Acidification of Growing Cloud Droplet by Rainout of SO sub(2)(g)

The acidification of cloud droplets during generation and growth was investigated using a mathematical model. All governing numerical equations in the model are provided, including those governing condensational growth, the radius of the cloud droplet, adsorption and dissolution of sulfur dioxide gas, and reactions and mass conservation of chemical species. Results showed that the rate of acidity variation was much faster than that of the radius variation. The transfer of the chemical mass and heat from the atmosphere to the cloud droplet was dependent upon the cloud condensation nuclei salt concentrations. A close correlation was noted between the time variation of acidity and that of the rate of temperature variation.