{"dp_type": "Project", "free_text": "Carbon-13"}
[{"awards": "1745078 Brook, Edward", "bounds_geometry": "POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60))", "dataset_titles": "Atmospheric methane across the Last Glacial Maximum and deglaciation from the GISP2, NEEM and WAIS Divide ice cores ; Atmospheric methane interpolar difference and four-box troposphere model output across the Last Glacial Maximum and Deglaciation; Carbon-13 isotopic composition of atmospheric methane across Heinrich Stadials 1 and 5, and Dansgaard Oesgher Event 12, WAIS Divide Ice Core, Antarctica", "datasets": [{"dataset_uid": "601735", "doi": null, "keywords": "Antarctica; Cryosphere; Greenland; Methane; West Antarctic Ice Sheet", "people": "Edwards, Jon S.; Rosen, Julia; Martin, Kaden; Riddell-Young, Benjamin; Brook, Edward; Lee, James", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric methane across the Last Glacial Maximum and deglaciation from the GISP2, NEEM and WAIS Divide ice cores ", "url": "https://www.usap-dc.org/view/dataset/601735"}, {"dataset_uid": "601736", "doi": null, "keywords": "Antarctica; Cryosphere; Greenland; Methane; Paleoclimate; West Antarctic Ice Sheet", "people": "Edwards, Jon S.; M\u00fchl, Michaela; Schmitt, Jochen; Fischer, Hubertus; Riddell-Young, Benjamin; Blunier, Thomas; Brook, Edward; Rosen, Julia; Buizert, Christo; Martin, Kaden; Lee, James", "repository": "USAP-DC", "science_program": null, "title": "Atmospheric methane interpolar difference and four-box troposphere model output across the Last Glacial Maximum and Deglaciation", "url": "https://www.usap-dc.org/view/dataset/601736"}, {"dataset_uid": "601683", "doi": "10.15784/601683", "keywords": "Antarctica; Cryosphere; Methane; West Antarctic Ice Sheet", "people": "Riddell-Young, Benjamin", "repository": "USAP-DC", "science_program": "WAIS Divide Ice Core", "title": "Carbon-13 isotopic composition of atmospheric methane across Heinrich Stadials 1 and 5, and Dansgaard Oesgher Event 12, WAIS Divide Ice Core, Antarctica", "url": "https://www.usap-dc.org/view/dataset/601683"}], "date_created": "Mon, 01 May 2023 00:00:00 GMT", "description": "This project will develop methods to measure the ratios of carbon-13 to carbon-12, and heavy to light hydrogen in methane in air trapped in ice cores. The ratios of the different forms of carbon and hydrogen are \"fingerprints\" of different sources of this gas in the past--for example wetlands in the tropics versus methane frozen in the sea floor. Once the analysis method is developed, the measurements will be used to examine why methane changed abruptly in the past, both during the last ice age, and during previous warm periods. The data will be used to understand how methane sources like wildfires, methane hydrates, and wetlands respond to climate change. This information is needed to understand future risks of large changes in methane in the atmosphere as Earth warms. \u003cbr/\u003e\u003cbr/\u003eThe project involves two tasks. First, the investigators will build and test a gas extraction system for methane isotopic measurements using continuous flow methods, with the goal of equaling or bettering the precision attained by the few other laboratories that make these measurements. The system will be interfaced with existing mass spectrometers at Oregon State University. The system consists of a vacuum chamber and sequence of traps, purification columns, and furnaces that separate methane from other gases and convert it to carbon dioxide or hydrogen for mass spectrometry. Second, the team will measure the isotopic composition of methane across large changes in concentration associated with two past interglacial periods and during abrupt methane changes of the last ice age. These measurements will be used to understand if the main reason for these concentration changes is climate-driven changes in emissions from wetlands, or whether other sources are involved, for example methane hydrates or wildfires.\u003cbr/\u003e\u003cbr/\u003eThis award reflects NSF\u0027s statutory mission and has been deemed worthy of support through evaluation using the Foundation\u0027s intellectual merit and broader impacts review criteria.", "east": 180.0, "geometry": "POINT(0 -89.999)", "instruments": null, "is_usap_dc": true, "keywords": "Antarctic Ice Sheet; TRACE GASES/TRACE SPECIES; METHANE", "locations": "Antarctic Ice Sheet", "north": -60.0, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Brook, Edward", "platforms": null, "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": null, "south": -90.0, "title": "Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores", "uid": "p0010416", "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": "609504", "doi": "10.7265/N5X9287C", "keywords": "Antarctica; Arctic; Atmosphere; Chemistry:Fluid; Cryosphere; Geochemistry; Glaciers/Ice Sheet; Greenland; 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"}, {"dataset_uid": "609502", "doi": "10.7265/N55T3HFP", "keywords": "Antarctica; Atmosphere; Chemistry:Fluid; Cryosphere; Geochemistry; Isotope; Paleoclimate; 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"}], "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; Firn Air Chemistry; Firn Air Isotope Measurements; Not provided; LABORATORY; South Pole; isotopes; Firn; deltaD; 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": "Not provided; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD INVESTIGATION; OTHER \u003e PHYSICAL MODELS \u003e LABORATORY; LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS", "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": "0338248 Takahashi, Taro", "bounds_geometry": "POLYGON((-68.0051 -52.7573,-67.35191 -52.7573,-66.69872 -52.7573,-66.04553 -52.7573,-65.39234 -52.7573,-64.73915 -52.7573,-64.08596 -52.7573,-63.43277 -52.7573,-62.77958 -52.7573,-62.12639 -52.7573,-61.4732 -52.7573,-61.4732 -53.96927,-61.4732 -55.18124,-61.4732 -56.39321,-61.4732 -57.60518,-61.4732 -58.81715,-61.4732 -60.02912,-61.4732 -61.24109,-61.4732 -62.45306,-61.4732 -63.66503,-61.4732 -64.877,-62.12639 -64.877,-62.77958 -64.877,-63.43277 -64.877,-64.08596 -64.877,-64.73915 -64.877,-65.39234 -64.877,-66.04553 -64.877,-66.69872 -64.877,-67.35191 -64.877,-68.0051 -64.877,-68.0051 -63.66503,-68.0051 -62.45306,-68.0051 -61.24109,-68.0051 -60.02912,-68.0051 -58.81715,-68.0051 -57.60518,-68.0051 -56.39321,-68.0051 -55.18124,-68.0051 -53.96927,-68.0051 -52.7573))", "dataset_titles": "Expedition Data", "datasets": [{"dataset_uid": "001572", "doi": "", "keywords": null, "people": null, "repository": "R2R", "science_program": null, "title": "Expedition Data", "url": "https://www.rvdata.us/search/cruise/LMG0603"}], "date_created": "Tue, 04 May 2010 00:00:00 GMT", "description": "This proposal is for the continuation and expansion of an underway program on the R/V Laurence M. Gould to measure dissolved carbon dioxide gas (pCO2) along with occasional total carbon dioxide (TCO2) in surface waters on transects of Drake Passage. The added observations include dissolved oxygen, as well as nutrient and carbon-13. The proposed work is similar to the underway measurement program made aboard R/V Nathaniel B. Palmer, and complements similar surface temperature and current data.\u003cbr/\u003eThe Southern Ocean is an important component of the global carbon budget. Low surface temperatures with consequently low vertical stability, ice formation, and high winds produce a very active environment for the exchange of gaseous carbon dioxide between the atmospheric and oceanic reservoirs. The Drake Passage is the narrowest point through which the Antarctic Circumpolar Current and its associated fronts must pass, and is the most efficient location for the measurement of latitudinal gradients of gas exchange. The generated time series will contribute towards two scientific goals: the quantification of the spatial and temporal variability and trends of surface carbon dioxide, oxygen, nutrients and C-13, and an understanding of the dominant processes that contribute to the observed variability.", "east": -61.4732, "geometry": "POINT(-64.73915 -58.81715)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e CTD; EARTH REMOTE SENSING INSTRUMENTS \u003e PASSIVE REMOTE SENSING \u003e POSITIONING/NAVIGATION \u003e GPS \u003e GPS; IN SITU/LABORATORY INSTRUMENTS \u003e PROFILERS/SOUNDERS \u003e ACOUSTIC SOUNDERS \u003e ADCP", "is_usap_dc": false, "keywords": "R/V