On the nature of hectometric continuum-type emissions in the near-Earth plasma

Physics of Plasmas. 2025. Vol. 32. P. 1–10.

Mogilevsky M. M., Shaposhnikov V., Chernyshov A., Chugunin D. V., D.A.Dorofeev

The ERG (Arase) satellite recently discovered a non-thermal hectometric continuum with a narrowband frequency structure. The mechanism behind the generation of this type of emission in the near-Earth plasma is still unknown. This study examines the potential use of electron cyclotron harmonics instability to explain the line structure of hectometric radio emissions for the first time. By analyzing the case of the non-thermal hectometric continuum, a proposed mechanism for the creation of a quasi-harmonic frequency structure resulting in quasiparallel emission bands is discussed. In other words, the double plasma resonance effect is suggested as a possible explanation for the observed emission bands in the dynamic spectrum of hectometric radio waves. It is demonstrated that the double plasma resonance mechanism could account for existing measurements of hectometric radiation and explain the presence of the non-thermal hectometric continuum in the near-Earth plasma.

Keywords: магнитосфера, magnetosphere, радиоизлучение, radio emission, Гектометровое излучение, hectometric continuum radiation