Scale-Dependent and Seasonal Performance of SILAM Model in Estonia

The SILAM model is running in Finnish Meteorological Institute (FMI) for European air quality forecasts (http://silam.fmi.fi). The 7 km resolution of both TNO-MACC emission grid and Nordic model domain is too coarse for urban and industrial areas. The Estonian modelling domain, operated jointly by the University of Tartu and Estonian Meteorological and Hydrological Institute (http://meteo.physic.ut.ee/silam, resolution 3.3 km) includes the Baltic countries and southern Finland. In this study the database of pollution sources on the territory of Estonia is refined and performance of SILAM with the new database is studied. The new database presents better spatial distribution, differences in yearly emission budgets should be looked into in further studies. Average concentrations of NOx, SO2 and particulate matter are reproduced rather well, NOx underestimated slightly and particulate matter significantly. The new database shows an improvement in hourly and daily correlations, especially for urban stations.