Electrical Processes in a Wind-Sand Flux on Desertified Areas

Desertified areas are the main source of dust aerosol. The emission and transport of dust aerosol in the near-surface layer of the atmosphere are markedly affected by electrification of the wind-sand flux. Electrical processes in a wind-sand flux have been studied experimentally. Based on data of synchronous measurements of the density of saltation electric currents and currents caused by transport of charged dust aerosol particles at heights of 4 and 12 cm in a desertified area in Astrakhan oblast, statistical characteristics of variations in the density and density moduli of these currents are calculated. It is shown that in a wind-sand flux in the height range from 4 to 12 cm, the density modules of saltation electric currents and currents caused by transport of dust aerosol decrease with height much more slowly (the logarithmic gradients are −0.025 and −0.07 cm−1) than the concentration of saltating particles (the logarithmic gradient is −0.32 cm−1). It is confirmed that the moduli of saltation electric current density correlate with each other and with the wind speed in the surface air layer more closely than the current densities themselves. The results obtained are of interest in developing models of dust aerosol emission in desertified areas.