Atmospheric Chemistry and Physics Discussions www.atmos-chem-phys-discuss.net 1680-7367 1680-7375 5 5 2005 10.5194/acpd-5-9621-2005 http://www.atmos-chem-phys-discuss.net/5/9621/2005/ http://www.atmos-chem-phys-discuss.net/5/9621/2005/acpd-5-9621-2005.html http://www.atmos-chem-phys-discuss.net/5/9621/2005/acpd-5-9621-2005.pdf 9621 9639 2005-10-05 Development and validation of tools for the implementation of European air quality policy in Germany (Project VALIUM) M. Schatzmann W. Bächlin S. Emeis J. Kühlwein B. Leitl W. J. Müller K. Schäfer H. Schlünzen Meteorological Institute, ZMAW, University of Hamburg, Germany Ingenieurbüro Lohmeyer GmbH & Co. KG, Karlsruhe, Germany Forschungszentrum Karlsruhe, IMK-IFU, Garmisch-Partenkirchen, Germany Institute of Energy Economics and the Rational Use of Energy, University of Stuttgart, Germany Lower Saxony State Agency for Ecology, Hanover, Germany In the framework of the German Atmospheric Research Program AFO-2000 a system of consistent coupled numerical models has been developed. The purpose of the model system is to serve as a tool for the execution of European urban air quality regulations. A consortium with the acronym VALIUM was formed, which consisted of German research institutes, environmental consultancies and an environmental agency. <br><br> A substantial part of the VALIUM program was devoted to the generation of a set of high quality data for the validation of the numerical model system. The validation data are based on a combination of field studies, tracer experiments and corresponding wind tunnel experiments. The field experiments were carried out inside and around a street canyon in a city district of Hanover/Germany. After a brief introduction to the VALIUM project a summary of the main results will be given.