{"dp_type": "Project", "free_text": "air samples"}
[{"awards": "1903681 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": "Final N2O isotopic data including isotopomer ratios for the last deglaciation and Heinrich Stadia 4/Dansgaard Oeschger Event 8; Preliminary nitrous oxide site preference isotopic data for last deglaciation from Taylor Glacier", "datasets": [{"dataset_uid": "601803", "doi": "10.15784/601803", "keywords": "Antarctica; Cryosphere; Ice Core; Nitrous Oxide; Taylor Glacier", "people": "Menking, Andy; Brook, Edward J.", "repository": "USAP-DC", "science_program": null, "title": "Final N2O isotopic data including isotopomer ratios for the last deglaciation and Heinrich Stadia 4/Dansgaard Oeschger Event 8", "url": "https://www.usap-dc.org/view/dataset/601803"}, {"dataset_uid": "601592", "doi": "10.15784/601592", "keywords": "Antarctica; Nitrous Oxide; Taylor Glacier", "people": "Brook, Edward J.; Menking, Andy", "repository": "USAP-DC", "science_program": null, "title": "Preliminary nitrous oxide site preference isotopic data for last deglaciation from Taylor Glacier", "url": "https://www.usap-dc.org/view/dataset/601592"}], "date_created": "Wed, 19 Jun 2024 00:00:00 GMT", "description": "The objective of this project was to understand why the nitrous oxide (N2O) content of the atmosphere was lower during the last ice age (about 20,000-100,000 years ago) than in the subsequent warm period (10,000 years ago to present) and why it fluctuated during climate changes within the ice age. Nitrous oxide is a greenhouse gas that contributes to modern global warming. It is thought that modern warming will in turn cause increases in natural sources of nitrous oxide from bacteria in soils and the ocean, creating a \"positive feedback.\" However, the amount these sources will increase is uncertain because the different ways that nitrous oxide are produced, and how sensitive they are to warmer climate, are not well known. This project measured a unique property of the nitrous oxide molecule in very large ancient air samples from a glacier in Antarctica. This method can distinguish between different microbial processes that produce nitrous oxide but it has not been applied yet to the time periods in question. The data provide information about how natural climate changes affect nitrous oxide production. This project developed two records of the intramolecular site preference of Nitrogen-15 in N2O. One record spans the last deglaciation (10,000-21,000 years ago) when atmospheric N2O concentration rose by 30 percent, and the other record spans millennial-scale climate changes during the last ice age when N2O varied by smaller amounts (Heinrich Stadial 4 and Dansgaard Oeschger 8, 35,000-41,000 years ago). The records will be used to understand what changes in the nitrogen cycle caused atmospheric N2O concentration to vary and what mechanisms link the N2O emissions to climate change. This work also allowed exploration of an isotopic tracer for in situ production of N2O that contaminates the atmospheric signal in particularly dusty ice. ", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Taylor Glacier; Nitrous Oxide; TRACE GASES/TRACE SPECIES; Ice Core; Stable Isotopes; NITROUS OXIDE", "locations": "Taylor Glacier", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Earth Sciences", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY", "persons": "Brook, Edward", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Deciphering Changes in Atmospheric Nitrous Oxide Concentration During the Last Ice Age Using the Intramolecular Site-Preference of Nitrogen Isotopes", "uid": "p0010465", "west": -180.0}, {"awards": "1643669 Petrenko, Vasilii; 1643664 Severinghaus, Jeffrey; 1643716 Buizert, Christo", "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": "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": "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"}, {"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": "Etheridge, David; Buizert, Christo ; Langenfelds, Ray L ; Ahn, Jinho ; Yoshida, Naohiro ; Joong Kim, Seong; Ghosh, Sambit; Toyoda, Sakae ", "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": "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"}], "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": "1543267 Brook, Edward J.; 1543229 Severinghaus, Jeffrey", "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": "Multi-site ice core Krypton stable isotope ratios; Noble Gas Data from recent ice in Antarctica for 86Kr problem", "datasets": [{"dataset_uid": "601195", "doi": "10.15784/601195", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Data; Krypton; Noble Gas; Xenon", "people": "Shackleton, Sarah; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Noble Gas Data from recent ice in Antarctica for 86Kr problem", "url": "https://www.usap-dc.org/view/dataset/601195"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Shackleton, Sarah; Brook, Edward J.; Etheridge, David; Buizert, Christo; Bereiter, Bernhard; Baggenstos, Daniel; Severinghaus, Jeffrey P.; Bertler, Nancy; Pyne, Rebecca L.; Mulvaney, Robert; Mosley-Thompson, Ellen", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Bereiter, Bernhard; Mosley-Thompson, Ellen; Mulvaney, Robert; Pyne, Rebecca L.; Bertler, Nancy; Etheridge, David; Baggenstos, Daniel; Brook, Edward J.; Severinghaus, Jeffrey P.; Shackleton, Sarah; Buizert, Christo", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}, {"dataset_uid": "601394", "doi": "10.15784/601394", "keywords": "Antarctica; Bruce Plateau; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Greenland Ice Cap; Ice Core; Ice Core Chemistry; Ice Core Records; James Ross Island; Krypton; Law Dome; Low Dome Ice Core; Roosevelt Island; Siple Dome; Siple Dome Ice Core; South Pole; SPICEcore; WAIS Divide; WAIS Divide Ice Core", "people": "Baggenstos, Daniel; Etheridge, David; Severinghaus, Jeffrey P.; Bereiter, Bernhard; Buizert, Christo; Pyne, Rebecca L.; Bertler, Nancy; Mulvaney, Robert; Brook, Edward J.; Mosley-Thompson, Ellen; Shackleton, Sarah", "repository": "USAP-DC", "science_program": "SPICEcore", "title": "Multi-site ice core Krypton stable isotope ratios", "url": "https://www.usap-dc.org/view/dataset/601394"}], "date_created": "Wed, 10 Jul 2019 00:00:00 GMT", "description": "Overview: The funded work investigated whether ice core 86Kr 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 (SH) westerly winds. Pressure variations drive macroscopic air movement in the firn column, which reduces the gravitational isotopic enrichment of slow-diffusing gases (such as Kr). The 86Kr deviation from gravitational equilibrium (denoted D86Kr) thus reflects the magnitude of pressure variations (among other things). Atmospheric reanalysis data suggest that pressure variability over Antarctica is linked to the Southern Annular Mode (SAM) index and the position of the SH westerly winds. Preliminary data from the WAIS Divide ice core show a large excursion in D86Kr during the last deglaciation (20-9 ka before present). In this project the investigators (1) performed high-precision 86Kr analysis on ice core and firn air samples to establish whether D86Kr is linked to pressure variability; (2) Refined the deglacial WAIS Divide record of Kr isotopes; (3) Investigated the role of pressure variability in firn air transport using firn air models with firn microtomography data and Lattice- Boltzmann modeling; and (4) Investigated how barometric pressure variability in Antarctica is linked to the SAM index and the position/strength of the SH westerlies in past and present climates using GCM and reanalysis data. A key finding was that D86Kr in recent ice samples (e.g. last 50 years) from a broad spatial array of sites in Antarctica and Greenland showed a significant correlation with directly measured barometric pressure variability at the ice core site. This strongly supports the hypothesis that 86Kr can be used as a paleo-proxy for storminess.\r\nIntellectual Merit: The SH westerlies are a key component of the global climate system; they are an important control on the global oceanic overturning circulation and possibly on atmospheric CO2 concentrations. Poleward movement of the SH westerlies during the last deglaciation has been hypothesized, yet evidence from proxy and modeling studies remains inconclusive. The funded work could provide valuable new constraints on deglacial movement of the SH westerlies. This record can be compared to high-resolution CO2 data from the same core, allowing us to test hypotheses that link CO2 to the SH westerlies. Climate proxies are at the heart of paleoclimate research. The funded work has apparently led to the discovery of a completely new proxy, opening up exciting new research possibilities and increasing the scientific value of existing ice cores. Once validated, the 86Kr proxy could be applied to other time periods as well, providing a long-term perspective on the movement of the SH westerlies. The funded work has furthermore provided valuable new insights into firn air transport. \r\n\r\nBroader impact: The Southern Ocean is presently an important sink of atmospheric CO2, thereby reducing the warming associated with anthropogenic CO2 emissions. Stratospheric ozone depletion and greenhouse warming have displaced the SH westerlies poleward, with potential consequences for the future magnitude of this oceanic carbon uptake. The funded work may provide a paleo-perspective on past movement of the SH westerlies and its link to atmospheric CO2, which could guide projections of future oceanic CO2 uptake, with strong societal benefits. The awarded funds supported and trained an early-career postdoctoral scholar at OSU, and fostered (international) collaboration. Data from the study will be available to the scientific community and the broad public through recognized data centers. During this project the PI and senior personnel have continued their commitment to public outreach through media interviews and speaking to schools and the public about their work. The PI provides services to the community by chairing the IPICS (International Partnership in Ice Core Sciences) working group and organizing annual PIRE (Partnerships in International Research and Education) workshops.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": "NOT APPLICABLE \u003e NOT APPLICABLE \u003e NOT APPLICABLE", "is_usap_dc": true, "keywords": "USA/NSF; FIRN; ICE CORE RECORDS; USAP-DC; Greenland; Xenon; Noble Gas; Ice Core; Amd/Us; Antarctica; AMD; LABORATORY; Krypton; ATMOSPHERIC PRESSURE", "locations": "Greenland; Antarctica", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Severinghaus, Jeffrey P.; Brook, Edward J.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last\r\ndeglaciation", "uid": "p0010037", "west": -180.0}, {"awards": "0739598 Aydin, Murat; 0739491 Sowers, Todd", "bounds_geometry": null, "dataset_titles": "Alkanes in Firn Air Samples, Antarctica and Greenland; Methane Isotopes in South Pole Firn Air, 2008", "datasets": [{"dataset_uid": "609502", "doi": "10.7265/N55T3HFP", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Isotope; Paleoclimate; Snow/ice; Snow/Ice; South Pole", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": null, "title": "Methane Isotopes in South Pole Firn Air, 2008", "url": "https://www.usap-dc.org/view/dataset/609502"}, {"dataset_uid": "609504", "doi": "10.7265/N5X9287C", "keywords": "Antarctica; Arctic; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Greenland; Snow/ice; Snow/Ice; South Pole; WAIS Divide", "people": "Saltzman, Eric; Aydin, Murat", "repository": "USAP-DC", "science_program": null, "title": "Alkanes in Firn Air Samples, Antarctica and Greenland", "url": "https://www.usap-dc.org/view/dataset/609504"}], "date_created": "Thu, 18 Aug 2011 00:00:00 GMT", "description": "This award supports a project to make measurements of methane and other trace gases in firn air collected at South Pole, Antarctica. The analyses will include: methane isotopes (delta-13CH4 and delta-DCH4), light non-methane hydrocarbons (ethane, propane, and n-butane), sulfur gases (COS, CS2), and methyl halides (CH3Cl and CH3Br). The atmospheric burdens of these trace gases reflect changes in atmospheric OH, biomass burning, biogenic activity in terrestrial, oceanic, and wetland ecosystems, and industrial/agricultural activity. The goal of this project is to develop atmospheric histories for these trace gases over the last century through examination of depth profiles of these gases in South Pole firn air. The project will involve two phases: 1) a field campaign at South Pole, Antarctica to drill two firn holes and fill a total of ~200 flasks from depths reaching 120 m, 2) analysis of firn air at University of California, Irvine, Penn State University, and several other collaborating laboratories. Atmospheric histories will be inferred from the measurements using a one dimensional advective/diffusive model of firn air transport. This study will provide new information about the recent changes in atmospheric levels of these gases, providing about a 90 year long time series record that connects the earlier surface and firn air measurements to present day. The project will also explore the possibility of in- situ production of light non-methane hydrocarbons in firn air that is relevant to the interpretation of ice core records. The broader impacts of this research are that it has the potential for significant societal impact by improving our understanding of climate change and man\u0027s input to the atmosphere. The results of this work will be disseminated through the peer review process, and will contribute to environmental assessments, such as the Inter-governmental Panel on Climate Change (IPCC) Climate Assessment and the Word Meteorological Organization (WMO) Stratospheric Ozone Assessment. This research will provide educational opportunities for graduate and undergraduate students, and will contribute to a teacher training program for K-12 teachers in minority school districts.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GC-MS", "is_usap_dc": true, "keywords": "FIELD INVESTIGATION; Isotope; Firn Air Chemistry; Firn Air Isotope Measurements; Not provided; LABORATORY; South Pole; Firn; Delta 13C; Carbon-13; Mass Spectrometer; Deuterium; Mass Spectrometry; Firn Air Samples; Carbon; Gas Chromatography; Polar Firn Air; GROUND-BASED OBSERVATIONS; Methane; Antarctica; Firn Air Isotopes; Delta Deuterium; FIELD SURVEYS; Firn Air; Chromatography; Methane Isotopes; Carbon Isotopes; Stable Isotopes", "locations": "Antarctica; South Pole", "north": null, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology", "paleo_time": null, "persons": "Aydin, Murat; Saltzman, Eric; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": null, "title": "Collaborative Research: Methane Isotopes, Hydrocarbons, and other Trace Gases in South Pole Firn Air", "uid": "p0000162", "west": null}, {"awards": "0440759 Sowers, Todd; 0440602 Saltzman, Eric; 0440701 Severinghaus, Jeffrey; 0440509 Battle, Mark; 0440498 White, James; 0440615 Brook, Edward J.", "bounds_geometry": "POINT(-112.085 -79.467)", "dataset_titles": "Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica; Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core; Methane Isotopes from the WAIS Divide Ice Core; Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A; WAIS ice core Methane Data, Carbon Dioxide Data", "datasets": [{"dataset_uid": "609638", "doi": "10.7265/N56971HF", "keywords": "Antarctica; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Temperature; WAIS Divide; WAIS Divide Ice Core", "people": "Orsi, Anais J.; Severinghaus, Jeffrey P.", "repository": "USAP-DC", "science_program": null, "title": "Surface Temperature Reconstruction from Borehole Temperature Measurement in WDC05A", "url": "https://www.usap-dc.org/view/dataset/609638"}, {"dataset_uid": "609412", "doi": "10.7265/N5251G40", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Snow/ice; Snow/Ice; WAIS Divide; WAIS Divide Ice Core", "people": "Saltzman, Eric", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Gases in Firn Air and Shallow Ice at the WAIS Drilling Site, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609412"}, {"dataset_uid": "609435", "doi": "10.7265/N5J67DW0", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Isotope; Methane; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Methane Isotopes from the WAIS Divide Ice Core", "url": "https://www.usap-dc.org/view/dataset/609435"}, {"dataset_uid": "609493", "doi": "10.7265/N5319SV3", "keywords": "Antarctica; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; WAIS Divide; WAIS Divide Ice Core", "people": "Mitchell, Logan E; McConnell, Joseph; Brook, Edward J.; Taylor, Kendrick C.; Sowers, Todd A.", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "WAIS ice core Methane Data, Carbon Dioxide Data", "url": "https://www.usap-dc.org/view/dataset/609493"}, {"dataset_uid": "601357", "doi": "10.15784/601357", "keywords": "Antarctica; Atmospheric Gases; Gas Measurement; Ice Core; Ice Core Gas Records; Trace Gases", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core", "url": "https://www.usap-dc.org/view/dataset/601357"}], "date_created": "Tue, 03 Feb 2009 00:00:00 GMT", "description": "This award supports a project to measure the elemental and isotopic composition of firn air and occluded air in shallow boreholes and ice cores from the WAIS Divide site, the location of a deep ice-coring program planned for 2006-07 and subsequent seasons. The three primary objectives are: 1) to establish the nature of firn air movement and trapping at the site to aid interpretations of gas data from the deep core; 2) to expand the suite of atmospheric trace gas species that can be measured in ice and replicate existing records of other species; and 3) to inter-calibrate all collaborating labs to insure that compositional and isotopic data sets are inter-comparable. The program will be initiated with a shallow drilling program during the 05/06 field season which will recover two 300+m cores and firn air samples. The ice core and firn air will provide more than 700 years of atmospheric history that will be used to address a number of important questions related to atmospheric change over this time period. The research team consists of six US laboratories that also plan to participate in the deep core program. This collaborative research program has a number of advantages. First, the scientists will be able to coordinate sample allocation a priori to maximize the resolution and overlap of records of interrelated species. Second, sample registration will be exact, allowing direct comparison of all records. Third, a coherent data set will be produced at the same time and all PI.s will participate in interpreting and publishing the results. This will insure that the best possible understanding of gas records at the WAIS Divide site will be achieved, and that all work necessary to interpret the deep core is conducted in a timely fashion. The collaborative structure created by the proposal will encourage sharing of techniques, equipment, and ideas between the laboratories. The research will identify impacts of various industrial/agricultural activities and help to distinguish them from natural variations, and will include species for which there are no long records of anthropogenic impact. The work will also help to predict future atmospheric loadings. The project will contribute to training scientists at several levels, including seven undergraduates, two graduate students and one post doctoral fellow.", "east": -112.085, "geometry": "POINT(-112.085 -79.467)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GC-MS; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e SPECTROMETERS/RADIOMETERS \u003e SPECTROMETERS \u003e SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e SAMPLERS \u003e BOTTLES/FLASKS/JARS \u003e FLASKS; IN SITU/LABORATORY INSTRUMENTS \u003e TEMPERATURE/HUMIDITY SENSORS \u003e THERMISTORS \u003e THERMISTORS", "is_usap_dc": true, "keywords": "Ice Core Chemistry; WAIS Divide; Firn; LABORATORY; Ice Core; Firn Air Isotope Measurements; Shallow Firn Air; FIELD INVESTIGATION; Ice Core Gas Records; GROUND-BASED OBSERVATIONS; Firn Isotopes; Wais Divide-project; Gas Data; Polar Firn Air; Not provided; Trace Gas Species; Trapped Gases; West Antarctic Ice Sheet; Deep Core; Ice Sheet; Gas; Firn Air Isotopes; FIELD SURVEYS; Air Samples; Atmospheric Gases; Isotope; Cores; Atmosphere; Ice Core Data; Surface Temperatures; Firn Air; Borehole; Antarctica", "locations": "West Antarctic Ice Sheet; Antarctica; WAIS Divide", "north": -79.467, "nsf_funding_programs": "Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology; Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE; PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Battle, Mark; Mischler, John; Saltzman, Eric; Aydin, Murat; White, James; Brook, Edward J.; Orsi, Anais J.; Severinghaus, Jeffrey P.; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "WAIS Divide Ice Core", "south": -79.467, "title": "Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site", "uid": "p0000368", "west": -112.085}, {"awards": "0338359 Saltzman, Eric", "bounds_geometry": "POINT(-148.81 -81.65)", "dataset_titles": "Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br); Antarctic Ice Cores: Methyl Chloride and Methyl Bromide; Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core; Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples", "datasets": [{"dataset_uid": "609131", "doi": "10.7265/N5P848VP", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Methane; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Methane and Carbonyl Sulfide Analysis of Siple Dome Ice Core Subsamples", "url": "https://www.usap-dc.org/view/dataset/609131"}, {"dataset_uid": "609279", "doi": "10.7265/N53B5X3G", "keywords": "Antarctica; Chemistry:ice; Chemistry:Ice; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core; WAISCORES", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Analysis of Siple Dome Ice Core: Carbonyl Sulfide (COS), Methyl Chloride (CH3Cl), and Methyl Bromide (CH3Br)", "url": "https://www.usap-dc.org/view/dataset/609279"}, {"dataset_uid": "609313", "doi": "10.7265/N5DN430Q", "keywords": "Antarctica; Atmosphere; Chemistry:fluid; Chemistry:Fluid; Geochemistry; Glaciers/ice Sheet; Glaciers/Ice Sheet; Glaciology; Ice Core; Ice Core Records; ITASE; Paleoclimate; Siple Dome Ice Core; South Pole; SPRESSO; SPRESSO Ice Core", "people": "Aydin, Murat; Williams, Margaret; Tatum, Cheryl; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Antarctic Ice Cores: Methyl Chloride and Methyl Bromide", "url": "https://www.usap-dc.org/view/dataset/609313"}, {"dataset_uid": "601357", "doi": "10.15784/601357", "keywords": "Antarctica; Atmospheric Gases; Gas Measurement; Ice Core; Ice Core Gas Records; Trace Gases", "people": "Aydin, Murat; Saltzman, Eric", "repository": "USAP-DC", "science_program": null, "title": "Ice Core Air Carbonyl Sulfide Measurements - SPRESSO Ice Core", "url": "https://www.usap-dc.org/view/dataset/601357"}], "date_created": "Wed, 16 Nov 2005 00:00:00 GMT", "description": "This award supports the analysis, in Antarctic ice cores, of the ozone depleting substances methyl bromide (CH3Br) and methyl chloride (CH3Cl), and the sulfur-containing gas, carbonyl sulfide (OCS). The broad scientific goal is to assess the level and variability of these gases in the preindustrial atmosphere. This information will allow testing of current models for sources and sinks of these gases from the atmosphere, and to indirectly assess the impact of anthropogenic activities on their biogeochemical cycles. Longer-term records will shed light on the climatic sensitivity of the atmospheric burden of these gases, and ultimately on the biogeochemical processes controlling them. These gases are present in ice at parts per trillion levels, and the current database consists entirely of a small number of measurements made in from a shallow ice core from Siple Dome, Antarctica. This project will involve studies of ice core samples from three Antarctic sites: Siple Station, Siple Dome, and South Pole. The sampling strategy is designed to accomplish several objectives: 1) to verify the atmospheric mixing ratios previously observed in shallow Siple Dome ice for OCS, CH3Br, and CH3Cl at sites with very different accumulation rates and surface temperatures; 2) to obtain a well-dated, high resolution record from a high accumulation rate site (Siple Station), that can provide overlap in mean gas age with Antarctic firn air samples; 3) explore Holocene variability in trace gas mixing ratios; and 4) to make the first measurements of these trace gases in Antarctic glacial ice. In terms of broader impact on society, this research will help to provide a stronger scientific basis for policy decisions regulating the production and use of ozone-depleting and climate-active gases. Specifically, the methyl bromide results will contribute to the current debate on the impact of recent regulation (via the Montreal Protocol and its Amendments) on atmospheric levels. Determination of pre-industrial atmospheric variability of ozone-depleting substances will help place more realistic constraints on scenarios used for future projections of stratospheric ozone and its climatic impacts. This research will involve the participation of both graduate and undergraduate students.", "east": -148.81, "geometry": "POINT(-148.81 -81.65)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; IN SITU/LABORATORY INSTRUMENTS \u003e CHEMICAL METERS/ANALYZERS \u003e GAS CHROMATOGRAPHS; IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES; 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 Gas Records; Carbonyl Sulfide; Siple Coast; Chloride; Trapped Gases; Snow; Ice Core Chemistry; Chromatography; Siple; GROUND STATIONS; Atmospheric Gases; Ozone Depletion; AWS Siple; Ice Sheet; Ice Core Data; Antarctica; Glaciology; West Antarctica; Atmospheric Chemistry; Ice Core; Stratigraphy; LABORATORY; Methane; Mass Spectrometer; GROUND-BASED OBSERVATIONS; WAISCORES; Msa; Mass Spectrometry; Not provided; Siple Dome; Gas Measurement", "locations": "Antarctica; Siple Coast; Siple Dome; West Antarctica; Siple", "north": -81.65, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Saltzman, Eric; Aydin, Murat; Williams, Margaret; Tatum, Cheryl", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS; Not provided; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.65, "title": "Methyl chloride and methyl bromide in Antarctic ice cores", "uid": "p0000032", "west": -148.81}, {"awards": "0125981 Sowers, Todd", "bounds_geometry": "POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83))", "dataset_titles": null, "datasets": null, "date_created": "Thu, 05 May 2005 00:00:00 GMT", "description": "0125981\u003cbr/\u003eSowers\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to construct an isotopic record of atmospheric methane and nitrous oxide over the last century from South Pole firn air. Over the last 150 years, atmospheric methane and nitrous oxide concentrations have risen in response to increased emissions from various anthropogenic activities. As this trend is liable to continue in the foreseeable future, it is important to understand the biogeochemical processes that contribute to the emissions of these two greenhouse gases. In this context, records of the variations in the atmospheric loading of trace gases found in ice cores and interstitial spaces in the snow near the surface of the ice sheet (firn air) provide fundamental boundary conditions for reconstructing historical emission records. One way to improve our understanding of the cycling of bioactive trace gases and their emission records is to use stable isotope tracers, which have been recorded in the ice cores and firn air. This project will develop records of carbon-13 and deuterium isotope ratios of methane, as well as the nitrogen-15, oxygen-18 and the isotopomer composition of nitrous oxide trapped in firn air samples collected in January 2001 at the South Pole. These measurements will allow isotopic records of these atmospheric gases to be reconstructed throughout the 20th century. Such records will help to establish the relative contribution of individual sources with a higher degree of confidence than is currently available.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": false, "keywords": "Not provided", "locations": null, "north": -62.83, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Sowers, Todd A.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -90.0, "title": "Generating an Isotopic Record of Atmospheric Methane and Nitrous Oxide Over the Last Century from South Pole Firn Air", "uid": "p0000086", "west": -180.0}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Deciphering Changes in Atmospheric Nitrous Oxide Concentration During the Last Ice Age Using the Intramolecular Site-Preference of Nitrogen Isotopes
