HR: 0800h
AN: A11A-0032    [Abstracts]
TI: Numerical Simulations of Aerosol Effects on Precipitation Pathways in Deep Convective Clouds
AU: * Tessendorf, S A
EM: sarah.tessendorf@noaa.gov
AF: CIRES/ESRL, NOAA ESRL DSRC R/CSD3 325 Broadway, Boulder, CO 80305,
AU: Feingold, G
EM: graham.feingold@noaa.gov
AF: NOAA/ESRL, DSRC R/CSD3 325 Broadway, Boulder, CO 80305,
AB: The Regional Atmospheric Modeling System (RAMS; version 4.3) is used to simulate two-dimensional idealized deep convection using a two-moment bulk microphysics scheme for two cases: the "clean" case is initialized with a low concentration (100/cc) of aerosol serving as cloud condensation nuclei (CCN), while the "polluted" case has a higher concentration of CCN (1000/cc). In this study, the microphysical sources and sinks for each precipitation type are studied to reveal the variations in precipitation pathways between the clean and polluted clouds. We will also repeat these simulations for varying thermodynamic profiles. Preliminary results from these initial simulations show that the more polluted cloud produces less precipitation, at least during its initial phase prior to the onset of secondary convection, which is consistent with other numerical studies of the effects of aerosol on the quantity of precipitation output. Furthermore, warm rain processes are the dominant source for rain in the clean case throughout the simulation, whereas rain sources in the polluted case quickly become dominated by ice processes. This presentation will focus on the dominant pathways for rain and how they vary between the clean and polluted cases, and with changing thermodynamic conditions.
DE: 0320 Cloud physics and chemistry
DE: 3311 Clouds and aerosols
DE: 3314 Convective processes
DE: 3354 Precipitation (1854)
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting