Abstract
Asian sandstorm particles called “Kosa”, which are emitted from the desert area of China and transported to the north pacific countries, can affect the cloud droplet formation. Sorption of the atmospheric gaseous species on the sand surface during the transport makes a kind of composite CCN. In order to investigate the effect of sand particles embedded in the composite CCN on the equilibrium cloud droplet size, numerical simulations are done using the new mathematical model for competitive growth of cloud droplets. The new model has been constructed based on the physicochemical consideration. The numerical results with composite CCN composed of kernel water-insoluble sand (quartz) and its coat of soluble chemicals (ammonium sulfate) show that the larger the kernel sand size, the more the amount of vapor is condensed. That is, sand kernel of composite CCN makes the net droplet size (exclusive sand) larger.
