Satellite observations of the partial pressure of carbon dioxide in the surface water of the Huanghai Sea and the Bohai Sea

Based on 5 831 continuous in situ measurements of the partial pressure of carbon dioxide on the sea surface p (CO₂), related parameters of the sea surface temperature (SST) and chlorophyll-a (Chl a) concentration in 2010 winter, spring and summer of the Huanghai Sea and the Bohai Sea, the inherent relations among them are investigated preliminarily. This study reveals that the seasonal variability of SST and Chl a concentration has a significant influence on p (CO₂). The authors have proposed a new algorithm to estimate p (CO₂) from SST and Chl a concentration measurements. Compared with the vessel data, the root mean square error (RMSE) of p (CO₂) retrieved by using the new model is 13.45 μatm (1atm=101.325 kPa) and the relative error is less than 4%. Then, SST and Chl a concentration data observed by satellite are used to retrieve p (CO₂) in the Huanghai Sea and the Bohai Sea; and a better accuracy can be obtained if the quality control for sea surface chlorophyll-a concentration observed by satellite is used. The RMSE of retrieved p (CO₂) data with quality control and that without quality control are 15.82 μatm and 31.74 μatm, respectively.