HR: 1340h
AN: A53B-1156    [Abstracts]
TI: Investigation of the Factors Influencing Volatile Chemical Fate During Steady-state Accretion on Wet-growing Hail
AU: * Michael, R A
EM: rmichael@mail.usf.edu
AF: Department of Civil and Environmental Engineering, 4202 E Fowler Avenue, ENB 118, Tampa, FL 33620, United States
AU: Stuart, A L
EM: astuart@hsc.usf.edu
AF: Department of Civil and Environmental Engineering, 4202 E Fowler Avenue, ENB 118, Tampa, FL 33620, United States
AU: Stuart, A L
EM: astuart@hsc.usf.edu
AF: Department of Environmental and Occupational Health, 13201 Bruce B. Downs Blvd, MDC 56, Tampa, FL 33612-3805, United States
AB: Phase partitioning during freezing affects the transport and distribution of volatile chemical species in convective clouds. This consequently can have impacts on tropospheric chemistry, air quality, pollutant deposition, and climate change. Here, we discuss the development, evaluation, and application of a mechanistic model for the study and prediction of volatile chemical partitioning during steady-state hailstone growth. The model estimates the fraction of a chemical species retained in a two-phase freezing hailstone. It is based upon mass rate balances over water and solute for accretion under wet-growth conditions. Expressions for the calculation of model components, including the rates of super-cooled drop collection, shedding, evaporation, and hail growth were developed and implemented based on available cloud microphysics literature. Solute fate calculations assume equilibrium partitioning at air-liquid and liquid-ice interfaces. Currently, we are testing the model by performing mass balance calculations, sensitivity analyses, and comparison to available experimental data. Application of the model will improve understanding of the effects of cloud conditions and chemical properties on the fate of dissolved chemical species during hail growth.
DE: 0320 Cloud physics and chemistry
DE: 0365 Troposphere: composition and chemistry
DE: 3311 Clouds and aerosols
DE: 3354 Precipitation (1854)
DE: 3369 Thermospheric dynamics (0358)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting