Observations of Ocean Surface Variables from Shipboard and Remote Sensing Platforms in the Korea Strait and East Sea During Spring

Surface ocean variables derived from satellite and reanalysis products are widely used to investigate marine environmental conditions and can be used as indicators of the physical and biological processes that control air-sea CO₂ exchange. This study collected both shipboard observations from R/V NARA and satellite reanalysis data (GOCI-II, GLORYS12V1, CMEMS) in the Korea Strait and East/Japan Sea during spring including sea surface temperature, salinity, and chlorophyll-a concentration, while direct CO₂ flux measurements were obtained via eddy covariance method. Spatial distributions showed distinct regional contrasts between KS and EJS although both regions acted as net sinks of atmospheric CO₂. Correlation analyses showed moderate agreement between in-situ and gridded products for SST and SSS. Two satellite-derived Chl-a products (GOCI-II and CMEMS) showed better agreement, supporting their combined use for characterizing biogeochemical variability. These variables are important for understanding upper-ocean hydrographic and biological conditions and for supporting studies related to marine carbon processes.