METHANESULFONIC-ACID, DIMETHYL-SULFOXIDE AND DIMETHYL SULFONE IN AEROSOLS

Aerosol concentrations of methanesulphonic acid (MSA), dimethyl sulphoxide (DMSO), dimethyl sulphone (DMSO2) and major anions have been measured from landbased stations (principally Plymouth, Devon, U.K.) and various shipboard stations in the North Sea and North Atlantic Ocean. Aerosol samples collected between July 1985 and July 1987 are analyzed both in terms of their back trajectories, and variation with time. These analyses suggest that NO3 and NSSS are anthropogenic in origin while DMSO2 appears to have a maritime source. MSA concentrations are highest in air masses with both oceanic and anthropogenic influences. DMSO, MSA, and DMSO2 all show seasonal cycles, with concentrations similar to previous published results. MSA was found to be concentrated on sub-μm particles. Rainfall MSA concentrations were measured over 2 years at Norwich and were found to exhibit a similar seasonality to the aerosol MSA concentrations. © 1990.