A modelling system for the transport and dispersion of photochemical pollutants: an application over a Mediterranean area

High ground-level ozone (O3 ) concentrations are frequently reached during summer period in the Mediterranean area, characterized by meteorological typical conditions that make possible the creation and persistence of photochemical pollution. Photochemical pollution is influenced by meteorology, physical and chemical processes and emissions. Therefore a combined modelling system that couples meteorological models, emissions pre-processors and dispersions models is needed. The modelling system used for this study consists of two meteorological models, the prognostic model RAMS and the diagnostic model CALMET, and the photochemical grid model CALGRID. The emission data have been obtained through disaggregation, modulation and splitting of national emission inventory CORINAIR and by direct estimation of road transport, agriculture and biogenic emissions. The system has been used to simulate summer photochemical smog episodes over the Salento Peninsula, in the Apulia region (South-Eastern Italy). An analysis of simulation results versus local network monitoring data has been performed.