Simulation of a Photochemical Smog Episode in the Rhine-Ruhr Area with a Three Dimensional Grid Model

An advanced Eulerian photochemical dispersion model is applied to the Rhine-Ruhr area in the FRG. One of the main features of this area are the complicated wind conditions induced by the complexity of the terrain. Therefore, special emphasis is given in the preparation of the three dimensional wind field as input for the dispersion model. Two methods of wind field generation are discussed, one based on interpolation of surface winds, the other on a prognostic mesoscale model. The calculated concentrations of ozone, NO and NO₂, utilizing both of the wind fields, are compared with measurements. Preliminary results are presented.