Ambient air, underway surface seawater measurements and calculated air-sea fluxes of benzene and toluene are shown in Figure . Positive fluxes indicate oceanic outgassing, i.e. sea-to-air flux. Interruptions in the air measurements were largely due to ship stack contamination. Fluxes were computed in two ways, using either measured air mole fractions or interpolated air measurements. Both sets of fluxes are weighted by the number of data points to avoid bias in the reported cruise means.