Two estimates of the ocean-to-atmosphere flux of dimethyl sulfide (DMS) are presented to determine the feasibility of using remotely sensed data to map the marine sources of a photoreactive trace gas. First, an empirical relationship between chlorphyll a and DMS in surface seawater (Andreae and Barnard, 1984) is used with NASA coastal zone color scanner (CZCS) data for chlorophyll a pigment to derive a mean DMS flux for a region in the tropical North Atlantic for October 1980. This is compared with the sea-to-air flux derived from a one-dimensional photochemical model that reproduces boundary layer concentrations of O3, CO, NO, and hydrocarbons measured on a cruise at the same location and time (Meteor 56/1). Both evaluations of DMS fluxes are in the range (2--7)¿109 molecules DMS cm-2 s-1 and agree well with fluxes based on the seawater DMS concentration given by Barnard et al. (1982) for the Meteor cruise. The applicability of the results to strategies for satellite remote sensing of the tropospheric sulfur cycle is discussed. For some species (e.g., DMS) surface sensing of sources is feasible, but only in regions and seasons where photoplankton pigment is a meaningful marker for biogenic emissions. The general applicability of ocean color to DMS determination awaits the development of an algorithm that can extract distributions of DMS emitting species from the optical signal. For other sulfur constituents (e.g., SO2, COS) atmospheric measurements are appropriate for determining tropospheric distribution. Wind, moisture, cloud, precipitation, and temperature data are also required for complete characterization of the marine sulfur cycle. ¿ American Geophysical Union 1990