GISP2 Ice Core Isotope Concentrations in Trapped Air Sowers, T.; Brook, E.J.; Etheridge, D.M.; Blunier, T.; Fuchs, A.; Leuenberger, M.; Chappellaz, J.A.; Barnola, J.M.; Wahlen, M.; Deck, B.; Weyhenmeyer, C. Sowers, T. Brook, E.J. Etheridge, D.M. Blunier, T. Fuchs, A. Leuenberger, M. Chappellaz, J.A. Barnola, J.M. Wahlen, M. Deck, B. Weyhenmeyer, C. earth science/paleoclimate/ice cores (delta 18O,oxygen gas,null,per mil AIR,null,ice cores,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/ice cores (depth at sample start,null,null,meter,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta 18O,oxygen gas,null,per mil AIR,null,ice cores,null,isotope ratio mass spectrometry|wet extraction,N,null) earth science/paleoclimate/ice cores (delta 15N,nitrogen gas,null,per mil AIR,null,ice cores,null,isotope ratio mass spectrometry|wet extraction,N,null) earth science/paleoclimate/ice cores (delta CO2/N2,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry|wet extraction,N,gravitationally corrected) earth science/paleoclimate/ice cores (depth at sample end,null,null,meter,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta 15N,nitrogen gas,null,per mil AIR,null,ice cores,null,isotope ratio mass spectrometry,N,null) earth science/paleoclimate/ice cores (sample identification,null,null,null,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta O2/N2,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry,N,gravitationally corrected) earth science/paleoclimate/ice cores (delta CO2/N2,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry,N,gravitationally corrected) earth science/paleoclimate/ice cores (depth,null,null,meter,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta 18O,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry,N,gravitationally corrected) earth science/paleoclimate/ice cores (ice age at sample end,null,null,calendar year before present,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta O2/N2,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry|wet extraction,N,gravitationally corrected) earth science/paleoclimate/ice cores (delta Ar/N2,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry,N,gravitationally corrected) earth science/paleoclimate/ice cores (delta O2/Ar,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry,N,gravitationally corrected) earth science/paleoclimate/ice cores (ice age at sample start,null,null,calendar year before present,null,ice cores,null,null,N,null) earth science/paleoclimate/ice cores (delta 18O,bulk atmosphere,null,per mil AIR,null,ice cores,corrected,isotope ratio mass spectrometry|wet extraction,N,gravitationally corrected) earth science/paleoclimate/ice core (GISP2>LATITUDE 72.6>LONGITUDE -38.5) We undertook an interlaboratory comparison of techniques used to extract and analyze trapped gases in ice cores. The intercomparison included analyses of standard reference gases and samples of ice from the Greenland Ice Sheet Project 2 (GISP2) site. Concentrations of CO2, CH4, the d18O of O2, the d15N of N2, and the O2/N2, and Ar/N2 ratios were measured in air standards and ice core samples. The standard reference scales for CO2 and CH4 were consistent at the +/-2% level. The dO2/N2 and d18O of O2 measurements showed substantial deviations between the two laboratories able to measure these ratios. The deviations are probably related to errors associated with calibration of the working standards. The dArN2 and d15N of N2 measurements were consistent. Five laboratories analyzed the CH4 concentration in a 4.2-m section of the GISP2 ice core. The average of 20 discrete CH4 measurements was 748+/-10 parts per billion by volume (ppbv). The standard deviation of these measurements was close to the total analytical uncertainty associated with the measurements. In all cases, those laboratories employing a dry extraction technique determined higher CH4 values than laboratories using a wet extraction technique. The origin of this difference is unclear but may involve uncertainties associated with blank corrections. Analyses of the CO2 concentration of trapped gases showed extreme variations which cannot be explained by analytical uncertainties alone. Three laboratories measured the [CO2] on 21 discrete depths yielding an average value of 283+/-13 parts per million by volume (ppmv). In this case, the standard deviation was roughly a factor of 2 greater than the analytical uncertainties. We believe the variability in the measured [CO2] results from impurities in the ice which may have compromised the [CO2] of trapped gases in Greenland ice. STUDY NOTES: Gas isotopes from 72 - 2235 meters depth. All data are presented using the delta notation where the standard is the present day atmosphere. The numbers in the column headings refer to the mass of the gas in question (ie. 32=16 O2, oxygen, 28=14 N2, nitrogen, 40=argon, 44 = CO2). NCDC-Paleoclimatology https://www.ncdc.noaa.gov/data-access/paleoclimatology-data - Bauer Bruce Investigator : Sowers, T. Investigator : Brook, E.J. Investigator : Etheridge, D.M. Investigator : Blunier, T. Investigator : Fuchs, A. Investigator : Leuenberger, M. Investigator : Chappellaz, J.A. Investigator : Barnola, J.M. Investigator : Wahlen, M. Investigator : Deck, B. Investigator : Weyhenmeyer, C. 1997-11-30 ONLINE Files online, ASCII https://www.ncdc.noaa.gov/paleo/study/17826 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/gascomp.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/gas.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/gascomp.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/gas.txt English https://www.ncdc.noaa.gov/paleo/study/17826 https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/gascomp.txt https://www1.ncdc.noaa.gov/pub/data/paleo/icecore/greenland/summit/gisp2/gases/gas.txt Todd Sowers, Ed Brook, David Etheridge, Thomas Blunier, Andreas Fuchs, Markus Leuenberger, Jerome Chappellaz, Jean Marc Barnola, Martin Wahlen, Bruce Deck, Connie Weyhenmeyer1997An interlaboratory comparison of techniques for extracting and analyzing trapped gases in ice coresJournal of Geophysical Research: Oceans102C1226527-2653810.1029/97JC00633http://onlinelibrary.wiley.com/enhanced/doi/10.1029/97JC00633/ START YEAR: 38646 cal yr BP * END YEAR: 169 cal yr BP -38.5 72.6 -38.5 72.6