Influence of emission input data on ozone level predictions for the upper rhine valley

The EUMAC zooming model (EZM) is applied to the Upper Rhine valley to study the wind flow and the transport and transformation of air pollutants in that area. The main purpose of the investigation is to prove the ability of the model system to analyse the regional air quality in an area characterized by a complex terrain. The results clearly show that the EZM is a useful tool to describe the air pollution levels in such a structured region. In addition to the wind field a detailed emissions inventory is necessary to obtain realistic results. This inventory should be highly resolved in space and time and should contain all major emission sources. A sensitivity study is carried out to investigate the influence of uncertain emission data on the calculated ozone concentrations. Varying the emissions of individual source types inside the estimated error range leads to changes of the maximal ozone concentrations of up to 10%. The results of the sensitivity study lead to useful conclusions with regard to the effectiveness of emission reductions at the regional scale.