Extended Abstract (644K)P1.14
Aerosol-Cloud-Chemistry Interactions in a Large Eddy Simulation
Graham Feingold, NOAA/ETL, Boulder, CO; and S. M. Kreidenweis
Cloud processing of aerosol through both drop collision-coalescence and aqueous chemistry is simulated with the aid of a large eddy simulation and fully coupled components that represent (i) size resolved aerosol, (ii) size-resolved microphysics, and (iii) the conversion of SO2 to sulfate via aqueous chemistry. Prior work with cloud parcel models has shown that the outcome of processing in a stratocumulus-capped marine boundary layer depends strongly on the cloud liquid water content, aerosol concentrations, trace gas concentrations, and contact time with a cloud. The current model represents spatial and temporal variability of these parameters at large eddy scales on the order of a few hundred meters and timescales on the order of a few seconds. A number of scenarios are presented here: (i) a case with relatively low aerosol concentrations where aqueous chemistry processing does not substantially affect drizzle; (ii) a case with intermediate aerosol concentrations of relatively large size where drizzle is suppressed by aqueous chemistry; (iii) a case with intermediate aerosol concentrations of relatively small size where drizzle is enhanced by aqueous chemistry. The simulations indicate that aqueous chemistry can modify the dynamics and microphysics of stratocumulus clouds and points to the complexity of the coupled system. This work suggests that parameterizations of the effects of cloud processing of aerosol require careful consideration of the myriad feedbacks in the cloudy boundary layer.
Poster Session 1, Cloud Physics Poster Session I (Parallel with Joint Poster Session JP1)
Monday, 3 June 2002, 1:00 PM-4:00 PM
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