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

该项目将建立一个云对地闪电（CG）近距离光学和电磁观测的新项目，与CG闪电之前、期间和之后发生的整个云内放电过程的远程观测同时进行。主要的科学目标是确定高时间分辨率观测到的闪电的CG成分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，将在位于俄克拉荷马大学诺曼校区的新国家气象中心大楼的天文台建立一个具有成本效益的长期观测能力。云层到地面的闪光将通过条纹胶片相机、光电二极管阵列和宽带电场变化（“慢”和“快”）天线来观察。这项工作将利用俄克拉荷马州中部几个现有的闪电和强风暴研究设施。其中包括俄克拉何马闪电测绘阵列，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。他们操作洛斯阿拉莫斯卫星阵列，这是一个扩展的研究级闪电定位和表征系统，覆盖俄克拉荷马中部，以及FORTE卫星，该卫星上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，在相对较长的时间内研究各种季节的各种风暴中的闪电。这个研究项目将记录和加强对CG闪电的定量理解，通过提供新的详细和协调的观测，这些观测已经被以前的闪电观测者定性地报道过。未来，无论何时在俄克拉何马州中部进行雷暴现场观测活动，高质量的光学和电磁CG闪电观测都将成为可能，而这些未来项目的额外费用很少。最后，该项目将利用正在进行的国家气象中心外展和教育项目，为本科生和高中生提供指导，并特别努力让美国土著学生参与其中。

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.