Ljubljana has an unfavourable geographical location in the basin, almost entirely surrounded by high hills. Winds in the basin are often weak and situations with temperature inversion are very frequent, therefore, many PM
daily limit value exceedances were observed in 2011. The Directive 2008/50/EC (EU, 2008) requires member states to adjust or provide new air quality plans in order to comply with air quality standards for over-polluted area in near future. This is why it is necessary to provide the action plan for PM
pollution reduction in Ljubljana. Firstly, it is important to determine the sources of PM
particles and its spatial distribution. In the present study traffic emissions as the major local emission source were estimated with the NEMO pollution model. The map of important point sources in Ljubljana was prepared as well as emissions from these sources were estimated. This detailed emissions database was then introduced into the CALPUFF/CALMET modelling system coupled with the meso-scale meteorological model ALADIN.
Keywords: Ljubljana basin, CALPUFF, ALADIN, traffic pollution, industry pollution, meso-scale meteorology, air quality, environmental pollution, PM 10, source determination, local scale, network emission model, NEMO