{"dp_type": "Project", "free_text": "Pollutants"}
[{"awards": "1542723 Alexander, Becky", "bounds_geometry": "POINT(-112.05 -79.28)", "dataset_titles": "WAIS Divide ice core nitrate isotopes", "datasets": [{"dataset_uid": "601456", "doi": "10.15784/601456", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Chemistry; Ice Core Records; Nitrate; Nitrate Isotopes; WAIS Divide Ice Core; West Antarctic Ice Sheet", "people": "Alexander, Becky", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide ice core nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601456"}], "date_created": "Mon, 13 Feb 2023 00:00:00 GMT", "description": "The Earth\u0027s atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate.\u003cbr/\u003e\u003cbr/\u003eThis award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA.", "east": -112.05, "geometry": "POINT(-112.05 -79.28)", "instruments": null, "is_usap_dc": true, "keywords": "Nitrate Isotopes; ICE CORE RECORDS; WAIS Divide; LABORATORY", "locations": "WAIS Divide", "north": -79.28, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -79.28, "title": "Measuring an Ice-core Proxy for Relative Oxidant Abundances over Glacial-interglacial and Rapid Climate changes in a West Antarctic Ice Core", "uid": "p0010403", "west": -112.05}, {"awards": "1643716 Buizert, Christo; 1643664 Severinghaus, Jeffrey; 1643669 Petrenko, Vasilii", "bounds_geometry": "POLYGON((112 -66,112.2 -66,112.4 -66,112.6 -66,112.8 -66,113 -66,113.2 -66,113.4 -66,113.6 -66,113.8 -66,114 -66,114 -66.1,114 -66.2,114 -66.3,114 -66.4,114 -66.5,114 -66.6,114 -66.7,114 -66.8,114 -66.9,114 -67,113.8 -67,113.6 -67,113.4 -67,113.2 -67,113 -67,112.8 -67,112.6 -67,112.4 -67,112.2 -67,112 -67,112 -66.9,112 -66.8,112 -66.7,112 -66.6,112 -66.5,112 -66.4,112 -66.3,112 -66.2,112 -66.1,112 -66))", "dataset_titles": "Concentration and isotopic composition of atmospheric N2O over the last century; Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2; Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy; Law Dome firn air and ice core 14CO concentration", "datasets": [{"dataset_uid": "601693", "doi": "10.15784/601693", "keywords": "Antarctic; Antarctica; Anthropogenic Emission; Atmosphere; Greenhouse Gas; Greenland; Ice Core Data; Nitrification And Denitrification Processes; Nitrous Oxide; Site-Specific 15N Isotopomer; Styx Glacier", "people": "Joong Kim, Seong; Yoshida, Naohiro ; Toyoda, Sakae ; Buizert, Christo ; Langenfelds, Ray L ; Ghosh, Sambit; Etheridge, David; Ahn, Jinho ", "repository": "USAP-DC", "science_program": null, "title": "Concentration and isotopic composition of atmospheric N2O over the last century", "url": "https://www.usap-dc.org/view/dataset/601693"}, {"dataset_uid": "601846", "doi": "10.15784/601846", "keywords": "Antarctica; Carbon-14; Cryosphere; Firn Air; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; Law Dome; Snow/ice; Snow/Ice", "people": "Petrenko, Vasilii", "repository": "USAP-DC", "science_program": null, "title": "Law Dome firn air and ice core 14CO concentration", "url": "https://www.usap-dc.org/view/dataset/601846"}, {"dataset_uid": "601598", "doi": "10.15784/601598", "keywords": "Antarctica; Firn; Firn Density; Gravitational Settling; Inert Gases; Law Dome", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Law Dome DE08-OH firn air 15N, O2/N2, Ar/N2, 18O of O2", "url": "https://www.usap-dc.org/view/dataset/601598"}, {"dataset_uid": "601597", "doi": "10.15784/601597", "keywords": "Antarctica; Ice Core; Law Dome; Noble Gas", "people": "Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Law Dome DE08-OH site noble gases in ice: testing the 86Krexcess proxy", "url": "https://www.usap-dc.org/view/dataset/601597"}], "date_created": "Fri, 17 Jun 2022 00:00:00 GMT", "description": "Hydroxyl radicals are responsible for removal of most atmospheric trace gases, including pollutants and important greenhouse gases. They have been called the \"detergent of the atmosphere\". Changes in hydroxyl radical concentration in response to large changes in reactive trace gas emissions, which may happen in the future, are uncertain. This project aims to provide the first estimates of the variability of atmospheric hydroxyl radicals since about 1880 AD when anthropogenic emissions of reactive trace gases were minimal. This will improve understanding of their stability in response to large changes in emissions. The project will also investigate whether ice cores record past changes in Southern Hemisphere westerly winds. These winds are a key component of the global climate system, and have an important influence on ocean circulation and possibly on atmospheric carbon dioxide concentrations. The project team will include three early career scientists, a postdoctoral researcher, and graduate and undergraduate students, working in collaboration with senior scientists and Australian collaborators. \u003cbr/\u003e \u003cbr/\u003eFirn air and shallow ice to a depth of about 233 m will be sampled at the Law Dome high-accumulation coastal site in East Antarctica. Trapped air will be extracted from the ice cores on site immediately after drilling. Carbon-14 of carbon monoxide (14CO) will be analyzed in firn and ice-core air samples. Corrections will be made for the in situ cosmogenic 14CO component in the ice, allowing for the atmospheric 14CO history to be reconstructed. This 14CO history will be interpreted with the aid of a chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere hydroxyl radical concentration after about 1880 AD. An additional component of the project will analyze Krypton-86 in the firn-air and ice-core samples. These measurements will explore whether ice-core Krypton-86 acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere westerly winds.\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": 114.0, "geometry": "POINT(113 -66.5)", "instruments": null, "is_usap_dc": true, "keywords": "AMD; TRACE GASES/TRACE SPECIES; Law Dome; Amd/Us; USAP-DC; LABORATORY; ICE CORE AIR BUBBLES; USA/NSF", "locations": "Law Dome", "north": -66.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Petrenko, Vasilii; Murray, Lee T; Buizert, Christo; Petrenko, Vasilii; Murray, Lee T", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -67.0, "title": "Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability", "uid": "p0010341", "west": 112.0}, {"awards": "1543328 Van Mooy, Benjamin", "bounds_geometry": null, "dataset_titles": "Lipidomics of Antarctic waters. (TBD)", "datasets": [{"dataset_uid": "200149", "doi": "TBD", "keywords": null, "people": null, "repository": "BCO-DMO", "science_program": null, "title": "Lipidomics of Antarctic waters. (TBD)", "url": "https://www.bco-dmo.org/data"}], "date_created": "Fri, 19 Jun 2020 00:00:00 GMT", "description": "The depletion of stratospheric ozone over Antarctica leads to abnormally high levels of ultraviolet radiation (UVR) from the sun reaching the surface of the ocean. This phenomenon is predicted to continue for the next half century, despite bans on ozone-destroying pollutants. Phytoplankton in the near surface ocean are subjected to variable amounts of UVR and contain a lot of lipids (fats). Because phytoplankton are at the base of the food chain their lipids makes their way into the Antarctic marine ecosystem\u0027s food web. The molecular structures of phytoplankton lipids are easily altered by UVR. When this happens, their lipids can be transformed from healthy molecules into potentially harmful molecules(oxylipins) known to be disruptive to reproductive and developmental processes. This project will use state-of-the-art molecular methods to answer questions about extent to which UVR damages lipid molecules in phytoplankton, and how these resultant molecules might effect the food chain in the ocean near Antarctica. \u003cbr/\u003e\u003cbr/\u003e\u003cbr/\u003eLipid peroxidation is often invoked as consequence of increased exposure of phytoplankton to UVR-produced reactive oxygen species (ROS), but the literature is practically silent on peroxidized lipids and their byproducts (i.e. oxylipins) in the ocean. In waters of the West Antarctic Peninsula (WAP), spring-time blooms of diatoms contribute significantly to overall marine primary production. Oxylipins from diatoms can be highly bioactive; their impact on zooplankton grazers, bacteria, and other phytoplankton has been the subject of intense study. However, almost all of this work has focused on the production of oxylipins via enzymatic pathways, not by pathways involving UVR and/or ROS. Furthermore, rigorous experimental work on the effects of oxylipins has been confined almost exclusively to pure cultures and artificial communities. Thus, the true potential of these molecules to disrupt carbon cycling is very poorly-constrained, and is entirely unknown in the waters of the WAP. Armed with new highly-sensitive, state-of-the-art analytical techniques based on high-mass-resolution mass spectrometry, the principal investigator and his research group have begun to uncover an exquisite diversity of oxylipins in natural WAP planktonic communities. These techniques will be applied to understand the connections between UVR, ROS, oxylipins, and carbon cycling. The project will answer the question of how UVR, via ROS, affects oxylipin production by diatoms in WAP surface waters in controlled experiments conducted at a field station. With the answer to this question in hand, the project will also seek to answer how this phenomenon impacts the flow of carbon, particularly the export of organic carbon from the system, during a research cruise. The level of UVR-induced stresses experienced by oxylipin-rich planktonic communities in the WAP is unique, making Antarctica the only location for answering these fundamental questions. Major activities will include laboratory experiments with artificial membranes and diatom cultures, as well field experiments with phytoplankton, zooplankton, and bacteria in WAP waters.", "east": null, "geometry": null, "instruments": null, "is_usap_dc": true, "keywords": "Oxylipins; Palmer Station; UV Radiation; USAP-DC; West Antarctic Shelf; NOT APPLICABLE; AQUATIC SCIENCES; Phytoplankton", "locations": "West Antarctic Shelf; Palmer Station", "north": null, "nsf_funding_programs": "Antarctic Organisms and Ecosystems", "paleo_time": null, "persons": "Van Mooy, Benjamin", "platforms": "OTHER \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "repo": "BCO-DMO", "repositories": "BCO-DMO", "science_programs": null, "south": null, "title": "Production and Fate of Oxylipins in Waters of the Western Antarctic Peninsula: Linkages Between UV Radiation, Lipid Peroxidation, and Carbon Cycling", "uid": "p0010109", "west": null}, {"awards": "0538049 Steig, Eric; 0538520 Thiemens, Mark", "bounds_geometry": "POINT(-112.085 -79.5)", "dataset_titles": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core; WAIS Divide sulfate and nitrate isotopes; WAIS ice core isotope data #387, 385 (full data link not provided)", "datasets": [{"dataset_uid": "609479", "doi": "10.7265/N5BG2KXH", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Thiemens, Mark H.", "repository": "USAP-DC", "science_program": null, "title": "Multiple Isotope Analysis of Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609479"}, {"dataset_uid": "601007", "doi": "10.15784/601007", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Nitrate; Oxygen Isotope; Sulfate; WAIS Divide; WAIS Divide Ice Core", "people": "Alexander, Becky; Steig, Eric J.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS Divide sulfate and nitrate isotopes", "url": "https://www.usap-dc.org/view/dataset/601007"}, {"dataset_uid": "002512", "doi": "", "keywords": null, "people": null, "repository": "Project website", "science_program": null, "title": "WAIS ice core isotope data #387, 385 (full data link not provided)", "url": "http://www.waisdivide.unh.edu/"}], "date_created": "Tue, 25 Apr 2017 00:00:00 GMT", "description": "0538520\u003cbr/\u003eThiemens\u003cbr/\u003eThis award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions.", "east": -112.085, "geometry": "POINT(-112.085 -79.5)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Isotope Ratios; Temperature; Sulfate; West Antarctic; Paleoatmosphere; LABORATORY; Ice Core; Ice Core Data; Mass Independent Fractionation; FIELD SURVEYS; Not provided; Accumulation Rate; Oxygen Isotope; FIELD INVESTIGATION; Ice Core Chemistry; Isotope", "locations": "West Antarctic", "north": -79.5, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Alexander, Becky; Steig, Eric J.; Thiemens, Mark H.", "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": "Project website; USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.5, "title": "Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core", "uid": "p0000020", "west": -112.085}, {"awards": "1332492 Lohmann, Rainer", "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": "Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food Web", "datasets": [{"dataset_uid": "600138", "doi": "10.15784/600138", "keywords": "Animal Tracking; Antarctica; Antarctic Peninsula; Atmosphere; Biota; Chemistry:fluid; Chemistry:Fluid; Human Dimensions; McMurdo Sound; Oceans; Palmer Station; Pollution; Ross Sea; Sample/collection Description; Sample/Collection Description; Seals; Southern Ocean; Weddell Sea", "people": "Lohmann, Rainer", "repository": "USAP-DC", "science_program": null, "title": "Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food Web", "url": "https://www.usap-dc.org/view/dataset/600138"}], "date_created": "Tue, 09 Jun 2015 00:00:00 GMT", "description": "Many persistent organic pollutants (POPs), though banned in the U.S. since the 1970s, remain in the environment and continue to reach hitherto pristine regions such as the Arctic and Antarctic. The overall goals of this RAPID project are to better understand the remobilization of POPs from melting glaciers in the Antarctic, and their transfer into the food-web. Legacy POPs have characteristic chemical signatures that will be used ascertain the origin of POPs in the Antarctic atmosphere and marine food-web. Samples that were collected in 2010 will be analyzed for a wide range of legacy POPs, and their behavior will be contrasted with results for emerging contaminants. The intellectual merit of the proposed research combines (a) the use of chemical signatures to assess whether melting glaciers are releasing legacy POPs back into the Antarctic marine ecosystem, and (b) a better understanding of the food-web dynamics of legacy POPs versus emerging organic pollutants.\u003cbr/\u003e\u003cbr/\u003eThe broader impacts of the proposed research project will include the training of the next generation of scientists through support for a graduate student and a postdoctoral scholar. As well, this work will result in a better understanding of the relationship between pollutants, trophic food web ecology and global climate change in the pristine Antarctic ecosystem.", "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 Organisms and Ecosystems", "paleo_time": null, "persons": "Lohmann, Rainer", "platforms": "Not provided", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "RAPID: Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food WEB", "uid": "p0000344", "west": -180.0}, {"awards": "0230288 Anastasio, Cort", "bounds_geometry": "POLYGON((123.30014 -75.093445,123.307404 -75.093445,123.314668 -75.093445,123.321932 -75.093445,123.329196 -75.093445,123.33646 -75.093445,123.343724 -75.093445,123.350988 -75.093445,123.358252 -75.093445,123.365516 -75.093445,123.37278 -75.093445,123.37278 -75.0952669,123.37278 -75.0970888,123.37278 -75.0989107,123.37278 -75.1007326,123.37278 -75.1025545,123.37278 -75.1043764,123.37278 -75.1061983,123.37278 -75.1080202,123.37278 -75.1098421,123.37278 -75.111664,123.365516 -75.111664,123.358252 -75.111664,123.350988 -75.111664,123.343724 -75.111664,123.33646 -75.111664,123.329196 -75.111664,123.321932 -75.111664,123.314668 -75.111664,123.307404 -75.111664,123.30014 -75.111664,123.30014 -75.1098421,123.30014 -75.1080202,123.30014 -75.1061983,123.30014 -75.1043764,123.30014 -75.1025545,123.30014 -75.1007326,123.30014 -75.0989107,123.30014 -75.0970888,123.30014 -75.0952669,123.30014 -75.093445))", "dataset_titles": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "datasets": [{"dataset_uid": "609519", "doi": "10.7265/N5MS3QP0", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Dome C Ice Core; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Physical Properties; Snow/ice; Snow/Ice", "people": "Anastasio, Cort; Robles, Tony", "repository": "USAP-DC", "science_program": "Dome C Ice Core", "title": "Light Absorption Coefficients for Soluble Species in Snow, Dome C, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609519"}], "date_created": "Wed, 07 Mar 2007 00:00:00 GMT", "description": "Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions.", "east": 123.37278, "geometry": "POINT(123.33646 -75.1025545)", "instruments": "EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e PHOTON/OPTICAL DETECTORS \u003e PHOTOMETERS \u003e SPECTROPHOTOMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e HPLC; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e ION CHROMATOGRAPHS", "is_usap_dc": true, "keywords": "Snow Chemistry; Antarctica; Snowpack Chemistry; Snow Samples; Hydrogen Peroxide; Snow Properties; Pollutants; Chemistry; Light Absorption; Antarctic; Chemical Species; Snow; East Antarctica; Organic Compounds; Photochemistry; LABORATORY", "locations": "Antarctica; East Antarctica; Antarctic", "north": -75.093445, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Anastasio, Cort; Robles, Tony", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Dome C Ice Core", "south": -75.111664, "title": "Laboratory Studies of Photochemistry in Antarctic Snow and Ice", "uid": "p0000175", "west": 123.30014}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||
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Measuring an Ice-core Proxy for Relative Oxidant Abundances over Glacial-interglacial and Rapid Climate changes in a West Antarctic Ice Core
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1542723 |
2023-02-13 | Alexander, Becky |
|
The Earth's atmosphere is a highly oxidizing medium. The abundance of oxidants such as ozone in the atmosphere strongly influences the concentrations of pollutants and greenhouse gases, with implications for human health and welfare. Because oxidants are not preserved in geological archives, knowledge of how oxidants have varied in the past under changing climate conditions is extremely limited. This award will measure a proxy for oxidant concentrations in a West Antarctic ice core over several major climate transitions over the past 50,000 years. These measurements will complement similar measurements from a Greenland ice core, which showed significant changes in atmospheric oxidants over major climate transitions covering this same time period. The addition of measurements from Antarctica will allow researchers to examine if the oxidant changes suggested by the Greenland ice core record are regional or global in scale. Knowledge of how oxidants vary naturally with climate will better inform predictions of the composition of the future atmosphere under a warming climate.<br/><br/>This award will support measurements of the isotopic composition of nitrate in a West Antarctic ice core as a proxy for oxidant concentrations in the past atmosphere. The nitrogen isotopes of nitrate provide information on the degree of preservation of nitrate in the ice core record, and thus aid in the interpretation of the observed variability in the observed nitrate concentrations and oxygen isotopes in ice core records. By providing information about the spatial scale of oxidant changes over abrupt climate change events during the last glacial period, this project may also improve our understanding of mechanisms driving these abrupt events. Insight from this project will prove valuable for forecasting the response of stratospheric circulation to climate change, which has large implications for climate feedbacks and tropospheric composition. In addition, the information gleaned from this project on the mechanisms and feedbacks during abrupt climate change events will help determine the likelihood of such rapid events occurring in the future, which would have dramatic impacts on humankind. This award will provide training for one graduate and one undergraduate student, and will support the development of a hands-on activity related to rapid climate change to be used at the annual Polar Science Weekend at the Pacific Science Center in Seattle, WA. | POINT(-112.05 -79.28) | POINT(-112.05 -79.28) | false | false | |||
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability
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1643716 1643664 1643669 |
