Numerical Study of Oil Spill in the Southern Brazilian Shelf

The oil and derivatives outpouring in the marine ecosystem can create chronic effects in short, medium and long timescales. The numeric modeling of these processes are animportant tool with low operating cost for the analysis and forecast of these events. Therefore, this tool can support decisions provided by the governmental agencies with respect the policy of management of the environment. In this way, the aim of this work is present the results of a hypothetical oil spill along the oceanic region off the Southern Brazilian Shelf (SBS), considering real hydrodynamic and dynamic processes associated with the spilled oil. The numerical model used to simulate the oil spill has been developed at the Universidade Federal do Rio Grande - FURG and it runs coupled to the hydrodynamic model TELEMAC3D (EDF - France) that provide the current field used by the oil model to evaluate the trajectories of lagrangian tracers. The results indicate a displacement around 9.5 km with an estimated mean velocity around 0.07 m/s, consistent with mean circulation pattern of this region. The area of the oil spilled has increased by one order of magnitude after 32hs of simulation. The evaporation and the strong emulsification results in an rapid increase of the oil density from 980 kg/m-3 to 1015 kg/m-3 suggesting that some part of the oil spilled starts to sink.