Comparison between the results of a new version of the AVACTA II atmospheric diffusion model and tracer experiments

A new version of the AVACTA II code (a code recommended by EPA) has been implemented and evaluated. AVACTA II is a code based on a mixed segment-puff approach, which allows numerical simulations of both non-stationary and nonhomogeneous conditions. In our version, the wind field is calculated through the 3D mass-consistent code WINDS developed st the Department of Physics of the University of Genoa, Italy. The model evaluation of this new version of the AVACTA II code has been performed using field experiment data on flat, but rough, terrain (Karlsruhe Nuclear Research Center (KNRC) tracer experiments) and wind tunnel measurements (EPA Rushil experiments) both in flat and complex terrain. A comparison is made between simulated and measured concentration distributions. The results of these evaluations are very encouraging.