The above graph shows the resampled and simplified topography, as it is seen by the model
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Download all necessary input files and use them as an example
Within the framework of the POLLUMET summer smog investigation program an intensive field measurement campaign was carried out on the Swiss Plateau during 29 - 30 July 1993. To compare the model output with reality and to give an interpretation of the concentrations found during that episode, a simulation of these days was carried out and compared with meteorological and chemical measurements. The above figure shows the model domain extending from Payerne in the West to Frauenfeld in the East (length of domain is 200 km). It is limited by the Alps in the Southeast and by the Jura mountains in the Northwest (width of domain is 90 km). The most densely populated areas within the domain can be found around the cities of Bern, and Zürich. The lowlands have generally more inhabitants (and pollution) than the mountains, which are only sparsely populated. The horizontal grid cell size was 2km x 2km . The original topography therefore had to be simplified to be suitable for the model.
The
above graph shows the resampled and simplified topography, as it is
seen by the model
Strong westerly winds transport relatively clean air into the Swiss plateau. Elevated concentrations by local emissions are generated on the lakes of Neuchâtel and Zürich. In the East of Zürich, a big plume can be observed.
The dynamic build up of ozone and the influence of westerly winds can be viewed in this MPEG-animation.
Since
total lifetime of NOx is rather small, NO and NO2 are normally found
in the neighborhood of important pollutant sources.