Frontal enhancement of dimethylsulfide concentrations across a Gulf Stream meander

Aqueous and atmospheric dimethyl sulfide (DMS) concentrations (0.4–4 nM, 5–350 ppt) were determined across a Gulf Stream meander in April 1989. Physical processes along and across the front were expected to result in biological changes also reflected in DMS levels. Highest concentrations of aqueous DMS (3–4 nM) were observed in surface waters coinciding with Slope waters at, or inshore of, the Gulf Stream north wall. This water also contained the highest chlorophyll levels (up to 2.6 μg chl/l) which co-varied with the sea surface DMS concentrations. Concentrations of atmospheric DMS were lower and more constant (21 ± 9 ppt) outside the frontal area, either in Slope or Stream waters. At the northern wall of the Gulf Stream, a strikingly sharp increase in atmospheric DMS (up to 350 ppt) was observed.