Precipitation of Energetic Electrons from the Earth’s Radiation Belt Stimulated by High-Power HF Radio Waves for Modification of the Midlatitude Ionosphere

Abstract

Based on the results of the experiments performed in [2005][2006][2007][2008][2009][2010] within the framework of the Sura -DEMETER program, we analyze the features of the precipitations of energetic electrons (with energies E ≈ 100 keV) from the Earth's radiation belt. The modification of the ionospheric F 2 region was conducted by means of high-power HF O-mode radio waves radiated in the CW regime. The precipitations were detected using the equipment onboard DEMETER, a French microsatellite. The conditions of precipitation appearance were determined, and it was found that the electron precipitation region was stretched along the geomagnetic meridian to a distance of 1300 km; the size of the region in the transverse direction is about 400 km. It was shown by ionosonde measurements that such precipitations lead to increased absorption of radio waves in the lower ionosphere. It is assumed that the mechanism for precipitation of electrons from the Earth's radiation belt is determined by the interaction of energetic electrons with VLF radio waves, which are generated due to the interaction of the amplitude-unmodulated O-mode pump wave with the ionospheric plasma near the wave reflection height.

Exceptional middle latitude electron precipitation detected by balloon observations: implications for atmospheric composition

“…Here the electron scattering dominates the inward radial diffusion, resulting in an "impenetrable barrier" for electrons (Baker et al, 2014;Foster et al, 2016), which precipitate into the atmosphere. It is commonly accepted that the slot between the belts (L ∼ 3) arises from electron scattering by the waves which can be either of natural or artificial origin, as initiated by VLF emission of artificial transmitters (e.g., Gombosi et al, 2017;Frolov et al, 2020;Zhao et al, 2019). However, natural or anthropogenic phenomena in the magnetosphere resulting in midlatitude electron precipitation are still not well understood.…”

Exceptional middle latitude electron precipitation detected by balloon observations: implications for atmospheric composition

“…It is commonly accepted that the slot between the belts (L ∼3) arises from electron scattering by the waves which can be of either natural or artificial origin initiated by VLF emission of man-made transmitters (e.g. Gombosi et al, 2017;Frolov et al, 2020;Zhao et al, 2019). However, natural or anthropogenic phenomena in the magnetosphere resulting in midlatitude electron precipitation still are not well understood.…”

HF-Induced Artificial Injection of Energetic Electrons from the Earth’s Radiation Belt as a Powerful Source for Modification of Ionized and Neutral Components of the Earth’s Atmosphere

“…Below, on the basis of the results obtained in [26][27][28], we briefly consider the main AIEE characteristics, which have been found in ionosphere heating experiments as a result of F 2 region pumping by high-power HF radio waves. It is clear that features of AIEE (and AIT also) should strongly depend on the following:…”

“…Before research on AIEE properties began, the features of natural energetic electron precipitations in the vicinity of the SURA facility were previously investigated in the absence of ionosphere modifications by powerful HF radio waves [26][27][28]. In particular, we analyzed the relationship between the intensity of natural precipitations and the value of the geomagnetic activity index K p (or its daily value ΣK p ), as well as the connection of precipitations with both aurora electro jet index AE and the geomagnetic activity development stage.…”