HR: 08:20h
AN: A41G-02 INVITED    [Abstracts]
TI: Iodine: The missing halogen of polar tropospheric chemistry
AU: * Saiz-Lopez, A
EM: alfonso.saiz-lopez@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Boxe, C S
EM: Christopher.Boxe@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AU: Chance, K
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden street, Cambridge, 02138-1516, United States
AU: Kurosu, T P
EM: tkurosu@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden street, Cambridge, 02138-1516, United States
AU: Liu, X
EM: xliu@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden street, Cambridge, 02138-1516, United States
AU: Mahajan, A
EM: a.s.mahajan05@leeds.ac.uk
AF: University of Leeds, School of Chemistry, Leeds, LS2 9JT, United Kingdom
AU: Plane, J M
EM: J.M.C.Plane@leeds.ac.uk
AF: University of Leeds, School of Chemistry, Leeds, LS2 9JT, United Kingdom
AU: Sander, S P
EM: Stanley.P.Sander@jpl.nasa.gov
AF: NASA Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109, United States
AB: Iodine is important in the Earth's troposphere for several reasons, including the catalytic destruction of ozone, altering the oxidizing capacity, and the formation of ultra-fine aerosol, all with potential impacts on climate. Nevertheless, the role of iodine chemistry has so far remained virtually unconsidered in studies of the polar troposphere. Only recently, the occurrence of high concentrations of IO over vast sea-ice covered areas of the Southern Ocean and around coastal Antarctica has been reported. The sources of such a large iodine burden in the Antarctic atmosphere remain unknown. This talk will address ground- and satellite-based observations of the IO radical over coastal Antarctica. Also, it presents a novel mechanism for biologically-induced iodine release from sea-ice surfaces that initiates an autocatalytic cycle, termed iodine explosion. Numerical modeling studies on the impact of iodine upon the chemistry of the Antarctic troposphere will also be presented.
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0315 Biosphere/atmosphere interactions (0426, 1610)
DE: 0322 Constituent sources and sinks
DE: 0330 Geochemical cycles (1030)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting