Dark Lightning

闪电科学中最大的谜团之一是窄双极事件(NBE)，这是一种星际间快速的电荷转移。它的物理仍然是谜，因为NBE：(A)缺乏容易检测到的光输出，不像所有其他已知的可比电流的闪电；(B)缺乏任何可检测到的通道准备(LEADER)过程，同样不同于所有其他已知的闪电；以及(C)与任何闪电相比，辐射最强大的高频(HF)和甚高频(VHF)发射。这项研究将使用卫星和地面观测数据来研究NBE的性质。特别是，该项目涉及通过研究所有甚高频事件来分析数据中的偏振和光谱信息。这项研究将提高目前对NBE物理的理解，并可能促进我们对闪电引发过程的了解。空间闪电遥感是监测对流天气过程的重要手段。探测和了解声内电荷转移可能会改善对恶劣天气的预测。这项研究还可能揭示闪电引发过程、地面伽马射线闪电或大气中任何其他类型的异常放电。一名研究生也将接受这一学科领域的培训。

One of the biggest mysteries in lightning science is the Narrow Bipolar Event (NBE), a rapid intracloud charge transfer. Its physics remains enigmatic, because the NBE: (a) lacks readily detectable light output, unlike all other known lightning of comparable current; (b) lacks any detectable channel-preparation (leader) process, again unlike all other known lightning strokes; and (c) radiates the most powerful High-Frequency (HF) and Very-High-Frequency (VHF) emissions compared with those of any lightning.Intellectual merit. This study will investigate the properties of NBEs using both satellite- and ground-based observational data. In particular, the project involves analyzing polarization and spectral information in the data by studying all VHF events. The research will improve current understanding of the physics of NBEs, and may advance our knowledge on lightning initiation processes.Broader impacts. The remote sensing of lightning from space is an important proxy for monitoring convective weather processes. Detecting and understanding of intracloud charge transfer may improve prediction of severe weather. The research may also shed light on lightning initiation processes, terrestrial gamma ray flashes, or any other types of unusual discharges in the atmosphere. A graduate student will be trained in this subject area as well.