Solubility of atmospheric aerosol particles and its impact on cloud microphysics

A new method called `SoFA' was developed to determine the water-soluble fractions of large atmospheric aerosol particles (APs) in five narrow size bands (geometrical radii: 0.4, 0.6, 0.9, 1.3, 1.8 micrometer) and one broad size band (geometrical radius greater than or equal to 2.3 micrometers). An entraining air parcel model was used to investigate the impact of the water-soluble fractions on cloud microphysics. The model simulations show an influence on nucleation scavenging, cloud interstitial aerosol, and drop size population. The same AP-number distribution causes either a precipitating or a non-precipitating cloud depending only upon different water-soluble fractions of the particles.