Optical and Electromagnetic Investigations of Cloud-to-Ground Lightning in the Context of In-Cloud Discharge Processes

该项目将建立一个新的云对地闪电近距离光学和电磁观测计划，该计划将与发生在云对地闪电之前、期间和之后的整个云内放电过程的较远距离观测同步进行。主要的科学目标是确定以高时间分辨率观测到的闪电CG分量的各种特征与整个云内放电过程的关系。为了实现这一目标，将在俄克拉荷马大学诺曼分校新的国家天气中心大楼的天文台建立具有成本效益的长期观测能力。云对地闪光将通过扫描胶片相机、光电二极管阵列和宽带电场变化(“慢”和“快”)天线来观测。这项工作将利用俄克拉荷马州中部现有的几个闪电和强风暴研究设施。其中包括俄克拉荷马闪电测绘阵列，以及从佛罗里达大学借来的现有光学观测系统。此外，还将与洛斯阿拉莫斯国家实验室的同事合作。他们运行着洛斯阿拉莫斯闪电阵列，这是一个覆盖俄克拉荷马州中部的扩展研究级闪电定位和表征系统，以及Forte卫星，上面装有光学闪电探测器，定期经过该地区。这种独特的长期观测能力的建立将提供一个前所未有的机会，在相对较长的一段时间内研究各种季节的风暴中的闪电。这一研究计划将记录和加强对CG闪电的量化理解，方法是对闪电的各种特征提供新的、详细的和协调的观测，这些观察已经由以前的闪电观察者以轶事和定性的方式报道。未来，只要在俄克拉荷马州中部进行观测雷暴现场活动，高质量的光学和电磁CG闪电观测将成为可能，而这些未来计划几乎不会增加成本。最后，该项目将利用国家天气中心正在进行的外联和教育项目，对本科生和高中生进行指导，特别是让美洲原住民学生参与进来。

This project will establish a new program of close-range optical and electromagnetic observations of cloud-to-ground (CG) lightning, to be obtained simultaneously with longer-range observations of entire in-cloud discharge processes that occur before, during, and after CG flashes. The primary scientific goal is to determine how various characteristics of the CG component of lightning flashes, observed with high time resolution, relate to the entire in-cloud discharge process. To accomplish this goal, a cost-effective long-term observing capability will be established in the observatory at the new National Weather Center Building on the campus of the University of Oklahoma in Norman, OK. Cloud-to-ground flashes will be observed by means of a streak-film camera, a photodiode array, and broadband electric-field-change ("slow" and "fast") antennas. The work will take advantage of several existing operational facilities for lightning and severe-storm research in central Oklahoma. These include the Oklahoma Lightning Mapping Array, and existing optical observing systems on loan from the University of Florida. In addition, there will be collaboration with colleagues at the Los Alamos National Laboratory. They operate the Los Alamos Sferics Array, an extended research-grade lightning location and characterization system that covers central Oklahoma, and the FORTE satellite, with optical lightning detectors on board, which periodically passes over the region.The establishment of this unique long-term observing capability will provide an unprecedented opportunity to study lightning in a variety of storms in all seasons over a relatively long period of time. This program of research will document and enhance quantitative understanding of CG lightning flashes by providing new detailed and coordinated observations of various features of flashes that have been reported anecdotally and qualitatively by previous lightning observers. In the future, whenever observational thunderstorm field campaigns are undertaken in central Oklahoma, high-quality optical and electromagnetic CG lightning observations will be possible at little additional cost to these future programs. Finally, the project will take advantage of ongoing National Weather Center outreach and education programs to engage in mentorship of undergraduate and high-school students, with a special effort to involve Native American students.