated in the Polar Regions and their response under continued warming is very difficult to predict. One reason for this uncertainty is a lack of observations of ice behavior and melt under conditions of warming, as it is a relatively new global climate state lasting only a few generations so far. Researchers will investigate ice growth on Antarctica under past warm conditions using geological archives embedded in the layers of sand and mud under the sea floor near Antarctica. By peeling back at the layers beneath the seafloor investigators can read the history book of past events affecting the ice sheet. The Antarctic continent on the South Pole, carries the largest ice mass in the world. The investigator's findings will substantially improve scientists understanding of the response of ice sheets to global warming and its effect on sea level rise.<br/><br/><br/>Abstract (technical)<br/>The melt of land based ice is raising global sea levels with at present only minor contributions from polar ice sheets. However, the future role of polar ice sheets in climate change is one of the most critical uncertainties in predictions of sea level rise around the globe. The respective roles of oceanic and atmospheric greenhouse forcing on ice sheets are poorly addressed with recent measurements of polar climatology, because of the extreme rise in greenhouse forcing the earth is experiencing at this time. Data on the evolution of the West Antarctic ice sheet is particularly sparse. To address the data gap, researchers will reconstruct the timing and spatial distribution of Antarctic ice growth through the last greenhouse to icehouse climate transition around 37 to 33 Ma. They will collect sedimentological and geochemical data on core samples from a high-latitude paleoarchive to trace the shutdown of the chemical weathering system, the onset of glacial erosion, ice rafting, and sea ice development, as East and West Antarctic ice sheets coalesced in the Weddell Sea sector. Their findings will lead to profound increases in the understanding of the role of greenhouse forcing in ice sheet development and its effect on the global climate system.<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.
In the past, Earth's climate underwent dramatic changes that influenced physical, chemical, geological, and biological processes on a global scale. Such changes left an imprint in Earth's atmosphere, as shown by the variability in abundances of trace gases like carbon dioxide and methane. In return, changes in the atmospheric trace gas composition affected Earth's climate. Studying compositional variations of the past atmosphere helps us understand the history of interactions between global biogeochemical cycles and Earth?s climate. The most reliable information on past atmospheric composition comes from analysis of air entrapped in polar ice cores. This project aims to generate ice-core records of relatively short-lived, very-low-abundance trace gases to determine the range of past variability in their atmospheric levels and investigate the changes in global biogeochemical cycles that caused this variability. This project measures three such gases: carbonyl sulfide, methyl chloride, and methyl bromide. Changes in carbonyl sulfide can indicate changes in primary productivity and photosynthetic update of carbon dioxide. Changes in methyl chloride and methyl bromide significantly impact natural variability in stratospheric ozone. In addition, the processes that control atmospheric levels of methyl chloride and methyl bromide are shared with those controlling levels of atmospheric methane. The measurements will be made in the new ice core from the South Pole, which is expected to provide a 40,000-year record.<br/><br/>The primary focus of this project is to develop high-quality trace gas records for the entire Holocene period (the past 11,000 years), with additional, more exploratory measurements from the last glacial period including the period from 29,000-36,000 years ago when there were large changes in atmospheric methane. Due to the cold temperatures of the South Pole ice, the proposed carbonyl sulfide measurements are expected to provide a direct measure of the past atmospheric variability of this gas without the large hydrolysis corrections that are necessary for interpretation of measurements from ice cores in warmer settings. Furthermore, we will test the expectation that contemporaneous measurements from the last glacial period in the deep West Antarctic Ice Sheet Divide ice core will not require hydrolysis loss corrections. With respect to methyl chloride, we aim to verify and improve the existing Holocene atmospheric history from the Taylor Dome ice core in Antarctica. The higher resolution of our measurements compared with those from Taylor Dome will allow us to derive a more statistically significant relationship between methyl chloride and methane. With respect to methyl bromide, we plan to extend the existing 2,000-year database to 11,000 years. Together, the methyl bromide and methyl chloride records will provide strong measurement-based constraints on the natural variability of stratospheric halogens during the Holocene period. In addition, the methyl bromide record will provide insight into the correlation between methyl chloride and methane during the Holocene period due to common sources and sinks.
This award supports the deployment and analysis of data from an oriented laser dust logger in the South Pole ice core borehole to complement study of the ice core record. Before the core is even processed, data from the borehole probe will immediately determine the depth-age relationship, augment 3D mapping of South Pole stratigraphy, aid in searches for the oldest ice in Antarctica, and reveal layers of volcanic or extraterrestrial fallout. Regarding the intellectual merit, the oriented borehole log will be essential for investigating features in the ice sheet that may have implications for ice core chronology, ice flow, ice sheet physical properties and stability in response to climate change. The tools and techniques developed in this program have applications in glaciology, biogeoscience and exploration of other planetary bodies. The program aims for a deeper understanding of the consequences and causes of abrupt climate change. The broader impacts of the project are that it will include outreach and education, providing a broad training ground for students and post-docs. Data and metadata will be made available through data centers and repositories such as the National Snow and Ice Data Center web portal. <br/><br/>The laser dust logger detects reproducible paleoclimate features at sub-centimeter depth scale. Dust logger data are being used for synchronizing records and dating any site on the continent, revealing accumulation anomalies and episodes of rapid ice sheet thinning, and discovering particulate horizons of special interest. In this project we will deploy a laser dust logger equipped with a magnetic compass to find direct evidence of preferentially oriented dust. Using optical scattering measurements from IceCube calibration studies at South Pole and borehole logs at WAIS Divide, we have detected a persistent anisotropy correlated with flow and crystal fabric which suggests that the majority of insoluble particulates must be located within ice grains. With typical concentrations of parts-per-billion, little is known about the location of impurities within the polycrystalline structure of polar ice. While soluble impurities are generally thought to concentrate at inter-grain boundaries and determine electrical conductivity, the fate of insoluble particulates is much less clear, and microscopic examinations are extremely challenging. These in situ borehole measurements will help to unravel intimate relationships between impurities, flow, and crystal fabric. Data from this project will further develop a unique record of South Pole surface roughness as a proxy for paleowind and provide new insights for understanding glacial radar propagation. This project has field work in Antarctica.
This proposal requests support for a project to drill and recover a new ice core from South Pole, Antarctica. The South Pole ice core will be drilled to a depth of 1500 m, providing an environmental record spanning approximately 40 kyrs. This core will be recovered using a new intermediate drill, which is under development by the U.S. Ice Drilling Design and Operations (IDDO) group in collaboration with Danish scientists. This proposal seeks support to provide: 1) scientific management and oversight for the South Pole ice core project, 2) personnel for ice core drilling and core processing, 3) data management, and 3) scientific coordination and communication via scientific workshops. The intellectual merit of the work is that the analysis of stable isotopes, atmospheric gases, and aerosol-borne chemicals in polar ice has provided unique information about the magnitude and timing of changes in climate and climate forcing through time. The international ice core research community has articulated the goal of developing spatial arrays of ice cores across Antarctica and Greenland, allowing the reconstruction of regional patterns of climate variability in order to provide greater insight into the mechanisms driving climate change. The broader impacts of the project include obtaining the South Pole ice core will support a wide range of ice core science projects, which will contribute to the societal need for a basic understanding of climate and the capability to predict climate and ice sheet stability on long time scales. Second, the project will help train the next generation of ice core scientists by providing the opportunity for hands-on field and core processing experience for graduate students and postdoctoral researchers. A postdoctoral researcher at the University of Washington will be directly supported by this project, and many other young scientists will interact with the project through individual science proposals. Third, the project will result in the development of a new intermediate drill which will become an important resource to US ice core science community. This drill will have a light logistical footprint which will enable a wide range of ice core projects to be carried out that are not currently feasible. Finally, although this project does not request funds for outreach activities, the project will run workshops that will encourage and enable proposals for coordinated outreach activities involving the South Pole ice core science team.
The temperature of the earth is controlled, in part, by heat trapping gases that include carbon dioxide, methane, and nitrous oxide. Despite their importance to climate, direct measurements of these gases in the atmosphere are limited to the last 50 years at best. Air trapped in ice cores extends those data back hundreds of millennia, and measurements of greenhouse gases in ice cores underpin much of our understanding of global chemical cycles relevant to modern climate change. Existing records vary in quality and detail. The proposed work fills gaps in our knowledge of nitrous oxide and carbon dioxide over the last 10,000 years. New measurements from an ice core from the South Pole will be used to determine what role changes in ocean and land based processes played in controlling these gases, which decreased during the first 2,000 years of this time period, then gradually increased toward the present. The work will address a major controversy over whether early human activities could have impacted the atmosphere, and provide data to improve mathematical models of the land-ocean-atmosphere system that predict how future climate change will impact the composition of the atmosphere and climate. <br/><br/>For nitrous oxide the work will improve on existing concentration records It will also develop measurement of the isotopomers of nitrous oxide and explore their utility for understanding aspects of the Holocene nitrous oxide budget. The primary goal is to determine if marine and/or terrestrial emissions of nitrous oxide change in response to changes in Holocene climate. A new Holocene isotopic record for carbon dioxide (stable carbon and oxygen isotopes), will improve the precision of existing records by a factor 5 and increase the temporal resolution. These data will be used to evaluate controversial hypotheses about why carbon dioxide concentrations changed in the Holocene and provide insight into millennial scale processes in the carbon cycle, which are not resolved by current isotopic data. A graduate student and post doc will receive advanced training during and the student and principle investigator will conduct outreach efforts targeted at local middle school students. The proposed work will also contribute to teaching efforts by the PI and to public lectures on climate and climate change. The results will be disseminated through publications, data archive, and the OSU Ice Core Lab web site. New analytical methods of wide utility will also be developed and documented.
Aydin/1644245<br/><br/>This award supports a project to measure ethane in ice core air extracted from the recently drilled intermediate depth South Pole ice core (SPICECORE). Ethane is an abundant hydrocarbon in the atmosphere. The ice core samples that will be used in this analysis will span about 150 years before present to about 55,000 years before present and therefore, ethane emissions linked to human activities are not a subject of this study. The study will focus on quantifying the variability in the natural sources of ethane and the processes that govern its removal from the atmosphere. A long-term ice core ethane record will provide new knowledge on the chemistry of Earth?s atmosphere during time periods when human influence was either much smaller than present day or non-existent. The broader impacts of this work include education and training of students and a contribution to a better understanding of the chemistry of the atmosphere in the past and how it has been impacted by past changes in climate.<br/><br/>Natural sources that emit ethane are both geologic (e.g. seeps, vents, mud volcanoes etc.) and pyrogenic (wild fires) which is commonly called biomass burning. Ethane is removed from the atmosphere via oxidation reactions. The ice core ethane measurements have great potential as a proxy for gaseous emissions from biomass burning. This is especially true for time periods preceding the industrial revolution when atmospheric variability of trace gases was largely controlled by natural processes. Another objective of this study is to improve understanding of the causes of atmospheric methane variability apparent which are in the existing ice core records. Methane is a simpler hydrocarbon than ethane and more abundant in the atmosphere. Even though the project does not include any methane measurements; the commonalities between the sources and removal of atmospheric ethane and methane mean that ethane measurements can be used to gain insight into the causes of changes in atmospheric methane levels. The broader impacts of the project include partial support for one Ph.D. student and support for undergraduate researchers at UC Irvine. The PIs group currently has 4 undergraduate researchers. The PI and the graduate students in the UCI ice core laboratory regularly participate in on- and off-campus activities such as laboratory tours and lectures directed towards educating high-school students and science teachers, and the local community at large about the scientific value of polar ice cores as an environmental record of our planet's past. The results of this research will be disseminated via peer-review publications and will contribute to policy-relevant activities such as the IPCC Climate Assessment. Data resulting from this project will be archived in a national data repository. This award does not have field work in Antarctica.
Waddington/1246045 <br/><br/>This award supports a project to investigate the onset and growth of folds and other disturbances seen in the stratigraphic layers of polar ice sheets. The intellectual merit of the work is that it will lead to a better understanding of the grain-scale processes that control the development of these stratigraphic features in the ice and will help answer questions such as what processes can initiate such disturbances. Snow is deposited on polar ice sheets in layers that are generally flat, with thicknesses that vary slowly along the layers. However, ice cores and ice-penetrating radar show that in some cases, after conversion to ice, and following lengthy burial, the layers can become folded, develop pinch-and-swell structures (boudinage), and be sheared by ice flow, at scales ranging from centimeters to hundreds of meters. The processes causing these disturbances are still poorly understood. Disturbances appear to develop first at the ice-crystal scale, then cascade up to larger scales with continuing ice flow and strain. Crystal-scale processes causing distortions of cm-scale layers will be modeled using Elle, a microstructure-modeling package, and constrained by fabric thin-sections and grain-elongation measurements from the West Antarctic Ice Sheet divide ice-core. A full-stress continuum anisotropic ice-flow model coupled to an ice-fabric evolution model will be used to study bulk flow of anisotropic ice, to understand evolution and growth of flow disturbances on the meter and larger scale. Results from this study will assist in future ice-core site selection, and interpretation of stratigraphy in ice cores and radar, and will provide improved descriptions of rheology and stratigraphy for ice-sheet flow models.The broader impacts are that it will bring greater understanding to ice dynamics responsible for stratigraphic disturbance. This information is valuable to constrain depth-age relationships in ice cores for paleoclimate study. This will allow researchers to put current climate change in a more accurate context. This project will provide three years of support for a graduate student as well as support and research experience for an undergraduate research assistant; this will contribute to development of talent needed to address important future questions in glaciology and climate change. The research will be communicated to the public through outreach events and results from the study will be disseminated through public and professional meetings as well as journal publications. The project does not require field work in Antarctica.
Steig/1043092<br/><br/>This award supports a project to contribute one of the cornerstone analyses, stable isotopes of ice (Delta-D, Delta-O18) to the ongoing West Antarctic Ice Sheet Divide (WAIS) deep ice core. The WAIS Divide drilling project, a multi-institution project to obtain a continuous high resolution ice core record from central West Antarctica, reached a depth of 2560 m in early 2010; it is expected to take one or two more field seasons to reach the ice sheet bed (~3300 m), plus an additional four seasons for borehole logging and other activities including proposed replicate coring. The current proposal requests support to complete analyses on the WAIS Divide core to the base, where the age will be ~100,000 years or more. These analyses will form the basis for the investigation of a number of outstanding questions in climate and glaciology during the last glacial period, focused on the dynamics of the West Antarctic Ice Sheet and the relationship of West Antarctic climate to that of the Northern polar regions, the tropical Pacific, and the rest of the globe, on time scales ranging from years to tens of thousands of years. One new aspect of this work is the growing expertise at the University of Washington in climate modeling with isotope-tracer-enabled general circulation models, which will aid in the interpretation of the data. Another major new aspect is the completion and use of a high-resolution, semi-automated sampling system at the University of Colorado, which will permit the continuous analysis of isotope ratios via laser spectroscopy, at an effective resolution of ~2 cm or less, providing inter-annual time resolution for most of the core. Because continuous flow analyses of stable ice isotopes is a relatively new measurement, we will complement them with parallel measurements, every ~10-20 m, using traditional discrete sampling and analysis by mass spectrometry at the University of Washington. The intellectual merit and the overarching goal of the work are to see Inland WAIS become the reference ice isotope record for West Antarctica. The broader impacts of the work are that the data generated in this project pertain directly to policy-relevant and immediate questions of the stability of the West Antarctic ice sheet, and thus past and future changes in sea level, as well as the nature of climate change in the high southern latitudes. The project will also contribute to the development of modern isotope analysis techniques using laser spectroscopy, with applications well beyond ice cores. The project will involve a graduate student and postdoc who will work with both P.I.s, and spend time at both institutions. Data will be made available rapidly through the Antarctic Glaciological Data Center, for use by other researchers and the public.
Funds are provided to enable applications of powerful mathematical concepts and computational tools for rigorous sensitivity analysis, pseudo-spectra and generalized stability theory, and advanced state estimation in the context of large-scale ice sheet modeling. At the center of the proposal is the generation and application of adjoint model (ADM) and tangent linear model (TLM) components of the new Community Ice Sheet Model (CISM). The goal will be achieved through rigorous use of automatic differentiation (AD) to ensure synchronicity between the ongoing model development and improvement in terms of better representation of higher-order stress terms (which account for crucial fast flow regimes) of the nonlinear forward model (NLM) code and the derivative codes. The adjoint enables extremely efficient computation of gradients of scalar-valued functions in very high-dimensional control spaces. A hierarchy of applications is envisioned: (1) sensitivity calculations in support of the Intergovernmental Panel on Climate Change (IPCC) in order to determine to which control variables the polar ice sheet volumes are most sensitive; based on adjoint sensitivity maps, to establish quantitative estimates of ice sheet volume changes for relevant forcing scenarios; and to assess how sensitivities change when including higher-order stress terms; (2) coupling of the ADM and TLM to calculate pseudo-spectra or singular vectors (SV?s) of relevant ice sheet norms; SV?s provide perturbation patterns which lead to non-normal growth, optimally amplifying norm kernels over finite times; among the many applications of SV?s are optimal initialization of ensembles to assess uncertainties; SV?s are calculated through matrix-free iterative solution of a generalized eigenvalue problem via Lanczos or Arnoldi implicit restart algorithms; (3) a long-term goal is the development of an ice sheet state estimation system based on the adjoint or Lagrange Multiplier Method (LMM) in order to synthesize, in a formal manner, the increasing number and heterogeneous types of observations with a three-dimensional, state-of-the-art ice sheet model; an important requirement is that the adjoint incorporate new schemes that are being developed for CISM to capture crucial, but as yet unrepresented physical processes.
This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a project to develop a robust analytical technique for measuring the stable isotopes of CO2 in air trapped in polar ice, and to reconstruct the ä13C of CO2 over the last glacial to interglacial transition (20,000 to 10,000 years BP) and through the Holocene. The bulk of these measurements will be made on newly cored ice from the WAIS Divide Ice Core. A robust record ä13C of CO2 will be a valuable addition to the rich data produced from this project. The intellectual merit of the proposed work relates to the fact that explaining glacial-interglacial changes in atmospheric CO2 remains a major challenge for paleoclimatology. The lack of a coherent, widely accepted explanation underscores uncertainties in the basic mechanisms that control the carbon cycle, and that lack of understanding limits our ability to confidently predict how the carbon cycle will change in the future, in the face of a potentially major perturbation of both global temperature and the CO2 content of the atmosphere. A widely accepted record of this parameter could transform our understanding of how the carbon cycle and climate change are linked. The broader impacts of the work include training of graduate student at OSU who will conduct much of the lab work and will also participate in fieldwork at the WAIS Divide Core site. The student will also participate in a number of organized outreach efforts and will develop his own outreach effort, through weblogs and other communication of his research. The PIs will communicate the results from this project to a variety of audiences through academic courses and public talks. The proposed work addresses a major topic in biogeochemistry, the origin of glacial-interglacial CO2 cycles. The results are relevant to understanding changes in the carbon cycle due to human activities because the lack of clear understanding of past variations contributes to public uncertainty about the importance of modern climate change. The proposed funding will also contribute to analytical infrastructure at OSU and develop an analytical capability for an ice core measurement currently not available in the United States.
This award supports an aerogeophysical study of the Gamburtsev Subglacial Mountains (GSM), a Texas-sized mountain range buried beneath the ice sheets of East Antarctica. The project would perform a combined gravity, magnetics, and radar study to achieve a range of goals including: advancing our understanding of the origin and evolution of the polar ice sheets and subglacial lakes; defining the crustal architecture of East Antarctica, a key question in the earth's history; and locating the oldest ice in East Antarctica, which may ultimately help find ancient climate records. Virtually unexplored, the GSM represents the largest unstudied area of crustal uplift on earth. As well, the region is the starting point for growth of the Antarctic ice sheets. <br/>Because of these outstanding questions, the GSM has been identified by the international Antarctic science community as a research focus for the International Polar Year (2007-2009). In addition to this study, NSF is also supporting a seismological survey of the GSM under award number 0537371. Major international partners in the project include Germany, China, Australia, and the United Kingdom. For more information see IPY Project #67 at IPY.org. In terms of broader impacts, this project also supports postdoctoral and graduate student research, and various forms of outreach including a focus on groups underrepresented in the earth sciences.
Hulbe/0838810 <br/><br/>This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5).<br/><br/>This award supports a modeling study of the processes in West Antarctic grounding zones, the transition from ice resting on bedrock to ice floating on the ocean surface with an eye toward understanding the interrelated causes of rapid change in grounding line configuration and outlet flow. A combination of satellite remote sensing and numerical modeling will be used to investigate both past and ongoing patterns of change. New high-resolution surface elevation maps made from a novel combination of satellite laser altimetry and remotely observed surface shape provide a unique view of grounding zones. These data will be used to diagnose events associated with the shutdown of Kamb Ice Stream, to investigate a recent discharge event on Institute Ice Stream and to investigate ongoing change at the outlet of Whillans Ice Stream, along with other modern processes around the West Antarctic. An existing numerical model of coupled ice sheet, ice stream, and ice shelf flow will be used and improved as part of the research project. The broader impacts of the project relate to the importance of understanding the role of polar ice sheets in global sea level rise. The work will contribute to the next round of deliberations for the Intergovernmental Panel on Climate Change (IPCC). Improved views, interpretations, and insights into the physical processes that govern variability in ice sheet outlet streams will help correct the shortcomings of the last IPCC report that didn?t include the role of ice sheets in sea level rise. The PIs have a strong record of public outreach, involvement in the professional community, and student training.
This award supports a project to fully characterize the microstructure in ice cores, in particular the microstructural locations of impurities, grain orientations and strain gradients. This work will complement the optical observations, electrical conductivity measurement, and precise, detailed measurements of the soluble ion and gas contents that are performed by others. Linking the concentrations of soluble ions and gases, measured to a few parts per billion, to the optically determined annual layer structure and the stable isotope data in ice cores has enabled a great deal to be established about the concentrations and depth/age distributions of particles, trace gases and impurities for several polar ice cores. Ice core studies carried out by several groups contribute immensely to our understanding of paleoclimate and, to our ability to predict future climate change. The work will build on previous measurements and technique development in this area, as well as focusing on new techniques to characterize ice cores. The work will use both scanning electron microscopy (SEM) coupled with X-ray energy dispersive spectroscopy (EDS) and confocal scanning optical microscopy coupled with Raman spectroscopy (RS) to determine the microstructural locations of impurities and correlate this information with depth/age, and impurity type and concentration for several polar ice cores. The Broader Impacts of the proposed work are that knowledge of the location of impurities coupled with the grain orientation (both c- and a-axis) and grain misorientation information will allow paleoclimatologists to better interpret ice core data and other scientists to understand and model the physical and mechanical properties of natural ice sheets. Other Broader Impacts of the work are that the work will be performed and lead to the education of a Ph.D. student. At the end of the project, as well as the knowledge gained from coursework, the graduate student will have experience in ice core specimen preparation and characterization using scanning electron microscopy, x-ray microanalysis, confocal scanning microscopy, Raman spectroscopy and ion chromatography. Results from the research will be published in refereed journals, presented at conferences, and placed on a web page.
This award supports a project to fully develop the analytical protocols needed to exploit a relatively new technique for the analysis of soluble organic matter in ice core samples. The technique couples Electrospray ionization to high resolution Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). Sample volume will be reduced and pre-concentration steps will be eliminated. Following method optimization a suite of ice core samples will be studied from several Antarctic and Greenland locations to address several hypothesis driven research questions. Preliminary results show that a vast record of relatively high molecular weight organic material exists in ice core samples and intriguing results from a few samples warrant further investigation. Several important questions related to developing a better understanding of the nature and paleo record of organic matter in ice cores will be addressed. These include developing a better understanding of the origin of nitrogen and sulfur isotopes in pre-industrial vs. modern samples, developing the methods to apply molecular biomarker techniques, routinely used by organic geochemists for sediment analyses, to the analysis of organic matter in ice cores, tracking the level of oxidation of homologous series of compounds and using them as a proxy for atmospheric oxidant levels in the past and determining whether or not high resolution FTICR mass spectral analysis can provide the ice core community with a robust method to analyze organic materials at the molecular level. The intellectual merit of this work is that this analytical method will provide a new understanding of the nature of organic matter in ice, possibly leading to the discovery of multitudes of molecular species indicative of global change processes whose abundances can be compared with other change proxies. The proposed studies are of an exploratory nature and potentially transformative for the field of ice core research and cryobiology. The broader impacts of these studies are that they should provide compelling evidence regarding organic matter sources, atmospheric processing and anthropogenic inputs to polar ice and how these have varied over time. The collaborative work proposed here will partner atmospheric chemistry/polar ice chemistry expertise with organic geochemistry expertise, resulting in significant contributions to both fields of study and significant advances in ice core analysis. Training of both graduate and undergraduate students will be a key component of the project and students will be involved in collaborative research using advanced analytical instrumentation, presentation of research results at national meetings, and will participate in manuscript preparation.
Barletta <br/>0828786<br/><br/>This award supports a Small Grant for Exploratory Research (SGER) for a project to conduct a limited scope, proof-of-concept study of the application of Raman spectroscopy to the analysis of ice cores. As a non-destructive analytical tool with high spatial resolution, Raman spectroscopy has found widespread application in situations where water is a major constituent in the sample, including marine science and the analysis of clathrates in ice-cores themselves. Raman can provide information at high enough sensitivity (ppm to ppb) to make its use as a non-destructive survey tool for ice core samples attractive. Laser-based techniques such as Raman can be used to obtain chemical information at near diffraction-limited resolution allowing particulates on the order of 1micron or less to be characterized. Preliminary work has demonstrated the selectivity of Raman spectroscopy for determining related polyatomic species (ions and compounds), and the ability to discern oxidation state from such analysis. In spite of the potential of this technique, instrumentation necessary to analyze ice core samples using micro-Raman spectroscopy with UV excitation is not readily available. Even with visible excitation, libraries of Raman spectra necessary for mixture de-convolution are not available. The proposed effort is a novel extension of Raman into the area of polar and climatic research, providing data on chemical speciation hitherto unavailable, of critical importance to the understanding of the biology present in glacial ice as well as the sources of particulate material found in ice cores. Since the availability of ice-core material at critical horizons is limited, this non-destructive technique will help to maximize the information obtained from these samples. The broader impacts of the work are that it will bring a new researcher into the field of polar ice core analysis and it has the potential to also bring a new non-destructive technique into the field. Finally, the research will take place at a predominately undergraduate institution in South Alabama with a large proportion (24% of undergraduates) of minority students. The proposed effort is high-risk because, although based upon established principles of vibrational spectroscopy, the application to the analytical problems of trace environmental analysis are unique, and the precision requirements are stringent. Moreover, this work will demonstrate the feasibility of an integrated approach to ice core analysis, while addressing specific problems in glaciology.
This award is for the continuation of the Center for Remote Sensing of Ice Sheets (CReSIS), an NSF Science and Technology Center (STC) established in June 2005 to study present and probable future contributions of the Greenland and Antarctic ice sheets to sea-level rise. The Center?s vision is to understand and predict the role of polar ice sheets in sea level change. In particular, the Center?s mission is to develop technologies, to conduct field investigations, to compile data to understand why many outlet glaciers and ice streams are changing rapidly, and to develop models that explain and predict ice sheet response to climate change. The Center?s mission is also to educate and train a diverse population of graduate and undergraduate students in Center-related disciplines and to encourage K-12 students to pursue careers in science, technology, engineering and mathematics (STEM-fields). The long-term goals are to perform a four-dimensional characterization (space and time) of rapidly changing ice-sheet regions, develop diagnostic and predictive ice-sheet models, and contribute to future assessments of sea level change in a warming climate. In the first five years, significant progress was made in developing, testing and optimizing innovative sensors and platforms and completing a major aircraft campaign, which included sounding the channel under Jakobshavn Isbræ. In the second five years, research will focus on the interpretation of integrated data from a suite of sensors to understand the physical processes causing changes and the subsequent development and validation of models. Information about CReSIS can be found at http://www.cresis.ku.edu.<br/><br/>The intellectual merits of the STC are the multidisciplinary research it enables its faculty, staff and students to pursue, as well as the broad education and training opportunities it provides to students at all levels. During the first phase, the Center provided scientists and engineers with a collaborative research environment and the opportunity to interact, enabling the development of high-sensitivity radars integrated with several airborne platforms and innovative seismic instruments. Also, the Center successfully collected data on ice thickness and bed conditions, key variables in the study of ice dynamics and the development of models, for three major fast-flowing glaciers in Greenland. During the second phase, the Center will collect additional data over targeted sites in areas undergoing rapid changes; process, analyze and interpret collected data; and develop advanced process-oriented and ice sheet models to predict future behavior. The Center will continue to provide a rich environment for multidisciplinary education and mentoring for undergraduate students, graduate students, and postdoctoral fellows, as well as for conducting K-12 education and public outreach. The broader impacts of the Center stem from addressing a global environmental problem with critical societal implications, providing a forum for citizens and policymakers to become informed about climate change issues, training the next generation of scientists and engineers to serve the nation, encouraging underrepresented students to pursue careers in STEM-related fields, and transferring new technologies to industry. Students involved in the Center find an intellectually stimulating atmosphere where collaboration between disciplines is the norm and exposure to a wide variety of methodologies and scientific issues enriches their educational experience. The next generation of researchers should reflect the diversity of our society; the Center will therefore continue its work with ECSU to conduct outreach and educational programs that attract minority students to careers in science and technology. The Center has also established a new partnership with ADMI that supports faculty and student exchanges at the national level and provides expanded opportunities for students and faculty to be involved in Center-related research and education activities. These, and other collaborations, will provide broader opportunities to encourage underrepresented students to pursue STEM careers. <br/><br/>As lead institution, The University of Kansas (KU) provides overall direction and management, as well as expertise in radar and remote sensing, Uninhabited Aerial Vehicles (UAVs), and modeling and interpretation of data. Five partner institutions and a DOE laboratory play critical roles in the STC. The Pennsylvania State University (PSU) continues to participate in technology development for seismic measurements, field activities, and modeling. The Center of Excellence in Remote Sensing, Education and Research (CERSER) at Elizabeth City State University (ECSU) contributes its expertise to analyzing satellite data and generating high-level data products. ECSU also brings to the Center their extensive experience in mentoring and educating traditionally under-represented students. ADMI, the Association of Computer and Information Science/Engineering Departments at Minority Institutions, expands the program?s reach to underrepresented groups at the national level. Indiana University (IU) provides world-class expertise in CI and high-performance computing to address challenges in data management, processing, distribution and archival, as well as high-performance modeling requirements. The University of Washington (UW) provides expertise in satellite observations of ice sheets and process-oriented interpretation and model development. Los Alamos National Laboratory (LANL) contributes in the area of ice sheet modeling. All partner institutions are actively involved in the analysis and interpretation of observational and numerical data sets.
Edwards/0739780<br/><br/>This award supports a project to develop a 2,000-year high-temporal resolution record of biomass burning from the analysis of black carbon in the WAIS Divide bedrock ice core. Pilot data for the WAIS WD05A core demonstrates that we now have the ability to reconstruct this record with minimal impact on the amount of ice available for other projects. The intellectual merit of this project is that black carbon (BC) aerosols result solely from combustion and play a critical but poorly quantified role in global climate forcing and the carbon cycle. When incorporated into snow and ice, BC increases absorption of solar radiation making seasonal snow packs, mountain glaciers, polar ice sheets, and sea ice much more vulnerable to climate warming. BC emissions in the Southern Hemisphere are dominated by biomass burning in the tropical regions of Southern Africa, South America and South Asia. Biomass burning, which results from both climate and human activities, alters the atmospheric composition of greenhouse gases, aerosols and perturbs key biogeochemical cycles. A long-term record of biomass burning is needed to aid in the interpretation of ice core gas composition and will provide important information regarding human impacts on the environment and climate before instrumental records. The broader impacts of the project are that it represents a paradigm shift in our ability to reconstruct the history of fire from ice core records and to understand its impact on atmospheric chemistry and climate over millennial time scales. This type of data is especially needed to drive global circulation model simulations of black carbon aerosols, which have been found to be an important component of global warming and which may be perturbing the hydrologic cycle. The project will also employ undergraduate students and is committed to attracting underrepresented groups to the physical sciences. The project?s outreach component will be conducted as part of the WAIS project outreach program and will reach a wide audience.
0538494<br/>Meese<br/>This award supports a project for physical properties research on snow pits and firn/ice cores with specific objectives that include stratigraphic analysis including determination of accumulation rates, annual layers, depth hoar, ice and wind crusts and rates of grain growth with depth. Studies of firn densification rates and how these parameters relate to the meteorology and climatology over the last 200 years of snow accumulation in Antarctica will also be investigated. The project will also determine the seasonality of accumulation by co-registration of stratigraphy and chemistry and determination of chemical species at the grain boundaries, how these may change with depth/densification (and therefore temperature), precipitation, and may affect grain growth. Fabric analyses will be made, including variation with depth, location on undulations and if any variation exists with climate/chemistry. The large spatial coverage of the US ITASE program offers the opportunity to determine how these parameters are affected by a large range of temperature, precipitation and topographic effects. The intellectual merit of the project includes the fact that ITASE is the terrestrial equivalent of a polar research vessel that provides a unique, logistically efficient, multi-dimensional (x, y, z and time) view of the atmosphere, ice sheet and their histories. Physical properties measurements/ analyses are an integral part of understanding the dynamic processes to which the accumulated snow is subjected. Recent advancements in the field along with multiple core sites provide an excellent opportunity to gain a much broader understanding of the spatial, temporal and physical variables that impact firnification and the possible resultant impact on climatic interpretation. In terms of broader impacts, the data collected by US ITASE and its international ITASE partners is available to a broad scientific community. US ITASE has an extensive program of public outreach and provides significant opportunities for many students to experience multidisciplinary Antarctic research. A graduate student, a post-doctoral fellow and at least one undergraduate would be funded by this work. Dr. Meese is also a member of the New England Science Collaborative, an organization that educates the public on climate change based on recent scientific advancements.
This award supports a study of the physical nature and environmental origin of optical features (light and dark zones) observed by video in boreholes in polar ice. These features appear to include an annual signal, as well as longer period signals. Borehole logs exist from a previous project, and in this lab-based project the interpretation of these logs will be improved. The origin of the features is of broad interest to the ice-core community. If some components relate to changes in the depositional environment beyond seasonality, important climatic cycles may be seen. If some components relate to post-depositional reworking, insights will be gained into the physical processes that change snow and firn, and the implications for interpretation of the chemical record in terms of paleoclimate. In order to exploit these features to best advantage in future ice-core and climate-change research, the two principal objectives of this project are to determine what physically causes the optical differences that we see and to determine the environmental processes that give rise to these physical differences. In the laboratory at NICL the conditions of a log of a borehole wall will be re-created as closely as possible by running the borehole video camera along sections of ice core, making an optical log of light reflected from the core. Combinations of physical variables that are correlated with optical features will be identified. A radiative-transfer model will be used to aid in the interpretation of these measurements, and to determine the optimum configuration for an improved future logging tool. An attempt will be made to determine the origin of the features. Two broad possibilities exist: 1) temporal changes in the depositional environment, and 2) post-depositional reworking. This project represents an important step toward a new way of learning about paleoclimate with borehole optical methods. Broader impacts include enhancing the infrastructure for research and education, since this instrument will complement high-resolution continuous-melter chemistry techniques and provide a rapid way to log physical variables using optical features as a proxy for climate signals. Since no core is required for this method, it can be used in rapidly drilled access holes or where core quality is poor. This project will support a graduate student who will carry out this project under the direction of the Principal Investigator. K-12 education will be enhanced through an ongoing collaboration with a science and math teacher from a local middle school. International collaboration will be expanded through work on this project with colleagues at the Norwegian Polar Institute and broad dissemination of results will occur through a project website for the general public.
This project develops a system of airborne instruments to explore the polar ice sheets and their underlying environments. The instrument suite includes an ice-penetrating radar, laser altimeter, gravimeter and magnetometer. Airborne geophysical measurements are key to understanding the 99% of Antarctica and 85% of Greenland covered by ice, which have thus far been studied at the postage stamp level. Projects linking ice sheet behavior to underlying geology will immediately benefit from this system, but even more exciting are the system's potential uses for work at the frontiers of polar science, such as: 1) exploring subglacial lakes, recently discovered and potentially the most unique sites on Earth for understanding life in extreme environments; 2) locating the deepest, oldest ice, which would offer million year and older samples of the atmosphere and 3) interpreting Antarctica's subglacial geology, which contains unique and unstudied volcanoes, mountains, and tectonic provinces. In terms of broader impacts, this project constructs research infrastructure critical to society's understanding of sea level rise, and supports a project involving domestic, international, and private sector collaborations.
0122520<br/>Gogineni<br/><br/>Sea level has been rising over the last century. Although the immediate impact of sea level rise may be less severe than other effects of global climate change, the long-term consequences can be much more devastating since nearly 60% of the world population lives in coastal regions. Scientists have postulated that excess water is being released from polar ice sheets due to long-term, global climate change, but there are insufficient data to confirm these theories. Understanding the interactions between the ice sheets, oceans and atmosphere is essential to quantifying the role of ice sheets in sea level rise. Toward that end, this research project involves the innovative application of information technology in the development and deployment of intelligent radar sensors for measuring key glaciological parameters. <br/><br/>Radar instrumentation will consist of a synthetic aperture radar (SAR) that can operate in bistatic or monostatic mode. One important application of the SAR will be in the determination of basal conditions, particularly the presence and distribution of basal water. Basal water lubricates the ice/bed interface, enhancing flow, and increasing the amount of ice discharged into the ocean. Another application of the SAR will be to measure ice thickness and map internal layers in both shallow and deep ice. Information on near-surface internal layers will be used to estimate the average, recent accumulation rate, while the deeper layers provide a history of past accumulation and flow rates. A tracked vehicle and an automated snowmobile will be used to test and demonstrate the utility of an intelligent radar in glaciological investigations.<br/><br/>The system will be developed to collect, process and analyze data in real time and in conjunction with a priori information derived from archived sources. The combined real time and archived information will be used onboard the vehicles to select and generate an optimum sensor configuration. This project thus involves innovative research in intelligent systems, sounding radars and ice sheet modeling. In addition it has a very strong public outreach and education program, which include near-real-time image broadcasts via the world wide web
0538630<br/>Severinghaus<br/>This award supports a project to produce the first record of Kr/N2 in the paleo-atmosphere as measured in air bubbles trapped in ice cores. These measurements may be indicative of past variations in mean ocean temperature. Knowing the mean ocean temperature in the past will give insight into past variations in deep ocean temperature, which remain poorly understood. Deep ocean temperature variations are important for understanding the mechanisms of climate change. Krypton is highly soluble in water, and its solubility varies with temperature, with higher solubilities at colder water temperatures. A colder ocean during the last glacial period would therefore hold more krypton than today's ocean. Because the total amount of krypton in the ocean-atmosphere system is constant, the increase in the krypton inventory in the glacial ocean should cause a resultant decrease in the atmospheric inventory of krypton. The primary goal of this work is to develop the use of Kr/N2 as an indicator of paleo-oceanic mean temperature. This will involve improving the analytical technique for the Kr/N2 measurement itself, and measuring the Kr/N2 in air bubbles in ice from the last glacial maximum (LGM) and the late Holocene in the Vostok and GISP2 ice cores. This provides an estimate of LGM mean ocean temperature change, and allows for a comparison between previous estimates of deep ocean temperature during the LGM. The Vostok ice core is ideal for this purpose because of the absence of melt layers, which compromise the krypton and xenon signal. Another goal is to improve precision on the Xe/N2 measurement, which could serve as a second, independent proxy of ocean temperature change. A mean ocean temperature time series during this transition may help to explain these observations. Additionally, the proposed work will measure the Kr/N2 from marine isotope stage (MIS) 3 in the GISP2 ice core. Knowing the past ocean temperature during MIS 3 will help to constrain sea level estimates during this time period. The broader impacts of the proposed work: are that it will provide the first estimate of the extent and timing of mean ocean temperature change in the past. This will help to constrain previously proposed mechanisms of climate change involving large changes in deep ocean temperature. This project will also support the education of a graduate student. The PI gives interviews and talks to the media and public about climate change, and the work will enhance these outreach activities. Finally, the work will occur during the International Polar Year (IPY), and will underscore the unique importance of the polar regions for understanding the global atmosphere and ocean system.
0538683<br/>Lal<br/>This award supports a project to continue development of a new method for estimating solar activity in the past. It is based on measurements of the concentrations of in-situ produced C-14 in polar ice by cosmic rays, which depend only on (i) the cosmic ray flux, and (ii) ice accumulation rate. This is the only direct method available to date polar ice, since it does not involve any uncertain climatic transfer functions as are encountered in the applications of cosmogenic C-14 data in tree rings, or of Be-10 in ice and sediments. An important task is to improve on the temporal resolution during identified periods of high/low solar activity in the past 32 Kyr. The plan is to undertake a study of changes in the cosmic ray flux during the last millennium (1100-1825 A.D.), during which time 4 low and 1 high solar activity epoch has been identified from historical records. Sunspot data during most of these periods are sparse. Adequate ice samples are available from ice cores from the South Pole and from Summit, Greenland and a careful high resolution study of past solar activity levels during this period will be undertaken. The intellectual merit of the work includes providing independent verification of estimated solar activity levels from the two polar ice records of cosmic ray flux and greatly improve our understanding of solar-terrestrial relationships. <br/>The broader impacts include collaboration with other scientists who are experts in the application of the atmospheric cosmogenic C-14 and student training. Both undergraduates and a graduate student will be involved in the proposed research. Various forms of outreach will also be used to disseminate the results of this project, including public presentations and interactions with the media.
Saltzman/0636953<br/><br/>This award supports a project to measure methyl chloride, methyl bromide, and carbonyl sulfide in air extracted from Antarctic ice cores. Previous measurements in firn air and shallow ice cores suggest that the ice archive contains paleo-atmospheric signals for these gases. The goal of this study is to extend these records throughout the Holocene and into the last Glacial period to examine the behavior of these trace gases over longer time scales and a wider range of climatic conditions. These studies are exploratory, and both the stability of these trace gases and the extent to which they may be impacted by in situ processes will be assessed. This project will involve sampling and analyzing archived ice core samples from the Siple Dome, Taylor Dome, Byrd, and Vostok ice cores. The ice core samples will be analyzed by dry extraction, with gas chromatography/mass spectrometry with isotope dilution. The ice core measurements will generate new information about the range of natural variability of these trace gases in the atmosphere. The intellectual merit of this project is that this work will provide an improved basis for assessing the impact of anthropogenic activities on biogeochemical cycles, and new insight into the climatic sensitivity of the biogeochemical processes controlling atmospheric composition. The broader impact of this project is that there is a strong societal interest in understanding how man's activities impact the atmosphere, and how atmospheric chemistry may be altered by future climate change. The results of this study will contribute to the development of scenarios used for future projections of stratospheric ozone and climate change. In terms of human development, this project will support the doctoral dissertation of a graduate student in Earth System Science, and undergraduate research on polar ice core chemistry. This project will also contribute to the development of an Earth Sciences teacher training curriculum for high school teachers in the Orange County school system in collaboration with an established, NSF-sponsored Math and Science Partnership program (FOCUS).
This award supports a comprehensive study of land-based polar ice cliffs. Through field measurements, modeling, and remote sensing, the physics underlying the formation of ice cliffs at the margin of Taylor Glacier in the McMurdo Dry Valleys will be investigated. At three sites, measurements of ice deformation and temperature fields near the cliff face will be combined with existing energy balance data to quantify ice-cliff evolution over one full seasonal cycle. In addition, a small seismic network will monitor local "ice quakes" associated with calving events. Numerical modeling, validated by the field data, will enable determination of the sensitivity of ice cliff evolution to environmental variables. There are both local and global motivations for studying the ice cliffs of Taylor Glacier. On a global scale, this work will provide insight into the fundamental processes of calving and glacier terminus A better grasp of ice cliff processes will also improve boundary conditions required for predicting glaciers' response to climate change. Locally, the Taylor Glacier is an important component of the McMurdo Dry Valleys landscape and the results of this study will aid in defining ecologically-important sources of glacial meltwater and will lead to a better understanding of moraine formation at polar ice cliffs. This study will help launch the career of a female scientist, will support one graduate student, and provide experiential learning experiences for two undergraduates. The post-doctoral researcher will also use this research in the curriculum of a wilderness science experiential education program for high school girls.
