High-Speed Video and Electrical Study of Upward Lightning Triggered by Towers

这项研究将解决闪电是如何被触发并从高层建筑物（如建筑物和塔楼）向上传播的。 现有的文献和以前的观察表明，附近的闪光可以创造条件，有利于向上领导人启动从高的物体。 这些研究人员的目标是量化和了解这些条件，并确定负责向上先导启动的触发闪光组件。 电磁和光学传感器的组合将记录来自南达科他州拉皮德城附近多个输电塔的向上闪电。 电磁传感器将包括电场计、快场和慢场变化传感器以及两个干涉仪。 这些传感器的操作将与高速视频、标准清晰度视频和数字静止图像摄像机协调。使用这些资产进行的观测将沿着国家闪电探测网络（NLDN）和气象数据（即，雷达、卫星、热力学探测和气象表面参数），以确定影响或对于从高物体开始向上先导、风暴类型、发生向上闪电的区域和发展阶段至关重要的闪电类型及其特性，以及在同一闪光中触发多个高物体上的向上先导的条件。这项研究的智力价值集中在一个更对触发和传播雷电通道的机制有完整的物理学基础的理解，这些雷电通道是高大建筑物上特有的。 这项工作的更广泛的影响将包括与巴西闪电研究人员的合作互动，他们将参加南达科他州的实地项目，通过加强研究生和本科生课堂培训，对各种实地观察和相关数据分析技术进行方法和解释，并通过会议和同行评审文献传播这些研究结果。这项研究的结果将有利于社会，通过增加对雷击对高层建筑和其他用于电信和能源生产的高层建筑上的居住者和设备的潜在危险影响的理解和保护。 此外，还将向地区小学和中学以及服务俱乐部/组织介绍与这项研究有关的情况，以提高对闪电的认识，激发对高等教育和大气研究的兴趣。

This research will address how lightning is triggered and propagates upward from tall structures such as buildings and towers. Existing literature and previous observations suggest that nearby flashes can create conditions favorable for upward leader initiation from tall objects. The objective of these investigators is to quantify and understand these conditions and deter-mine a triggering flash component responsible for upward leader initiation. A combination of electromagnetic and optical sensors will record upward lightning flashes from multiple transmission towers near Rapid City, South Dakota. Electromagnetic sensors will include electric field meters, fast and slow field change sensors, and two interferometers. Operation of these sensors will be coordinated with high-speed video, standard-definition video, and digital still image cameras. Observations made with these assets will be analyzed along with National Lightning Detection Network (NLDN) and meteorological data (i.e., radar, satellite, thermodynamic sounding and meteorological surface parameters) to determine types of flashes and their properties that affect or are critical for the initiation of upward leaders from tall objects, storm type, region and stage of development during which upward lightning occurs, and the conditions for triggering upward leaders on multiple tall objects during the same flash.The intellectual merit of this research is centered upon a more complete physics-based understanding of mechanisms involved in triggering and propagation of lightning channels that are unique to strikes on tall structures. Broader impacts of this effort will include collaborative interactions with lightning researchers based in Brazil, who will participate in the South Dakota-based field program, through enhanced graduate student and undergraduate-classroom training in the methodology and interpretation of a diverse set of field observations and associated data analysis techniques, and through dissemination of these findings via conferences and in the peer-reviewed literature. Findings from this research will benefit society through increasing understanding of and protection from potentially hazardous effects of lightning strikes to both occupants and equipment mounted on high-rise buildings and other tall structures utilized for telecommunications and energy production. In addition, presentations related to this research will be made to regional elementary and secondary schools, and service clubs/organizations to increase lightning awareness and stimulate interest in higher education and atmospheric research.