HR: 0800h
AN: A21C-0889    [Abstracts]
TI: Halogen Atom Ratios in the Springtime Arctic Troposphere as Determined From Measurements of Halogenated Volatile Organic Compounds
AU: * Keil, A
EM: keilad@purdue.edu
AF: Department of Chemistry, Purdue University, 560 Oval Drive, Lafayette, IN 47907-2084 United States
AU: Shepson, P B
EM: pshepson@purdue.edu
AF: Department of Chemistry, Purdue University, 560 Oval Drive, Lafayette, IN 47907-2084 United States
AB: The concentrations of a suite of halogenated volatile organic compounds (HVOCs) were measured near Barrow, Alaska from January to April 2005. The HVOCs are produced from the reaction of ethene and propene with bromine and chlorine atoms, which are important atmospheric oxidants in the Arctic troposphere. Chlorine atom oxidation is responsible for significant decreases in non-methane hydrocarbons and bromine atoms are thought to be responsible for the catalytic destruction of tropospheric ozone and mercury. The HVOC concentrations are used to probe the sources of these halogen atoms and their relative ambient concentrations. We find evidence for local production of the halogen atom precursors, and determine [Br]/[Cl] to be between 20 and 300, somewhat lower than those determined by VOC decay methods.
DE: 0365 Troposphere: composition and chemistry
DE: 0394 Instruments and techniques
DE: 0794 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: Fall Meeting 2005