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Emission, evolution, and radiative properties of particles from biomass burning in Brazil

Show simple item record Reid, Jeffrey Spencer en_US 2009-10-07T00:52:26Z 2009-10-07T00:52:26Z 1998 en_US
dc.identifier.other b42771328 en_US
dc.identifier.other 41752823 en_US
dc.identifier.other Thesis 47641 en_US
dc.description Thesis (Ph. D.)--University of Washington, 1998 en_US
dc.description.abstract In this dissertation measurements of the physical, chemical, and radiative properties of biomass-burning particles, obtained by the Cloud and Aerosol Research Group (CARG), Department of Atmospheric Science, are described and discussed. Data on aging smoke particles were collected by the CARG from the University of Washington C-131A aircraft as part of the Smoke, Clouds, and Radiation (SCAR) studies on the US West Coast (SCAR-C, September, 1994), and in Brazil (SCAR-B, August and September, 1995).The physical and optical characteristics of smoke particles were measured from three prescribed forest fires on the U.S. West Coast, and from nineteen forest, cerrado, and grass fires in Brazil. The sizes of the particles from tropical forest fires were related to fuel type, fire intensity, and combustion efficiency. An analysis of smoke particles in regional hazes in Brazil suggests that as smoke aerosols age, their particle sizes increase by $\sim$30-50% by coagulation and gas-to-particle conversion. Furthermore, condensation and gas-to-particle conversion of organic vapors increase the aerosol mass by $\sim$20-40%. One-third to one-half of this mass growth likely occurs in the first few hours of aging due to the condensation of large primary organic molecules. The remaining mass growth probably is probably produced by photochemical and cloud processing over time periods of several days.Changes in particle sizes and compositions during the aging of smoke in Brazil have a large impact on the optical properties of the aerosol. Over a two to four day period, the fine particle mass scattering efficiency increased by more than 30%, and the single-scattering albedo increased by $\sim$0.04-0.1. Conversely, the Angstrom coefficient, backscatter ratio, and mass absorption efficiency decreased significantly with age, due no doubt to particle growth.Smoke particles are also shown to affect some cloud properties, Although in the presence of heavy smoke (CN concentrations $>$2,500 cm$\sp{-3}$), perturbations in smoke particle concentration do not affect the cloud droplet effective radius of convective cumuliform clouds. However, in stratiform clouds, smoke particles may affect the cloud droplet effective radius and hence cloud reflectivity. en_US
dc.format.extent x, 301 p. en_US
dc.language.iso en_US en_US
dc.rights Copyright is held by the individual authors. en_US
dc.rights.uri en_US
dc.subject.other Theses--Atmospheric sciences en_US
dc.title Emission, evolution, and radiative properties of particles from biomass burning in Brazil en_US
dc.type Thesis en_US

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