A procedure for estimating 3D turbulent parameters from the outputs of a circulation model to be used as input of a random flight model for complex terrain dispersion simulation is presented. It is based on parameterization schemes for surface layer parameters and wind velocity standard deviation profiles available in the literature. The predictions of various schemes (two for surface layer quantities and three either for the PBL depth or standard deviation profiles) have been compared to observations carried out in the alpine region (south Switzerland) during
the second TRANSALP campaign by three Doppler Sodar and two sonic anemometers
