Disequilibrium between the short-lived radon daughter products in the lower atmosphere resulting from their washout by rain

Abstract

The concentration changes of the short-lived daughter products of Rn222 in air due to washout have been computed according to a three-phase (gas-aerosol-raindrop) model for a wide range of values of the system parameters. It is shown that the ratio of Pb214 to Bi214 concentrations is a sensitive measure of the relative washout efficiences of free atoms and of aerosol particles by rain. Preliminary experimental results which give the measured values of this ratio for rainy days are presented.