Overview on the Model
The MECTM model has originally been developed at Meteorological Institute, University of Hamburg (Lenz et al., 2000; Müller et al. 2000). MECTM is using METRAS output for the meteorology and employs the same non-uniform grid (areas between 10x10 km2 and 2500x2500 km2). Prognostic equations are solved for several pollutants (e.g. NOx, O3, SO2 , NH3, Pb, nitrate, sulphate). The dry deposition is calculated from a resistance model, it depends on pollution and land use characteristics. Chemical transformations are included in the model using the RADM2 gas phase chemistry from Stockwell et al.,. Simple aerosol dynamics as well as the sectional aerosol model SEMA of von Salzen and Schlünzen (1999) are alternatively used to calculate aerosol influences. The lateral model boundaries are open or MECTM is nested in results of a coarser model (e.g. climate model or transport model). At the model top constant concentration values are prescribed, or again the nesting technique is used. By using meteorology output of METRAS, MECTM may be employed to calculate pollutant concentrations in the air and the deposition to the ground dependent on the sources (industry, power stations, household, car and ship traffic). Emission scenario studies can be performed.