|
1903681 |
2024-06-19 | Brook, Edward | The objective of this project was to understand why the nitrous oxide (N2O) content of the atmosphere was lower during the last ice age (about 20,000-100,000 years ago) than in the subsequent warm period (10,000 years ago to present) and why it fluctuated during climate changes within the ice age. Nitrous oxide is a greenhouse gas that contributes to modern global warming. It is thought that modern warming will in turn cause increases in natural sources of nitrous oxide from bacteria in soils and the ocean, creating a "positive feedback." However, the amount these sources will increase is uncertain because the different ways that nitrous oxide are produced, and how sensitive they are to warmer climate, are not well known. This project measured a unique property of the nitrous oxide molecule in very large ancient air samples from a glacier in Antarctica. This method can distinguish between different microbial processes that produce nitrous oxide but it has not been applied yet to the time periods in question. The data provide information about how natural climate changes affect nitrous oxide production. This project developed two records of the intramolecular site preference of Nitrogen-15 in N2O. One record spans the last deglaciation (10,000-21,000 years ago) when atmospheric N2O concentration rose by 30 percent, and the other record spans millennial-scale climate changes during the last ice age when N2O varied by smaller amounts (Heinrich Stadial 4 and Dansgaard Oeschger 8, 35,000-41,000 years ago). The records will be used to understand what changes in the nitrogen cycle caused atmospheric N2O concentration to vary and what mechanisms link the N2O emissions to climate change. This work also allowed exploration of an isotopic tracer for in situ production of N2O that contaminates the atmospheric signal in particularly dusty ice. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | ||||||
Collaborative Research: Reconstructing Carbon-14 of Atmospheric Carbon Monoxide from Law Dome, Antarctica to Constrain Long-Term Hydroxyl Radical Variability
|
1643669 1643664 1643716 |
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 | ||||||
Collaborative research: Kr-86 as a proxy for barometric pressure variability and movement of the SH westerlies during the last
deglaciation
|
1543267 1543229 |
2019-07-10 | Severinghaus, Jeffrey P.; Brook, Edward J. | Overview: The funded work investigated whether ice core 86Kr 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 (SH) westerly winds. Pressure variations drive macroscopic air movement in the firn column, which reduces the gravitational isotopic enrichment of slow-diffusing gases (such as Kr). The 86Kr deviation from gravitational equilibrium (denoted D86Kr) thus reflects the magnitude of pressure variations (among other things). Atmospheric reanalysis data suggest that pressure variability over Antarctica is linked to the Southern Annular Mode (SAM) index and the position of the SH westerly winds. Preliminary data from the WAIS Divide ice core show a large excursion in D86Kr during the last deglaciation (20-9 ka before present). In this project the investigators (1) performed high-precision 86Kr analysis on ice core and firn air samples to establish whether D86Kr is linked to pressure variability; (2) Refined the deglacial WAIS Divide record of Kr isotopes; (3) Investigated the role of pressure variability in firn air transport using firn air models with firn microtomography data and Lattice- Boltzmann modeling; and (4) Investigated how barometric pressure variability in Antarctica is linked to the SAM index and the position/strength of the SH westerlies in past and present climates using GCM and reanalysis data. A key finding was that D86Kr in recent ice samples (e.g. last 50 years) from a broad spatial array of sites in Antarctica and Greenland showed a significant correlation with directly measured barometric pressure variability at the ice core site. This strongly supports the hypothesis that 86Kr can be used as a paleo-proxy for storminess. Intellectual Merit: The SH westerlies are a key component of the global climate system; they are an important control on the global oceanic overturning circulation and possibly on atmospheric CO2 concentrations. Poleward movement of the SH westerlies during the last deglaciation has been hypothesized, yet evidence from proxy and modeling studies remains inconclusive. The funded work could provide valuable new constraints on deglacial movement of the SH westerlies. This record can be compared to high-resolution CO2 data from the same core, allowing us to test hypotheses that link CO2 to the SH westerlies. Climate proxies are at the heart of paleoclimate research. The funded work has apparently led to the discovery of a completely new proxy, opening up exciting new research possibilities and increasing the scientific value of existing ice cores. Once validated, the 86Kr proxy could be applied to other time periods as well, providing a long-term perspective on the movement of the SH westerlies. The funded work has furthermore provided valuable new insights into firn air transport. Broader impact: The Southern Ocean is presently an important sink of atmospheric CO2, thereby reducing the warming associated with anthropogenic CO2 emissions. Stratospheric ozone depletion and greenhouse warming have displaced the SH westerlies poleward, with potential consequences for the future magnitude of this oceanic carbon uptake. The funded work may provide a paleo-perspective on past movement of the SH westerlies and its link to atmospheric CO2, which could guide projections of future oceanic CO2 uptake, with strong societal benefits. The awarded funds supported and trained an early-career postdoctoral scholar at OSU, and fostered (international) collaboration. Data from the study will be available to the scientific community and the broad public through recognized data centers. During this project the PI and senior personnel have continued their commitment to public outreach through media interviews and speaking to schools and the public about their work. The PI provides services to the community by chairing the IPICS (International Partnership in Ice Core Sciences) working group and organizing annual PIRE (Partnerships in International Research and Education) workshops. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | ||||||
Collaborative Research: Methane Isotopes, Hydrocarbons, and other Trace Gases in South Pole Firn Air
|
0739598 0739491 |
2011-08-18 | Aydin, Murat; Saltzman, Eric; Sowers, Todd A. |
|
This award supports a project to make measurements of methane and other trace gases in firn air collected at South Pole, Antarctica. The analyses will include: methane isotopes (delta-13CH4 and delta-DCH4), light non-methane hydrocarbons (ethane, propane, and n-butane), sulfur gases (COS, CS2), and methyl halides (CH3Cl and CH3Br). The atmospheric burdens of these trace gases reflect changes in atmospheric OH, biomass burning, biogenic activity in terrestrial, oceanic, and wetland ecosystems, and industrial/agricultural activity. The goal of this project is to develop atmospheric histories for these trace gases over the last century through examination of depth profiles of these gases in South Pole firn air. The project will involve two phases: 1) a field campaign at South Pole, Antarctica to drill two firn holes and fill a total of ~200 flasks from depths reaching 120 m, 2) analysis of firn air at University of California, Irvine, Penn State University, and several other collaborating laboratories. Atmospheric histories will be inferred from the measurements using a one dimensional advective/diffusive model of firn air transport. This study will provide new information about the recent changes in atmospheric levels of these gases, providing about a 90 year long time series record that connects the earlier surface and firn air measurements to present day. The project will also explore the possibility of in- situ production of light non-methane hydrocarbons in firn air that is relevant to the interpretation of ice core records. The broader impacts of this research are that it has the potential for significant societal impact by improving our understanding of climate change and man's input to the atmosphere. The results of this work will be disseminated through the peer review process, and will contribute to environmental assessments, such as the Inter-governmental Panel on Climate Change (IPCC) Climate Assessment and the Word Meteorological Organization (WMO) Stratospheric Ozone Assessment. This research will provide educational opportunities for graduate and undergraduate students, and will contribute to a teacher training program for K-12 teachers in minority school districts. | None | None | false | false | |||||
Collaborative Research: Gases in Firn Air and Shallow Ice at the Proposed WAIS Divide Drilling Site
|
0440759 0440602 0440701 0440509 0440498 0440615 |
2009-02-03 | Battle, Mark; Mischler, John; Saltzman, Eric; Aydin, Murat; White, James; Brook, Edward J.; Orsi, Anais J.; Severinghaus, Jeffrey P.; Sowers, Todd A. | This award supports a project to measure the elemental and isotopic composition of firn air and occluded air in shallow boreholes and ice cores from the WAIS Divide site, the location of a deep ice-coring program planned for 2006-07 and subsequent seasons. The three primary objectives are: 1) to establish the nature of firn air movement and trapping at the site to aid interpretations of gas data from the deep core; 2) to expand the suite of atmospheric trace gas species that can be measured in ice and replicate existing records of other species; and 3) to inter-calibrate all collaborating labs to insure that compositional and isotopic data sets are inter-comparable. The program will be initiated with a shallow drilling program during the 05/06 field season which will recover two 300+m cores and firn air samples. The ice core and firn air will provide more than 700 years of atmospheric history that will be used to address a number of important questions related to atmospheric change over this time period. The research team consists of six US laboratories that also plan to participate in the deep core program. This collaborative research program has a number of advantages. First, the scientists will be able to coordinate sample allocation a priori to maximize the resolution and overlap of records of interrelated species. Second, sample registration will be exact, allowing direct comparison of all records. Third, a coherent data set will be produced at the same