HR: 08:00h
AN: A21D-01    [Abstracts]
TI: Overview of the Antarctic Tropospheric Chemistry Investigation (ANTCI)
AU: * Eisele, F L
EM: eisele@ucar.edu
AF: National Center for Atmospheric Research, 1850 Table Mesa Dr., Boulder, CO 80305 United States
AU: * Eisele, F L
EM: eisele@ucar.edu
AF: Georgia Institute of Technology, 311 Ferst Dr., Atlanta, GA 30332 United States
AU: Davis, D D
EM: Dpigarden@aol.com
AF: Georgia Institute of Technology, 311 Ferst Dr., Atlanta, GA 30332 United States
AB: The first ANTCI campaign took place during the austral spring/early summer from the second half of November through December of 2003. It consisted of ground based measurements at the South Pole and Twin Otter aircraft studies over portions of the polar plateau, glacial valleys, and the coast of the Ross Sea. The study makes use of previous findings of the Investigation of Sulfur Chemistry in the Antarctic Troposphere (ISCAT) and Sulfur Chemistry of the Antarctic Troposphere Experiment (SCATE) to define and address critical questions about what controls oxidation rates in the Antarctic troposphere and how these rates influence the evolution of reactive sulfur and nitrogen gases in the atmosphere prior to their incorporation into the ice core record. Ground based studies focused on vertical mixing and local photochemistry and sulfur chemistry. Boundary layer mixing heights were determined by several different methods including: acoustic sounder measurements up to 80 m, tethered balloon measurements of meteorological parameters and ozone to 500 m, and tethered balloon measurements of NO to 100m. These vertical measurements were designed to supplement a much larger suite of chemical measurements made from the South Pole ARO building in order to explore how chemical emissions from the snow mix into the lower troposphere and influence the photochemical oxidation process and its products. Aircraft measurements began the process of defining the horizontal extent of elevated NO concentrations over the plateau, which is presumed to result in enhanced photochemical oxidation rates. Flights also briefly investigated flow along large glacial valleys and the outflow of reactive nitrogen from the continent and the inflow of reactive sulfur gases like dimethyl sulfide.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0365 Troposphere--composition and chemistry
DE: 0368 Troposphere--constituent transport and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting