Atmospheric sulfur cycling in the tropical Pacific marine boundary layer (12 degrees S,135 degrees W): A comparison of field data and model results .2. Sulfur dioxide Academic Article uri icon

abstract

  • The atmospheric chemistry of sulfur dioxide over the tropical South Pacific Ocean is investigated by using results from field measurements and numerical models. Simultaneous real time measurements of sulfur dioxide and its biogenic precursor dimethylsulfide were made at 12S, 135W for a 6day period from March 3 through March 9, 1992. The mean SO2 and DMS mole fractions were 71 56 pmol mol1 (1) and 453 93 pmol mol1 (1) respectively. These concentrations are compared to those predicted by a timedependent photochemical box model of the marine boundary layer. Model estimates of the yield of SO2 from DMS oxidation range from 27% to 54%. Even with low yields, DMS is the dominant source of SO2 in this region. Estimates of vertical entrainment velocities based on the tropospheric ozone budget suggest that vertical entrainment is a minor source of SO2. The relative rates of various loss mechanisms for SO2 are dry deposition to the sea surface (58%), incloud oxidation (9%), OH oxidation (5%), and uptake by seasalt aerosols (28%).

published proceedings

  • JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES

author list (cited authors)

  • Yvon, S. A., & Saltzman, E. S.

citation count

  • 38

complete list of authors

  • Yvon, SA||Saltzman, ES

publication date

  • March 1996