LMG", "locations": null, "north": -52.7573, "nsf_funding_programs": "Antarctic Ocean and Atmospheric Sciences", "paleo_time": null, "persons": "Takahashi, Taro", "platforms": "WATER-BASED PLATFORMS \u003e VESSELS \u003e SURFACE \u003e R/V LMG", "repo": "R2R", "repositories": "R2R", "science_programs": null, "south": -64.877, "title": "Collaborative Research: Processes Driving Spatial and Temporal Variability of Surface pCO2 in the Drake Passage", "uid": "p0000572", "west": -68.0051}, {"awards": "9526556 Sowers, Todd", "bounds_geometry": "POINT(-148.3023 -81.403)", "dataset_titles": "Carbon-13 Isotopic Composition of Atmospheric Methane in Firn Air, South Pole and Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609310", "doi": "10.7265/N5ST7MR2", "keywords": "Antarctica; Atmosphere; Chemistry:Fluid; Cryosphere; Geochemistry; Siple Dome; Snow/Ice; South Pole", "people": "Sowers, Todd A.", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Carbon-13 Isotopic Composition of Atmospheric Methane in Firn Air, South Pole and Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609310"}], "date_created": "Mon, 09 Jul 2007 00:00:00 GMT", "description": "This award is for support for a program to reconstruct records of the isotopic composition of paleoatmospheric methane and nitrous oxide covering the last 200,000 years. High resolution measurements of the carbon-13 isotopic composition of methane from shallow ice cores will help to determine the relative contributions of biogenic (wetlands, rice fields and ruminants) and abiogenic (biomass burning and natural gas) methane emissions which have caused the concentrations of this gas to increase at an exponential rate during the anthropogenic period. Isotopic data on methane and nitrous oxide over glacial/interglacial timescales will help determine the underlying cause of the large concentration variations that are known to occur. This project will make use of a new generation mass spectrometer which is capable of generating precise isotopic information on nanomolar quantities of methane and nitrous oxide, which means that samples can be 1000 times smaller than those needed for a standard isotope ratio instrument. The primary objective of the work is to further our understanding of the biogeochemical cycles of these two greenhouse gases throughout the anthropogenic period as well as over glacial interglacial timescales.", "east": -148.3023, "geometry": "POINT(-148.3023 -81.403)", "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS", "is_usap_dc": true, "keywords": "Ice Core; Firn Air Isotope Measurements; Ice Core Chemistry; Firn Isotopes; Stable Isotopes; Methane; Carbon; Paleoclimate; LABORATORY; AGDC; Siple Dome; Antarctica; Ice Core Data; Firn Air Isotopes; Antarctic Ice Sheet", "locations": "Antarctica; Antarctic Ice Sheet; Siple Dome", "north": -81.403, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": "PHANEROZOIC \u003e CENOZOIC \u003e QUATERNARY \u003e HOLOCENE", "persons": "Sowers, Todd A.", "platforms": "OTHER \u003e PHYSICAL MODELS \u003e LABORATORY", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": -81.403, "title": "Constructing Paleoatmospheric Records of the Isotopic Composition of Methane and Nitrous Oxide", "uid": "p0000611", "west": -148.3023}, {"awards": "0125900 Sowers, Todd", "bounds_geometry": "POINT(-148.8 -81.7)", "dataset_titles": null, "datasets": null, "date_created": "Thu, 26 May 2005 00:00:00 GMT", "description": "0125900\u003cbr/\u003eSowers\u003cbr/\u003e\u003cbr/\u003eThis award supports a project to improve the understanding of the biogeochemical processes that control CH4 emissions. Records of the concentration of methane in trapped gases in ice tell us about changes in atmospheric loading through time. Such records do not, however, provide information on the individual sources or sinks. One way to refine our understanding of the cycling of bioactive trace gases like methane is to use stable isotope records of trapped gases in ice cores. This project will measure the Deuterium/Hydrogen (D/H) ratio of methane trapped in shallow/recent ice (covering the last ~ 200 years) at Siple Dome, Antarctica. The proposed work will complement current efforts to measure the carbon-13 isotope ratio of methane in ice cores and will provide fundamental information on the various sources and sinks of atmospheric methane over the last 200 years.", "east": -148.8, "geometry": "POINT(-148.8 -81.7)", "instruments": null, "is_usap_dc": false, "keywords": "Siple Dome; Not provided; CH4; Methane; Antarctica; Ice Core", "locations": "Siple Dome; Antarctica", "north": -81.7, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Sowers, Todd A.", "platforms": "Not provided", "repositories": null, "science_programs": null, "south": -81.7, "title": "Constructing the first D/H record of atmospheric methane covering the last two centuries.", "uid": "p0000754", "west": -148.8}, {"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}, {"awards": "9980691 Wahlen, Martin", "bounds_geometry": null, "dataset_titles": "Atmospheric CO2 Trapped in the Ice Core from Siple Dome, Antarctica", "datasets": [{"dataset_uid": "609202", "doi": "10.7265/N5N877Q9", "keywords": "Antarctica; Chemistry:Fluid; CO2; Cryosphere; Geochemistry; Glaciers/Ice Sheet; Ice Core Records; Paleoclimate; Siple Dome; Siple Dome Ice Core", "people": "Wahlen, Martin; Ahn, Jinho; Deck, Bruce", "repository": "USAP-DC", "science_program": "Siple Dome Ice Core", "title": "Atmospheric CO2 Trapped in the Ice Core from Siple Dome, Antarctica", "url": "https://www.usap-dc.org/view/dataset/609202"}], "date_created": "Thu, 11 Dec 2003 00:00:00 GMT", "description": "9980691\u003cbr/\u003eWahlen\u003cbr/\u003e\u003cbr/\u003eThis award is for support for three years of funding to reconstruct the atmospheric carbon dioxide (CO2) and carbon-13 isotope (d13C) concentration in ice cores from Antarctica over several climatic periods. Samples from the Holocene, the Last Glacial Maximum (LGM)-Holocene transition and glacial stadial/interstadial episodes will be examined. Samples from the Siple Dome ice core drilled in 1998/99 will be made, in addition to measurements from the Taylor Dome and Vostok ice cores. The major objectives are to investigate the phase relationships between variations in the concentration of atmospheric CO2, its carbon isotope composition, and temperature changes (indicated by 18dO and dD of the ice) during deglaciations as well as across rapid climate change events (e.g. Dansgaard-Oeschger events). This will help to determine systematic changes in the global carbon cycle during and between different climatic periods, and to ascertain if the widely spread northern hemisphere temperature stadial/interstadial events produced a global atmospheric carbon dioxide signal. Proven experimental techniques will be used.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "FIELD SURVEYS; Siple Dome; Ice Core; USAP-DC; Carbon Dioxide", "locations": "Siple Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Wahlen, Martin; Ahn, Jinho; Deck, Bruce", "platforms": "LAND-BASED PLATFORMS \u003e FIELD SITES \u003e FIELD SURVEYS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Siple Dome Ice Core", "south": null, "title": "CO2 and Delta 13CO2 in Antarctic Ice Cores", "uid": "p0000166", "west": null}, {"awards": "9615292 Wahlen, Martin", "bounds_geometry": null, "dataset_titles": "Carbon-Isotopic Composition of Atmospheric CO2 since the Last Glacial Maximum; Taylor Dome Ice Core Chemistry, Ion, and Isotope Data", "datasets": [{"dataset_uid": "609246", "doi": "", "keywords": "Antarctica; Chemistry:Ice; Cryosphere; Geochemistry; Glaciers/Ice Sheet; Ice Core Records; Isotope; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Steig, Eric J.; Mayewski, Paul A.; Indermuhle, A.; Sowers, Todd A.; Smith, Jesse; Brook, Edward J.", "repository": "USAP-DC", "science_program": "Taylor Dome Ice Core", "title": "Taylor Dome Ice Core Chemistry, Ion, and Isotope Data", "url": "https://www.usap-dc.org/view/dataset/609246"}, {"dataset_uid": "609108", "doi": "10.7265/N54F1NN5", "keywords": "Antarctica; Atmosphere; Chemistry:Fluid; Cryosphere; Geochemistry; Glaciers/Ice Sheet; Glaciology; Ice Core Records; Paleoclimate; Taylor Dome; Taylor Dome Ice Core", "people": "Wahlen, Martin", "repository": "USAP-DC", "science_program": null, "title": "Carbon-Isotopic Composition of Atmospheric CO2 since the Last Glacial Maximum", "url": "https://www.usap-dc.org/view/dataset/609108"}], "date_created": "Tue, 01 Jan 2002 00:00:00 GMT", "description": "This award is for support of a program to reconstruct the record of atmospheric carbon dioxide (and the carbon-13 isotopes of carbon dioxide) over several intervals, including the Last Glacial Maximum-Holocene transition, interstadial episodes, the mid-Holocene, the last 1000 years and the penultimate glacial period, using ice from the Taylor Dome and Vostok ice cores. The major objective of this study is to investigate the phase relationship between variations of the greenhouse gases occluded in the ice cores and temperature changes (indicated by oxygen and deuterium isotopes) during the last deglaciation. In addition, the concentration of atmospheric carbon dioxide over the past 1000 years and during the mid-Holocene will be determined in these cores.", "east": null, "geometry": null, "instruments": "IN SITU/LABORATORY INSTRUMENTS \u003e SPECTROMETERS/RADIOMETERS \u003e MASS SPECTROMETERS; IN SITU/LABORATORY INSTRUMENTS \u003e CORERS \u003e CORING DEVICES", "is_usap_dc": true, "keywords": "USAP-DC; Ice Core; isotopes; GROUND-BASED OBSERVATIONS; Carbon; Trapped Gases; Glaciology; GROUND STATIONS; Taylor Dome; Carbon Dioxide; Antarctica; Nitrogen", "locations": "Antarctica; Taylor Dome", "north": null, "nsf_funding_programs": "Antarctic Glaciology", "paleo_time": null, "persons": "Steig, Eric J.; Wahlen, Martin; Smith, Jesse; Brook, Edward J.; Indermuhle, A.; Mayewski, Paul A.; Sowers, Todd A.", "platforms": "LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND-BASED OBSERVATIONS; LAND-BASED PLATFORMS \u003e PERMANENT LAND SITES \u003e GROUND STATIONS", "repo": "USAP-DC", "repositories": "USAP-DC", "science_programs": "Taylor Dome Ice Core", "south": null, "title": "Carbon Dioxide and Carbon Isotopes in the Taylor Dome and Vostok Ice Cores", "uid": "p0000153", "west": null}]
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Project Title/Abstract/Map | NSF Award(s) | Date Created | PIs / Scientists | Dataset Links and Repositories | Abstract | Bounds Geometry | Geometry | Selected | Visible | |||||
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Tracing Past Methane Variations with Stable Isotopes in Antarctic Ice Cores
|
1745078 |
2023-05-01 | Brook, Edward | This project will develop methods to measure the ratios of carbon-13 to carbon-12, and heavy to light hydrogen in methane in air trapped in ice cores. The ratios of the different forms of carbon and hydrogen are "fingerprints" of different sources of this gas in the past--for example wetlands in the tropics versus methane frozen in the sea floor. Once the analysis method is developed, the measurements will be used to examine why methane changed abruptly in the past, both during the last ice age, and during previous warm periods. The data will be used to understand how methane sources like wildfires, methane hydrates, and wetlands respond to climate change. This information is needed to understand future risks of large changes in methane in the atmosphere as Earth warms. <br/><br/>The project involves two tasks. First, the investigators will build and test a gas extraction system for methane isotopic measurements using continuous flow methods, with the goal of equaling or bettering the precision attained by the few other laboratories that make these measurements. The system will be interfaced with existing mass spectrometers at Oregon State University. The system consists of a vacuum chamber and sequence of traps, purification columns, and furnaces that separate methane from other gases and convert it to carbon dioxide or hydrogen for mass spectrometry. Second, the team will measure the isotopic composition of methane across large changes in concentration associated with two past interglacial periods and during abrupt methane changes of the last ice age. These measurements will be used to understand if the main reason for these concentration changes is climate-driven changes in emissions from wetlands, or whether other sources are involved, for example methane hydrates or wildfires.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria. | POLYGON((-180 -60,-144 -60,-108 -60,-72 -60,-36 -60,0 -60,36 -60,72 -60,108 -60,144 -60,180 -60,180 -63,180 -66,180 -69,180 -72,180 -75,180 -78,180 -81,180 -84,180 -87,180 -90,144 -90,108 -90,72 -90,36 -90,0 -90,-36 -90,-72 -90,-108 -90,-144 -90,-180 -90,-180 -87,-180 -84,-180 -81,-180 -78,-180 -75,-180 -72,-180 -69,-180 -66,-180 -63,-180 -60)) | POINT(0 -89.999) | false | false | ||||||
