The THOR Integrated Model System A contribution to subproject GLOREAM

An integrated model system, THOR, for air pollution applications has been developed. The model system includes several meteorological and air pollution models capable of operating for different applications at different spatial scales – ranging from hemispheric scale over European and urban background scales to urban street scale. Coupling models over different scales, makes it possible to account for contributions from local, near-local as well as remote emission sources in order to describe the air quality at a specific location- e.g. in a street canyon. The main purposes of the system are forecasting, nowcasting, emission reduction scenarios, retrospective analysis and air pollution assessments. Furthermore, the system is used in connection with the urban and background monitoring programs in Denmark. In this paper, an overview of the model system will be given, including a short description of the individual models. The integrated system was initially developed for air pollution forecasting. An example of the model performance with respect to forecasted air pollution concentrations in an urban street canyon is presented. The THOR model system The development of the THOR system, including detailed descriptions of some of the model