HR: 16:35h
AN: A34C-03 INVITED    [Abstracts]
TI: Effects of Organic Particle Types and Mixtures on Aerosol Water
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: Takahama, S
EM: stakahama@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: Gilardoni, S
EM: sgilardoni@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: Hawkins, L N
EM: lnahid@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
AB: Some organic compounds are hydrophobic, limiting their water uptake in aerosol particles. If such compounds represent a significant fraction of atmospheric particle numbers, then the expected direct aerosol radiative forcing is smaller than if all particles grow with the efficiency of sulfate in humid conditions. Internal mixtures of organic compounds with sulfate can take up water efficiently. The distribution of organic compounds among particles can have an important effect on aerosol water. Recent measurements by near-edge x-ray absorption fine spectrum (NEXAFS) scanning transmission microscopy (STXM) show that organic particles include many different compositions, including fourteen distinct organic compositions. Yet ambient measurements often reflect internally mixed particles with similar hygroscopic properties. This apparent contradiction increases the uncertainty with which future changes in aerosol composition impact climate.
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0322 Constituent sources and sinks
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting