Saturn's elusive nightside polar arc
Saturn's elusive nightside polar arc
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DOI：
10.1002/2014gl061081
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发表时间：
2014-09
影响因子：
5.2
通讯作者：
A. Radioti;D. Grodent;J. Gérard;S. Milan;R. Fear;C. Jackman;B. Bonfond;W. Pryor
中科院分区：
文献类型：
--
作者：
A. Radioti;D. Grodent;J. Gérard;S. Milan;R. Fear;C. Jackman;B. Bonfond;W. Pryor
夜侧极弧是地球上最令人费解的极光发射之一。它们是从夜侧极光椭圆形延伸到开放磁场线区域（极帽）的特征，它们代表了磁尾动力学的光学特征。在这里，我们报告了对土星弧的首次观测，该弧附着在夜侧主椭圆形处并延伸到极冠区域，类似于地球上的跨极弧。我们表明，类似地球的极弧特别可能发生在快速旋转和内部影响的磁层中，例如土星的磁层。最后，我们讨论了土星极弧与尾重联相关的可能性，并讨论了太阳风在土星磁尾动力学中的作用。
Nightside polar arcs are some of the most puzzling auroral emissions at Earth. They are features which extend from the nightside auroral oval into the open magnetic field line region (polar cap), and they represent optical signatures of magnetotail dynamics. Here we report the first observation of an arc at Saturn, which is attached at the nightside main oval and extends into the polar cap region, resembling a terrestrial transpolar arc. We show that Earth‐like polar arcs can exceptionally occur in a fast rotational and internally influenced magnetosphere such as Saturn's. Finally, we discuss the possibility that the polar arc at Saturn is related to tail reconnection and we address the role of solar wind in the magnetotail dynamics at Saturn.