The Arctic Ocean in summer is thought to be a nexus of biogenic dimethylsulfide (DMS) production associated, in part, with diversified niches within or bordering dynamic sea-ice where DMS-rich microbial communities may thrive. However, critical uncertainties remain regarding the strength of sources, sinks and efflux of marine DMS in the Arctic. Quantifying contemporary oceanic reservoirs of DMS is pivotal for the prediction and interpretation of future reservoirs of this climate-active compound. While a global DMS database of ca. 50,000 points exists, only 2.5% of these inputs originate from Arctic oceans highlighting the relevance of continued sampling efforts particularly in the context of rapid and conspicuous climate alterations in this part of the Global Ocean. A joint NETCARE-ArcticNet campaign aboard the CCGS Amundsen during July and August 2016 served as the launching platform for the deployment of a high frequency autonomous underway DMS sampling instrument (MIMS – Membrane Inlet Mass Spectrometer). Providing real-time data, the MIMS allowed the detection of surface reservoirs of oceanic DMS at greater spatial and temporal scales than traditional single-sample gas chromatography analysis, in conjunction with measurements of temperature, salinity and fluorescence (water line TSG sensor)