Collaborative Research: 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: Processes Driving Spatial and Temporal Variability of Surface pCO2 in the Drake Passage
|
0338248 |
2010-05-04 | Takahashi, Taro |
|
This proposal is for the continuation and expansion of an underway program on the R/V Laurence M. Gould to measure dissolved carbon dioxide gas (pCO2) along with occasional total carbon dioxide (TCO2) in surface waters on transects of Drake Passage. The added observations include dissolved oxygen, as well as nutrient and carbon-13. The proposed work is similar to the underway measurement program made aboard R/V Nathaniel B. Palmer, and complements similar surface temperature and current data.<br/>The Southern Ocean is an important component of the global carbon budget. Low surface temperatures with consequently low vertical stability, ice formation, and high winds produce a very active environment for the exchange of gaseous carbon dioxide between the atmospheric and oceanic reservoirs. The Drake Passage is the narrowest point through which the Antarctic Circumpolar Current and its associated fronts must pass, and is the most efficient location for the measurement of latitudinal gradients of gas exchange. The generated time series will contribute towards two scientific goals: the quantification of the spatial and temporal variability and trends of surface carbon dioxide, oxygen, nutrients and C-13, and an understanding of the dominant processes that contribute to the observed variability. | POLYGON((-68.0051 -52.7573,-67.35191 -52.7573,-66.69872 -52.7573,-66.04553 -52.7573,-65.39234 -52.7573,-64.73915 -52.7573,-64.08596 -52.7573,-63.43277 -52.7573,-62.77958 -52.7573,-62.12639 -52.7573,-61.4732 -52.7573,-61.4732 -53.96927,-61.4732 -55.18124,-61.4732 -56.39321,-61.4732 -57.60518,-61.4732 -58.81715,-61.4732 -60.02912,-61.4732 -61.24109,-61.4732 -62.45306,-61.4732 -63.66503,-61.4732 -64.877,-62.12639 -64.877,-62.77958 -64.877,-63.43277 -64.877,-64.08596 -64.877,-64.73915 -64.877,-65.39234 -64.877,-66.04553 -64.877,-66.69872 -64.877,-67.35191 -64.877,-68.0051 -64.877,-68.0051 -63.66503,-68.0051 -62.45306,-68.0051 -61.24109,-68.0051 -60.02912,-68.0051 -58.81715,-68.0051 -57.60518,-68.0051 -56.39321,-68.0051 -55.18124,-68.0051 -53.96927,-68.0051 -52.7573)) | POINT(-64.73915 -58.81715) | false | false | |||||
Constructing Paleoatmospheric Records of the Isotopic Composition of Methane and Nitrous Oxide
|
9526556 |
2007-07-09 | Sowers, Todd A. |
|
This award is for support for a program to reconstruct records of the isotopic composition of paleoatmospheric methane and nitrous oxide covering the last 200,000 years. High resolution measurements of the carbon-13 isotopic composition of methane from shallow ice cores will help to determine the relative contributions of biogenic (wetlands, rice fields and ruminants) and abiogenic (biomass burning and natural gas) methane emissions which have caused the concentrations of this gas to increase at an exponential rate during the anthropogenic period. Isotopic data on methane and nitrous oxide over glacial/interglacial timescales will help determine the underlying cause of the large concentration variations that are known to occur. This project will make use of a new generation mass spectrometer which is capable of generating precise isotopic information on nanomolar quantities of methane and nitrous oxide, which means that samples can be 1000 times smaller than those needed for a standard isotope ratio instrument. The primary objective of the work is to further our understanding of the biogeochemical cycles of these two greenhouse gases throughout the anthropogenic period as well as over glacial interglacial timescales. | POINT(-148.3023 -81.403) | POINT(-148.3023 -81.403) | false | false | |||||
Constructing the first D/H record of atmospheric methane covering the last two centuries.
