Second-generation inorganic aerosol model

Abstract

Accurate prediction of the size distribution of the inorganic components of atmospheric aerosols must account for both therthermodynamic properties of the aerosol particles and transport between the gas and aerosol phases. For volatile inorganic species the transport rate is governed by the particle surface partial pressures which, in turn, is determined by the phase state and composition of the aerosol. We develop a model of the temporal composition of atmospheric aerosol particles based on their transport and thermodynamic properties. Included in the model is an improved theory of the temperature and composition dependence of deliquescence. Components of the model are tested against measurements of activity coefficients in single- and multicomponent aqueous solutions and general agreement is found. Aerosol water predictions are significantly higher under conditions of low relative humidity due to the improved theory of deliquescence.