Leif G. Anderson Chemical data of depth profiles of stations in international water collected during the SWERUS-C3 Arctic expedition Bolin Centre Database 2018 Datafile Marine Marine chemistry Arctic Ocean Hydrography Nutrients Carbon system Earth science > Oceans > Ocean chemistry Leif Anderson 2018-01-10T12:48:46+00:00 English 1.0 None Water samples were collected using a rosette system equipped with 24 bottles of Niskin type each having a volume of 7 L. The bottles were closed at predefined depth during the return of the CTD-rosette package from the bottom to the surface. Water samples for all constituents were drawn soon after the rosette was secured in a CTD container and all analysis were performed on the ship, typically within 24 hours of sampling. State of the art analytical techniques were used resulting in the following data quality. For oxygen precision was determined using replicates from the same depth and was better than 0.5 µmol/kg, with the accuracy determined by titrating standards to better than 0.1% of the concentration. The precision for nutrients, based on 28 determinations of standards, were 1.2%, 2.7% and 1.3% for NO3, PO4 and SiO4, respectively. Accuracy was determined from analysis of CRM to -0.1 µmol/L for NO3 and -0.02 µmol/L for PO4. For both DIC and TA the precision was determined to better than 2 µmol/kg from duplicate sample analysis, with the accuracy set by calibration against certified reference materials (CRM, Batch #123 and #136), supplied by A. Dickson, Scripps Institution of Oceanography (USA). For pH the accuracy was estimated to 0.006 from internal consistency calculations of analysed CRM samples and the precision, defined as the absolute mean difference of duplicate samples, was 0.001 pH units. The seawater pH is reported on the total scale and in situ temperature. All data is contained in one xlsx file. Leif G. Anderson is PI of the chemical data.