Kinetics Investigations of Atmospheric Chemical Reactions

摘要

Two gas-phase kinetics investigations were performed using a low-pressure, fast-flow system with mass spectrometric detection. The first investigation was a study of the rates of the reactions of diatomic sulfur, S2, with O, O2, O3, N2O, NO and NO2 at 409K and low pressure (0.89-3.0 Torr). The reaction with atomic oxygen was found to be fast. Under the experimental conditions, S2 did not react with any of the other species, but upper limits to the reaction rate constants are reported. The second investigation was a study of the synergistic coupling of atmospheric bromine and chlorine chemistry. It is concluded that the ClO+BrO reaction could account for a large fraction of the spring-time 'ozone hole' reported recently, provided that at least 20 ppt of total inorganic bromine is present, and it may provide a source of chlorine dioxide of sufficient magnitude to explain the recent measurements of this species in the Antarctic stratosphere.