📝 SummarXiv

Abstract

During solar storms, the polar cusp often exhibits electron populations with distinct velocity distributions, which may be associated with the two-stream instability. This study reveals the evolution of the two-stream instability associated with electron velocities and the interaction between the growth phase of the two-stream instability and the electrostatic solitary waves (ESWs). The results from particle-in-cell (PIC) simulations are compared with satellite observational data and computational outcomes. The potential risks associated with two-stream instability, including surface charge accumulation and communication system interference on spacecraft, are also explored. The findings show that, in the high-latitude polar cusp region, the interaction between the solar wind plasma propagating along magnetic field lines and the upward-moving ionospheric plasma could drive two-stream instability, leading to the formation of electron hole structures in phase space and triggering a bipolar distribution of ESWs. When the spatial magnetic field and wave vector meet specific conditions, the enhanced electron cyclotron motion could suppress the formation of two-stream instability and electron hole structures, leading to a reduction in the amplitude of the ESWs. The results offer valuable insights for a deeper understanding of the impact of solar storms on the polar cusp environment, as well as for monitoring electromagnetic environment and ensuring the stable operation of spacecraft.