| Summary: | As part of the MOCCHA 2018 campaign onboard I/B Oden, Sea surface microlayer (SML) and underlying water (ULW) samples were taken from an open lead system in the central arctic. Sampling occured during the autumn freeze-up from 18.08.18 - 08.09.18. Latitude ranged from 88.7644-89.5474 degrees and longitude ranged from 38.1087-45.7652 degrees as the ice pack moved over time, elevevation remained 0. Sea surface microlayer samples were collected using the glass plate technique (Harvey and Burzell, 1972, doi:10.4319/lo.1972.17.1.0156) via rotating glass disks equipped to a catamaran and underlying water samples were collected from 1 meter depth. Seven variables were sampled for; transparent exopolymer particles (TEP), coomassie stainable particles (CSP), surfactants, chlorophyll a, particulate organic carbon (POC), particulate organic nitrogen (PON) and particulate organic phosphorous (POP). Their concentrations are presented here in micrograms per litre. sea surface microlayer (SML) and undrlaying water (ULW) samples were brought back to a wet lab onboard I/B Oden. All samples were stored in their respective states until processing and analysis could be done after the expedition in laboratories of the University of Oldenburg. Transparent exopolymer particles (TEP) were measured by filtering seawater, in triplicates, onto 0.2 µm polycarbonate filters under low vacuum (< 100mmHg) and staining with alcian blue solution (0.02 g alcian blue in 100mL of acetic acid solution of pH 2.5) for 5 s. The 0.2 µm filters collect both large TEP aggregates and smaller colloidal TEP material. Filters were placed in Eppendorf tubes and stored at -18 °C until processing back in the home laboratory. In the laboratory, Alcian blue stain was extracted for 2 h in 80% sulfuric acid, with gentle agitation applied to reduce bubble formation, and analysed using a spectrophotometer (VWR UV-1600PC, precision of 1±0.2%T) following (Passow and Alldredge, 1995, doi:10.4319/lo.1995.40.7.1326.). The stock solution of Alcian blue was calibrated ...
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