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

这项研究将研究闪电是如何从建筑物和塔楼等高层建筑中触发和向上传播的。现有的文献和以前的观察表明，附近的闪光可以为从高物体向上启动领导者创造有利的条件。这些研究人员的目标是量化和理解这些条件，并确定一个触发闪光的成分，该成分负责向上引导的启动。电磁和光学传感器的组合将记录南达科他州拉皮特城附近多个输电塔发出的向上闪电。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。这些传感器的运行将与高速视频、标清视频和数字静止图像摄像机相协调。利用这些资产进行的观测将与国家闪电探测网络(NLDN)和气象数据(即雷达、卫星、热力学探测和气象地面参数)一起进行分析，以确定闪电的类型及其对从高空物体上启动向上引流的性质、风暴类型、发生向上闪电的地区和发展阶段以及在同一闪电期间在多个高层物体上触发向上引流的条件。这项研究的学术价值集中在对高层建筑上独特的闪电通道的触发和传播机制的更全面的物理理解上。这项工作的更广泛影响将包括与巴西的闪电研究人员进行协作互动，这些研究人员将参加南达科他州的实地方案，加强研究生和本科生课堂上关于各种实地观察和相关数据分析技术的方法学和解释的培训，以及通过会议和同行评议文献传播这些研究结果。这项研究的结果将通过增加对闪电对居住者和安装在高层建筑和用于电信和能源生产的其他高层建筑上的设备的潜在危险影响的了解和保护，使社会受益。此外，还将向地区中小学和服务俱乐部/组织介绍与这项研究有关的情况，以提高对闪电的认识，并激发人们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.