Atmospheric DMS was adsorbed on tenax columns and desorbed onto a Hewlett
Packard 5890 gas chromatograph (GC) fitted with a Sievers Model 355 sulfur chemiluminescence detector (SCD) detection system on board the Amundsen. Atmospheric DMS samples were collected en route to the North Water Polyna and as the ship moved in ice-free and ice-pack conditions. Daily shipboard sulphur dioxide and size-segregated cascade impactor aerosol sulphate and methane sulfonic acid (MSA) samples were collected using filters fitted to high volume samplers on board the Amundsen. High volume samplers were operated continuously. The contribution of gases and aerosols from ship stack emissions was determined using CO2 Li-Cor measurements with an air inlet in the vicinity of the high volume samplers. Corresponding size segregated aerosol samples were collected at Alert using high volume samplers for the duration of the ship study. Filter samples from the high volume samplers returned to the Isotope Science Laboratory in Calgary will be analyzed for ion chemistry and S and O isotope analyses (IC for anions, ICP-MS for cations, EA-IRMS for S and O isotope analyses) to define the contribution of SO2 and aerosol sulphate from DMS oxidation.
