Dust resuspension under weak wind conditions: direct observations and model
1A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russia
2Space Research Institute, Russian Academy of Sciences, Moscow, Russia
3State institution "Karpov Physics and Chemistry Institute", Moscow, Russia
Abstract. Here we report the results of the direct observations of fine scale mineral dust aerosol carried out over extensive sand areas in desertificated lands of Kalmykia in 2007, 2009 and 2010 under conditions of weak wind and strong heating of the surface with near absence of saltation processes. Measurements show that the fine mineral dust aerosol in the chosen region constitutes a considerable fraction of the entire air aerosol in the atmospheric surface layer (in terms of both the number of particles and their mass). Data of fine aerosol mass concentrations are treated on the basis of physical model estimates obtained for fluid dynamic parameters in the viscous thermal boundary layer near the ground surface. The deviations of mass concentrations from background are linked to temperature drop in the thermal layer near the surface and the value of friction velocity.