A semi-analytical model of chlorophyll-a concentration in Pear River Estuary under various tidal conditions

For researches on the retrieval of water parameter, the present semi-analytical model can hardly meet the inversion accuracy of chlorophyll-a concentration of the Pearl River Estuary because the coupling interference between phytoplankton and suspended particles would cover the IOPs characters of water-color components. Based on the 4-days sampling waters under different geographical sites and tidal conditions, this paper mainly studies the coupling effect of suspended particles to the absorption character of the phytoplankton, and find that the absorption peak around 676 nm is rarely affected by the high load of suspended particles in waters. Combining the hydrodynamic features of the Pear River Estuary, robust relationships between the phytoplankton absorption at 676 nm and the chlorophyll-a concentration are presented to adapt the spatial-tidal variation. At last, a new modeling way involving these relationships are offered to build the semi-analytical model of chlorophyll-a concentration in Pear River Estuary.