Author(s)

S. Shiba, K. Hirata & S. Yagi

Abstract

Acidification of growing cloud droplet by absorption of S(>2(g) S. Shiba', Y. Hirata' & S. Yagi^ * Department of Chemical Science and Engineering, Osaka University, Japan ^ Department of Industrial and Systems Engineering, Setsunan University, Japan Abstract Cloud droplets grow by condensing the atmospheric water vapor into themselves, being aided with such cloud condensation nuclei (CCN) as (NH^Sdi particles. Simultaneously by the rainout, i.e., the absorption of the atmospheric gaseous pol- lutants as SO2(g) and HNOsCg), the cloud droplets are acidified during their growth. The rainout (in-cloud scavenging) is the important process of acid rain formation along with the washout (below-cloud scavenging). However, the acidification pro- cess by rainout have not been made clear yet. In order to estimate the contribution of rainout to acid rain formation, the acidification of growing cloud droplets is in- vestigated numerically, using a mathematical model based on the physico-chemical cons

Keywords