Clouds affect the distributions and abundance of atmospheric constituents in many ways. This session seeks abstracts that address 1) vertical transport and redistribution of trace gases and aerosols by clouds; 2) wet scavenging; 3) aqueous chemistry; 4) lightning NOx production; 5) modification of photolysis rates; and 6) resulting downwind effects on new particle formation and photochemistry. Results from both field measurement programs (such as SOAS, SENEX, DC3, SEAC4RS, CONTRAST) and modeling studies are sought.