太阳风中低频离子静电孤波

THE ELECTROSTATIC ION SOLITARY WAVES WITH LOW FREQUENCIES IN THE SOLAR WIND

本文给出在太阳风超声速流动条件下，离子静电孤波的传播特性，结果与Ｈｅｌｉｏｓ１，２卫星观测的静电离子噪声做了比较．离子声波扰动的非线性发展使太阳风等离子体呈规则的小尺度起伏，离子声波在马赫锥外传播，因此理论预言密度起伏不沿着太阳风速度方向。

This paper indicates that under the condition of super sonic stream of the solar wind the electrostatic ion solitary waves propagate with very different properties. The results can be campared with the electrostatic ion noises observed by Hellos 1,2. The nonlinear evolution of the ion acoustic disturbance makes the solar wind plasma fluctuating regularly in small scale. The ion acoustic wave propagates outside Mach Cone. Based on this understanding, we could predict that the density fluctuations of the solar wind are not along solar wind velocity but in the transverse direction.