May 14, 2008

Antarctic Ice Cores Revised 800KYr CO2 Data

by
Bereiter, B.; Eggleston, S.; Schmitt, J.; Nehrbass-Ahles, C.; Stocker, T.F.; Fischer, H.; Kipfstuhl, S.; Chappellaz, J.A.
,
NOAA National Centers for Environmental Information
  • The European Project for Ice Coring in Antarctica Dome ice core from Dome C (EDC) has allowed for the reconstruction of atmospheric CO2 concentrations for the last 800,000 years
  • Revisits the oldest part of the EDC CO2 record using different air extraction methods and sections of the core
  • Corrected record presented here resolves partly - but not completely - the issue with a different correlation between CO2 and Antarctic temperatures found in this oldest part of the records
  • Provides an update of 800,000 years atmospheric CO2 history including recent studies covering the last glacial cycle
  • Original study abstract:
    • States that changes in past atmospheric carbon dioxide concentrations can be determined by measuring the composition of air trapped in ice cores from Antarctica
    • States that so far, the Antarctic Vostok and EPICA Dome C ice cores have provided a composite record of atmospheric carbon dioxide levels over the past 650,000 years
    • Presents results of the lowest 200 m of the Dome C ice core, extending the record of atmospheric carbon dioxide concentration by two complete glacial cycles to 800,000 yr before present
    • Finds, from previously published data and the present work, that atmospheric carbon dioxide is strongly correlated with Antarctic temperature throughout eight glacial cycles but with significantly lower concentrations between 650,000 and 750,000 yr before present