Very-Low-Frequency (VLF) transmitters operate worldwide mostly at frequencies of 10–30 kilohertz for submarine communications. While it has been of intense scientific interest and practical importance to understand whether VLF transmitters can affect the natural environment of charged energetic particles, for decades there remained little direct observational evidence that revealed the effects of these VLF transmitters in geospace. Here we report a radially bifurcated electron belt formation at energies of tens of kiloelectron volts (keV) at altitudes of ~0.8–1.5 Earth radii on timescales over 10 days. Using Fokker-Planck diffusion simulations, we provide quantitative evidence that VLF transmitter emissions that leak from the Earth-ionosphere waveguide are primarily responsible for bifurcating the energetic electron belt, which typically exhibits a single-peak radial structure in near-Earth space. Since energetic electrons pose a potential danger to satellite operations, our findings demonstrate the feasibility of mitigation of natural particle radiation environment.

超低频 (VLF) 发射机在全球范围内主要以 10-30 kHz 的频率运行，用于海底通信。虽然了解甚低频发射机是否会影响带电高能粒子的自然环境具有强烈的科学兴趣和实际重要性，但几十年来，几乎没有直接的观测证据来揭示这些甚低频发射机在地球空间中的影响。在这里，我们报告了在 10 天的时间尺度上，在约 0.8-1.5 个地球半径的高度，以数十千电子伏 (keV) 的能量形成了径向分叉电子带。使用福克-普朗克扩散模拟，我们提供了定量证据，证明从地球电离层波导泄漏的甚低频发射机发射是导致高能电子带分叉的主要原因，该电子带通常在近地空间中呈现单峰径向结构。由于高能电子对卫星运行构成潜在危险，我们的研究结果证明了缓解自然粒子辐射环境的可行性。