Dispersion and deposition of gas and aerosol particles in urban environment: examples of in situ experiments for predictive model validation

Abstract

International audienceIn terms of chronic or accidental release of radioactive particles into the atmosphere, knowing atmospheric gas and particle dispersion, as well as particle-bound radionuclide deposition flux on ground surfaces is essential to assess risks on both populations and environments. Protecting urban environments and populations living in the vicinity is a major issue. However, urban areas are among the least studied environments due to their complexity in terms of dynamics, thermal properties and spatial heterogeneity. Our work focus on how in situ experiments help constraining predictive models of atmospheric gas and particle dispersion, and particle-bound radionuclide deposition flux on various spatiotemporal scales in urban environments. Examples of past and ongoing studies will be presented. Our in situ experiments use tracing gas (SF6 and He), tracing particles (fluorescein) or natural radionuclides already present in environment such as 7Be. Results will be discussed during the conference