NUMERICAL SIMULATION OF ACIDIFICATION PROCESSES IN COLD CUMULUS CLOUDS

In this paper, a 1-D time dependent cold cumulus chemistry model is presented. In the cold cumulus model, 4 categories of hydrometeors: cloud drops, raindrops, cloud ice crystals, graupel particles, and 18 microphysical interactions are considered, In the chemical model, the source and sink terms for pollutants include: the complicated interactions between pollutants (gases and aerosol particles) and the hydrometeors (especially ice crystals and graupel particles), the exchanges of chemical compounds between two hydrometeors accompanying microphysical processes and the aqueous oxidations of S (IV) to S (VI). The two models are combined to study the acidification processes in cold cumulus clouds.