CCGS Amundsen Underway Dissolved Gas Measurements: O2/Ar, O2, N2 and Total Dissolved Gas Pressure

A Membrane inlet mass spectrometer (MIMS) and a flow-through optode / gas tension device (GTD) system were deployed on the CCGS Amundsen to obtain measurements of dissolved gases from the ship's underway seawater supply line (nominal intake ~7.5 m). These autonomous sensors provided measurements of dissolved O2/Ar ratios, O2 saturation and concentration and total dissolved gas pressure (TDGP) at approximately 10-20 s intervals. Nitrogen (N2) saturation data were derived from O2 and TDGP observations. This dataset provides calibrated O2/Ar, O2 and TDGP data, and uncalibrated N2 data. The underway gas data are complemented by hydrographic observations of surface seawater temperature and salinity (obtained by the Amundsen Science research group) collected via underway thermosalinograph (TSG), and information on the ship's sampling time and location.