{"NOAAStudyId":"17825","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":"1997-11-30","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-17825.xml","doi":null,"earliestYearBP":63000,"earliestYearCE":-61050,"entryId":"noaa-icecore-17825","funding":[],"investigators":"Smith, H.J.; Wahlen, M.; Mastroianni, D.; Taylor, K.C.; Mayewski, P.A.","mostRecentYearBP":46000,"mostRecentYearCE":-44050,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/17825","originalSource":null,"publication":[{"abstract":"The CO2 content of air occluded in Greenland Ice Sheet Project 2 (GISP2) ice formed over two separate intervals of rapidly changing climate, centered at approximately 46 and 63 kyr B. P., is as much as 90 ppm more during warm periods (interstadials) than during cold periods (stadials). These CO2 variations are superimposed on changes in annual layer thickness and d18O of the ice and do not show the 200- to 700-year offsets which would be expected for concurrent variations in the atmosphere and the ice. The CO2 concentrations during the stadials are similar to the atmospheric values recorded by Antarctic ice of the same age, so processes occurring in the ice after bubble enclosure must be enriching the air trapped in GISP2 ice formed during the interstadials. This conclusion is supported by Ca content and electrical conductivity measurements of the ice, which show that adequate carbonate is present to produce these enrichments and that CO2 content is high only when the electrical conductivity (a proxy for H+ concentration) is high. High-resolution mapping of one 4-cm section of ice shows a 200-ppm increase in the CO2 content of the trapped air, from approximately 275 to 475 ppm. Analyses of the total inorganic carbon of ice from both the LGM and Holocene show that most of the Ca in the ice is from CaCO3 and that the d13CO2 approaches that of soil and marine carbonates. These results show that the CO2 record preserved in ice can be altered by in situ decarbonation reactions and that only ice containing either abundant carbonate or essentially no carbonate contains a reliable record of paleoatmospheric CO2.","author":{"name":"H. J. Smith, M. Wahlen, D. Mastroianni, K. Taylor, P. Mayewski"},"citation":"H. J. Smith, M. Wahlen, D. Mastroianni, K. Taylor, P. Mayewski. 1997. The CO2 concentration of air trapped in Greenland Ice Sheet Project 2 ice formed during periods of rapid climate change. Journal of Geophysical Research: Oceans, 102(C12), 26577-26582. doi: 10.1029/97JC00163","edition":null,"identifier":{"id":"10.1029/97JC00163","type":"doi","url":"http://dx.doi.org/10.1029/97JC00163"},"issue":"C12","journal":"Journal of Geophysical Research: Oceans","pages":"26577-26582","pubRank":"1","pubYear":1997,"reportNumber":null,"title":"The CO2 concentration of air trapped in Greenland Ice Sheet Project 2 ice formed during periods of rapid climate change","type":"publication","volume":"102"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"19978","geo":{"geoType":"Feature","geometry":{"coordinates":["72.6","-38.5"],"type":"POINT"},"properties":{"easternmostLongitude":"-38.5","maxElevationMeters":"3200","minElevationMeters":"3200","northernmostLatitude":"72.6","southernmostLatitude":"72.6","westernmostLongitude":"-38.5"}},"locationName":"Continent>North America>Greenland","mappable":"Y","paleoData":[{"NOAADataTableId":"28143","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>atmospheric gas"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/co2.txt","linkText":"GISP2 CO2 Concentrations","urlDescription":"Data File","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>depth at sample start"},{"cvAdditionalInfo":null,"cvDataType":"CLIMATE FORCING|ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"atmospheric material>bulk atmosphere","cvMethod":"mechanical dry extraction","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":"mechanical dry extraction","cvSeasonality":null,"cvShortName":null,"cvUnit":"parts per million","cvWhat":"chemical composition>compound>inorganic compound>carbon dioxide"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":null,"cvMethod":null,"cvSeasonality":null,"cvShortName":null,"cvUnit":"count","cvWhat":"sampling metadata>number of samples"}]}],"dataTableName":"GISP21997CO2","dataTableNotes":null,"earliestYear":63000,"earliestYearBP":63000,"earliestYearCE":-61050,"mostRecentYear":46000,"mostRecentYearBP":46000,"mostRecentYearCE":-44050,"species":[],"timeUnit":"cal yr BP"}],"siteName":"GISP2"}],"studyCode":null,"studyName":"GISP2 Ice Core CO2 Data","studyNotes":"CO2 concentrations of air extracted from GISP2 ice from depths spanning two separate stadials (cold periods) centered at approximately 46 kyBP and 63 kyBP.","version":"1.0","xmlId":"15517"}