Flash photolysis resonance fluorescence investigation of the reaction of O /P-3/ atoms with ClONO2

The rate constant for the reaction of O (P-3) atoms with ClONO2 at 10 torr total pressure is assessed over the temperature range 225-273 K by the flash photolysis resonance fluorescence technique. The data, taken together with results given by Molina et al. (1977), have been used to formulate an Arrhenius expression suitable for stratospheric modeling applications. Comparison of the rate of ClONO2 destruction via the oxygen atom reaction with the solar photolysis rate shows that chemical reaction accounts for less than 15% of the CLONO2 removal at altitudes between 20 and 30 km.