Oxidation is a key atmospheric process and impacts such issues as climate change, air quality, and acid rain. Current belief is that reactions involving OH and NO3 to be the predominate mechanism in initiating removal processes. This outlook could change with the recent discovery that stabilized Criegee radicals (sCI) also have a significant capacity to oxidize compounds such as NO2 and SO2.Here measurements from the University of Colorado Sulfuric, OH, and MSA Instrument, SUOMI, will be presented and various atmospheric oxidation processes will be explored. Conventional OH oxidation of sulfur ranging from anthropogenic SO2 emissions to marine DMS emissions will be discussed. A recently discovered attribute of the SUOMI is its sensitivity to stabilized Criegee intermediates, sCIs. Along these lines, airborne and ground based measurements of sCI in and over regions with high BVOC emissions will be presented. These observations reveal an increase in the overall oxidizing capacity of these regions over that of OH oxidation alone. Moreover, these oxidation reactions involving sCIs yield products with low volatilities such as sulfuric acid or extremely low volatility organic compounds (ELVOCs) and which have a significant impact upon particle formation and growth.

Aspects of atmospheric oxidation: Conventional and new outlooks

248th National Meeting (2014)

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