High-resolution simulations of the wind flow and the ozone formation during the heilbronn ozone experiment

The Heilbronn ozone experiment was performed in the period 23–26 June 1994 in the state of Baden-Württemberg, Germany, with the intention to investigate if peak ozone concentrations during summer smog periods may be reduced by the aid of short term local scale interventions. Extensive meteorological and air quality measurements carried out during the experiment provide valuable information on the prevailing situation. In addition, high-resolution model simulations with the EUMAC Zooming Model (EZM) were performed to complete the picture at areas where no observations were available and to facilitate assessing the effectiveness of the emission reduction interventions. The observational data enable a very detailed evaluation of the simulation results. The results of both measurements and simulations reveal that the interventions lead to air quality improvements with regard to the primary pollutant concentrations but only to minor changes in peak ozone levels. The main conclusion from the Heilbronn ozone experiment is that concerted large-scale interventions to the primary pollutant sources are needed for decisive reductions of peak ozone concentrations in Central Europe.