Abstract
Computed values of equilibrium sizes and composition of uncharged and charged aqueous solution droplets of HNO3 and HCl at 25°C, relative humidifies from 5 to 101%, and solute vapor activities from 10− to 107 are presented. Threshold concentrations for heteromolecular nucleation of HNO3 and HCl at 40, 30, 20, 10, 0, and −10°C are also given as a function of the relative humidity. It is shown that atmospheric concentrations of HNO3 and HCl can participate in nucleation at temperatures below 20°C and relative humidifies above 98%. The nature of the nucleation of HNO3 and HCl in the atmosphere including ion-induced nucleation for which there is no threshold and some of the available experimental results are discussed.
