A record of atmospheric CO sub(2) during the last 40,000 years from the Siple Dome, Antarctica ice core

• Published in: Journal of Geophysical Research. D. Atmospheres 2004-07, Vol.109 (D13)
• Main Authors: Ahn, Jinho, Wahlen, Martin, Deck, Bruce L, Brook, Ed J, Mayewski, Paul A, Taylor, Kendrick C, White, James WC
• Format: Article
• Language: English
• ISSN: 0148-0227
• DOI: 10.1029/2003JD004415

We have measured the CO sub(2) concentration of air occluded during the last 40,000 years in the deep Siple Dome A (hereafter Siple Dome) ice core, Antarctica. The general trend of CO sub(2) concentration from Siple Dome ice follows the temperature inferred from the isotopic composition of the ice and is mostly in agreement with other Antarctic ice core CO sub(2) records. CO sub(2) rose initially at similar to 17.5 kyr B.P. (thousand years before 1950), decreased slowly during the Antarctic Cold Reversal, rose during the Younger Dryas, fell to a local minimum at around 8 kyr B.P., and rose continuously since then. The CO sub(2) concentration never reached steady state during the Holocene, as also found in the Taylor Dome and EPICA Dome C (hereafter Dome C) records. During the last glacial termination, a lag of CO sub(2) versus Siple Dome isotopic temperature is probable. The Siple Dome CO sub(2) concentrations during the last glacial termination and in the Holocene are at certain times greater than in other Antarctic ice cores by up to 20 ppm ( mu mol CO sub(2)/mol air). While in situ production of CO sub(2) is one possible cause of the sporadic elevated levels, the mechanism leading to the enrichment is not yet clear.