Venus Atmosphere: Structure and Stability of the ClOO Radical

Abstract

The ClOO radical has been suggested as an important intermediate in a Cl atom catalyzed combination of CO and O2 enabling conservation of the observed low mixing ratios for CO and O2/ in the predominantly C O2 Venusian atmosphere. We review evidence concerning the existence, structure and stability of this radical. From theoretical considerations we conclude that the decomposition rate for ClOO in conditions appropriate to the Venus atmosphere is pressure-dependent with a second-order rate constant given approximately byThis rate is probably sufficiently slow to enable the oxidation of CO by ClOO to successfully compete with ClOO decomposition, at least to the extent required to maintain the observed composition of the Venus atmosphere.