  The paper analyzes the phenomenon of turbulent thermal diffusion in the Earth
atmosphere, its relation to the turbulent diffusion and its potential impact on
aerosol distribution. This phenomenon was predicted theoretically more than 10
years ago and detected recently in the laboratory experiments. This effect
causes a non-diffusive flux of aerosols in the direction of the heat flux and
results in formation of long-living aerosol layers in the vicinity of
temperature inversions. We demonstrated that the theory of turbulent thermal
diffusion explains the GOMOS aerosol observations near the tropopause (i.e.,
the observed shape of aerosol vertical profiles with elevated concentrations
located almost symmetrically with respect to temperature profile). In
combination with the derived expression for the dependence of the turbulent
thermal diffusion ratio on the turbulent diffusion, these measurements yield an
independent method for determining the coefficient of turbulent diffusion at
the tropopause. We evaluated the impact of turbulent thermal diffusion to the
lower-troposphere vertical profiles of aerosol concentration by means of
numerical dispersion modelling, and found a regular upward forcing of aerosols
with coarse particles affected stronger than fine aerosols.
