HR: 11:50h
AN: A42A-07    [Abstracts]
TI: Contrast Between the Sources and Atmospheric Processing of Fine Particles from Asia and North America Measured During INTEX B
AU: * Weber, R
EM: rweber@eas.gatech.edu
AF: Georgia Tech, 311 Ferst, Atlanata, GA 30032, United States
AU: Peltier, R
EM: rpeltier@eas.gatech.edu
AF: Georgia Tech, 311 Ferst, Atlanata, GA 30032, United States
AU: Hecobian, A
EM: arsineh.hecobian@eas.gatech.edu
AF: Georgia Tech, 311 Ferst, Atlanata, GA 30032, United States
AU: Blake, D
EM: drblake@uci.edu
AF: University of California, Irvine, 570 Rowland Hill, Irvine, CA 92697, United States
AU: Atlas, E
EM: drblake@uci.edu
AF: University of Miami, RSMAS, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Riemer, D
EM: driemer@rsmas.miami.edu
AF: University of Miami, RSMAS, 4600 Rickenbacker Causeway, Miami, FL 33149, United States
AU: Karl, T
EM: tomkarl@ncar.edu
AF: NCAR, PO Box 300, Boulder, CO 80307, United States
AU: Apel, E
EM: apel@acd.ucar.edu
AF: NCAR, PO Box 300, Boulder, CO 80307, United States
AU: Campos, T
EM: campos@ucar.edu
AF: NCAR, PO Box 300, Boulder, CO 80307, United States
AU: Stohl, A
EM: ast@nilu.no
AF: Norwegian Institute for Air Research, PO Box 100, Kjeller, N-2027, Norway
AB: During the Intercontinental Chemical Transport Experiment, Phase B (INTEX B), conducted in the spring of 2006, airborne measurements were made in the United States Pacific Northwest of the major inorganic ions and the water-soluble organic carbon (WSOC) of submicron (PM1.0) aerosol. An atmospheric trajectory and a particle dispersion model for CO sources (Flexpart) was used to segregate air masses into those of primarily Asian influence (greater than 75 percent Asian CO) or North American influence (greater than 75 percent North American CO). Measured components of fine particle mass mostly consisted of water-soluble organic carbon and sulfate, with highest median WSOC and sulfate concentrations in North American air masses. Curiously, the fraction of sulfate to WSOC was significantly higher at altitudes above 3 km, opposite to what has been observed closer to Asia and in the northeastern United States. The observations could be explained by loss of sulfate and organic aerosol due to precipitation scavenging near Asia, with reformation of only sulfate during advection from Asia to North America. WSOC sources were investigated by multivariate linear regression analyses of volatile organic compounds (VOCs). In Asian air masses detected over the Pacific Northwest, of the WSOC variability that could be explained (49 percent), most was related to fossil fuel combustion VOCs, compared to North American air masses, where 75 percent of the WSOC variability was explained through a nearly equal combination of fossil fuel combustion and biogenic VOCs. The most distinct WSOC plumes of the mission were from the California Central Valley, where WSOC variability was related to a mix of biogenic and anthropogenic VOCs. These plumes appeared to be related to secondary organic aerosol formation associated with cloud processing.
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting