http://bolin.su.se/data/oden-ryder-2019-surface-seawater-ph-alkalinity-1 Adam Ulfsbo Bolin Centre Database 2021 Datafile Marine Marine chemistry Arctic Ocean Underway Carbonate system Ryder 2019 expedition Icebreaker Oden Earth science > Oceans Adam Ulfsbo 2021-02-17T11:01:03+00:00 English 1 The underway measurements of seawater pH and TA are organized in a comma-separated values (csv) file and include the following parameters: * Year * Month * Day * Hour * Minute * Second * Latitude (decimal degrees north) * Longitude (decimal degrees east) * Salinity (practical salinity, PSS-78) from the laboratory seawater intake system (SBE43) * Temperature (°C) from the laboratory seawater intake system (SBE43) * Temperature (°C) from the ship's hull (PT-100) * Seawater pH on the total scale, at 25 °C, and 0 db pressure * Total alkalinity (micromols per kilogram seawater) The surface seawater intake system is situated at 8 meters depth on the Icebreaker Oden and is pumped up to the main laboratory on the main bow deck. The seawater from the intake system is sub-sampled for measurements of seawater pH and TA with a temporal resolution of 10 minutes. These observations are accompanied by recordings of time, latitude, longitude, salinity laboratory seawater intake temperature, and the vessel's hull temperature. Seawater pH was measured spectrophotometrically with a CONTROS HydroFIA pH analyzer ([Aßmann et al. 2011](https://doi.org/10.5194/os-7-597-2011)) on the total scale at a constant salinity of 35 and thermostated at 25 °C. The data were processed with in-situ salinites from the vessel's underway thermosalinograph (SBE43) post-cruise. Total alkalinity was measured spectrophotometrically with a CONTROS HydroFIA TA analyzer [(Seelmann et al. 2019)](https://doi.org/10.1002/lom3.10329) at a constant salinity of 35 and thermostated at 25 °C. The data were processed with in-situ salinites from the vessel's underway thermosalinograph (SBE43) post-cruise. For more details, see the cruise report ([Jakobsson et al. 2020](http://www.diva-portal.org/smash/record.jsf?pid=diva2%3A1458256)).