Simulation of realistic location-related wind distributions with the mesoscale model FITNAH

Knowledge of the frequency distribution of wind direction, wind speed and stability classes is of fundamental importance for providing an expert opinion, not only in the course of governmental authorisation procedure. To seriously and responsibly carry out immission forecasts (dispersion calculations) for air-pollution such as dust, gases or odours, a corresponding location-related distribution is imperative. The calculation of realistic location-related wind distributions by means of numerical simulation is demonstrated by the application to the area of Stuttgart. The simulations have been performed with the well known mesoscale model FITNAH. In comparison to measured data, it can be shown that FITNAH is able to provide realistic location-related wind distributions even if very complex terrain structures are involved. Furthermore, it is evident that the application of FITNAH has great advantages in comparison to simple diagnostic wind field models. Because of the recently achieved state of computer power of PC's, the routinely and cost-effective use of FITNAH for providing expert opinion is now possible.