{"NOAAStudyId":"17845","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-17845.xml","doi":null,"earliestYearBP":247618,"earliestYearCE":-245668,"entryId":"noaa-icecore-17845","funding":[],"investigators":"Wolff, E.W.; Moore, J.C.; Clausen, H.B.; Hammer, C.U.","mostRecentYearBP":466,"mostRecentYearCE":1484,"onlineResourceLink":"https://www.ncdc.noaa.gov/paleo/study/17845","originalSource":null,"publication":[{"abstract":"High-resolution continuous profiles were obtained on the Greenland Ice Core Project (GRIP) ice core using two different electrical methods. After correction for temperature and density, the electrical conductivity method (ECM) technique responds only to acidity, while dielectric profiling (DEP) responds to acid, ammonium, and chloride. Detailed chemistry on a section of glacial-age ice allows us to confirm the calibration factor for chloride in DEP. Acidity dominates the DEP variability in the Holocene, Allerod/Bolling, and larger interstadials; ammonium dominates in the Younger Dry as, while chloride is the major contributor in cold periods including smaller interstadials. From the electrical signals plotted on a linear timescale we can deduce the background (nonvolcanic) acidity of the ice, varying from always acidic in the Holocene to always alkaline in the cold periods. In the interstadials, the ice is close to neutral, with most of it acidic in larger interstadials, most of it alkaline in smaller ones, and rapid alternations within interstadials. It is not clear whether neutralization of individual acidic particles occurred in the atmosphere or whether acid and alkaline particles coexisted until deposition in the snowpack. The changes in acidity observed at GRIP apply at least to all of Greenland and probably to much of North America. There would have been ecological effects and important changes in the uptake of some chemicals onto ice. If acidic sulfate particles were neutralized and removed from the atmosphere, which remains uncertain, then there are atmospheric chemistry and radiative effects that require further investigation.","author":{"name":"Eric W. Wolff, John C. Moore, Henrik B. Clausen, Claus U. Hammer"},"citation":"Eric W. Wolff, John C. Moore, Henrik B. Clausen, Claus U. Hammer. 1997. Climatic implications of background acidity and other chemistry derived from electrical studies of the Greenland Ice Core Project ice core. Journal of Geophysical Research: Oceans, 102(C12), 26325-26332. doi: 10.1029/96JC02223","edition":null,"identifier":{"id":"10.1029/96JC02223","type":"doi","url":"http://dx.doi.org/10.1029/96JC02223"},"issue":"C12","journal":"Journal of Geophysical Research: Oceans","pages":"26325-26332","pubRank":"1","pubYear":1997,"reportNumber":null,"title":"Climatic implications of background acidity and other chemistry derived from electrical studies of the Greenland Ice Core Project ice core","type":"publication","volume":"102"}],"reconstruction":"N","scienceKeywords":null,"site":[{"NOAASiteId":"19973","geo":{"geoType":"Feature","geometry":{"coordinates":["72.58","-37.63"],"type":"POINT"},"properties":{"easternmostLongitude":"-37.63","maxElevationMeters":null,"minElevationMeters":null,"northernmostLatitude":"72.58","southernmostLatitude":"72.58","westernmostLongitude":"-37.63"}},"locationName":"Continent>North America>Greenland","mappable":"Y","paleoData":[{"NOAADataTableId":"28166","coreLengthMeters":null,"dataFile":[{"NOAAKeywords":["earth science>paleoclimate>ice core>physical properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/","linkText":"GRIP Dielectric Profiling (DEP) and Electrical Conductivity (ECM) 2 cm Data Files","urlDescription":"Data Folder","variables":[]},{"NOAAKeywords":["earth science>paleoclimate>ice core>physical properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/gripdep.txt","linkText":"GRIP Dielectric Profiling (DEP) and Electrical Conductivity (ECM) Averaged","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":"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 at sample start"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":"dielectric profiling","cvSeasonality":null,"cvShortName":null,"cvUnit":"microsiemens per meter","cvWhat":"electrical property>electrical conductivity"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":"direct current electrical conductivity measurement","cvSeasonality":null,"cvShortName":null,"cvUnit":"micromole","cvWhat":"electrical property>electrical conductivity"}]},{"NOAAKeywords":["earth science>paleoclimate>ice core>physical 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properties"],"fileUrl":"https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/grip/ecm/dep9.dat","linkText":"dep9.dat","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>depth at sample start"},{"cvAdditionalInfo":null,"cvDataType":"ICE CORES","cvDetail":null,"cvError":null,"cvFormat":"Numeric","cvMaterial":"hydrologic material>bulk ice","cvMethod":"dielectric profiling","cvSeasonality":null,"cvShortName":null,"cvUnit":"microsiemens per meter","cvWhat":"electrical property>electrical conductivity"}]}],"dataTableName":"GRIP1997DEP","dataTableNotes":null,"earliestYear":247618,"earliestYearBP":247618,"earliestYearCE":-245668,"mostRecentYear":466,"mostRecentYearBP":466,"mostRecentYearCE":1484,"species":[],"timeUnit":"cal yr BP"}],"siteName":"GRIP"}],"studyCode":null,"studyName":"GRIP Ice Core Dielectric Profiling and Electrical Conductivity Data ","studyNotes":"GRIP Ice Core Dielectric Profiling (DEP) and Electrical Conductivity (ECM) Data. The files dep1.dat, dep2.dat, etc. contain DEP (dielectric profiling) data from the GRIP ice core drilled at Summit, Greenland at 2 cm resolution.  The file gripdep.dat contains averages over a 55 cm interval.  The ECM values were originally gathered continuously for every 1 cm of the core, but in file are averaged in 55cm intervals.","version":"1.0","xmlId":"15557"}