This award supports a small grant for exploratory research to study the processes that contribute to the melting and break-up of tabular polar icebergs as they drift north. This work will enable the participation of a group of U.S. scientists in this international project which is collaborative with the Instituto Antartico Argentino. The field team will place weather instruments, firn sensors, and a video camera on the iceberg to measure the processes that affect it as it drifts north. In contrast to icebergs in other sectors of Antarctica, icebergs in the northwestern Weddell Sea drift northward along relatively predictable paths, and reach climate and ocean conditions that lead to break-up within a few years. The timing of this study is critical due to the anticipated presence of iceberg A43A, which broke off the Ronne Ice Shelf in February 2000 and which is expected to be accessible from Marambio Station in early 2006. It has recently been recognized that the end stages of break-up of these icebergs can imitate the rapid disintegrations due to melt ponding and surface fracturing observed for the Larsen A and Larsen B ice shelves. However, in some cases, basal melting may play a significant role in shelf break-up. Resolving the processes (surface ponding/ fracturing versus basal melt) and observing other processes of iceberg drift and break up in-situ are of high scientific interest. An understanding of the mechanisms that lead to the distintegration of icebergs as they drift north may enable scientists to use icebergs as proxies for understanding the processes that could cause ice shelves to disintegrate in a warming climate. A broader impact would thus be an ability to predict ice shelf disintegration in a warming world. Glacier mass balance and ice shelf stability are of critical importance to sea level change, which also has broader societal relevance.
9909436 <br/>Farley<br/><br/>This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports an investigation of the uplift history of the Dry Valleys segment of the Transantarctic Mountains. The overall goal is to further constrain the exhumation history of the Transantarctic Mountains by using the newly developed apatite (U-Th)/He dating method on samples collected in vertical profiles. This approach, combined with existing apatite fission track information will constrain the rate and patterns of exhumation across the Transantarctic Mountains since their inception as a rift-flank uplift in the early Cenozoic.<br/><br/>This project will complement other projects and build on previous interpretations of the exhumation and tectonic history determined using apatite fission track thermochronology. It will bridge the gap between information on erosion rates determined from fission track thermochronology and from cosmogenic surface exposure dating and integrate the exhumation history of the mountains with their landscape evolution. As such, the results from this project will address an outstanding problem in Antarctic science; namely the stability of the East Antarctic Ice Sheet, and the timing of the transition from a "warm" dynamic ice sheet to a cold polar ice sheet. Highly relevant to this issue is the landscape evolution of the Transantarctic Mountains because many diverse lines of evidence for the rate of landscape evolution have been used to argue for a dynamic ice sheet up until either the Pliocene (the "dynamic" ice sheet model) or the middle Miocene (the "stable" ice sheet model). Understanding the past stability or dynamic fluctuations of the East Antarctic ice sheet with respect to the climate record is, of course, important for understanding how the present ice sheet may respond to global warming.<br/><br/>The specific objective of this project is to determine apatite (U-Th)/He age versus elevation trends for a number of vertical profiles from locations within the Transantarctic Mountain front and across the structural grain of the range. Fission track data already exist for all of these profiles, with apatite fission track ages ranging from 150-30 Ma. The greater precision of the (U-Th)/He technique and the fact it records information at lower temperatures (closure temperature of ~70 degrees Celsius; limits of 40-85 degrees Celsius for the He partial retention zone) will allow examination of the exhumation history of the TAM in more detail from ca 130 Ma to ~20 Ma. Another facet is to examine areas where Cretaceous exhumation is recorded and areas where the fission track profiles indicate periods of thermal and tectonic stability and minimal erosion throughout the Cretaceous. The variation of timing of the onset of more rapid exhumation accompanying uplift and formation of the Transantarctic Mountains in the early Cenozoic will also be examined.
Ice streams are believed to play a major role in determining the response of their parent ice sheet to climate change, and in determining global sea level by serving as regulators on the fresh water stored in the ice sheets. Ice streams are characterized by rapid, laterally confined flow which makes them uniquely identifiable within the body of the more slowly and more homogeneously flowing ice sheet. But while these characteristics enable the identification of ice streams, the processes which control ice-stream motion and evolution, and differences among ice streams in the polar regions, are only partially understood. Understanding the relative importance of lateral and basal drags, as well as the role of gradients in longitudinal stress, is essential for developing models for future evolution of the polar ice<br/>sheets. In this project, physical statistical models will be used to explore the processes that control ice-stream flow, and to compare these processes between seemingly different ice-stream systems. In particular, Whillans Ice Stream draining into the Ross Ice Shelf, will be compared with Recovery and RAMP glaciers draining into the Ronne-Filchner Ice Shelf, and the Northeast Ice Stream in Greenland. Geophysical models lie at the core of the approach, but are embellished by modeling various components of variability statistically. One important component comes from the uncertainty in observations on basal elevation, surface elevation, and surface velocity. In this project new observational data collected using remote-sensing techniques will be used. The various components, some of which are spatial, are combined hierarchically using Bayesian statistical methodology. All these components will be combined mathematically into a physical statistical model that yields the posterior distribution for basal, longitudinal, and lateral stress fields, and velocity fields, conditional on the data. Inference based on this distribution will be carried out via Markov chain Monte Carlo techniques, to obtain estimates of these unknown fields along with uncertainty measures associated with them.
This award supports a two-year project to continue work developing the techniques to make carbon monoxide (CO) measurements in ice core samples. Carbon monoxide is an important atmospheric chemical constituent as it is a primary sink for hydroxyl radical (OH) (and therefore influences the oxidizing capacity of the atmosphere) and because the concentrations of three major greenhouses gases , carbon dioxide (CO2), methane (CH4) and ozone (O3) are directly tied to the concentration of CO. In light of recent anthropogenic increases in the emissions of CO, CO2, CH4 and NOx, it is desirable to understand this complex chemical system and the changes in the greenhouse forcing resulting from perturbation. Because it is difficult to test the accuracy of models for past and future conditions for which no direct atmospheric measurements of trace gas concentrations are available these measurements must be obtained in other ways. Polar ice cores provide a means to make these measurements. Further work is necessary to refine the analytical technique and additional measurements are necessary to investigate the accuracy of these results and to establish the nature of temporal trends in CO. It is anticipated that the CO record, combined with existing or new data for CO2, CH4 , N2O and other paleoclimate variables, will provide further constraints on model studies of the effect of changing atmospheric chemistry on greenhouse forcing.
Kanagaratnam, Pannirselvam; Braaten, David; Bauer, Rob
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This award supports a project to build and test a 12-18 GHz radar system with a plane wave antenna. This is a wideband radar operating over a frequency range of 12 to 18 GHz to detect near-surface internal firn layers of the ice sheet with better than 10 cm resolution to a depth of approximately 7 m. These measurements will allow determination of spatially continuous snow accumulation rate in the firn, which would be useful along a traverse and is of critical importance to the validation of CryoSat and ICESAT satellite missions aimed at assessing the current state of mass balance of the polar ice sheets. The antenna system planned for the radar is relatively compact, and will be located on the sledge carrying the radar systems. The broad scientific focus of this project will be to investigate important glacial processes relevant to ice sheet mass balance. The new radar will allow the characterization (with high depth resolution) of the spatial variability of snow accumulation rate along a traverse route for interpreting data from CryoSat and ICESAT missions. As part of this project, we will institute a strong outreach program involving K-12 education and a minority institution of higher education. We currently work closely with the Advanced Learning Technology Program (ALTec) at the University of Kansas to develop interactive, resource-based lessons for use on-line by students of all grade levels, and we will develop new resources related to this project. We currently have an active research and education collaboration with faculty and undergraduate students at neighboring Haskell Indian Nations University, in Lawrence, Kansas, and we will expand our collaboration to include this project.
