safe air Algorithms to simulate the transport of pollutant elements: a model validation exercise and sensitivity analysis

The safe air model numerically simulates transport and diffusion of airborne pollutants at local and regional scales using Gaussian plume segments and/or puffs. This model is able to deal with both non-stationary and inhomogeneous conditions. safe air Is composed of a meteorological pre-processor, the WINDS model, to build a three-dimensional (3D) wind field starting from available wind measurements, and by a pollutant dispersion simulator, the P6 model. This paper deals with two different algorithms included in P6, which allow the determination of the advection of plume elements using the 3D wind field reconstructed by WINDS. A validation exercise concerning the two cited algorithms has been performed using laboratory data from the Environmental Protection Agency wind tunnel RUSHIL experiments (flat terrain and a two-dimensional schematic hill, neutral atmospheric conditions). This paper also contains a sensitivity analysis concerning the same algorithms when the model is applied to a hypothetical emission above a very complex real orography (Regione Liguria, Italy).