The SAFE_AIR II dispersion model: Description and statistical evaluation of its dispersion module against wind tunnel data from area sources

SAFE_AIR II is a model which simulates transport and diffusion of airborne pollutants emitted in the low atmosphere above complex orography at both local and regional scale, under non-stationary and inhomogeneous emission and meteorological conditions. The aim of this paper is the assessment of the performance of the dispersive module (P6) of SAFE_AIR II in simulating pollutant concentrations due to releases from area sources. This analysis has been carried out comparing the results of model simulations with the data collected in a U.S. Environmental Protection Agency Meteorological Wind Tunnel. Three different scenarios have been investigated in order to understand the effects of the shape and orientation of the area source. To compare measured concentrations against the corresponding predicted ones, both graphical analyses and appropriate statistical indices have been used. The capability of the code to simulate area sources has been outlined.