Spatial and temporal variability of atmospheric sulfur-containing gases and particles during the Albatross campaign

TO investigate the oxidation chemistry of dimethylsulfide (DMS) in the mari ne atmosphere, atmospheric DMS, SO2, as well as several DMS oxidation produ cts in aerosol phase such as non-sea-salt sulfate (nss-SO4), methanesulfona te (MSA), and dimethylsulfoxide (DMSOp) have been measured during the Albat ross campaign in the Atlantic Ocean from October 9 to November 2, 1996. Lon g-range transport, local sea-to-air flux of DMS (F-DMS), marine boundary la yer (MBL) height variation, and photochemistry were found to be the major f actors controlling atmospheric DMS concentration which ranged from 29 to 39 6 parts per trillion by volume (pptv) (mean of 120+/-68 pptv) over the crui se. The spatial variability of MSA and DMSOp follows the latitudinal variat ions of F-DMS A 2-day period of intensive photochemistry associated with qu ite stable atmospheric conditions south of the equator allowed the observat ion of anticorrelated diurnal variations between DMS and its main oxidation products. A chemical box model describing sulfur chemistry in the marine a tmosphere was used to reproduce these variations and investigate coherence of experimentally calculated fluxes F-DMS With observed DMS atmospheric con centrations. The model results reveal chat the measured OH levels are not s ufficient to explain the observed DMS daytime variation. Oxidizing species other than OH, probably BrO, must be involved in the oxidation of DMS to re produce the observed data.