Space-borne radar observation of near-surface wind effect on anomalously highly-directional backscattering of radio waves from aeolian processes of sand and dust transporting in desert regions

Subject and purpose. The purpose of this work is to study the effect of wind on the anomalous scattering of radio waves during aeolian processes of sand and dust transporting. Мethods and methodology. The article analyzes the spatial variations of the near-surface wind and their effect on the characteristics of anomalously narrowly directed radio wave backscattering according to the long-term studies of desert regions of Al-Jouf, Akshar and Trarza in Mauritania by Envisat-1 satellite SAR. Results. Analysis of SAR data indicates that intensity of radio wave scattering on the leeward slopes of sand ridges is more than 12...15 dB higher than the one from the slopes located in the "wind shadow" zone, which indicates the direct influence of the surface wind on the back scattering of radio waves during aeolian sand and dust transportation. The dependences of changes in the backscattering coefficient s 0 on the angle of local irradiation q along sections of fragments of homogeneous sections of the surface radar images are obtained. Conclusion. SAR data indicate that the spatial distribution of the maximum intensity values of anomalously narrowly directed backscattering of radio waves corresponds to the spatial distribution of the near-surface wind. The intensity of backscattering of radio waves, starting at a speed of 2 m/s and higher, steadily depends on the wind speed.