HR: 09:15h
AN: A21D-06 INVITED     [Abstracts]
TI: Modeling and analysis of atmospheric chemistry over the South Pole during ANTCI
AU: * Crawford, J H
EM: James.H.Crawford@nasa.gov
AF: NASA Langley Research Center, MS 483, Hampton, VA 23681
AU: Chen, G
EM: Gao.Chen-1@nasa.gov
AF: NASA Langley Research Center, MS 483, Hampton, VA 23681
AU: Davis, D D
AF: Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA 30332
AU: Buhr, M
AF: Sonoma Technology, Inc., 607 Virginia St., Golden, CO 80403
AU: Eisele, F L
AF: National Center for Atmospheric Research, Atmospheric Chemistry Division, Boulder, CO 80305
AU: Mauldin, R L
AF: National Center for Atmospheric Research, Atmospheric Chemistry Division, Boulder, CO 80305
AU: Huey, L G
AF: Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA 30332
AU: Tanner, D
AF: Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA 30332
AU: Sjostedt, S
AF: Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA 30332
AU: Tan, D
AF: Georgia Institute of Technology, School of Earth and Atmospheric Sciences, Atlanta, GA 30332
AU: Dibb, J E
AF: University of New Hampshire, Climate Change Research Center, Durham, NH 03824
AU: Hutterli, M
AF: University of Arizona, Department of Hydrology and Water Resources, Tucson, AZ 85721
AU: Blake, D R
AF: University of California, Irvine, Department of Chemistry, Irvine, CA 92717
AB: The Antarctic Tropospheric Chemistry Investigation (ANTCI) was conducted at the South Pole during the austral spring of 2003 (22 November to 29 December). This program builds upon the Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) study also conducted at the South Pole in November-December of 1998 and 2000. Although the ISCAT results revealed that very little gas phase sulfur reaches the South Pole, observations of unexpectedly high levels of NOx (routinely reaching a few hundred pptv) were found due to snowpack emissions into the shallow boundary layer of the polar plateau. These NOx emissions in the presence of 24-hr sunlit conditions were also critical to the enhanced OH levels that were observed. Here, the latest measurements from the South Pole are examined in the context of an expanded array of deployed instrumentation. Particular attention will be paid to the interdependence between HOx and NOx with NOx values encompassing a broader range (<10 pptv to ~1 ppbv) than previously observed during the ISCAT experiments. Also of special interest will be observations during the partial (86%) eclipse on 23 November, 2003 which provided a natural setting for testing the internal consistency of the measurements through their response to rapid changes in sunlight conditions. Taking advantage of measurements of HNO3, HO2NO2, and HONO; discussion of the NOy budget will focus on the influence of boundary layer chemical cycling on post-depositional losses of nitrate observed in ice cores from across the polar plateau.
DE: 9310 Antarctica
DE: 3322 Land/atmosphere interactions
DE: 0317 Chemical kinetic and photochemical properties
DE: 0322 Constituent sources and sinks
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting