EAGER: Multi-frequency Studies of Lightning Initiation and Propagation

闪电是最严重的自然灾害之一，在美国平均造成的死亡人数超过飓风或龙卷风[见http://www.nws.noaa.gov/om/hazstats.shtml]]，并对财产和敏感设备造成重大损失。虽然闪电已经被研究了几十年，但闪电物理学的几个基本方面仍然没有被理解，包括它们是如何开始的，以及它们是如何通过云层和晴朗的空气传播到地面的。该研究项目将以一种新的方式关注闪电的产生和传播，以帮助解释闪电的这两个基本方面是如何工作的。拟议的测量将在佛罗里达州的NASA肯尼迪航天中心（KSC）进行。闪电在KSC特别频繁，造成昂贵的操作延误，有时会损坏敏感的火箭和航天飞机车辆和/或设施。该项目的观测方案是使用五个不同的“眼睛”（测量系统）来观察闪电过程：(1)慢速天线，(2)快速天线，(3)由七个交叉环路磁传感器组成的网络，(4)KSC现场磨坊网络和(5)KSC闪电探测和测距（LDAR）系统。所有这些传感器都在观察闪电加速和移动电荷时引起的电或磁变化。这五种类型的传感器在闪电研究中是众所周知的，但这五种传感器以前从未一起用于观察闪电。不同的仪器对闪光的不同部分做出反应：有些部分只有几米长，而另一些则长达几千米。该项目的一个关键特征将是使用最近开发的交叉环路传感器网络技术，该技术允许人们确定来自闪电的长（~1000米）快速电磁脉冲的位置。在云内和云对地闪电中发现的这些长脉冲的位置，在过去是不为人知的。该项目的智力价值源于将这五个传感器的数据结合起来，为闪电的产生和传播提供了新的见解。该项目更广泛的影响主要分为两类：提高雷电安全性和培训新科学家。更好地了解特定危害（在本例中是闪电）背后的机制，可以带来新的和改进的方法来保护人民和财产免受这种危害。防雷系统主要以科学为基础，确定闪电如何产生和传播可能会揭示保护地面和空中物体的新方法。该项目对培养和培养几名新科学家也很重要，其中包括一名攻读博士学位的研究生和两名有意从事科学研究的物理学本科生。该项目的结果也将在同行评议的文献中广泛传播。

Lightning is one of the worst natural hazards, killing more people in the USA on average than hurricanes or tornadoes [see http://www.nws.noaa.gov/om/hazstats.shtml] and causing substantial damage to property and sensitive equipment. Although lightning flashes have been studied for many decades, several fundamental aspects of lightning physics are still not understood, including how they begin (initiate) and how they travel (propagate) through clouds and clear air to the ground. This research project will focus on lightning initiation and lightning propagation in a new way to help explain how these two fundamental aspects of lightning may work. The measurements proposed will be made at the NASA Kennedy Space Center (KSC) in Florida. Lightning is especially frequent at KSC, causes expensive operational delays, and sometimes damages sensitive rocket and shuttle vehicles and/or facilities.The observation scheme for this project is to use five different 'eyes' (measurement systems) to observe lightning processes: (1) slow antennas, (2) fast antennas, (3) a network of seven crossed-loop magnetic sensors, (4) the KSC field mill network and (5) the KSC Lightning Detection And Ranging (LDAR) system. All of these sensors look at the electric or magnetic changes caused by lightning as it accelerates and moves charge. The five types of sensors are well known in lightning research, but all five have never before been used together to observe flashes. The different instruments respond to different parts of a flash: some parts are only a few meters in length while others are as long as a few thousand meters. A key feature of this project will be the use of a recently developed technique for the crossed-loop sensor network that allows one to determine the location of long (~1000 meter), fast electromagnetic pulses from lightning. The locations of these long pulses, found in both in-cloud and cloud-to-ground lightning flashes, have not been known in the past. The intellectual merit of the project stems from combining the data from these five sensors to provide new insights into how lightning initiation and lightning propagation work.The main broader impacts of the project fall into two categories: improving lightning safety and training new scientists. Developing a better understanding of the mechanisms behind a particular hazard (lightning, in this case) can lead to new and improved ways of protecting people and property from that hazard. Lightning protection systems are primarily based in science, and determining how lightning initiates and propagates may reveal new ways to protect objects on the ground and in the air. This project will also be important for the development and training of several new scientists, including one graduate student pursuing a Ph.D. degree, and two undergraduate physics students interested in being involved in scientific research. The results of this project will also be broadly disseminated in the peer-reviewed literature.