2022-06-17 | Petrenko, Vasilii; Murray, Lee T; Buizert, Christo; Petrenko, Vasilii; Murray, Lee T | Hydroxyl radicals are responsible for removal of most atmospheric trace gases, including pollutants and important greenhouse gases. They have been called the "detergent of the atmosphere". Changes in hydroxyl radical concentration in response to large changes in reactive trace gas emissions, which may happen in the future, are uncertain. This project aims to provide the first estimates of the variability of atmospheric hydroxyl radicals since about 1880 AD when anthropogenic emissions of reactive trace gases were minimal. This will improve understanding of their stability in response to large changes in emissions. The project will also investigate whether ice cores record past changes in Southern Hemisphere westerly winds. These winds are a key component of the global climate system, and have an important influence on ocean circulation and possibly on atmospheric carbon dioxide concentrations. The project team will include three early career scientists, a postdoctoral researcher, and graduate and undergraduate students, working in collaboration with senior scientists and Australian collaborators. <br/> <br/>Firn air and shallow ice to a depth of about 233 m will be sampled at the Law Dome high-accumulation coastal site in East Antarctica. Trapped air will be extracted from the ice cores on site immediately after drilling. Carbon-14 of carbon monoxide (14CO) will be analyzed in firn and ice-core air samples. Corrections will be made for the in situ cosmogenic 14CO component in the ice, allowing for the atmospheric 14CO history to be reconstructed. This 14CO history will be interpreted with the aid of a chemistry-transport model to place the first observational constraints on the variability of Southern Hemisphere hydroxyl radical concentration after about 1880 AD. An additional component of the project will analyze Krypton-86 in the firn-air and ice-core samples. These measurements will explore whether ice-core Krypton-86 acts as a proxy for barometric pressure variability, and whether this proxy can be used in Antarctic ice cores to infer past movement of the Southern Hemisphere westerly winds.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POLYGON((112 -66,112.2 -66,112.4 -66,112.6 -66,112.8 -66,113 -66,113.2 -66,113.4 -66,113.6 -66,113.8 -66,114 -66,114 -66.1,114 -66.2,114 -66.3,114 -66.4,114 -66.5,114 -66.6,114 -66.7,114 -66.8,114 -66.9,114 -67,113.8 -67,113.6 -67,113.4 -67,113.2 -67,113 -67,112.8 -67,112.6 -67,112.4 -67,112.2 -67,112 -67,112 -66.9,112 -66.8,112 -66.7,112 -66.6,112 -66.5,112 -66.4,112 -66.3,112 -66.2,112 -66.1,112 -66)) | POINT(113 -66.5) | false | false | ||||
Production and Fate of Oxylipins in Waters of the Western Antarctic Peninsula: Linkages Between UV Radiation, Lipid Peroxidation, and Carbon Cycling
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1543328 |
2020-06-19 | Van Mooy, Benjamin |
|
The depletion of stratospheric ozone over Antarctica leads to abnormally high levels of ultraviolet radiation (UVR) from the sun reaching the surface of the ocean. This phenomenon is predicted to continue for the next half century, despite bans on ozone-destroying pollutants. Phytoplankton in the near surface ocean are subjected to variable amounts of UVR and contain a lot of lipids (fats). Because phytoplankton are at the base of the food chain their lipids makes their way into the Antarctic marine ecosystem's food web. The molecular structures of phytoplankton lipids are easily altered by UVR. When this happens, their lipids can be transformed from healthy molecules into potentially harmful molecules(oxylipins) known to be disruptive to reproductive and developmental processes. This project will use state-of-the-art molecular methods to answer questions about extent to which UVR damages lipid molecules in phytoplankton, and how these resultant molecules might effect the food chain in the ocean near Antarctica. <br/><br/><br/>Lipid peroxidation is often invoked as consequence of increased exposure of phytoplankton to UVR-produced reactive oxygen species (ROS), but the literature is practically silent on peroxidized lipids and their byproducts (i.e. oxylipins) in the ocean. In waters of the West Antarctic Peninsula (WAP), spring-time blooms of diatoms contribute significantly to overall marine primary production. Oxylipins from diatoms can be highly bioactive; their impact on zooplankton grazers, bacteria, and other phytoplankton has been the subject of intense study. However, almost all of this work has focused on the production of oxylipins via enzymatic pathways, not by pathways involving UVR and/or