红闪（sprite）对地闪的非线性响应与干涉效应研究

项目名称： 红闪（sprite）对地闪的非线性响应与干涉效应研究

项目编号： No.41275009

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 天文学、地球科学

项目作者： 张其林

作者单位： 南京信息工程大学

项目金额： 88万元

中文摘要： 红闪（sprite）是发生在40-90km中间层的一种瞬态发光现象，其在全球气候变化、对流层-中间层（或电离层底部）电动力耦合效应等方面具有重要的学术价值。但目前在sprite的触发机制及其极低频（ELF）信号在地球-电离层波导腔中的传播等方面存在许多未解之谜。因此，本项目拟开展sprite对地闪的非线性响应与干涉效应研究。首先，利用多站ELF同步观测资料，通过反卷积方法，反演地闪及sprite电流矩（或电荷矩）。然后，考虑地磁场的经纬度变化和中间层电参数的非线性效应， 建立地球-电离层ELF/VLF非线性耦合模式，研究sprite对地闪的非线性响应。最后，利用全球舒曼共振(SR)传输模式，研究sprite与地闪在ELF频段的干涉效应。研究结果将进一步揭示sprite的触发机制，提高全球超强地闪和sprite放电参量及其时空分布的反演精度。

中文关键词： 红闪；地闪；非线性响应；干涉；极低频

英文摘要： Sprite is a large-scale optical phenomena occuring above thunderstorms at altitudes ranging from 40 to 90 km in the mesosphere and lower ionosphere,which plays an important role in the global climate changes and the dynamic coupling of quasi-electrostatic thunderstorms fields to the mesosphere and lower ionosphere.However,there are still many important but unsolved problems including of the initiation mechanisms of the sprite and its propagation characteristics of the radiated ELF (extremely lowe frequency) wave in the Earth-ionosphere cavity.Therefore,the nonlinear response of the sprite to the intense cloud-to-ground lightning (CG) and their interference effect will be studied. Firstly, based on the ELF data recorded simultaneously at several stations, the lightning source charge moment changes (CMC) or the current moment(CM) are extracted from remotely measured magnetic fields with a deconvolution technique;Secondly,initiation mechanisms of the long-delayed sprites are studied by using the improved nonlinear coupling model between the earth and the ionosphere,taking into an account of the nonlinear response of the sprite to the intense CG;Finally, the interference effect between the intense CG and the sprite is simulated by the global Shumman Resonance (SR) model.The results are very helpful in further reve

英文关键词： Sprite；CG lightning；Nonlinear response；Interference effect；Very low frequency