Seabird 911plus systems equipped with dual temperature-conductivity-oxygen sensors were employed. All systems had a 24-bottle water sampling rosette with 10 l Niskin bottles. Water sampling, processing, and calibration followed GO-SHIP recommendations (Swift, 2010; McTaggart et al., 2010; Uchida et al., 2010) and included the recommended steps Data Conversion, Sensor Time-Alignment, Creation of Bottle Files, Outlier Removal, Pressure Sensor Filtering, Conductivity Cell Thermal Mass Correction, Ship Roll Correction and Deck Offset Correction by Loop Editing, as well as Derivation of Calculated Properties. After these steps, conductivity and oxygen readings were calibrated against values determined with salinometry and Winkler titration , respectively. Finally, the downcast data was averaged over 1 dbar wide intervals. An independent upcast calibration was used to obtain calibrated CTDO values coincident with the discrete water samples. A SUNA nitrate probe (Satlantic) was mounted on the CTD frame as an additional instrument during all shallow casts (<2000dbar). The nitrate measurements were also calibrated against water samples and the CTD data was supplemented accordingly.

PO-GLOBAL-SVN = 1146 used on 08-Dec-2025 10:35:47Matlab = 9.14.0.2206163 (R2023a)Release = 1nc_project = Jellyweb Madeiranc_uncertainty_p = 2.000000nc_uncertainty_t = 0.002000nc_uncertainty_s = 0.003000nc_uncertainty_o = 3.000000