Parametric excitation of ELF-waves and ion acceleration due to injection of strong VLF-waves into the ionosphere

It is shown according to the data from the Kosmos-1809 satellite that propagation of a strong whistler VLF-wave through the ionosphere is followed by generation of ELF waves and acceleration of ionospheric ions. Excitation of ELF waves correlated with the VLF transmitter pulses occurred in the 70-400 Hz frequency range with the intensity peak of about 8x10-6 V/m Hz1/2 140-180 Hz frequencies. Amplification of an ion flux in the VLF wave area took place in the 15-700 eV energy range. The maximum intensity of (2-4)x104 cm-2xs-1xeV-1xsr-1 was observed at 20-70 eV energies. The accelerated ion fluxes are anisotropic. The experimental results are explained by the mechanism of superthermal ion acceleration by electromagnetic ion-cyclotron waves excited in the ionospheric plasma during parametric instability of wistlers