Simulation of traffic-induced air pollution on regional to local scales

The model system CARLOS (Chemistry and Atmospheric transport in Regional and LOcal Scale) has been developed with the aim to simulate atmospheric transport and air chemistry on local scales taking into account the influence of large-scale transport. The system has been applied to a photochemical smog episode in summer 1997. Multiple nested simulations from the European scale down to a nest containing mainly the city of Wuppertal, Germany were carried out. The emission inventory for Wuppertal is based on microscopic traffic flow simulations. The simulated concentration pattern in Wuppertal is strongly influenced by local properties like terrain and emission structure as well as by specific regional factors such as urban plumes of cities nearby.