CEDAR: Natural and Rocket-Triggered Lightning in the Mesosphere-Lower Thermosphere-Ionosphere (MLTI) System

CEDAR：中间层-低层热层-电离层 (MLTI) 系统中的自然闪电和火箭触发闪电

• 批准号: 0940248
• 负责人: Robert Moore
• 金额: $ 27.5万
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-15 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0940248&HistoricalAwards=false
• 关键词: CEDAR; Natural; Rocket; Triggered; Lightning

The research project will quantitatively investigate the effects of both natural and rocket-triggered lightning in the mesosphere-lower thermosphere-ionosphere (MLTI) region of the atmosphere between 60 and 100 km altitude. The experimental effort will focus on several outstanding questions regarding the production of light-emitting phenomena known collectively as transient luminous events (TLEs) by natural lightning and will investigate the possible role of rocket-triggered lightning as a source for these disturbances. The primary theoretical effort will combine state-of-the-art numerical models to predict the mesospheric/ionospheric reaction to realistic return-stroke currents consistent with observations. The experimental effort centers on lightning observed at and near the International Center for Lightning Research and Testing (ICLRT) in Camp Blanding, Florida. The project will provide simultaneous wideband (1 Hz-20 MHz) observations of the causative lightning waveforms (both natural and rocket-triggered), photometric observations for the optical detection of transient luminous events, and narrowband (200-Hz bandwidth) observations of very low frequency (VLF, 3-30 kHz) signals that are sensitive to conductivity changes in the D-region ionosphere. These systems will provide continuous monitoring of ionospheric events related to natural lightning throughout the three-year period of the award. Attempts to trigger lightning using the classical rocket-and-wire technique will be performed during intense nighttime thunderstorms. This program will address the following questions: 1) What are the wideband (1 Hz-20 MHz) characteristics of lightning that successfully produce TLEs? 2) What are the wideband characteristics of lightning that successfully produce ionospheric conductivity changes that scatter VLF signals? 3) What characteristics of TLEs are most closely associated with the observed VLF scattering?

该研究项目将定量调查60至100公里高度之间的大气中层-低热层-电离层（MLTI）区域的自然闪电和火箭触发闪电的影响。实验工作将集中在几个悬而未决的问题上，这些问题涉及到由自然闪电产生的统称为瞬态发光事件（TLEs）的发光现象，并将研究火箭触发的闪电作为这些干扰源的可能作用。主要的理论工作将结合最先进的数值模型来预测中间层/电离层对与观测相符的实际回冲程电流的反应。实验的重点是在佛罗里达州布兰丁营的国际闪电研究和测试中心（ICLRT）及其附近观察到的闪电。该项目将同时提供宽带（1hz - 20mhz）对闪电波形（自然和火箭触发）的观测，对瞬态发光事件进行光学探测的光度观测，以及对d区电离层电导率变化敏感的极低频（VLF, 3- 30khz）信号的窄带（200hz带宽）观测。这些系统将在合同的三年期间持续监测与自然闪电有关的电离层事件。在夜间强烈的雷暴期间，将尝试使用经典的火箭和电线技术来触发闪电。该计划将解决以下问题：1)成功产生TLEs的闪电的宽带（1hz - 20mhz）特性是什么？2)成功产生电离层电导率变化并散射VLF信号的闪电的宽带特性是什么？3) TLEs的哪些特性与观测到的VLF散射最密切相关？