The effect of H2O adsorption on cloud drop activation of insoluble particles: a theoretical framework R. Sorjamaa1 and A. Laaksonen1,2 1University of Kuopio, Department of Physics, P.O. Box 1627, 70211 Kuopio, Finland 2Finnish Meteorological Institute, P.O. Box 503, 00101 Helsinki, Finland
Abstract. Cloud droplet activation of wettable insoluble compounds
has been studied theoretically by assuming that droplet growth
happens through multilayer adsorption. The idea is to include an adsorption isotherm
in Köhler theory instead of the solute term. This makes it possible
to describe the equilibrium growth of insoluble particles and to
find out their critical saturation ratios. The critical saturation ratios
calculated in this way are comparable to those of completely soluble particles
at certain ranges of adsorption isotherm parameter values. The results indicate
that adsorption could cause wettable insoluble compounds to activate in atmospheric conditions.
However, more data on the adsorption parameters for wettable organic substances is needed to confirm this conclusion.
Citation: Sorjamaa, R. and Laaksonen, A.: The effect of H2O adsorption on cloud drop activation of insoluble particles: a theoretical framework, Atmos. Chem. Phys., 7, 6175-6180, doi:10.5194/acp-7-6175-2007, 2007.