Model Simulation of Very Low-Frequency and Low-Frequency Lightning Signal Propagation Over Intermediate Ranges
Model Simulation of Very Low-Frequency and Low-Frequency Lightning Signal Propagation Over Intermediate Ranges
复制标题
中距离甚低频和低频闪电信号传播的模型仿真
DOI：
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
A. Jacobson
中科院分区：
文献类型：
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作者：
X. Shao;A. Jacobson
本文提出了一个甚低频和低频闪电信号在几百公里到几千公里范围内传播的模型模拟。该模型是地面和电离层反射波的合成。地面波是在一个球形地球，具有有限的电导率建模。电离层波模拟是基于最近开发的全波模型，该模型将电离层的下部视为磁化、各向异性、碰撞和冷电子介质。在本文中，只有第一跳电离层反射，虽然高阶反射可以很容易地实现的模型。为了演示的目的，模拟结果进行比较，在白天和夜间的各种距离的负云对地中风的实际观测。然而，模型本身可以用于任何类型的闪电放电事件，包括发生在地面上的云内事件。这个模型，加上多站洛斯阿拉莫斯Sferic阵列测量的闪电放电，可能提供一种替代手段，用于监测电离层下部的时间和空间变化。
A model simulation for very low-frequency and low-frequency lightning signal propagation over ranges of hundreds to a couple of thousand kilometers is presented in this paper. The model is a composite of ground and ionospheric-reflected waves. The ground wave is modeled over a spherical earth that has a finite conductivity. The ionospheric-wave simulation is based on a recently developed full-wave model that treats the lower portion of the ionosphere as a magnetized, anisotropic, collisional, and cold-electron medium. In this paper, only the first-hop ionosphere reflection is presented, although higher order reflections can be readily implemented by the model. For the purpose of demonstration, the modeled results are compared to actual observations of negative cloud-to-ground strokes at various distances for day and nighttime. The model itself, however, can be used for any type of lightning discharge event, including the incloud events that occur above the ground. This model, together with multistation Los Alamos Sferic Array measurements of lightning discharges, might provide an alternate means for monitoring the temporal and spatial variations of the lower portion of the ionosphere.