Lightning Initiation and In-Cloud Electromagnetic Activity in Mississippi Thunderstorms

密西西比雷暴中的闪电起始和云内电磁活动

• 批准号: 1742930
• 负责人: Maribeth Stolzenburg
• 金额: $ 34.51万
• 依托单位: University of Mississippi
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-04-15 至 2022-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1742930&HistoricalAwards=false
• 关键词: Lightning; Initiation; Cloud; Electromagnetic; Activity

Although much is already known about lightning flashes, we still do not understand how a flash initiates. Somehow the initiation processes turn the non-conducting air into a short, thin conductor or initial lightning channel; the rest of the flash then develops from this initial channel. Researchers do not yet fully understand exactly what physical mechanisms cause the first sparks of a lightning flash and how those sparks transform the non-conducting air into the highly conductive lightning channel. This study will analyze several months of lightning data to gain new understanding of initiation processes. This project combines an unusual suite of traditional and state-of-the-art research sensors to advance the understanding of lightning initiation. This research has strong societal impact through potentially improved understanding of lighting initiation and improved lightning warning systems. This research seeks to analyze lightning data collected in northern Mississippi during summer 2016 to study cloud discharge events that lead to lightning initiation. Those events include fast positive breakdown, narrow bipolar events (NBEs), initial electric field changes (IECs), and initial breakdown pulses (IBPs). The novelty, and potentially transformative aspect of this new research, is in the new data, which includes measurements from an electric field derivative sensor and a very high frequency (VHF) sensor. The VHF sensor is particularly suitable for studying the lightning initiating events, because although not well understood, electrical discharges in air are known to produce HF and VHF radiation.  The analysis will take into consideration the recent discovery of fast positive breakdown and will investigate how fast positive breakdown is connected to the events that follow. A similar line of research will be conducted to study how VHF pulses affect IECs or IBPs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

虽然我们对闪电已经有了很多了解，但我们仍然不知道闪电是如何产生的。 初始过程以某种方式将不导电的空气变成短而薄的导体或初始闪电通道;然后，闪光的其余部分从这个初始通道发展。 研究人员还没有完全理解究竟是什么物理机制导致了闪电的第一个火花，以及这些火花如何将不导电的空气转化为高导电性的闪电通道。 这项研究将分析几个月的闪电数据，以获得新的理解的启动过程。 该项目结合了一套不寻常的传统和最先进的研究传感器，以促进对闪电启动的理解。 这项研究通过潜在地提高对闪电启动的理解和改进闪电预警系统，具有强大的社会影响。 这项研究旨在分析2016年夏季在北方密西西比收集的闪电数据，以研究导致闪电启动的云放电事件。 这些事件包括快速正击穿、窄双极事件（NBE）、初始电场变化（IEC）和初始击穿脉冲（IBP）。 这项新研究的新奇和潜在的变革性方面在于新数据，其中包括来自电场导数传感器和甚高频（VHF）传感器的测量结果。 VHF传感器特别适合于研究闪电引发事件，因为虽然还没有很好地了解，但空气中的放电已知会产生HF和VHF辐射。分析将考虑最近发现的快速正击穿，并将调查快速正击穿与随后的事件之间的联系。 将进行类似的研究，以研究甚高频脉冲如何影响IEC或IBP。该奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

项目成果

Electric field change and VHF waveforms of Positive Narrow Bipolar Events in Mississippi thunderstorms

• DOI: 10.1016/j.atmosres.2020.105000
• 发表时间: 2020-04
• 期刊: Atmospheric Research
• 影响因子: 5.5
• 作者: S. Bandara;T. Marshall;S. Karunarathne;M. Stolzenburg

Groups of narrow bipolar events within thunderstorms

• DOI: 10.1016/j.atmosres.2021.105450
• 发表时间: 2021-04
• 期刊: Atmospheric Research
• 影响因子: 5.5
• 作者: S. Bandara;T. Marshall;S. Karunarathne;M. Stolzenburg

The Mechanism of the Origin and Development of Lightning From Initiating Event to Initial Breakdown Pulses (v.2)

• DOI: 10.1029/2020jd033191
• 发表时间: 2020-11-27
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
• 影响因子: 4.4
• 作者: Kostinskiy, Alexander Yu;Marshall, Thomas C.;Stolzenburg, Maribeth
• 通讯作者: Stolzenburg, Maribeth

Characterizing three types of negative narrow bipolar events in thunderstorms

• DOI: 10.1016/j.atmosres.2019.05.013
• 发表时间: 2019-10
• 期刊: Atmospheric Research
• 影响因子: 5.5
• 作者: S. Bandara;T. Marshall;S. Karunarathne;N. Karunarathne;R. Siedlecki;M. Stolzenburg

A study of lightning flash initiation prior to the first initial breakdown pulse

• DOI: 10.1016/j.atmosres.2018.10.013
• 发表时间: 2019-03
• 期刊: Atmospheric Research
• 影响因子: 5.5
• 作者: T. Marshall;S. Bandara;N. Karunarathne;S. Karunarathne;I. Kolmašová;R. Siedlecki;M. Stolzenburg