Interaction Between Aerosol Particles and Stratocumulus Clouds

The aim of the paper was to develop a numerical model to study the interaction between aerosol particles and stratocumulus clouds in different air mass types. A detailed microphysical scheme was incorporated into an idealized two-dimensional kinematic model to investigate the role of the aerosol particles in the formation of the cloud, regeneration and the wash out of the aerosol particles. The calculations were made with different cloud condensation nuclei size distributions and concentrations typical for maritime, rural and remote continental air mass types, furthermore with two different updraft profiles. The water droplets were formed on soluble ammonium-sulfate aerosol particles. The drops grew by condensation and collision coalescence in the updraft core, but they evaporated due to the subsaturation in the downdraft region. The model clearly simulated the regeneration of the aerosol particles. The majority of the water soluble particles were washed out by nucleation scavenging. The efficiency of the scavenging of the water insoluble particles depended on the concentration of the water soluble aerosol particles. Results of the simulation show that in the case of the stratocum