| 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 occurred during the autumn freeze-up from 18.08.18 - 08.09.18. Latitude ranged from 88.7644-89.5474 degrees and longitude ranged from -129.5000 - 47.998700 degrees as the ice pack moved over time. 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). Replicate concentrations of TEP and CSP are presented here in micrograms per liter using the spectrophotometric method (Passow and Alldredge, 1995, doi:10.4319/lo.1995.40.7.1326) and thus referenced to xanthan gum and bovine serum albumin standards respectively. TEP was measured by filtering seawater (25-225 ml), in triplicates, onto 0.2 µm polycarbonate filters under low vacuum (< 100 mm Hg). After filtration, samples were stained with Alcian Blue solution (0.02 g alcian blue in 100mL of acetic acid solution of pH 2.5) for 5 s. Filters are pre-soaked in 1M HCL solution to reduce background staining of filters. Samples were placed in Eppendorf tubes and stored at −18°C until processing back in the home laboratory (within 6 months). 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). The stock solution of Alcian blue was calibrated using the xanthan gum (Carl Roth) standard according to Passow and Alldredge (1995). A calibration of the ...
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