A prognostic capability of aerosols on a global scale is required for reliable prediction of climate change as well as for improving weather forecast. A prognostic representation of aerosols is often implemented in many climate models (Textor et al., 2006, for a review). However, it is quite a novelty in global weather forecast systems due to the requirements of a proper assimilation system (Morctrette et al., 2009). As part of the project Global Environmental Monitoring using Satellite and in-situ data (GEMS), the European Centre for Medium-range Weather Forecasts (ECMWF) has developed a model to include a number of aerosol chemical components like sea salt, dust, sulphate, organic matter and black carbon.