This session combines elements of the atmospheric sciences related to weather, atmospheric composition and climate to address environmental and safety issues such as air pollution, hazardous compounds and their effects. It covers research on processes driving the physical, chemical and biological state of the atmosphere, their understanding, modelling, variability and interactions at all scales from local and urban to global, based on observations, simulations and theory. Contributions on development of observation and modelling techniques also fit within the scope of the session.

Possible topics for papers and posters include, but not exclusively:
• Air quality modelling and forecasting, including ensemble techniques, online coupled and integrated systems, numerical environmental prediction and services, and inverse dispersion modelling;
• Chemical weather and meteorological processes affecting transport, transformation, biogeochemical cycling and deposition of atmospheric constituents and pollutants;
• Meteorological and chemical data assimilation of satellite and remote sensing data and global data analysis;
• Feedback processes between meteorology, air quality and climate change,
• Long-range transport and interactions between local/regional scales and continental/global scales;
• Urban meteorology and air pollution, boundary layer dynamics and impact of surface heterogeneity (e.g., complex terrain, vegetation) in dispersion modelling;
• Odour dispersion and odour control;
• Biological weather, bio-aerosols as well as pollen dispersion, transport and sources;
• Atmospheric monitoring and evaluation for environmental issues (e.g., air quality and health, stratospheric ozone, UV-radiation, atmospheric composition, acidification and eutrophication of water bodies) as well as integrated system of systems (e.g., GEOSS);
• Nuclear/chemical/biological emergency responses: population exposure, forecasting, monitoring and impacts of biomass fires, volcano plumes, transportation, or other human activities;
• Treaty monitoring (e.g., CLTRAP, Kyoto, Montreal) and mitigation strategies.

In addition to the above possible topics, the session can also serve as a dissemination forum for large consortium projects, including COST ES1004 (EuMetChem), ES1006, TD1105 (EuNetAir), WMO/GURME, GMES MACC II, CAMS related activities and FP7 TRANSPHORM, PEGASOS and Marco Polo.