Atmospheric and Surface Seawater CO2 Measurements on R/V ISABU in the Western North Pacific in the Summer of 2018

Abstract

The ocean takes up approximately 24% of anthropogenic carbon dioxide (CO<sub>2</sub>) emitted into the atmosphere in a year. The oceanic CO<sub>2</sub> uptake shows regional and seasonal differences depending on physical and chemical characteristics of seawater and biological activities (such as CO<sub>2</sub> fixation). In the tropical Western North Pacific, the surface water temperature is high, the supply of deep water is limited, and tropical cyclones usually pass in summer. We investigated atmospheric and sea surface CO<sub>2</sub> concentrations in this area using the continuous underway pCO2 measuring system equipped on the Research Vessel ISABU of Korea Institute of Ocean Science and Technology for about 21 days from August 29 to September 19, 2018. During the cruise, 9,367 CO<sub>2</sub> data were obtained from this measuring system with temperature, salinity, and GPS information. Higher CO<sub>2</sub> concentrations of the surface seawater than those of the atmosphere were observed in the areas of 22°N-23.5°N and 29°N-35°N where CO<sub>2</sub> was emitted into the atmosphere, while most of the areas between 17.5°N and 20.5°N were sinks for the atmospheric CO<sub>2</sub>. This dataset can be used for future research on the distribution of partial pressure of carbon dioxide over the global ocean surface.