HR: 08:15h
AN: A41E-02    [Abstracts]
TI: CCN and absorption in biomass burning, urban pollution and dust particles observed in-situ over North America
AU: * Shinozuka, Y
EM: yohei@hawaii.edu
AF: Department of Oceanography, University of Hawaii, 1000 Pope Road, Honolulu, HI 96822, United States
AU: Clarke, A D
EM: tclarke@soest.hawaii.edu
AF: Department of Oceanography, University of Hawaii, 1000 Pope Road, Honolulu, HI 96822, United States
AU: Kapustin, V N
EM: kapustin@soest.hawaii.edu
AF: Department of Oceanography, University of Hawaii, 1000 Pope Road, Honolulu, HI 96822, United States
AU: Howell, S G
EM: showell@soest.hawaii.edu
AF: Department of Oceanography, University of Hawaii, 1000 Pope Road, Honolulu, HI 96822, United States
AU: DeCarlo, P
EM: decarlop@colorado.edu
AF: University of Colorado, UCB 216 CIRES Building Room 317, Boulder, CO 80309-0216, United States
AU: Jimenez, J L
EM: jose.jimenez@colorado.edu
AF: University of Colorado, UCB 216 CIRES Building Room 317, Boulder, CO 80309-0216, United States
AB: For possible remote sensing of cloud condensation nuclei (CCN) concentration, we stratify their relationship with optical properties using comprehensive aircraft observations over the USA, Mexico and northeastern Pacific Ocean. We use size distribution, volatility, chemical mass, and scattering and absorption spectra measured for biomass burning, urban pollution and dust aerosols from DC8 and C130 aircraft during INTEX-NA, MIRAGE, IMPEX and INTEX-B. Our preliminary results show the scattering wavelength dependence stratifies the link between aerosol extinction and number in a nearly identical manner over the different regions. Also, volatile organic compounds measured with an aerosol mass spectrometer (AMS) appear associated with suppressed particle growth around the CCN critical activation diameter (30 - 140 nm) and steep absorption wavelength dependence. These observations suggest the potential for remotely sensed single scattering albedo spectra to detect the presence of organic compounds and reduced CCN concentration. Coarse dust particles are also associated with high absorption wavelength dependence and low aerosol number, but are distinguished from the dominantly submicron biogenic components by different scattering wavelength dependence. The link between absorption and microphysical properties are addressed for soot and inorganic components as well, with a focus on the variation in volume absorption efficiency with mixing and ageing status. Volatile material condenses upon the soot particles as they age. Heating the aerosol to 400C upstream of a particle soot absorption photometer (PSAP) resulted in 0 - 30% reduction in soot absorption, presumably due to removal of the volatile coatings.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly