Numerical simulations of oil spill and blowout episodes in the Adriatic Sea

The increase in the number of oil spill incidents has led to the improvement of numerical methods in order to simulate the phenomena of oil dispersion. The processes that determinate the fate of an oil spill are very complex and the forecast of both short- and long-term behavior of the spilled oil is necessary to organize some recovery actions and minimize the impacts of oil contamination of estuarine area, harbors or wetlands. For instance, the underwater blowout is not a trivial task, due to the three-dimensional nature of the process and the little knowledge of the hydrodynamic field at large depths. In this paper the coupling of the community model POM (Princeton Ocean Model) with the Lagrangian dispersion model LASEMOD (LAgrangianSEaMODel) is used to investigate the temporal and spatial evolution of an oil spill and an underwater blowout due to offshore drilling that occurs nearby the Adriatic coast in Italy. The POM is a three-dimensional, free surface, sigma coordinate, primitive equation ocean model which includes a turbulence sub-model. The LASEMOD is a three-dimensional, first-order autoregressive model for the particle velocities. Such a model is based on the so called “well-mixed condition” and takes into account the integral time scale of the turbulence. LASEMOD can also model some several processes that change the physical characteristics of the oil, such as spreading, slick formation, evaporation, emulsification, sedimentation and beaching. Simulations show with reasonably accuracy the time evolution of the concentration field and provide a useful insight into the evaluation of the environmental impact of oil spills along the coast.