Partial pressure (or fugacity) of carbon dioxide, water temperature, salinity and other variables collected from surface underway observations during the FerryBox ship Blue Horizon cruises in the Aegean Sea and Mediterranean Sea from 2023-08-02 to 2023-09-05 (NCEI Accession 0312025)

This dataset includes partial pressure (or fugacity) of carbon dioxide, water temperature, salinity and other variables collected from surface underway observations during the FerryBox ship Blue Horizon Ferris in the Aegean Sea and Mediterranean Sea from 2023-08-02 to 2023-09-05. A flow-through membrane pCO2 sensor is integrated with the POSEIDON FerryBox installed on the Blue Horizon commercial vessel in 2023. The vessel sailed in the South Aegean Sea with the main serviced ports being Piraeus and Heraklion. The factory calibration of this sensor happened in 2021, whereas during the use in 2023 daily calibration was made with zero cardridge and two gases : 351.4ppm, 493.1 ppm . We selected data starting 1.5 hour after the vessel departure so that the initialization of the measurement system does not influence the results. The mean difference between the intake temperature sensor and the FerryBox temperature sensor was 1.1 °C.