HR: 0800h
AN: U31A-0006    [Abstracts]
TI: In Situ Production Of CO$_2$ In The Antarctic Siple Dome Ice Core Record
AU: * Ahn, J
EM: jiahn@ucsd.edu
AF: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92092 United States
AU: Wahlen, M
EM: mwahlen@ucsd.edu
AF: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92092 United States
AU: Deck, B L
EM: bdeck@ucsd.edu
AF: Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92092 United States
AU: Brook, E J
EM: brooke@geo.oregonstate.edu
AF: Department of Geosciences, Oregon State University, Corvallis, OR 97331 United States
AU: Mayewski, P A
AF: Climate Change Institute, University of Maine, Orono, ME 04469 United States
AU: Taylor, K C
EM: Kendrick.Taylor@dri.edu
AF: Desert Research Institute, University of Nevada, Reno, NV 89512 United States
AU: White, J W
EM: james.white@colorado.edu
AF: Institute of Arctic and Alpine Research (INSTAAR), University of Colorado, Boulder, CO 80309 United States
AU: Fitzpatrick, J J
EM: jfitz@usgs.gov
AF: National Ice Core Laboratory, U.S. Geological Survey, Denver, CO 80225 United States
AB: Understanding how the atmospheric concentration of CO$_2$ changed in the past in response to other changes in the climate system provides us with a better understanding of how current and future changes in the carbon cycle will influence our future climate. CO$_2$ records from Antarctic ice cores are considered to be representative of paleoatmospheric concentrations because its low dust content might not allow significant in situ production of CO$_2$ by carbonate-acid reaction as shown in Greenland ice cores. Despite similarities in general time series of CO$_2$ records with other Antarctic ice cores, at some depth intervals, the Siple Dome ice shows higher CO$_2$ concentrations by up to 20 ppm (¯¨mol CO$_2$/mol air) than those in other Antarctic ice cores. In order to examine the possible mechanisms of CO$_2$ production in the Siple Dome ice core, we check the CO$_2$ difference between Siple Dome and Taylor Dome or Dome C. With the latest results of chemical and physical studies of the Siple Dome ice we discuss three possible mechanisms for the in situ production of CO$_2$ in the Siple Dome ice core: (1) carbonate-acid reaction, (2) oxidation of organic compounds, and (3) snowmelting/refreezing.
DE: 3344 Paleoclimatology
DE: 1827 Glaciology (1863)
DE: 1615 Biogeochemical processes (4805)
DE: 0325 Evolution of the atmosphere
SC: Union [U]
MN: 2004 AGU Fall Meeting