VERTICAL TRANSPORT OF SULFUR-DIOXIDE AND DIMETHYL SULFIDE IN DEEP CONVECTION AND ITS ROLE IN NEW PARTICLE FORMATION

The NASA Pacific Exploratory Mission-West experiment in 1991 and 1994 covered large portions of the western Pacific Ocean troposphere and tr ansects of the troposphere of the equatorial and subtropical North Pac ific Ocean. Sulfur dioxide and dimethyl sulfide were concurrently meas ured from the surface to 12 km. In 1991, sulfur dioxide had significan t anthropogenic and volcanic sources. In 1994, sulfur dioxide aloft wa s significantly lower than in 1991. During both periods, deep convecti on was responsible for the distribution of sulfur dioxide and dimethyl sulfide, An assessment is made of the proportion of sulfur dioxide th at could be made from dimethyl sulfide convected to high altitude. The subsequent formation of new aerosol particles from sulfur dioxide at high altitude is evaluated.