VLF emissions and electron precipitations stimulated by emissions of power transmission line harmonics

A variety of VLF emissions stimulated by the emission of power transmission line harmonics has been revealed in sonograms as a stable frequency-periodic structure. In contrast to ordinary line harmonics, these emissions are characterized by a considerable (more than 50%) spectrum widening and the absence of a decrease in their amplitude with increasing number of harmonics. It has been demonstrated that the periodic spectral structure is observed only during periods of moderate activity and pseudobreakups and is absent on geophysically quiet and magnetically active days. The signs of the correlation between these emissions and the aurora have been identified.