Dimethyl sulfide cycling in the sea surface microlayer in the southwestern Pacific – Part 1: Enrichment potential determined using a novel sampler

Abstract. Elevated dimethyl sulfide (DMS) concentrations in the sea surface microlayer (SML) have been previously related to DMS air–sea flux anomalies southwestern Pacific. To further address this, DMS, its precursor dimethylsulfoniopropionate (DMSP), and ancillary variables were sampled SML also subsurface water at 0.5 m depth (SSW) different masses east of New Zealand. Despite high phytoplankton biomass some stations, chlorophyll a enrichment factor (EF) was low (< 1.06), DMSP enriched one station with EF ranging from 0.81 1.25. determined using novel gas-permeable tube technique which measured consistently higher than traditional glass plate technique; however, significant present only station, 0.40 1.22. influenced by community composition, correlations dinoflagellate Gymnodinium biomass, respectively. correlated between SSW, difference ratio attributable greater loss atmosphere SML. In absence enrichment, did not influence emissions, calculated 2.28 11.0 µmol m−2 d−1 consistent climatological estimates for region. These results confirm previous regional observations that is associated abundance but indicate additional factors are required support