Modeling of marine circulation and hypothetical discharges in Callao Bay, Peru

The objective was to simulate the marine circulation and hypothetical discharges in Callao Bay, taking into account climatological seasonal variations and considering the direction and intensity of wind forcing. ROMS (Regional Oceanic Model System) model with the nesting tool AGRIF (Adaptive Grid Refinement in FORTRAN) were used. An hybrid bathymetry was used from ETOPO2, GEBCO, DHN and IMARPE; winds from MWF-Quikscat, tides from TPXO6.2, initial conditions from WOA, boundary conditions from COADS, and information of rivers, aquatic quality and domestic effluents. The model represented adequately the patterns of temperature, salinity and circulation at large scale and small scale in Callao Bay. The hypothetical domestic effluent discharges were transported predominately towards north, with seasonal variations (to northwest in summer, due to rivers discharges). Simulations with northern winds scenarios, showed a transport of hypothetical discharges to Miraflores Bay. During this study period, observed pollutants concentration in Callao Bay exceeded the environmental quality standards of the Water Law, so the introduction of additional effluents should be avoided, and an adequate treatment and disposal system (i.e. treatment plant and submarine emissary) should be implemented.