The equipment on Sea Cargo Express (WILL CHANGE).At the cargo vessel Sea Cargo Express, an upgraded automatic CO2 measurement system from General Oceanics was installed in 2022. The system consists of an equilibrator, which revceives seawater at a flow of 3 L/min. A spiral nozzle forms a regular spray of seawater in the equilibrator, thus, equilibrium between the water and the gas phase is achieved quickly. The gas phase is then pumped through a Non-Dispersive Infrared (NDIR) detector, where the mole fraction of carbon dioxide is measured. From this, the fugacity of CO2 (fCO2) is calculated by using the respective sea surface temperature and salinity. Regularly, the system switches to measure four different reference gases as well as atmospheric CO2. In addition to CO2, the sea surface temperature and the sea surface salinity are determined by a thermosalinograph (SBE45), and dissolved oxygen of the sea surface is measured by an Aanderaa Oxygen Optode. The water intake is at 4 m depth.