HR: 14:10h
AN: A43E-03    [Abstracts]
TI: Acid-Catalyzed Organic Reactions Change the Optical Properties of Atmospheric Sulfuric Acid Aerosols
AU: * Noziere, B
EM: bnoziere@rsmas.miami.edu
AF: University of Miami / RSMAS, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AU: Esteve, W
EM: westeve@rsmas.miami.edu
AF: University of Miami / RSMAS, 4600 Rickenbacker Causeway, Miami, FL 33149 United States
AB: Unlike most environments present at Earth$'$s surface atmospheric aerosols can be favorable to organic reactions. We present series of laboratory experiments showing that the absorption index of sulfuric acid solutions exposed to gas-phase carbonyl compounds known to be present in the atmosphere (acetone, acetaldehyde, methyl ethyl ketone) increases dramatically in the near UV and visible range (190-1100 nm), where aerosols have a direct impact on Earth's radiative balance. Our results show that the absorption index of stratospheric sulfuric aerosols exposed to 100 pptV of acetaldehyde (1 pptV = 10$^{-12}$ v/v) would increase by four orders of magnitude over their lifetime. Rough estimates based on previous radiative calculations suggest that this reaction could result in an increase the radiative forcing of sulfate aerosols of the order of 0.01 W m$^{-2}$.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0317 Chemical kinetic and photochemical properties
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting