Stability of the Vertical Distribution of Dust Aerosol in Light and Moderate Winds

Abstract

The profiles of dust aerosol mass concentration obtained with multilevel (0.2, 0.4, 0.8, 1.6, and 3.2 m) daytime measurements in arid conditions in 2020–2022 show a power dependence on height. We distinguish three main types of changes in concentration with height: a) in low wind (degrees are close to –0.5); b) spike changes in concentration when wind increases (degrees reach and exceed –1); c) inversions (concentration increases with height at two or three lower levels of measurements): weak – about –20 mkg/cm3, significant – more than 50 mkg/cm3. The power dependence of –0.5 is explained by the collective effect of the rise of the ensemble of closely located bubbles of air warmed around the dust particles. In weak and moderate winds, this mode is more common. Burst changes in concentration are associated with the emergence of turbulent structures.