Observational analysis of the Hooghly Estuarine features and tidal effects using a high resolution biophysical model

Estuarine biogeochemistry plays a key role in the cycling of biological and chemical parameters. In the present study, a first attempt has been made towards the coupling of a realistic three-dimensional estuarine circulation model with biophysical model in the Hooghly Estuary (21°36´-22°16´N and 87°42´-88°15´E) to simulate and capture the varying effect of plankton biomass with response to river discharge and tidal effect. In-situ observational data for physico-chemical and biological parameters were collected from different sampling stations during 2003-2010 are assimilated using successive over relaxation method (SOR) and multiscale objective analysis (OA) and incorporated in Regional Ocean Modeling System (ROMS) to setup a higher resolution both in horizontal (0.5 km × 0.5 km) and vertical (8 vertical levels) biogeochemical model. Strong tidal influence with sliding growth of phytoplankton (less than 1mg/l) towards south and low dissolved oxygen (DO) is low (5.27 mg/l) in the Haldi River mouth also affects water quality.