Formation and Growth of Sulfate Aerosols in the Presence of Hydrocarbons: Results from the 2013 Summer Oil Sands FOSSILs Field Campaign, Alberta, Canada

Abstract:

Sulfur dioxide oxidation and the effect of oxidation products in formation and growth of aerosols have been studied widely. Despite this, significant gaps still exist in understanding the role of organic matter in SO2 oxidation. Organic molecules, such as Criegee radicals originating from biogenic sources, are expected to be important for SO2 oxidation in addition to organic molecules of anthropogenic origin. A study of SO2 and aerosol sulfate downwind of the oil sands region was conducted as part of the FOSSILS campaign in the summer of 2013 to better understand aerosol growth from SO2 oxidation in the presence of hydrocarbons and the distribution of sulfate in size-segregated aerosols. Hydrocarbons present in the atmosphere during the sampling campaign, collected using evacuated canisters, were characterized using a pre-concentration trap coupled to a GC-FID. The results from this campaign will be explored to determine SO2 oxidation pathways and the effects of oxidation products to aerosol formation and growth.