Partial pressure of carbon dioxide, temperature, salinity and other variables collected from surface underway observations during Ships of Opportunity (SOOP) M/V Celebrity Equinox cruise lines in the Caribbean Sea, North Atlantic Ocean in 2025 (NCEI Accession 0302087)

This dataset consists of the surface underway measurements of mole fraction of CO2 in the equilibrator headspace (dry) at equilibrator temperature (ppm), mole fraction of CO2 measured in dry outside air (ppm), mole fraction of CO2 in outside air associated with each water analysis. These values are interpolated between the bracketing averaged good xCO2_ATM analyses (ppm), barometric pressure in the equilibrator headspace (hPa), barometric pressure measured outside, corrected to sea level (hPa), water temperature in equilibrator (°C), sea surface temperature (°C), sea surface salinity, fugacity of CO2 in sea water at SST and 100% humidity (μatm), fugacity of CO2 in air corresponding to the interpolated xCO2 at SST and 100% humidity (μatm), sea water fCO2 minus interpolated air fCO2 (μatm). The measurement were performed during the SOOP M/V Celebrity Equinox cruises in the Caribbean Sea, North Atlantic Ocean in 2025.