雷电活动对F区电离层扰动及不稳定耦合效应影响的研究

The studies on thunderstorm-induced disturbances of ionosphere and instability, are to reveal the role in coupling of Earth’s atmospheric and ionosphere by the gravity waves generated by thunderstorms and electromagnetic fields of lightning. They also are of great significance in perfection of global electric circuits. Relying on Kunming Observatories, using the thunderstorm and lightning detection system, a low-light TLEs detector and various detectors of ionosphere, experiments on the thunderstorm-ionosphere collaborative observation will be carried out. The data of lightning, TLEs and ionosphere will be obtained to study on the influence on characteristics of F layer by lightning activities. First of all, the ionosphere disturbances caused by thunderstorms or lightning activities was analyzed. The role of gravity wave caused by thunderstorms will be discussed in the formation of disturbances. Next, the features and variations of ionosphere irregularity above thunderstorms will be illustrated. Relationship among drift velocity, electron density, virtual height and gravity wave with the ionosphere instability will be studied. Finally, the role of wind shear in formation of the ionosphere disturbances will be discussed..Using the circuit models for Es-F coupling, the physical mechanisms of the ionosphere perturbation induced by lightning and the instability coupling effect will be explored.

雷暴及其雷电诱发的电离层扰动及不稳定性研究对揭示雷暴产生的重力波及雷电电场在大气-电离层耦合中的作用、促进对全球电路的认识等具有重要科学意义。本项目依托昆明电波观测站，利用雷电探测系统、低光度TLEs探测仪及多种电离层探测仪开展雷暴-电离层协同观测试验，研究雷暴及雷电活动与电离层F区特性的关系。首先，分析雷暴及闪电引起的小尺度电离层扰动特征，明确不同类型雷暴（有无TLEs）诱发的电离层扰动的差异及其响应规律；其次，详细分析雷暴上方电离层不规则体的线迹分布规律及演变特征，研究离子体漂移速度、电子密度和反射高度等的变化，进而讨论重力波与电离层不稳定性的关系；最后，探讨风切变在电离层扰动、不规则体成因和不稳定性中的作用；结合Es-F层耦合模型及不稳定性理论，研究闪电电场和雷暴诱发的重力波及风切变对局部环境电场的调制效应，建立雷暴驱动下的Es-F层耦合电路模型，揭示Es-F层不稳定耦合的物理机制。

雷暴活动与电离层的相关研究，对揭示雷暴活动对雷电电磁场在雷暴-电离层耦合中的作用、完善全球电路模型等具有重要意义。项目依托昆明电波观测站，利用雷电探测系统、低光度TLEs探测仪及多种电离层探测仪开展了雷暴-电离层协同观测试验，获取雷电、中高层大气放电事件（TLEs）、电离层等资料，开展雷电活动对电离层特性影响的研究；开展了对流层雷电和电离层活动的相关性分析；对不同强度、类型的雷暴特征及变化规律进行了分类讨论，并优化了雷暴云内部辐射脉冲的定位算法；分析Na层电子密度和闪电活动的关系。