{"NOAAStudyId":"14651","contactInfo":{"address":"325 Broadway, E/NE31","city":"Boulder","constraints":"Please cite original publication, online resource, dataset and publication DOIs (where available), and date accessed when using downloaded data. If there is no publication information, please cite investigator, title, online resource, and date accessed. The appearance of external links associated with a dataset does not constitute endorsement by the Department of Commerce/National Oceanic and Atmospheric Administration of external Web sites or the information, products or services contained therein. For other than authorized activities, the Department of Commerce/NOAA does not exercise any editorial control over the information you may find at these locations. These links are provided consistent with the stated purpose of this Department of Commerce/NOAA Web site.","country":"USA","dataCenterUrl":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data","email":"paleo@noaa.gov","fax":"303-497-6513","longName":"National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce ","phone":"303-497-6280","postalCode":"80305-3328","shortName":"DOC/NOAA/NESDIS/NCEI","state":"CO","type":"CONTACT INFORMATION"},"contributionDate":"2013-06-17","dataPublisher":"NOAA","dataType":"ICE CORES","dataTypeInformation":"https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/ice-core","difMetadataLink":"http://www1.ncdc.noaa.gov/pub/data/metadata/published/paleo/dif/xml/noaa-icecore-14651.xml","doi":null,"earliestYearBP":164013,"earliestYearCE":-162063,"entryId":"noaa-icecore-14651","funding":[{"fundingAgency":"European Union","fundingGrant":null},{"fundingAgency":"Deutsche Forschungsgemeinschaft","fundingGrant":null},{"fundingAgency":"US National Science Foundation","fundingGrant":null},{"fundingAgency":"European Research Council","fundingGrant":null}],"investigators":"Möller, L.; Sowers, T.; Bock, M.; Spahni, R.; Behrens, M.; Schmitt, J.; Miller, H.; Fischer, H.","mostRecentYearBP":9937,"mostRecentYearCE":-7987,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/14651","originalSource":null,"publication":[{"abstract":"During the last glacial cycle, greenhouse gas concentrations fluctuated on decadal and longer timescales. Concentrations of methane, as measured in polar ice cores, show a close connection with Northern Hemisphere temperature variability, but the contribution of the various methane sources and sinks to changes in concentration is still a matter of debate. Here we assess changes in methane cycling over the past 160,000 years by measurements of the carbon isotopic composition d13C of methane in Antarctic ice cores from Dronning Maud Land and Vostok. We find that variations in the d13C of methane are not generally correlated with changes in atmospheric methane concentration, but instead more closely correlated to atmospheric CO2 concentrations. We interpret this to reflect a climatic and CO2-related control on the isotopic signature of methane source material, such as ecosystem shifts in the seasonally inundated tropical wetlands that produce methane. In contrast, relatively stable d13C values occurred during intervals of large changes in the atmospheric loading of methane. We suggest that most methane sources - most notably tropical wetlands - must have responded simultaneously to climate changes across these periods.","author":{"name":"Lars Möller, Todd Sowers, Michael Bock, Renato Spahni, Melanie Behrens, Jochen Schmitt, Heinrich Miller, and Hubertus Fischer"},"citation":"Lars Möller, Todd Sowers, Michael Bock, Renato Spahni, Melanie Behrens, Jochen Schmitt, Heinrich Miller, and Hubertus Fischer. 2013. Independent variations of CH4 emissions and isotopic composition over the past 160,000 years. Nature Geoscience, 6, 885-890. doi: 10.1038/ngeo1922","edition":null,"identifier":{"id":"10.1038/ngeo1922","type":"doi","url":"http://dx.doi.org/10.1038/ngeo1922"},"issue":null,"journal":"Nature Geoscience","pages":"885-890","pubRank":"1","pubYear":2013,"reportNumber":null,"title":"Independent variations of CH4 emissions and isotopic composition over the past 160,000 years","type":"publication","volume":"6"}],"reconstruction":"N","scienceKeywords":["carbon cycle"],"site":[{"NOAASiteId":"19976","geo":{"geoType":"Feature","geometry":{"coordinates":["-78.47","106.8"],"type":"POINT"},"properties":{"easternmostLongitude":"106.8","maxElevationMeters":"2892","minElevationMeters":"2892","northernmostLatitude":"-78.47","southernmostLatitude":"-78.47","westernmostLongitude":"106.8"}},"locationName":"Continent>Antarctica","mappable":"Y","paleoData":[{"NOAADataTableId":"24737","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>carbon isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/vostok/vostok2013d13ch4.txt","linkText":"vostok2013d13ch4.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>gas age"},{"cvAdditionalInfo":"methane synchronization","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>gas age"},{"cvAdditionalInfo":"Antarctic unified age scale","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>gas age"},{"cvAdditionalInfo":"Antarctic unified age scale; EDC3 corrected","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>gas age"},{"cvAdditionalInfo":"deviations due to krypton interference","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"corrected for gravitational settling","cvDataType":"ICE CORES","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"corrected for krypton","cvDataType":"ICE CORES","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"corrected for interlaboratory offset","cvDataType":"ICE CORES","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"}]}],"dataTableName":"Vostokd13CH4","dataTableNotes":null,"earliestYear":164013,"earliestYearBP":164013,"earliestYearCE":-162063,"mostRecentYear":49690,"mostRecentYearBP":49690,"mostRecentYearCE":-47740,"species":[],"timeUnit":"cal yr BP"}],"siteName":"Vostok"},{"NOAASiteId":"20568","geo":{"geoType":"Feature","geometry":{"coordinates":["-75",".07"],"type":"POINT"},"properties":{"easternmostLongitude":"0.07","maxElevationMeters":"2892","minElevationMeters":"2892","northernmostLatitude":"-75","southernmostLatitude":"-75","westernmostLongitude":"0.07"}},"locationName":"Continent>Antarctica","mappable":"Y","paleoData":[{"NOAADataTableId":"24735","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>carbon isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/maud/edml2013d13ch4.txt","linkText":"edml2013d13ch4.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Character","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":null,"cvWhat":"sampling metadata>notes"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":"Antarctic unified age scale","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>gas age"},{"cvAdditionalInfo":"corrected for machine specific drift","cvDataType":"ICE CORES","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"deviations due to krypton interference","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"corrected for krypton","cvDataType":"ICE CORES","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":"corrected for glacial offset due to gravitational settling","cvDataType":"ICE CORES","cvDetail":"corrected","cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":"one standard deviation","cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VPDB","cvWhat":"chemical composition>isotope>isotope ratio>delta 13C"}]}],"dataTableName":"EDMLd13CH4","dataTableNotes":null,"earliestYear":78770,"earliestYearBP":78770,"earliestYearCE":-76820,"mostRecentYear":9937,"mostRecentYearBP":9937,"mostRecentYearCE":-7987,"species":[],"timeUnit":"cal yr BP"},{"NOAADataTableId":"24736","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>hydrogen isotopes"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/maud/edml2013ddch4.txt","linkText":"edml2013ddch4.txt","urlDescription":"Data","variables":[{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"meter","cvWhat":"depth variable>depth"},{"cvAdditionalInfo":"Antarctic unified age scale","cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"calendar year before present","cvWhat":"age variable>age>ice age"},{"cvAdditionalInfo":"standard deviation of the standard air measurements used to calibrate dD to the VSMOW scale","cvDataType":"ICE CORES","cvDetail":null,"cvError":"one standard deviation","cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil","cvWhat":"chemical composition>isotope>isotope ratio>delta 2H"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"chemical composition>compound>organic compound>hydrocarbon>alkane>n-alkane>methane","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"per mil VSMOW","cvWhat":"chemical composition>isotope>isotope ratio>delta 2H"}]}],"dataTableName":"EDMLdDCH4","dataTableNotes":null,"earliestYear":84536,"earliestYearBP":84536,"earliestYearCE":-82586,"mostRecentYear":53490,"mostRecentYearBP":53490,"mostRecentYearCE":-51540,"species":[],"timeUnit":"cal yr BP"}],"siteName":"EPICA Dronning Maud Land"}],"studyCode":null,"studyName":"Antarctic Ice Cores 160KYr Methane Isotope Data","studyNotes":"We reconstructed atmospheric d13CH4 records using wet extraction techniques and continuous flow gas\nchromatography combustion isotope ratio mass spectrometry (GC/C/IRMS) measurements performed on ice core\nmaterial from both the European Project for Ice Coring in Antarctica (EPICA) core from Dronning Maud Land\n(EDML) and the Vostok cores. At the Alfred Wegener Institute (AWI) we analyzed 151 samples from the EDML core\n(including 32 replicates, reproducibility of 0.2 , 1s) to construct a high resolution record between 20 kyr and 75 kyr BP\n(1.000 years before present, present referring to 1950 AD) with an average temporal resolution of better than one\nsample every 500 years. The period covering the two most pronounced climatic excursions in the Greenland\ntemperature record during MIS 3 (DO events 7 and 8) were sampled with a resolution of ~200 years. A\ncomplementary record of 79 samples of Vostok ice core material was measured at the Pennsylvania State University\n(PSU) covering a time period from 50 kyr to 160 kyr BP with an analytical uncertainty of 0.3 (1s), equivalent to an\naverage temporal resolution of 1660 years.\nThe two records were corrected for an instrumental interference from atmospheric krypton, for gravitational settling in\nthe firn, and a minor inter-laboratory offset of 0.14 .\nAll d13C values are reported versus Vienna PeeDee Belemnite (VPDB).\nWe further analyzed 20 samples of EDML ice for dD(CH4) with an external precision of about 2.5 (1s). The\nmeasurements were performed at the University of Bern using a purge and trap extraction coupled to a gas\nchromatography pyrolysis isotope ratio mass spectrometer (GC/P/IRMS) and cover the MIS 5/4 transition with an\naverage resolution of 1.5 kyr in between 54 and 85 kyr BP. The dD(CH4) values are reported with respect to\nthe international Vienna Standard Mean Ocean Water (VSMOW) scale.","version":"1.0","xmlId":"12649"}