{"NOAAStudyId":"9898","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":"2010-10-04","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-9898.xml","doi":null,"earliestYearBP":63750,"earliestYearCE":-61800,"entryId":"noaa-icecore-9898","funding":[{"fundingAgency":"Swiss National Science Foundation","fundingGrant":null},{"fundingAgency":"University of Bern","fundingGrant":null},{"fundingAgency":"Prince Albert II of Monaco Foundation","fundingGrant":null}],"investigators":"Lüthi, D.; Bereiter, B.; Stauffer, B.; Winkler, R.; Schwander, J.; Kindler, P.; Leuenberger, M.; Kipfstuhl, S.; Capron, E.; Landais, A.; Fischer, H.; Stocker, T.F.","mostRecentYearBP":30775,"mostRecentYearCE":-28825,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/9898","originalSource":null,"publication":[{"abstract":"CO2 measurements on the EPICA (European Project for Ice Coring \nin Antarctica) DML ice core in depth levels just below the bubble \nice-clathrate ice transformation zone (1230-2240 m depth) were \nperformed. In the youngest part (1230-1600 m), they reveal \nvariations of up to 25 ppmv around the mean atmospheric \nconcentration within centimetres, corresponding to a snow \ndeposition interval of a few years. Similar results are found \nat corresponding depth regions of the Dome C and the Talos Dome \nice cores. Since we can exclude all hitherto known processes \naltering the concentration of CO2 in ice cores, we present \na hypothesis about spatial fractionation of air components \nrelated to episodically increasing clathrate formation followed \nby diffusion processes from bubbles to clathrates. This hypothesis \nis supported by optical line-scan observations and by O2/N2 \nmeasurements at the same depth where strong CO2 variations are \ndetected. Below the clathrate formation zone, this small-scale \nfractionation process is slowly smoothed out, most likely by \ndiffusion, regaining the initial mean atmospheric concentration. \nAlthough this process compromises the representativeness of a \nsingle CO2 measurement on small ice samples in the clathrate \nformation zone of an ice core, it does not affect the mean \natmospheric CO2 concentration if CO2 values are averaged over \na sufficiently long depth scale (>10 cm in case of the EPICA \nDML ice core).\n","author":null,"citation":"Lüthi, D., B. Bereiter, B. Stauffer, R. Winkler, J. Schwander,\nP. Kindler, M. Leuenberger, S. Kipfstuhl, E. Capron, A. Landais,\nH. Fischer, and T.F. Stocker. 2010.\nCO2 and O2/N2 variations in and just below the bubble-clathrate \ntransformation zone of Antarctic ice cores. \nEarth and Planetary Science Letters, Vol. 297, pp. 226-233.  \ndoi:10.1016/j.epsl.2010.06.023  \n","edition":null,"identifier":{"id":"10.1016/j.epsl.2010.06.023","type":"doi","url":"http://dx.doi.org/10.1016/j.epsl.2010.06.023"},"issue":null,"journal":"Earth and Planetary Science Letters","pages":null,"pubRank":"1","pubYear":2010,"reportNumber":null,"title":"CO2 and O2/N2 variations in and just below the bubble-clathrate  transformation zone of Antarctic ice cores","type":"publication","volume":null}],"reconstruction":"N","scienceKeywords":["carbon cycle"],"site":[{"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":"18747","coreLengthMeters":536,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>atmospheric gas"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/maud/edml-co2-64-30ka.txt","linkText":"edml-co2-64-30ka.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":null,"cvDataType":"CLIMATE FORCING|ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"atmospheric material>bulk atmosphere","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"parts per million","cvWhat":"chemical composition>compound>inorganic compound>carbon dioxide"},{"cvAdditionalInfo":null,"cvDataType":"CLIMATE FORCING|ICE CORES","cvDetail":null,"cvError":"one standard deviation","cvFormat":"Numeric","cvMaterial":"atmospheric material>bulk atmosphere","cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"parts per million","cvWhat":"chemical composition>compound>inorganic compound>carbon dioxide"}]},{"NOAAKeywords":["earth science>paleoclimate>ice core>atmospheric gas"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/antarctica/maud/edml-co2-64-30ka.xls","linkText":"edml-co2-64-30ka.xls","urlDescription":"Data","variables":[]}],"dataTableName":"EDML 1207-1743m","dataTableNotes":null,"earliestYear":63750,"earliestYearBP":63750,"earliestYearCE":-61800,"mostRecentYear":30775,"mostRecentYearBP":30775,"mostRecentYearCE":-28825,"species":[],"timeUnit":"cal yr BP"}],"siteName":"EPICA Dronning Maud Land"}],"studyCode":null,"studyName":"EPICA Dronning Maud Land Ice Core 64-30KYr CO2 Data","studyNotes":"CO2 record from the EPICA Dronning Maud Land ice core covering \nthe time period between 64000 and 30000 yr BP. \n\n","version":"1.0","xmlId":"8790"}