Dispersion in the Atmosphere of a Pollutant Drifting at the Sea Surface; Galerne Project

Within this project, Meteo-France is in charge of evaluating the transport of the patch of pollution at the sea surface and the atmospheric dispersion of the chemical substance linked to its evaporation. A modelling system has been settled, which consists of the coupling of two models: The first one, MOTHY, is Meteo-France operational drift forecast system in case of marine pollution. It is a trajectory pollutant model coupled with an hydrodynamic ocean model. The second one, PERLE, is a meso-scale atmospheric dispersion modelling system used in operations in case of accidental releases of pollutant into the atmosphere. Meso-scale meteorological fields are simulated by the non-hydrostatic MESO-NH model (8km and 2km resolution nested grids); a lagrangian particle model, LPDM (M.Uliasz,1994) from the Colorado State University, is used in this study to simulate the atmospheric transport of the pollutant. The coupling essentially consists in evaluating the moving surface source term for PERLE associated with the simulated drift forecasted by MOTHY and with the evaporation rate using the results obtained by other partners within the project working on the evaluation of evaporation rates depending on the considered pollutant.