Ray tracing of whistler-mode chorus elements: implications for generation mechanisms of rising and falling tone emissions
Ray tracing of whistler-mode chorus elements: implications for generation mechanisms of rising and falling tone emissions
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口哨模式合唱元素的光线追踪：对升调和降调发射的生成机制的影响
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
D. Nunn
中科院分区：
文献类型：
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作者：
K. Yamaguchi;T. Matsumuro;Y. Omura;D. Nunn
抽象的。使用一个完善的磁层甚低频（VLF）射线追踪方法，在这项工作中，我们跟踪传播的个别上升和下降的频率元素的VLF合唱从他们的产生点在赤道地区的磁层通过至少一个反射在较低的混合共振点。与Bortnik及其同事最近的工作不同，他们的重点是证明磁层嘶嘶声起源于合唱，我们在这里跟踪整个合唱元素在赤道平面上的运动，特别关注穿过磁力线的运动，旋转，以及波脉冲的压缩或扩展。在赤道处的上升合唱的生成点，发现元素波脉冲在生成区域中保持大部分场对准。然而，对于在赤道上游4000公里处的降调生成点，当脉冲穿过赤道时，波场具有实质性的振幅、位移和压缩，这对降调合唱生成理论具有实质性的影响。
Abstract. Using a well-established magnetospheric very-low-frequency (VLF) ray tracing method, in this work we trace the propagation of individual rising- and falling-frequency elements of VLF chorus from their generation point in the equatorial region of the magnetosphere through to at least one reflection at the lower-hybrid resonance point. Unlike recent work by Bortnik and co-workers, whose emphasis was on demonstrating that magnetospheric hiss has its origins in chorus, we here track the motion in the equatorial plane of the whole chorus element, paying particular regard to movement across field lines, rotation, and compression or expansion of the wave pulse. With a generation point for rising chorus at the equator, it was found the element wave pulse remained largely field aligned in the generation region. However, for a falling tone generation point at 4000 km upstream from the equator, by the time the pulse crosses the equator the wavefield had substantial obliquity, displacement, and compression, which has substantial implications for the theory of falling chorus generation.