雷暴云顶和低电离层之间的大气放电现象研究进展

Research Progress of Lightning Discharges Between Thundercloud Top and Lower Ionosphere

雷暴云顶和低电离层之间的大气放电是20世纪90年代(1989年)新发现的一类大空间尺度(垂直尺度几十千米,水平尺度甚至达到几百千米)放电现象,由于它们的持续时间比较短(ms量级),因此又被称为瞬态发光事件(Transient Luminous Events,TLEs)。由于瞬态发光事件连接对流层、平流层、中间层、低热层等多个大气层,因此是对流层与上层大气之间物质能量交换的重要瞬态物理过程,对这类放电现象的研究,有助于揭示整层大气间的耦合机制问题。瞬态发光事件对中高层大气的物理性质、化学性质、空间电磁环境及临近空间内飞行器的安全运行有直接影响。截至目前,已经发现的瞬态发光现象包括红色精灵(又称为"红闪",sprites)、淘气精灵(elves)、蓝色喷流(blue jets)、蓝色启辉器(blue starters)、巨大喷流(gigantic jets)和光晕(halos)等多种形式。以上述几种放电现象为主线,对相关研究成果进行了介绍,同时对未来的研究工作进行了展望。

Lightning discharges between thundercloud top and lower ionosphere are a kind of large scale （vertical extension is about tens of kilometers, horizontal extension even reach hundreds of kilometers） discharges that were newly discovered in the 1990’s （1989）. They are also termed as transient luminous events （TLEs） because of their short durations. For the TLEs connecting the troposphere, stratosphere, mesosphere and the lower thermosphere, they are important transient physical processes in the mass and energy exchanges between troposphere and upper atmosphere. Research on the TLEs will help to reveal the coupling mechanisms of the entire atmosphere. The TLEs have direct impact on the physical and chemical properties of the middle and high level atmosphere, the space electromagnetic environment and the safe operation of aircraft in near space. Up to now, the known TLEs include sprites, elves, blue jets, blue starters, gigantic jets and halos. In this article we will review the scientific achievements according to the TLEs types and look forward to future research work on the TLEs.