Meteorological, optical, sea surface hydrography, and accompanying navigational and bathymetric data (10 minute averages) from the North Sea, Norwegian Sea, and Barents Sea on cruise DY167 (GApr19), July-August 2023

This dataset contains sea surface hydrography (temperature and salinity), optical (chlorophyll-a fluorescence, transmission) and meteorological (wind speed and direction, air temperature, air pressure, relative humidity, PAR, TIR) data collected from the ocean and atmosphere monitoring systems (‘surfmet’) on the RRS Discovery. Navigational (latitude, longitude) and bathymetric data are also provided. The data were collected continuously on cruise DY167 (GEOTRACES cruise GApr19) in July-August 2023 as the ship transited and conducted sampling stations in the North Sea, Norwegian Sea, and Barents Sea. Raw sensor data were recorded at a frequency of 1Hz. Questionable values from each data stream were removed and de-spiking routines (using either 3- or 5-point third-order median filters) were applied to noisy data streams. 10-minute averages were created. Sea surface measurements during 4 periods of cleaning and maintenance were removed. Sea surface salinity was calibrated against 107 independent samples collected from the underway system outlet nearest the sensor boards and analysed on a Guildline Autosal 8400B salinometer. The chlorophyll-a fluorescence was calibrated against 284 samples; 250 taken from the ‘FISH’ being towed at the surface behind the ship and 34 from the underway system outlet tap nearest the sensor. Samples to determine Chlorophyll a were filtered and frozen for 24 hours before being measured using a Turner Design Field fluorometer. This dataset was generated by the National Oceanography Centre (NOC) and the University of Liverpool (UoL), under Natural Environment Research Council (NERC) Discovery grant Nitrogen fixation in the Arctic Ocean, N-ARC (grant numbers NE/T000570/1 and NE/T001240/1).