Aerosols as heterogeneous nuclei

Abstract

The major purpose of determining the water and ice nucleating effectiveness of atmospheric aerosols is to evaluate their effects upon cloud and precipitation formation. A review of classical heterogeneous nucleation theory shows the nucleating effectiveness to depend in an important way upon so many complex factors that the only possible approach is direct measurement. The same complexities affect both the measuring technique and the action of the aerosol within clouds. Consequently the techniques must be adapted to the kind of natural environment that the aerosol will encounter, in each specific case, before any important conclusions can be drawn from nucleus measurements.