HR: 0830h
AN: A51F-0760 [PDF]
TI: Concerning Organic Aerosol Components and Ice Nucleation in the Upper Troposphere
AU: * DeMott, P J
EM: pdemott@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Cziczo, D J
EM: djcziczo@al.noaa.gov
AF: National Oceanic and Atmospheric Administration, Aeronomy Laboratory, Boulder, CO 80305 United States
AU: Brooks, S D
EM: sbrooks@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Prenni, A J
EM: prenni@lamar.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Kreidenweis, S M
EM: sonia@chem.atmos.colostate.edu
AF: Colorado State University, Department of Atmospheric Science, Fort Collins, CO 80523-1371 United States
AU: Murphy, D M
EM: dmurphy@al.noaa.gov
AF: National Oceanic and Atmospheric Administration, Aeronomy Laboratory, Boulder, CO 80305 United States
AB:
We have obtained evidence in recent field studies indicating an association of the presence of organic aerosol components
with impedance of homogeneous freezing nucleation of ice at upper tropospheric conditions. It is important to understand any
direct relation between certain organic compounds and ice nucleation because of implications for affecting the conditions of
formation, the ice phase composition and ultimately the radiative properties of upper tropospheric clouds. Laboratory studies
are being conducted to examine the impact of certain organic compounds on homogeneous freezing nucleation, either as pure
species or in mixture with ammonium sulfate. We will present the field evidence for impacts of organic compounds on ice
nucleation, discuss some ways that these substances could affect homogeneous ice nucleation and summarize the results of
ongoing studies of ice formation by certain organic acid/ammonium sulfate mixtures.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
DE: 0365 Troposphere--composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2003 Fall Meeting