Very low frequency subionospheric remote sensing of thunderstorm‐driven acoustic waves in the lower ionosphere
Very low frequency subionospheric remote sensing of thunderstorm‐driven acoustic waves in the lower ionosphere
复制标题
低电离层雷暴驱动声波的甚低频亚电离层遥感
DOI：
10.1002/2014jd021594
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
J. Snively
中科院分区：
文献类型：
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作者：
Robert A. Marshall;J. Snively
我们目前的观测窄带亚电离层甚低频发射机信号2001年3月20日，表现出超过1分贝的峰峰值的相干波动。光谱分析表明，波动的周期为1- 4分钟，并在很大程度上是相干的。从波多黎各到科罗拉多的信号的亚电离层传播路径经过两个对流和闪电活动区域，正如GOES卫星图像和国家闪电探测网络闪电数据所观察到的那样。我们认为，这些波动是由下面的对流活动发射的声波的证据，在80-90公里的高度范围内观察到夜间甚低频亚电离层遥感敏感。这些观测结果表明，甚低频亚电离层遥感可能提供一种独特的，24小时遥感技术的声波和重力波活动。我们重现这一事件在模拟中使用的重力和声波传播的流体模型来计算电离层扰动，然后由电磁传播模型来计算在VLF接收器的位置的扰动幅度。模拟结果表明，产生这些振幅扰动需要一个非常大的相干对流源。
We present observations of narrowband subionospheric VLF transmitter signals on 20 March 2001, exhibiting coherent fluctuations of over 1 dB peak to peak. Spectral analysis shows that the fluctuations have periods of 1–4min and are largely coherent. The subionospheric propagation path of the signal from Puerto Rico to Colorado passes over two regions of convective and lightning activity, as observed by GOES satellite imagery and National Lightning Detection Network lightning data. We suggest that these fluctuations are evidence of acoustic waves launched by the convective activity below, observed in the 80–90 km altitude range to which nighttime VLF subionospheric remote sensing is sensitive. These observations show that VLF subionospheric remote sensing may provide a unique, 24h remote sensing technique for acoustic and gravity wave activity. We reproduce this event in simulations using a fluid model of gravity and acoustic wave propagation to calculate the ionospheric disturbance, followed by an electromagnetic propagation model to calculate the perturbation amplitude at the location of the VLF receiver. Simulation results show that a very large and coherent convective source is required to produce these amplitude perturbations.