Remote sensing of particulate organic carbon and phytoplankton carbon in the northern South China Sea

Surface concentrations of particulate organic carbon (POC) and phytoplankton carbon (C phy ) in the northern South China Sea (NSCS) have been assessed successfully by remote sensing with appropriate regional tuning. Match-up comparisons between satellite derivations and field observations showed uncertainties of ± 28.5% for POC and ± 37.0% for C phy . The satellite-derived climatological distributions are consistent with previous reports. In the open NSCS where phytoplankton growth is controlled primarily by the convective overturn, both POC and C phy are higher in winter, associating with the effect of stronger northeast monsoons and surface cooling, than in summer, when surface heating and weaker southwest monsoons strengthen vertical stratification. Toward the coasts, because of terrestrial inputs, POC and C phy increase, varying by one order of magnitude. Particularly, they are prominently enhanced along the Pearl River plume, which may be extensive to the middle shelf in the summer according to high river discharge and northeastward coastal currents. Elevated POC and C phy are also found in the waters around the Taiwan Bank where upwelling occurs year round. Similar approaches on the remotely sensed POC and C phy may be applicable to other shelf-seas in order to improve our understanding in ocean carbon cycle.