HR: 0800h
AN: A21B-0728    [Abstracts]
TI: Examination of Organic Reactions in UT/LS Aerosols: Temperature Dependence in Sulfuric Acid Solution
AU: * Iraci, L T
EM: liraci@mail.arc.nasa.gov
AF: NASA Ames Research Center, MS 245-5, Moffett Field, CA 94035
AU: Michelsen, R R
EM: rmichelsen@mail.arc.nasa.gov
AF: National Research Council, NASA Ames Research Center MS 245-5, Moffett Field, CA 94035
AB: Sulfuric acid has been used for decades as an industrial catalyst for organic reactions, but its parallel role in atmospheric aerosols is relatively unexplored, despite identification of a wide array of organic compounds in particles. Several recent studies have demonstrated possible reactions in acidic particles, generally involving carbonyl groups (C=O) and leading to the formation of larger molecules. Reactions of oxygenated organic compounds in acidic solution are most often studied near room temperature, while the sulfate particles of the upper troposphere and lower stratosphere are significantly colder. Our studies of ethanal (acetaldehyde) suggest that reactivity in ~50 wt% H2SO4 solutions may be enhanced at lower temperatures, contrary to expectations. We will present temperature-dependent results of acid catalyzed condensation reactions, leading to formation of higher molecular weight products. Implications for aerosol composition and reactivity will be discussed.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0340 Middle atmosphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting