About the present version of the dispersion code SAFE_AIR

A new version of SAFE_AIR (an evolution of the AVACTA II code, a code “recommended” by EPA) has been recently produced. This version contains a few improvements among which: different algorithms to calculate the spatial average of the wind field providing the advection velocity of puffs and/or plume elements; different parameterization of deposition patterns. The model evaluation of some aspects of the new version was performed using field data (from the KNRC experiments: flat terrain, convectively unstable and neutral conditions) and laboratory data (from the EPA wind tunnel Rushil experiments, two-dimensional schematic hill, neutral conditions). The performance of the code was satisfactory in all cases.