Aerosol growth and the condensation coefficient for water: a review

The transfer of gas phase species to aerosols depends critically on the condensation (or sticking) coefficient. Reported values for water on water vary from 0.03 to 1. Theoretical arguments indicate that the condensation coefficient should be near unity for polar species on an aqueous surface. As long as heat transfer is properly accounted for, measurements on bulk water support this conclusion. The theory of aerosol growth is reviewed and a somewhat modified form is presented. Experimental measurements of aerosol growth are consistent with a condensation coefficient of unity but indicate that the thermal accommodation coefficient may be somewhat smaller. Aerosols grown on natural condensation nuclei may have smaller condensation coefficients owing to the presence of organic films.