We discuss one of the most difficult problems of artificial disturbance emerging in the lower ionosphere. We present the results of experiments on studying of the mechanism of the appearance of the artificial disturbances at the E-region altitudes when a powerful wave was reflected in the ionosphere F-layer. The perturbations were produced by a high-power radio wave of the ordinary mode radiated at frequency of 4,3 and 4,7 MHz by transmitters of the SURA heating facility. Soundings of the disturbed region by probe waves and a registration of reflected and scattered signals from it were carried out at two observation sites. One of them located near SURA facility (56,1°N, 46,1°E), the other, in 170 km to the East from it at the Observatory of Kasan State University (55,85°N, 48,8°E). Based on measurements of the time-altitude parameters of the probing signal, the artificial disturbance effect at heights below at 40–100 km of the powerful wave reflexions height was observed. Possible mechanisms of the appearance of the disturbances in the lower ionosphere and their effect on the probing radio-waves are discussed.
ACKNOWLEDGEMENT. The work is supported by Russian Science Foundation under Grant No 14-12-00556.