Study of the submicronic aerosol dry deposition on urban surfaces in a wind tunnel.

Pierre Roupsard (1) , Muriel Amielh (2) , Alexis Coppalle (3) , Hubert Branger (2) , P. Laguionie (1) , Olivier Connan (1) , D. Hébert (1) , Didier Maro (1) , M. Talbaut (3)

1 IRSN/PSE-ENV/SRTE/LRC - Laboratoire de Radioécologie de Cherbourg-Octeville
2 IRPHE - Institut de Recherche sur les Phénomènes Hors Equilibre
3 CORIA - Complexe de recherche interprofessionnel en aérothermochimie

To quantify the impact of an accidental or chronic pollution by an aerosol on an urban environment, dry deposition transfer coefficient, or dry deposition velocity, must be determined for the different surfaces composing this environment (roofs, walls and ground) as a function of the micrometeorological conditions. There are few data for the urban environment. Data have been acquired in laboratory but they are poorly representative of urban environments. Moreover field measurements are not related to micrometeorological parameters that are very important in the deposition phenomenon. In this study, the dry deposition velocities of a tracer aerosol, representative of the coagulation mode of the atmospheric aerosol, on three urban surfaces and for three wind speed were quantified experimentally in a wind tunnel. A significant increase of the deposition velocities with the roughness of the surfaces and the flow speed was observed. These dry deposition velocity measurements were achieved together with turbulence measurements.

Mots clés: urban surface; velocity deposit; wind tunnel; experiment; aerosol

Domaines: Mécanique des fluides [physics.class-ph]; Mécanique des fluides [physics.class-ph]; Océan, Atmosphère

Pierre Roupsard, Muriel Amielh, Alexis Coppalle, Hubert Branger, P. Laguionie, et al.. Study of the submicronic aerosol dry deposition on urban surfaces in a wind tunnel.. 26ème Congrès Français sur les aerosols, Jan 2011, Paris, France. pp.1-6. ⟨hal-00760194⟩