Atmospheric Gas-Aerosol Equilibrium: III. Thermodynamics of Crustal Elements Ca2+, K+, and Mg2+

Thermodynamics of the water-soluble crustal ionic species Ca2+, K +, and Mg2+ are added to that of those species already included (Na +, NH4+, CI-, N03-, and SO42 -) in the gas-particle equilibrium model SCAPE (Kim et aI., 1993ab) which estimates the state and composition of atmospheric inorganic species be- tween the gas and aerosol phases. Thermodynamic properties for the aerosol species that include the above ions, equilibrium constants, ionic activity coefficients, water activity, and deliquescence points, are estimated. Various methods for activity coefficient estimation are compared.