A steady state analysis has been made of the sources and sinks of sulfur in the remote marine atmosphere and of the study state exchanges of SO2 and (excess) sulfate between the sea, boundary layer, and free troposphere. Two situations were examined: an area of high biological productivity (Gulf of Guinea) and an area of low productivity (tropical Atlantic). The results of the analysis suggest that about one-third of the 'backgound' concentrations of SO2 and excess sulfate observed in the remote marine atmosphere mixes in from the free tropopshere, with the balance, ~100μgSm-2d-1, attributed to the local oxidation of reduced sulfur-bearing precursors in the boundary layer.