Nucleation of sulfuric acid-water and methanesulfonic acid-water solution particles: Implications for the atmospheric chemistry of organosulfur species

Binary nucleation theory is applied to the formation of aqueous sulfuric acid and aqueous methanesulfonic acid particles and the relative rates of aerosol formation in humid atmospheres are compared. An integral model is presented which describes nucleation of solution particles, aerosol growth, and condensable vapor source and depletion rates. To extend this model, the water activities of the ternary solution, sulfuric acid-methanesulfonic acid-water, are estimated, and growth of the nucleated aerosol by incorporation of both types of acid is considered. Predictions of both forms of the model are compared with the experimental results of Hatakeyama et al. Atmospheric Environment19, 135–141 (1985)] for the photooxidation of dimethylsulfide in humid air.