电离层加热中朗缪尔湍动的数值模拟研究

应用广义Zakharov模型, “全尺度”模拟了大功率电波垂直注入电离层后电磁波与电离层的非线性相互作用.在寻常波(O波)反射点附近, 无线电波参量衰减为电子等离子体波和离子声波两种波模, 接着, 伴随着坍塌、空洞形成以及强烈电子等离子体波的俘获相关过程, 形成的空洞会导致慢非寻常波(Z波)的有效激发并能向密度更高的电离层区域传播.模拟结果表明:在毫秒量级的时间尺度内, 大功率高频电波在电离层等离子体中的O波反射点附近激发出了电子朗缪尔波和离子声波, 同时波粒相互作用导致O波向Z波的转换并传播向更高区域.此研究有助于对参量衰减不稳定性的物理机制形成较直观的印象, 对理解大功率高频电波与电离层等的非线性相互作用也很有益处.

Numerical simulation of Langmuir turbulence in the ionosphere heating

The Zakharov model is used to complete the full-scale simulation study of the generation of topside ionospheric turbulence. At the reflection point of O-mode waves, electromaganetic wave degenerates to two waves: plasma wave and ion acoustic wave. Then, the perturbation of electrons leads to the conversion from O-mode waves into Z-mode waves, and Z-mode waves could propagate into higher area. The result shows that in the millisecond magnitude scale, the Langmuir wave and ion acoustic wave are excited at the reflecton point of O-mode wave, and it leads to locally strong disturbance of electrons. The interaction between waves and particles makes O-mode wave convert into Z-mode wave and Z-mode wave propagates into higher area. In the topside of ionosphere, Z-mode wave excites the parametric decay instability and electrostatic field occurred. This study helps the understanding of the nonlinear interaction between HF wave and plasma in the ionosphere.