|
0125900 |
2005-05-26 | Sowers, Todd A. | No dataset link provided | 0125900<br/>Sowers<br/><br/>This award supports a project to improve the understanding of the biogeochemical processes that control CH4 emissions. Records of the concentration of methane in trapped gases in ice tell us about changes in atmospheric loading through time. Such records do not, however, provide information on the individual sources or sinks. One way to refine our understanding of the cycling of bioactive trace gases like methane is to use stable isotope records of trapped gases in ice cores. This project will measure the Deuterium/Hydrogen (D/H) ratio of methane trapped in shallow/recent ice (covering the last ~ 200 years) at Siple Dome, Antarctica. The proposed work will complement current efforts to measure the carbon-13 isotope ratio of methane in ice cores and will provide fundamental information on the various sources and sinks of atmospheric methane over the last 200 years. | POINT(-148.8 -81.7) | POINT(-148.8 -81.7) | false | false | |||||
Generating an Isotopic Record of Atmospheric Methane and Nitrous Oxide Over the Last Century from South Pole Firn Air
|
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 | |||||
CO2 and Delta 13CO2 in Antarctic Ice Cores
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9980691 |
2003-12-11 | Wahlen, Martin; Ahn, Jinho; Deck, Bruce |
|
9980691<br/>Wahlen<br/><br/>This award is for support for three years of funding to reconstruct the atmospheric carbon dioxide (CO2) and carbon-13 isotope (d13C) concentration in ice cores from Antarctica over several climatic periods. Samples from the Holocene, the Last Glacial Maximum (LGM)-Holocene transition and glacial stadial/interstadial episodes will be examined. Samples from the Siple Dome ice core drilled in 1998/99 will be made, in addition to measurements from the Taylor Dome and Vostok ice cores. The major objectives are to investigate the phase relationships between variations in the concentration of atmospheric CO2, its carbon isotope composition, and temperature changes (indicated by 18dO and dD of the ice) during deglaciations as well as across rapid climate change events (e.g. Dansgaard-Oeschger events). This will help to determine systematic changes in the global carbon cycle during and between different climatic periods, and to ascertain if the widely spread northern hemisphere temperature stadial/interstadial events produced a global atmospheric carbon dioxide signal. Proven experimental techniques will be used. | None | None | false | false | |||||
Carbon Dioxide and Carbon Isotopes in the Taylor Dome and Vostok Ice Cores
|
9615292 |
2002-01-01 | Steig, Eric J.; Wahlen, Martin; Smith, Jesse; Brook, Edward J.; Indermuhle, A.; Mayewski, Paul A.; Sowers, Todd A. |
|
This award is for support of a program to reconstruct the record of atmospheric carbon dioxide (and the carbon-13 isotopes of carbon dioxide) over several intervals, including the Last Glacial Maximum-Holocene transition, interstadial episodes, the mid-Holocene, the last 1000 years and the penultimate glacial period, using ice from the Taylor Dome and Vostok ice cores. The major objective of this study is to investigate the phase relationship between variations of the greenhouse gases occluded in the ice cores and temperature changes (indicated by oxygen and deuterium isotopes) during the last deglaciation. In addition, the concentration of atmospheric carbon dioxide over the past 1000 years and during the mid-Holocene will be determined in these cores. | None | None | false | false |