An examination of inter-hemispheric conjugacy in a subauroral polarization stream
An examination of inter-hemispheric conjugacy in a subauroral polarization stream
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DOI：
10.1029/2012ja017784
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发表时间：
2012-08
影响因子：
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通讯作者：
B. Kunduri;J. Baker;J. Ruohoniemi;L. Clausen;A. Grocott;E. Thomas;M. Freeman;E. Talaat
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文献类型：
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作者：
B. Kunduri;J. Baker;J. Ruohoniemi;L. Clausen;A. Grocott;E. Thomas;M. Freeman;E. Talaat
在地磁扰动条件下，中纬度电离层在黄昏-午夜扇区受到强烈的极向电场的影响。这些电场导致在亚极光区产生一个纬度狭窄的向西向流动通道，称为亚极光极化流（SAPS）。如果将磁力线视为等势线，则预期在具有类似特征的磁共轭位置处同时发生诸如SAPS的电动事件。在本文中，我们提出了同时观测的SAPS事件在两个半球的中纬度SuperDARN雷达共轭领域的看法。我们分析了地磁条件和通道的特征之间的关系，如纬度位置，电场，总电位变化的通道，和彼得森电流。结果表明，环电流的强度和通道的纬度位置之间有很强的相关性。的通道的特性的跨半球比较表明，跨通道的电位变化是相似的，而电场，彼得森电流和通道的纬度宽度表现出的差异，是一致的，与相等的电位变化。我们将这些差异归因于两半球间电离层电导率的季节性差异和内磁层的磁畸变效应。
During geomagnetically disturbed conditions the midlatitude ionosphere is subject to intense poleward directed electric fields in the dusk-midnight sector. These electric fields lead to the generation of a latitudinally narrow westward directed flow channel in the subauroral region called a subauroral polarization stream (SAPS). If the magnetic field lines are treated as equipotentials, electrodynamic events such as SAPS are expected to occur simultaneously at magnetically conjugate locations with similar features. In this paper we present simultaneous observations of a SAPS event in both hemispheres made by midlatitude SuperDARN radars with conjugate fields-of-view. We analyze the relation between the geomagnetic conditions and the characteristics of the channels such as latitudinal location, electric field, total potential variations across the channels, and Pedersen current. The results suggest a strong correlation between the strength of the ring current and the latitudinal location of the channel. An inter-hemispheric comparison of the characteristics of the channel indicates that the potential variations across the channels are similar while the electric fields, Pedersen currents and latitudinal widths of the channel exhibit differences that are consistent with equal potential variations. We attribute these differences to seasonal differences in ionospheric conductivity between the hemispheres and magnetic distortion effects in the inner magnetosphere.