ROS. Furthermore, rigorous experimental work on the effects of oxylipins has been confined almost exclusively to pure cultures and artificial communities. Thus, the true potential of these molecules to disrupt carbon cycling is very poorly-constrained, and is entirely unknown in the waters of the WAP. Armed with new highly-sensitive, state-of-the-art analytical techniques based on high-mass-resolution mass spectrometry, the principal investigator and his research group have begun to uncover an exquisite diversity of oxylipins in natural WAP planktonic communities. These techniques will be applied to understand the connections between UVR, ROS, oxylipins, and carbon cycling. The project will answer the question of how UVR, via ROS, affects oxylipin production by diatoms in WAP surface waters in controlled experiments conducted at a field station. With the answer to this question in hand, the project will also seek to answer how this phenomenon impacts the flow of carbon, particularly the export of organic carbon from the system, during a research cruise. The level of UVR-induced stresses experienced by oxylipin-rich planktonic communities in the WAP is unique, making Antarctica the only location for answering these fundamental questions. Major activities will include laboratory experiments with artificial membranes and diatom cultures, as well field experiments with phytoplankton, zooplankton, and bacteria in WAP waters. | None | None | false | false | |||
Collaborative Research: Multiple-isotope Analysis of Nitrate and Sulfate in the West Antarctic Ice Sheet Divide Ice Core
|
0538049 0538520 |
2017-04-25 | Alexander, Becky; Steig, Eric J.; Thiemens, Mark H. | 0538520<br/>Thiemens<br/>This award supports a project to develop the first complete record of multiple isotope ratios of nitrate and sulfate covering the last ~100,000 years, from the deep ice core planned for the central ice divide of the West Antarctic Ice Sheet (WAIS). The WAIS Divide ice core will be the highest resolution long ice core obtained from Antarctica and we can expect important complementary information to be available, including accurate knowledge of past accumulation rates, temperatures, and compounds such as H2O2, CO and CH4. These compounds play significant roles in global atmospheric chemistry and climate. Especially great potential lies in the use of multiple isotope signatures. The unique mass independent fractionation (MIF) 17O signature of ozone is observed in both nitrate and sulfate, due to the interaction of their precursors with ozone. The development of methods to measure the multiple-isotope composition of small samples of sulfate and nitrate makes continuous high resolution measurements on ice cores feasible for the first time. Recent work has shown that such measurements can be used to determine the hydroxyl radial (OH) and ozone (O3) concentrations in the paleoatmosphere as well as to apportion sulfate and nitrate sources. There is also considerable potential in using these isotope measurements to quantify post depositional changes. In the first two years, continuous measurements from the upper ~100-m of ice at WAIS divide will be obtained, to provide a detailed look at seasonal through centennial scale variability. In the third year, measurements will be made throughout the available depth of the deep core (expected to reach ~500 m at this time). The broader impacts of the project include applications to diverse fields including atmospheric chemistry, glaciology, meteorology, and paleoclimatology. Because nitrate and sulfate are important atmospheric pollutants, the results will also have direct and relevance to global environmental policy. This project will coincide with the International Polar Year (2007-2008), and contributes to goals of the IPY, which include the fostering of interdisciplinary research toward enhanced understanding of atmospheric chemistry and climate in the polar regions. | POINT(-112.085 -79.5) | POINT(-112.085 -79.5) | false | false | ||||
RAPID: Origin of Persistent Organic Pollutants in the Antarctic Atmosphere, Snow and Marine Food WEB
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1332492 |
2015-06-09 | Lohmann, Rainer |
|
