Sea Surface CO2 Measurements on the R/V ISABU in the Northwestern Pacific in October 2019

Abstract

The ocean takes up anthropogenic carbon dioxide (CO<sub>2</sub>) emitted into the atmosphere. The oceanic CO<sub>2</sub> uptake shows seasonal and regional differences depending on numerous factors. We investigated distributions of atmospheric and sea surface CO<sub>2</sub> in the Northwestern Pacific using the continuous underway pCO2 measuring system equipped on the Research Vessel ISABU of Korea Institute of Ocean Science and Technology. During the cruise, 3,597 data of seawater CO<sub>2</sub> were obtained with sea surface temperature (SST), sea surface salinity (SSS), and GPS information for 13 days from October 4 to 17, 2019. Through the differences in CO<sub>2</sub> concentrations between seawater and the atmosphere, we confirmed that CO<sub>2</sub> concentrations of the sea surface were lower than those of the atmosphere in most of the surveyed areas. Higher SST and lower SSS were observed in the lower latitude area than 17°N in Philippine Sea, but latitudinal variation of CO<sub>2</sub> concentration was not significant.