HR: 12:05h
AN: A12A-08    [Abstracts]
TI: Sensitivity of Ozone to Bromine in the Lower Stratosphere
AU: * Salawitch, R J
EM: ross.salawitch@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr., MS 183-601, Pasadena, CA 91109 United States
AU: Sioris, C E
EM: csioris@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 United States
AU: Weisenstein, D K
EM: weisenstein@aer.com
AF: Atmospheric and Environmental Research, Inc, 131 Hartwell Ave., Lexington, MA 02421 United States
AU: Wennberg, P O
EM: wennberg@gps.caltech.edu
AF: California Institute of Technology, 110 N. Mudd, Pasadena, CA 91125 United States
AU: Kovalenko, L J
EM: ljk@caesar.jpl.nasa.gov
AF: California Institute of Technology, 110 N. Mudd, Pasadena, CA 91125 United States
AU: Chance, K
EM: kchance@cfa.harvard.edu
AF: Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 United States
AU: Ko, M K
EM: m.k.ko@larc.nasa.gov
AF: NASA Langley Research Center, 100 NASA Road, Hampton, VA 23681 United States
AU: McLinden, C A
EM: Chris.McLinden@ec.gc.ca
AF: Meteorological Service of Canada, 4905 Dufferin Street, Toronto, Ont M3H 5T4 Canada
AB: Measurements of BrO suggest that inorganic bromine (Bry) at and above the tropopause is 4 to 8 ppt greater than assumed in most ozone trend assessment models. This additional bromine is likely carried to the stratosphere by short-lived biogenic compounds and their decomposition products, including tropospheric BrO. Inclusion of this additional bromine in an ozone trend simulation increases the computed ozone depletion over the past ~25 years, leading to better agreement between measured and modeled ozone trends. Ozone loss increases because BrO associated with enhanced Bry provides a reaction partner for ClO, supplied by anthropogenic chlorine. Enhanced Bry causes photochemical loss of ozone below 16 km to switch from being controlled by pure HOx catalytic cycles (primarily HO2+O3) to a regime where loss by the BrO+HO2 cycle is nearly comparable to loss by HOx.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0317 Chemical kinetic and photochemical properties
DE: 0340 Middle atmosphere--composition and chemistry
DE: 0341 Middle atmosphere--constituent transport and chemistry (3334)
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting