TLEs and early VLF events: Simulating the important impact of transmitter‐disturbance‐receiver geometry
TLEs and early VLF events: Simulating the important impact of transmitter‐disturbance‐receiver geometry
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TLE 和早期 VLF 事件：模拟发射机-干扰-接收机几何结构的重要影响
DOI：
10.1002/2016ja022791
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
M. Cohen
中科院分区：
文献类型：
--
作者：
S. NaitAmor;H. Ghalila;M. Cohen
早期甚低频 (VLF) 事件是对亚电离层传播的 VLF 无线电发射机的扰动，当闪电活动靠近发射机-接收机路径时，有时会发生这种扰动。它们通常与瞬态发光事件 (TLE) 相关。最近的分析重点关注一种新型早期事件，其恢复时间持续数分钟，称为长恢复事件 (LORE)。这些事件的根本原因仍不清楚。奇怪的是，LORE 有时只出现在一条路径上，而在不同的发射器-接收器路径上观察到的同一事件并不表示 LORE。在本文中，我们观察并模拟了两种早期信号扰动的情况：第一种是典型的早期 VLF 事件，第二种是 LORE。两者均由北非的两台 AWESOME VLF 接收器于 2009 年 12 月 12 日 EuroSprite 活动期间录制。我们将观察结果与理论模型相结合，推断出最接近地再现观察到的扰动的电子密度变化。我们的结果解释了仅在一条路径上检测到 LORE 的情况，这是由于发射机-接收机几何形状造成的，这会显着影响模态内容，从而影响观察到的 VLF 恢复时间。
Early very low frequency (VLF) events are perturbations to subionospherically propagating VLF radio transmitters which sometimes occur when lightning activity is near the transmitter‐receiver path. They are often correlated to Transient Luminous Events (TLEs). Recent analysis have focused on a new type of early events whose recovery time persists for many minutes, called LOng Recovery Events (LOREs). The underlying cause of these events is still unclear. Curiously, LOREs sometimes appear on only one path, while the same event observed on a different transmitter‐receiver path does not indicate a LORE. In this paper we observe and simulate two cases of early signal perturbations: The first is a typical early VLF event, and the second is a LORE. Both were recorded by two AWESOME VLF receivers in North Africa on 12 December 2009, during the EuroSprite campaign. We combine observations with theoretical modeling to infer the electron density change that most closely reproduces the observed perturbation. Our results explain the cases where LOREs are detected on only one path as resulting from transmitter‐receiver geometry significantly which impacts the modal content and therefore the observed VLF recovery time.
影响因子：
4.4
作者：
van der Velde, Oscar A.;Bor, Jozsef;Farges, Thomas
通讯作者：
Farges, Thomas