fCO2 characteristics in marginal seas around Korea

Abstract

Fugacity of carbon dioxide, fCO2, in surface seawater, is a primary parameter in the research on the carbon cycle at air-sea interface. Hydrological, physical and biological processes control on fCO2 and this has a large spatial and seasonal variability. The East Japan Sea (EJS) has the various information that the changing carbon chemistry response of climate change because of its oceanic characteristics. In addition, the ECS is regarded as important continental shelf pump area. This study shows the spatiotemporal distribution characteristics of fCO2 and its controlling factors based on underway measurement data getting from the Ulleung Basin (UB) as part of southwestern EJS and the northern ECS area. The surface seawater fCO2 values in the UB shows that relatively high fCO2 values in summer owing to elevated sea surface temperature (SST) effect and in winter due to vertical entrainment of CO2-rich subsurface water despite the decreasing SST. Meanwhile, low fCO2 values occur in spring and fall caused by biological effect. The major factor on the fCO2 is SST in the UB but shows also temporal and seasonal variability due to biological uptake and vertical mixing effect. On the other hand, in the ECS, the distribution of fCO2 shows the different pattern comparing to the EJS. The higher fCO2 values occur in winter and summer than in spring and fall in the ECS. Our study reveals that the fCO2 in the ECS are mainly controll variability. The East Japan Sea (EJS) has the various information that the changing carbon chemistry response of climate change because of its oceanic characteristics. In addition, the ECS is regarded as important continental shelf pump area. This study shows the spatiotemporal distribution characteristics of fCO2 and its controlling factors based on underway measurement data getting from the Ulleung Basin (UB) as part of southwestern EJS and the northern ECS area. The surface seawater fCO2 values in the UB shows that relatively high fCO2 values in summer owing to elevated sea surface temperature (SST) effect and in winter due to vertical entrainment of CO2-rich subsurface water despite the decreasing SST. Meanwhile, low fCO2 values occur in spring and fall caused by biological effect. The major factor on the fCO2 is SST in the UB but shows also temporal and seasonal variability due to biological uptake and vertical mixing effect. On the other hand, in the ECS, the distribution of fCO2 shows the different pattern comparing to the EJS. The higher fCO2 values occur in winter and summer than in spring and fall in the ECS. Our study reveals that the fCO2 in the ECS are mainly control