Mr Leif Laursen Submitted by ll@dmi.dk DK-2100 Coepnhagen Ø Denmark ____________________________________________ Presentation: Integrated systems for weather and air quality forecasting Alexander Baklanov, Ulrik Korsholm, Alexander Mahura and Leif Laursen ____________________________________________ Abstract: During the last decade a new direction of atmospheric modelling - chemical weather forecasting (CWF) – has developed. This area includes the very short term variability of the chemical fields that exist due to the influence of meteorological variability and the heterogeneity of the emissions. However, in most recent publications this new direction is considered in a simplified context where only the main health affecting pollutants are predicted and where numerical weather prediction output is used as driver. Such CWF models limit the variability of the species, and feedbacks on the meteorological fields are neglected. Measurements and modelling studies showed that atmospheric processes (including precipitation, thunderstorms, radiation budget, cloud processes and boundary layer structure) depend on the concentration of chemical components, in particular aerosols. There-fore, CWF models have to be run online with the meteorological drivers using the same time steps and considering relevant two-way interactions between the meteorological, chemical and aerosol processes. In future prediction systems CWF models should include not only health affecting pol-lutants but also greenhouse gases, climate active aerosols and meteorological processes for the pre-diction of atmospheric composition, meteorology and climate. In the presentation the concept of CWF modelling with two-way interactions is discussed and an online model, Enviro-HIRLAM, containing such feedbacks will be described. ____________________________________________ Submission area: Oral