time and all PI.s will participate in interpreting and publishing the results. This will insure that the best possible understanding of gas records at the WAIS Divide site will be achieved, and that all work necessary to interpret the deep core is conducted in a timely fashion. The collaborative structure created by the proposal will encourage sharing of techniques, equipment, and ideas between the laboratories. The research will identify impacts of various industrial/agricultural activities and help to distinguish them from natural variations, and will include species for which there are no long records of anthropogenic impact. The work will also help to predict future atmospheric loadings. The project will contribute to training scientists at several levels, including seven undergraduates, two graduate students and one post doctoral fellow. | POINT(-112.085 -79.467) | POINT(-112.085 -79.467) | false | false | ||||||
Methyl chloride and methyl bromide in Antarctic ice cores
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0338359 |
2005-11-16 | Saltzman, Eric; Aydin, Murat; Williams, Margaret; Tatum, Cheryl | This award supports the analysis, in Antarctic ice cores, of the ozone depleting substances methyl bromide (CH3Br) and methyl chloride (CH3Cl), and the sulfur-containing gas, carbonyl sulfide (OCS). The broad scientific goal is to assess the level and variability of these gases in the preindustrial atmosphere. This information will allow testing of current models for sources and sinks of these gases from the atmosphere, and to indirectly assess the impact of anthropogenic activities on their biogeochemical cycles. Longer-term records will shed light on the climatic sensitivity of the atmospheric burden of these gases, and ultimately on the biogeochemical processes controlling them. These gases are present in ice at parts per trillion levels, and the current database consists entirely of a small number of measurements made in from a shallow ice core from Siple Dome, Antarctica. This project will involve studies of ice core samples from three Antarctic sites: Siple Station, Siple Dome, and South Pole. The sampling strategy is designed to accomplish several objectives: 1) to verify the atmospheric mixing ratios previously observed in shallow Siple Dome ice for OCS, CH3Br, and CH3Cl at sites with very different accumulation rates and surface temperatures; 2) to obtain a well-dated, high resolution record from a high accumulation rate site (Siple Station), that can provide overlap in mean gas age with Antarctic firn air samples; 3) explore Holocene variability in trace gas mixing ratios; and 4) to make the first measurements of these trace gases in Antarctic glacial ice. In terms of broader impact on society, this research will help to provide a stronger scientific basis for policy decisions regulating the production and use of ozone-depleting and climate-active gases. Specifically, the methyl bromide results will contribute to the current debate on the impact of recent regulation (via the Montreal Protocol and its Amendments) on atmospheric levels. Determination of pre-industrial atmospheric variability of ozone-depleting substances will help place more realistic constraints on scenarios used for future projections of stratospheric ozone and its climatic impacts. This research will involve the participation of both graduate and undergraduate students. | POINT(-148.81 -81.65) | POINT(-148.81 -81.65) | false | false | ||||||
Generating an Isotopic Record of Atmospheric Methane and Nitrous Oxide Over the Last Century from South Pole Firn Air
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0125981 |
2005-05-05 | Sowers, Todd A. | No dataset link provided | 0125981<br/>Sowers<br/><br/>This award supports a project to construct an isotopic record of atmospheric methane and nitrous oxide over the last century from South Pole firn air. Over the last 150 years, atmospheric methane and nitrous oxide concentrations have risen in response to increased emissions from various anthropogenic activities. As this trend is liable to continue in the foreseeable future, it is important to understand the biogeochemical processes that contribute to the emissions of these two greenhouse gases. In this context, records of the variations in the atmospheric loading of trace gases found in ice cores and interstitial spaces in the snow near the surface of the ice sheet (firn air) provide fundamental boundary conditions for reconstructing historical emission records. One way to improve our understanding of the cycling of bioactive trace gases and their emission records is to use stable isotope tracers, which have been recorded in the ice cores and firn air. This project will develop records of carbon-13 and deuterium isotope ratios of methane, as well as the nitrogen-15, oxygen-18 and the isotopomer composition of nitrous oxide trapped in firn air samples collected in January 2001 at the South Pole. These measurements will allow isotopic records of these atmospheric gases to be reconstructed throughout the 20th century. Such records will help to establish the relative contribution of individual sources with a higher degree of confidence than is currently available. | POLYGON((-180 -62.83,-144 -62.83,-108 -62.83,-72 -62.83,-36 -62.83,0 -62.83,36 -62.83,72 -62.83,108 -62.83,144 -62.83,180 -62.83,180 -65.547,180 -68.264,180 -70.981,180 -73.698,180 -76.415,180 -79.132,180 -81.849,180 -84.566,180 -87.283,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87.283,-180 -84.566,-180 -81.849,-180 -79.132,-180 -76.415,-180 -73.698,-180 -70.981,-180 -68.264,-180 -65.547,-180 -62.83)) | POINT(0 -89.999) | false | false |