Collaborative Research: CEDAR--Tomographic Array for Lightning and Ionospheric Studies (TALIS)

为了充分确定闪电对电离层密度结构的影响，该项目将部署共址的电离层和闪电高频阵列（1-30兆赫），用于D区和E区成像，并部署甚低频（0-500千赫）和甚高频（120-150兆赫）雷达，用于闪电研究。 观测方案将通过电离层数据同化四维（IDA 4D）模型的计算得到扩充。 该模型将利用所获得的观测结果以及其他机会性E区数据来源，特别是来自洛斯阿拉莫斯便携式脉冲发生器和Cibola飞行实验卫星的数据来源，对从E区延伸到上述高度的电离层进行层析成像重建。 这些活动的目标是阐明对流层和电离层之间的耦合过程，特别是闪电和E区电离增强（称为零星E）之间的相互作用。 目前的想法表明，有两种主要机制将能量从对流层传输到低电离层：第一种是机械波活动，第二种是与闪电相关的电效应，包括电磁脉冲和相对论电子。波的机械耦合可以在传播到F区之前增加零星E层的峰值等离子体密度。 闪电的放电产生电磁耦合，并可能通过从这些高度发现的流星金属原子的环境人口中产生更多的长寿金属离子来增加峰值等离子体密度。 然而，人们对闪电和电离层之间的电磁耦合知之甚少，尽管瞬态发光事件（TLE）的观测表明雷暴和中层和高层大气之间确实发生了相互作用。 目标是在回答以下关于电离层/对流层耦合的问题上取得重大进展：（1）闪电发射和零星E层发展之间的耦合机制是什么？(2)闪电发射与电离层电导变化之间的关系是什么？(3)在多大程度上我们可以使用测量的射频值的闪电发射和电离层的特性，同时建模和分析闪电发射的物理特性和电离层响应的详细结构？

In order to fully characterize the effect of lightning on ionospheric density structures, this project will deploy co-located ionosphere and lightning RF arrays at HF (1-30 MHz) for D- and E-region imaging, and VLF (0-500 kHz) and VHF (120-150 MHz) radars for lightning studies. The observational program will be augmented by computations from the Ionospheric Data Assimilation Four-Dimensional (IDA4D) model. The model will perform tomographic reconstruction of the ionosphere for heights extending from the E region to above using the observations obtained as well as other opportunistic E region data sources, most notably from the Los Alamos Portable Pulser (LAPP) with the Cibola Flight Experiment (CFE) satellite. The goal of these activities is to elucidate coupling processes between the troposphere and ionosphere, in particular the interaction between lightning and E region ionization enhancements known as sporadic-E. Current thinking suggests that there are two primary mechanisms that transport energy from the troposphere to the lower ionosphere: the first is mechanical wave activity and the second is electrical effects associated with lightning, including electromagnetic pulses and relativistic electrons. The mechanical coupling of waves may increase the peak plasma densities of sporadic-E layers before propagating into the F-region. Discharges from lightning couple electromagnetically and may increase the peak plasma densities by creating more long-lived metal ions from the ambient population of meteoric metal atoms found at these altitudes. However, very little is known about the electromagnetic coupling between lightning and the ionosphere, even though observations of Transient Luminous Events (TLE) indicate that interactions between thunderstorms and the middle and upper atmospheres do occur. The goal is to make significant progress in answering the following questions on ionosphere/troposphere coupling: (1) What is the coupling mechanism between lightning emissions and the development of sporadic E layers? (2) What is the relationship between lightning emissions and the variations of conductances in the ionosphere? (3) To what degree can we use measured RF values of the lightning emissions and characterization of the ionosphere to simultaneously model and analyze the physical characteristics of lightning emissions and the detailed structuring of the ionospheric response?