HR: 13:55h
AN: A43E-02    [Abstracts]
TI: Organic Aerosol Growth Mechanisms and their Climate Forcing Implications
AU: Maria, S F
EM: smaria@princeton.edu
AF: SciTec, Wall St., Princeton, NJ 08542 United States
AU: * Russell, L M
EM: lmrussell@ucsd.edu
AF: Scripps Institution of Oceanography, University of California San Diego, 9500 Gilman Dr. Mail Code 0221, La Jolla, CA 92093-0221 United States
AU: Gilles, M K
EM: mkgilles@lbnl.gov
AF: Lawrence Berkeley National Laboratories, Advanced Light Source, Berkeley, CA 94720 United States
AU: Myneni, S
EM: smyneni@princeton.edu
AF: Lawrence Berkeley National Laboratories, Advanced Light Source, Berkeley, CA 94720 United States
AB: Chemical reactions leave signatures in aerosol particle size distributions of organic functional group composition, from which we measured conversion rates of 13-24% per day. This rate varied little for both surface and volume-limited reactions on African mineral dust with primary organic, Asian black carbon, and American secondary organic aerosols, but all measured rates were a factor of three lower than the 60% per day typically used in climate models. The particle types observed reflected a range of altitudes from 85 to 2000 m above sea level, of natural and anthropogenic sources, and of reaction mechanisms all with very similar rates for converting from volatile or hydrophobic to condensed and hydrophilic organic compounds. These longer-lived, less-oxidized, hydrophobic organic particles will increase carbonaceous aerosol burdens in climate models by 70%.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0317 Chemical kinetic and photochemical properties
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting