Excitation of guided ELF-VLF waves through modification of the F2 ionospheric layer by high-power radio waves

Abstract

International audienceThe possibility of controlled excitation of ELF-VLF electromagnetic waves through modification of the F2 ionospheric layer by high-power high-frequency emission is demonstrated in a natural experiment by using the Sura midlatitude heating facility. The excited low-frequency waves can be used to explore the near-Earth space and stimulate the excitation of a magnetospheric maser

ELF/VLF Perturbations Above the Haarp Transmitter Recorded by the Demeter Satellite in the Upper Ionosphere

“…In particular, paper [1] considered the local (near the observation point) generation of quasielectrostatic ELF perturbations by a beam of accelerated electrons that formed due to the dependence of the time of arrival of electrons at the generation point on their velocity. In [26] it is also proposed to explain the observed ELF perturbations by the fast magnetosonic mode instability generated by fast electrons.…”

“…Note that papers [1,26] discuss observations of ELF perturbations in the upper ionosphere in the nighttime, while the ELF signals related to the HAARP transmitter which we consider here were observed in the daytime, i. e., under conditions of a high plasma density, which drastically impedes the beam instability development. Such a scenario is difficult to apply to the observations we analyze (the event of February 10, 2010) since the ELF perturbations have an almost constant intensity in the pauses during modulated heating, as well (modulation period 1.4 s).…”