This session is devoted to basic and applied research on atmospheric processes and phenomena driving the physical, chemical and biological state of the atmosphere, particularly as agents for the transport, dispersion, transformation and deposition of atmospheric compounds (including air pollutants, odours, pollen, ash, dust, GHGs, radionuclides and other substances naturally or incidentally released). Understanding atmospheric transport, dispersion and deposition, their variability and interactions at all spatial and temporal scales is crucial to the development of models used to simulate and predict the past, present and future state and composition of the Earth’s atmosphere.

Within this scope, the session draws from diverse elements of atmospheric sciences research related to weather, atmospheric composition and climate, and includes theoretical, numerical modelling and experimental studies on scales that can be global, regional, urban, local or multi-scale. Contributions on development of observation and modelling techniques also fit the scope of the session. Targeted towards both disciplinary and interdisciplinary audiences, this session invites oral and poster contributions on topics including, but not limited to, the following:
• Understanding and describing the role of meteorological, chemical and biological processes and phenomena on transport, dispersion, transformation, deposition and biogeochemical cycling of air pollutants;
• Characterization of the effects of the Earth’s surface heterogeneities (e.g., land-water and urban-rural contrasts; in land cover; orography) on such processes/phenomena;
• Feedback processes between meteorology, climate and atmospheric pollution;
• Urban meteorology (e.g. street-canyon circulation, heat and compound fluxes within and over cities);
• Build-up and large-scale transport of air pollution from urban agglomerations and point sources;
• Model development and evaluation using meteorological and chemical observations.

In addition to covering the above possible topics, the session can also serve as a dissemination forum for relevant projects, including COST Actions, GAW/SAG-GURME & SAG-APP, the Copernicus Atmosphere Service (CAMS), as well as national- and European-scale consortium projects. Please do contact the conveners if you wish to organise a compiled distinctive component in the session.