HR: 1330h
AN: A22C-1082    [PDF]
TI: Physical, Chemical, and Optical Properties of Smoke-Impacted Aerosols in Yosemite National Park
AU: Carrico, C
EM: carrico@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: * Kreidenweis, S
EM: sonia@chem.atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: Collett, J
EM: collett@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: McMeeking, G
EM: grm@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: Lee, T
EM: thlee@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: Carrillo, J
EM: heath@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: Herckes, P
EM: herckes@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AU: Engling, G
EM: gengling@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Ft. Collins, CO 80523 United States
AB: Elucidation of the role of prescribed and wild fires in North and Central America in influencing visibility in the western U.S. is an important component of regional haze issues. A field study was undertaken in Yosemite National Park in summer 2002 to characterize the physical, chemical and optical properties of ambient aerosols, including days that were heavily impacted by smoke. Observations indicate that the most likely sources of this smoke were the large fires in Oregon and Sequoia National Park that were burning during the study period, contributing to regional haze in some areas of the western U.S. Smoke-impacted periods, as indicated by multiple chemical tracers, featured shifts to larger mean particle diameters, increased fine aerosol mass fractions of organic carbon, and lower aerosol hygroscopicity, relative to non-smoke-impacted days. PM2.5 dry light scattering coefficients (530 nm) were quite high during smoke impacted periods, often exceeding 100 Mm$^{-1}$. We compare the optical characteristics of the smoke-impacted aerosols (mean size, refractive index, and hygroscopicity) with prior measurements of biomass-burning aerosols in Africa and South America.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0345 Pollution--urban and regional (0305)
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting