近地空间电网谐波辐射现象观测研究及形成机理探讨

The observations from solar quasi-synchronous satellite show that there are radiations at the nominal frequency and its harmonic frequencies of power grid over China. During the period of calm solar and geomagnetic activities, the local electron density has an enhanced perturbation and the energetic electron flux in some energy bands tend to decrease when the power grid harmonic radiations in the range of 4~5kHz occurred. Based on the wave-particle interaction theory in the magnetosphere, the right hand polarized and whistle-mode power grid harmonic radiation waves at several kilohertz propagating along the geomagnetic induction line can gyro-resonate with the energetic electrons gyrating along the geomagnetic induction line, which can lead to the pitch angle scattering of electrons and make it possible for the electrons to precipitate into the atmosphere, so that the plasma electron density will increase. It is also speculated that the power grid harmonic radiation waves can obtain the energy of energetic electrons in wave-particle cyclotron resonance, which help them propagate in the near-Earth space without much attenuation. With the development of power grid, their effects deserve close attention.