Convective Aerosol Transport in Desert Zones as a Factor of Increasing Air Temperature

The article discusses aerosol pollution of the atmosphere in the southern Aral Sea region as a factor of climate change in the region. The main causes of pollution are wind and the convective removal of soil particles from the underlying surface. The differences between both types of emission are shown. Since the effect of aerosol wind removal from the dried Aral bottom on the regional climate has been studied in our earlier studies, in this work, for the first time, only the convective removal of soil microparticles from desert surfaces is considered as a factor in increased summer air temperatures in the southern Aral Sea region. The paper presents the results of calculations of the mass aerosol concentration in the surface atmospheric layer that is due to convective flows. A quantitative assessment obtained via mathematical modeling showed the importance of the convective removal of aerosol in the southern Aral Sea region, which increases the aerosol concentration to 1.2 mg/m3. Numerical experiments showed that the increase in air temperature due to convective removal of soil particles, which ranges from 0.3 to 5°C, depends on the aerosol dispersion. The absence of precipitation in the southern Aral Sea region in July–August, which counteracts the convective removal of soil aerosol by washing the aerosol from the atmosphere and wetting the underlying surface, ensures the continuous flow of aerosol particles into the atmosphere, and this increases the climate-forming effect of the considered process. The significance of progressive desertification for global climate warming is estimated in many regions of the planet as a first approximation.

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