HR: 1330h
AN: A22C-1074    [PDF]
TI: EXPERIMENTAL STUDIES OF THE MICROPHYSICS OF CLOUD CONDENSATION NUCLEI AS A FUNCTION OF ORGANIC SOLUTE
AU: * Dure, E
EM: edure-@howard.edu
AF: NOAA CENTER FOR ATMOSPHEREIC SCIENCES, HOWARD UNIVERSITY 525 COLLEGE ST. NW, WASHINGTON, DC 20059 United States
AU: Morris, V R
EM: vmorris@howard.edu
AF: NOAA CENTER FOR ATMOSPHEREIC SCIENCES, HOWARD UNIVERSITY 525 COLLEGE ST. NW, WASHINGTON, DC 20059 United States
AU: Greene, N
EM: tashism@angelfire.com
AF: NOAA CENTER FOR ATMOSPHEREIC SCIENCES, HOWARD UNIVERSITY 525 COLLEGE ST. NW, WASHINGTON, DC 20059 United States
AB: Biomass burning has played, and continues to play a significant part in the lives of indigenous people across the world. Biomass burning results from brushfires, land clearing, and cloud-to-ground lightning strikes, this is particularly true in the tropics. A unique feature about the biomass burning aerosols is that its sources are overwhelmingly confined to the tropics despite evidence that their effects may be global in extent. Recently, Rosenfeld has argued that the inclusion of biomass aerosols into warm clouds can also inhibit precipitation. However, several reported case studies in the literature report precipitation enhancements due to aerosol entrainment as well. Quantitative relationships between the indirect forcing from clouds and anthropogenic aerosol inclusions have not been developed to a point where the resultant prediction of cloud optical properties is reliable. The problem is the lack of understanding of the basic microphysical processes governing cloud droplet nucleation and evolution. This level of understanding requires that the physical chemistry of the systems be well understood. Because such a large fraction of anthropogenic aerosol and specifically biomass aerosol are organic in nature, we have performed laboratory simulations of the nucleation of aerosols with organic inclusions. In our study, homogeneous and heterogeneous nucleation effects were studied for several organic solutions; n-Hexane, benzene, chlorobenzene, nitrobenzene, with and without crushed graphite. We will report results of the analyses of the size distribution characteristics, electrical mobility, and number density characteristics.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting