GAS-PHASE ATMOSPHERIC BROMINE PHOTOCHEMISTRY

This paper reviews the current knowledge of gas phase bromine photoche mistry and presents a budget study of atmospheric bromine species. The effectiveness of the ozone catalytic loss cycles involving bromine is quantified by considering their chain length and effectiveness. The c hain effectiveness is a new variable defined as the chain length multi plied by the rate of the cycle's rate-limiting step. The chain effecti veness enables a fair comparison of different catalytic cycles involvi ng species which have very different concentrations. This analysis cle arly shows that below 25 km the BrO/ClO and BrO/HO2 cycles are among t he most important ozone destruction cycles.