Impact of Different Clouds on Tropospheric Chemistry

Abstract

There are some experimental evidences that clouds can play an important role on the chemical composition of the troposphere through the modification of photolysis rates, the vertical transport of species and their removal by wet deposition and finally by the aqueous phase chemical reactions within cloud water or rainwater. Chemical analyses in several rainwater samples have demonstrated that it is necessary to know the type of cloud which led to the precipitations (Lefeivre, 1993). This is due to the fact that chemistry in presence of cloud depends on the microphysical features of the cloud which depend the rate of transfer toward aqueous phase. Here, we seek to appreciate the impact of a maritime cloud on tropospheric chemistry in a case of a remote atmosphere. We will make some comparisons with a case of a non-precipitating cloud appearing in the same conditions of temperature and humidity.