Formation of sulfur dioxide and methanesulfonic acid in the photooxidation of dimethyl sulfide in the air

Photooxidation of dimethyl sulfide (DMS) in air in the presence of NO was studied. Sulfur dioxide (SO 2 ) and methanesulfonic acid (CH 3 SO 3 H) are major sulfur‐containing products. In the reaction systems of DMS‐NO‐air with low initial NO concentration and DMS‐CH 3 ONO‐air, in which OH radical‐initiated photooxidation prevails, the yield of SO 2 was determined to be 20.7 ± 1.2 %. The yield of methanesulfonic acid is more than 50 % of the consumed DMS. Sulfuric acid was also detected as a minor product with a yield of less than 2 %. The implications of these results on the atmospheric sulfur cycle are discussed.