MODAL AEROSOL DYNAMICS MODEL FOR EUROPE - DEVELOPMENT AND FIRST APPLICATIONS

The Modal Aerosol Dynamics model for Europe (MADE) has been developed as an extension to mesoscale chemistry transport models to allow a mor e detailed treatment of aerosol effects in these models. Due to the co mplexity of the atmospheric aerosol system an approach has been chosen which is, on the one hand, fast enough for this application and, on t he other, provides sufficient information on the particle size distrib ution. In MADE, which is developed front the regional particulate mode l (RPM) the particle size distribution of the submicrometer aerosol is represented by two overlapping lognormal modes. The chemical composit ion is currently treated in the sulfate-nitrate-ammonium and water sys tem. Sources for aerosol particles are modelled through nucleation and emission. Coagulation, condensation, transport and deposition are con sidered as processes modifying the aerosol population in the atmospher e. Aerosol dynamics calculations are performed on-line within the chem istry-transport model. Process studies with a one-dimensional version of the model system are used to investigate the relative importance of the individual aerosol dynamic processes and the important links betw een between the gas and aerosol phase as well as meteorological parame ters. Results fi-om a first three-dimensional application of the fully coupled system of MADE and the European Air Pollution Dispersion mode l system (EURAD) are presented, showing the suitability of MADE as an aerosol dynamics model even within complex air quality models. The app lication of the new aerosol model provides information on particle num ber, size and surface area in addition to the chemical concentration f ields, which can be used to study a variety of aerosol-related air pol lution issues in subsequent studies. (C) 1998 Elsevier Science Ltd. Al l rights reserved.