This award supports a three-year renewal project to complete measurement of cosmogenic nuclides in the Siple Dome ice core as part of the West Antarctic ice core program. The investigators will continue to measure profiles of Beryllium-10 (half-life = 1.5x10 6 years) and Chlorine-36 (half-life = 3.0x10 5 years) in the entire ice core which spans the time period from the present to about 100 kyr. It will be particularly instructive to compare the Antarctic record with the detailed Arctic record that was measured by these investigators as part of the GISP2 project. This comparison will help separate global from local effects at the different drill sites. Cosmogenic radionuclides in polar ice cores have been used to study the long-term variations in several important geophysical variables, including solar activity, geomagnetic field strength, atmospheric circulation, snow accumulation rates, and others. The time series of nuclide concentrations resulting from this work will be applied to several problem areas: perfecting the ice core chronology, deducing the history of solar activity, deducing the history of variations in the geomagnetic field, and studying the possible role of solar variations on climate. Comparison of Beryllium-10 and Chlorine-36 profiles in different cores will allow us to improve the ice core chronology and directly compare ice cores from different regions of the globe. Additional comparison with the Carbon-14 record will allow correlation of the ice core paleoenvironment record to other, Carbon-14 dated, paleoclimate records.
This award, provided by the Antarctic Geology and Geophysics Program of the Office of Polar Programs, supports a project to investigate the Transantarctic Mountains and an adjacent region of East Antarctica. The East Antarctic shield is one of Earth's oldest and largest cratonic assemblies, with a long-lived Archean to early Paleozoic history. Long-standing interest in the geologic evolution of this shield has been rekindled over the past decade by tectonic models linking East Antarctica with other Precambrian crustal elements in the Rodinia and Gondwanaland supercontinents. It is postulated that the Pacific margin of East Antarctica was rifted from Laurentia during late Neoproterozoic breakup of Rodinia, and it then developed as an active plate boundary during subsequent amalgamation of Gondwanaland in the earliest Paleozoic. If true, the East Antarctic shield played a key role in supercontinent transformation at a time of global changes in plate configuration, terrestrial surficial process, sea level, and marine geochemistry and biota. A better understanding of the geological evolution of the East Antarctic shield is therefore critical for studying Precambrian crustal evolution in general, as well as resource distribution, biosphere evolution, and glacial and climate history during later periods of Earth history. Because of nearly complete coverage by the polar ice cap, however, Antarctica remains the single most geologically unexplored continent. Exposures of cratonic basement are largely limited to coastal outcrops in George V Land and Terre Adelie (Australian sector), the Prince Charles Mountains and Enderby Land (Indian sector), and Queen Maud Land (African sector), where the geology is reasonably well-known. By contrast, little is known about the composition and structure of the shield interior. Given the extensive ice cover, collection of airborne geophysical data is the most cost-effective method to characterize broad areas of sub-ice basement and expand our knowledge of the East Antarctic shield interior. <br/><br/>This project will conduct an airborne magnetic survey (coupled with ground-based gravity measurements) across an important window into the shield where it is exposed in the Nimrod Glacier area of the central Transantarctic Mountains. Specific goals are to:<br/>1. Characterize the magnetic and gravity signature of East Antarctic crustal basement exposed at the Ross margin (Nimrod Group),<br/>2. Extend the magnetic data westward along a corridor across the polar ice cap in order to image the crust in ice-covered areas,<br/>3. Obtain magnetic data over the Ross Orogen in order to image the ice-covered boundary between basement and supracrustal rocks, allowing us to better constrain the geometry of fundamental Ross structures, and<br/>4. Use the shape, trends, wavelengths, and amplitudes of magnetic anomalies to define magnetic domains in the shield, common building blocks for continent-scale studies of Precambrian geologic structure and evolution.<br/><br/>High-resolution airborne magnetic data will be collected along a transect extending from exposed rocks of the Nimrod Group across the adjacent polar ice cap. The Nimrod Group represents the only bona fide Archean-Proterozoic shield basement exposed for over 2500 km of the Pacific margin of Antarctica. This survey will characterize the geologically well-known shield terrain in this sector using geophysical methods for the first time. This baseline over the exposed shield will allow for better interpretation of geophysical patterns in other ice-covered regions and can be used to target future investigations. In collaboration with colleagues from the BGR (Germany), a tightly-spaced, "draped" helicopter magnetic survey will be flown during the 2003-04 austral summer, to be complemented by ground measurements of gravity over the exposed basement. Data reduction, interpretation and geological correlation will be completed in the second year. This project will enhance the education of students, the advancement of under-represented groups, the research instrumentation of the U.S. Antarctic Program, partnerships between the federal government and institutions of higher education, and cooperation between national research programs. It will benefit society through the creation of new basic knowledge about the Antarctic continent, which in turn may help with applied research in other fields such as the glacial history of Antarctica.
This award is for support of a study to establish a quantitative nuclear method for determination of Antarctic ablation and accumulation rates and to provide correction factors for the carbon 14 ages of ice samples dated using trapped carbon 14. Recent studies have established the presence of cosmogenic in-situ produced carbon 14 in polar ice. In conjunction with estimated carbon 14 production rates, measured concentrations of carbon 14 per gram of ice yield, ablation rates which are in good agreement with the values determined from stake measurements. Similar studies to determine accumulation rates have been tested and the estimates are consistent with previous studies. This study will expand the preliminary work done to date in order to improve the 14CO and 14CO2 vacuum extraction techniques, by lowering blank levels and by obtaining more complete separation of 14CO and 14CO2.
This award supports a two year project to analyze shallow (~150 m) ice cores from South Pole in order to construct an annually resolved, sulfate-based volcanic record covering the last 1400 years. Two shallow ice cores will be recovered at the South Pole during the 00/01 field season and will be used for this work. Volcanic records from polar ice cores provide valuable information for studies of the connection between volcanism and climate. The new records are expected to be continuous and to cover at least the last 1400 years. The information from these records will verify the volcanic events found in the few existing Antarctic records and resolve discrepancies in the timing and magnitude of major explosive eruptions <br/>determined from those earlier records. In order to achieve the objectives of the proposed research, funds are provided to assist with the construction of an analytical laboratory for ice core and environmental <br/>chemistry research.
This award supports a project to examine the physical processes that affect the manner in which heat, vapor and chemical species in air are incorporated into snow and polar firn. The processes include advection, diffusion, and the effects of solar radiation penetration into the snow. An understanding of these processes is important because they control the rate at which reactive and non-reactive chemical species in the atmosphere become incorporated into the snow, firn, and polar ice, and thus will affect interpretation of polar ice core data. Currently, the interpretation of polar ice core data assumes that diffusion controls the rate at which chemical species are incorporated into firn. This project will determine whether ventilation, or advection of the species by air movement in the firn, and radiation penetration processes have a significant effect. Field studies at the two West Antarctic ice sheet deep drilling sites will be conducted to determine the spatial and temporal extent for key parameters, and boundary conditions needed to model the advection, conduction, and radiation transmission/absorption processes. An existing multidimensional numerical model is being expanded to simulate the processes and to serve as the basis for ongoing and future work in transport and distribution of reactive chemical species.