Many persistent organic pollutants (POPs), though banned in the U.S. since the 1970s, remain in the environment and continue to reach hitherto pristine regions such as the Arctic and Antarctic. The overall goals of this RAPID project are to better understand the remobilization of POPs from melting glaciers in the Antarctic, and their transfer into the food-web. Legacy POPs have characteristic chemical signatures that will be used ascertain the origin of POPs in the Antarctic atmosphere and marine food-web. Samples that were collected in 2010 will be analyzed for a wide range of legacy POPs, and their behavior will be contrasted with results for emerging contaminants. The intellectual merit of the proposed research combines (a) the use of chemical signatures to assess whether melting glaciers are releasing legacy POPs back into the Antarctic marine ecosystem, and (b) a better understanding of the food-web dynamics of legacy POPs versus emerging organic pollutants.<br/><br/>The broader impacts of the proposed research project will include the training of the next generation of scientists through support for a graduate student and a postdoctoral scholar. As well, this work will result in a better understanding of the relationship between pollutants, trophic food web ecology and global climate change in the pristine Antarctic ecosystem. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | |||
Laboratory Studies of Photochemistry in Antarctic Snow and Ice
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0230288 |
2007-03-07 | Anastasio, Cort; Robles, Tony |
|
Photochemical reactions in snow can have important effects on the chemistry and composition of the snowpack as well as the overlying atmosphere. For example, recent measurements in the Antarctic and Arctic have revealed that sunlit snow releases a number of important pollutants to the atmosphere. Our ability to understand and model this chemistry is currently limited, in part because we lack fundamental photochemical information for a number of important chemical species in snow. This award supports research that will help fill this gap by characterizing the low-temperature photochemistry of three of these key species: nitrite (NO2-), nitrous acid (HNO2), and hydrogen peroxide (HOOH). We will measure quantum yields for these reactions on ice using a sensitive technique that we recently developed during a study of nitrate (NO3-) photochemistry. In addition to this basic research, we will also measure the rates of formation of hydroxyl radical (OH), nitrogen oxides (NOx), and HOOH in illuminated Antarctic snow samples. These measurements will be important inputs for future models, and will allow us to test whether known species (e.g., NO3-, NO2- and HNO2) are responsible for most of snowpack reactivity (e.g., OH formation). Overall, results from this award will significantly improve our ability to understand snowpack chemistry, and the resulting effects on the atmosphere, both in the Antarctic as well as in the many other regions with permanent or seasonal snow. These results will also strengthen efforts to use ice core records to monitor global change. In addition to these impacts, this award will help train students and a postdoctoral fellow, and results from this work will be integrated into two classes in order to expose students to some of the important issues facing polar regions. | POLYGON((123.30014 -75.093445,123.307404 -75.093445,123.314668 -75.093445,123.321932 -75.093445,123.329196 -75.093445,123.33646 -75.093445,123.343724 -75.093445,123.350988 -75.093445,123.358252 -75.093445,123.365516 -75.093445,123.37278 -75.093445,123.37278 -75.0952669,123.37278 -75.0970888,123.37278 -75.0989107,123.37278 -75.1007326,123.37278 -75.1025545,123.37278 -75.1043764,123.37278 -75.1061983,123.37278 -75.1080202,123.37278 -75.1098421,123.37278 -75.111664,123.365516 -75.111664,123.358252 -75.111664,123.350988 -75.111664,123.343724 -75.111664,123.33646 -75.111664,123.329196 -75.111664,123.321932 -75.111664,123.314668 -75.111664,123.307404 -75.111664,123.30014 -75.111664,123.30014 -75.1098421,123.30014 -75.1080202,123.30014 -75.1061983,123.30014 -75.1043764,123.30014 -75.1025545,123.30014 -75.1007326,123.30014 -75.0989107,123.30014 -75.0970888,123.30014 -75.0952669,123.30014 -75.093445)) | POINT(123.33646 -75.1025545) | false | false |