Production of the Atmospheric Oxidant Radicals OH and HO_2 from the Ozonolysis of Alkenes

摘要

The reactions of ozone with alkenes are of importance within atmospheric chemistry as a non-photolytic source of the oxidant radicals OH, HO_2 and RO_2. While OH yields are relatively well constrained, few data exist for production of HO_2 or RO_2. We report direct measurements of total radical yields from a range of small (C_2-C_5) alkenes, using LIF and PERCA techniques within large simulation chamber experiments. OH yields are found to be consistent with established understanding, while HO_2 yields are substantially smaller than previous measurements suggest, but in good agreement with those assumed within current atmospheric chemical mechanisms.