Continent-Scale Low Frequency Lightning Remote Sensing

这笔赠款将支持开发和应用探测和测量闪电发射的新无线电方法的基础研究。雷电每年造成巨大的物理和经济损失；高电荷转移的高能闪电具有重要的实际后果，如森林火灾和建筑物损坏。高冲击性闪电过程不是常规测量的。高能闪电和产生它们的气象条件还没有被很好地理解。闪电也会产生高能辐射，但具体发生的过程尚不清楚。该项目将对产生这些高影响现象的条件有新的了解，并将提供新的工具，改进对这些现象的检测和监测，以帮助减轻其影响。研究活动将涉及代表人数不足的群体的学生，并将促进创新教育活动。利用低频电磁场进行闪电遥感是探测和量化远距离、大范围闪电过程的有力工具。该项目有两个主要目标，建立在低频闪电遥感技术的基础上。首先，将恢复、改进和扩大一个多传感器雷电荷电瞬间变化网络；该网络将在全美范围内提供近乎实时的雷电脉冲电荷时刻变化测量。这个网络将为新的科学研究打开大门，例如雷暴结构和高电荷转移闪电之间的联系，并为美国各地的研究人员提供实时指导，这些研究人员的目标是与高能闪电相关的测量，如精灵。其次，将从全球现有的低频无线电传感器网络中挖掘新的和存档的观测数据的详细分析，以获得新的数据集，以提高我们对闪电以地面伽马射线闪光的形式产生高能辐射的机制的理解。对地面伽马射线闪电之前、期间和之后闪电电流和电荷运动的详细测量将阐明其产生背后的物理原理，并为可能的物理机制提供关键的实验约束。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This grant will support fundamental research that develops and applies new radio-based methods for detecting and measuring lightning discharges. Lightning causes substantial physical and economic damage every year; energetic lightning with high electric charge transfer has important practical consequences, such as forest fires and damage to structures. High impact lightning processes are not routinely measured. Energetic lightning flashes and meteorological conditions that create them are not well understood. Lightning also generates high energy radiation, but the specific process by which this occurs remains unknown. This project will develop new understanding of the conditions that produce these high impact phenomena and will deliver new tools for their improved detection and monitoring to help mitigate their impact. The research activities will involve students from under-represented groups and will enable innovative educational activities. Lightning remote sensing with low frequency electromagnetic fields is a powerful tool for probing and quantifying lightning processes from long distances and thus over a wide geographic area. This project has two main goals that build on low frequency lightning remote sensing techniques. First, a multi-sensor lightning charge moment change network will be resurrected, improved, and expanded; the network will deliver near real-time lightning impulse charge moment change measurements across the United States. This network will open the door to new scientific studies, such as the connection between thunderstorm structure and high charge transfer lightning, as well as deliver real-time guidance for researchers across the US who target measurements associated with energetic lightning, such as sprites. Second, detailed analysis of new and archived observations from an existing network of low frequency radio sensors across the globe will be mined for new datasets to improve our understanding of the mechanisms through which lightning generates high energy radiation in the form of terrestrial gamma-ray flashes. Detailed measurements of lightning current and charge motion before, during, and after terrestrial gamma-ray flashes will illuminate the physics behind their production and provide key experimental constraints on possible physical mechanisms.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.