Numerical Modeling of the hydrodynamics in the coastal area of Sao Paulo State Brazil

A numerical model was implemented for the whole coastal area of Sao Paulo State, Brazil, based on the Princeton Ocean Model. The model grid has 150 x 450 points and I I sigma levels, with uniform resolution of I Kin in the horizontal, and time steps of 180 and 6 seconds for the internal and external modes. The main advantage of the implemented model configuration is the possibility of using nested grids in estuarine regions of interest and subsequent use of dispersion and sediment transport models. Numerical experiments consider the coastal circulation driven by tidal, meteorological, density and river effects, separately or combined. A simulation with all the forcing effects shows the importance of the coastal channels in the amplification of the circulation, particularly in the Cananeia Iguape estuary, where surface currents reached 84.6 cm/s. In general, river effects are not very significant in Sao Paulo State coastal areas but, in the central part of the shelf, the low salinity induced by the rivers flows produces surface currents towards the open sea and strong deep currents towards the continent. The results of the model runs may be used in several applications, such as navigation operation and security, sediments transport estimates, monitoring of beaches evolutions and water quality control, especially in nested grids covering the estuaries and internal shallow regions.