Turbulence closure in atmospheric circulation model and its influence on the dispersion

In this work the comparisons between measured and numerically simulated tracer experiments are presented for two different datasets. Different versions of the model system RMS, including the Regional Atmospheric Modelling System (RAMS) and the dispersion model SPRAY, accounting for alternative turbulence closures are used. These last are the Mellor and Yamada model level 2.5 and two versions of the E-l model, the standard isotropic and anisotropic versions. Moreover, simulations performed with the CALPUFF dispersion model coupled with RAMS are also presented. The wind fields and the ground level concentrations produced by the two model systems are shown and compared.