Dust resuspension under weak wind conditions: direct observations and model 1A.M.Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences, Moscow, Russia
12 Jun 2012
2Space Research Institute, Russian Academy of Sciences, Moscow, Russia
3State institution "Karpov Physics and Chemistry Institute", Moscow, Russia
Received: 13 Jul 2011 – Published in Atmos. Chem. Phys. Discuss.: 25 Nov 2011Abstract. The results of direct observations of fine mineral dust aerosol
(0.15–15 μm) were carried out on extensive sand areas in
desertificated lands of Kalmykia in 2007, 2009, and 2010 under conditions of
weak wind and strong heating of the surface, almost in the absence of
saltation processes. These results show that the fine mineral dust aerosol
(0.15–0.5 μm) in the region under consideration contributes
considerably to the total aerosol content of the atmospheric surface layer.
Data on the mass concentrations of fine aerosol are treated on the basis of
physical model estimates obtained for fluid dynamic parameters in the viscous
thermal boundary layer near the ground surface. Deviations of these mass
concentrations from their background values are related to a temperature drop
in the thermal layer at the surface and from the values of friction velocity.
For small and moderate values of friction velocity, these mass concentrations
increase proportionally to a temperature drop with an exponent of about 0.5,
and, for high friction velocities, this exponent becomes negative
(~−0.5), which implies a decrease in these concentrations with an
increase in a temperature drop.
Revised: 09 May 2012 – Accepted: 21 May 2012 – Published: 12 Jun 2012
Citation: Chkhetiani, O. G., Gledzer, E. B., Artamonova, M. S., and Iordanskii, M. A.: Dust resuspension under weak wind conditions: direct observations and model, Atmos. Chem. Phys., 12, 5147-5162, doi:10.5194/acp-12-5147-2012, 2012.