A new mode of radio wave diffraction via the terrestrial surface plasmon on mountain range
A new mode of radio wave diffraction via the terrestrial surface plasmon on mountain range
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DOI：
10.1002/2016rs006068
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发表时间：
2016-08
期刊：
影响因子：
1.6
通讯作者：
M. Fujii
中科院分区：
文献类型：
--
作者：
M. Fujii
结果表明，通过地表等离激元介导的无线电波衍射的一种新的模式发生在山顶。如果地球表面存在移动的电荷，电磁理论预测无线电波和地面上的表面等离子体之间存在强耦合。如果由于某种地下活动的结果，地面上出现了足够数量的相同符号的电荷，它们将受到电斥力的作用。然后，表面电荷将向附近山峰的地形高点移动。然后，无线电波被证明与这样的电荷相互作用，并产生表面电荷的集体振荡，以诱导表面等离子体。在这里，它是澄清与大规模并行的超级计算机上的数值分析，这种相互作用发生在山顶上，从而导致奇怪的现象的随机衍射。根据地面上电荷的密度，相互作用变得足够强，导致无线电波从山区地形的粗糙表面强烈和随机散射和衍射。因此，山峰作为无线电波的第二个来源;出乎意料的是，无线电波通过异常衍射和散射从山峰重新辐射到各个方向，并且重新辐射的波可以在山脉上传播到视线之外，到达遥远的位置。这种效应可能是随机出现的，但与地壳岩石中的某些震前活动同时发生，对这些活动的观测可以对几百公里范围内地壳岩石的临界状态进行统计分析。
It is shown that a new mode of radio wave diffraction occurs at the peak of mountains mediated via the terrestrial surface plasmon. If mobile electrical charges exist on the Earth's surface, the electromagnetic theory predicts strong coupling between the radio wave and the surface plasmon on the ground. If sufficient amount of electrical charges of the same sign appear on the ground as a consequence of some underground preseismic activity, they will be subject to the electrical repulsive forces. The surface electrical charges will then move toward topographic highs of nearby mountain peaks. Radio waves are then shown to interact with such electrical charges and create collective oscillations of the surface charges to induce a surface plasmon. Here it is clarified with numerical analyses on a massively parallel supercomputer that such interactions occur on the peak of mountains, hence causing peculiar phenomena of random diffraction. Depending on the density of the electrical charges on the ground surface, the interaction becomes strong enough to cause intense and random scattering and diffraction of the radio wave from the rough surface of the mountain topography. Mountain peaks thus act as a secondary source of radio waves; unexpectedly, radio waves are reradiated from the peaks into various directions by the anomalous diffraction and scattering, and the reradiated wave can propagate beyond the line of sight over mountains to reach distant locations. Such effects may arise randomly but concurrently with some preseismic activity in the crustal rocks, of which observation may allow statistical analysis of the critical state of crustal rocks over a broad area of a few hundred kilometers.