On the origin of auroral fingers
On the origin of auroral fingers
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论极光手指的起源
DOI：
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发表时间：
1993
期刊：
影响因子：
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通讯作者：
G. Rostoker
中科院分区：
文献类型：
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作者：
W. Liu;G. Rostoker
在大规模磁层亚暴膨胀期活动的发展过程中，极光椭圆区可能变得非常宽。在这些事件期间，在通常被认为以无结构弥散极光为特征的空间区域中，晚扇区椭圆形的赤道部分不时出现清晰的离散弧形结构。有时，这些离散的极光形态会呈现南北方向，并在长达几分钟的时间内保持可识别的形态。大多数极光理论试图描述通常东西向排列的特征的起源。在本文中，我们提出，造成南北排列弧形结构的粒子起源于从相邻低纬度边界层注入中央等离子体片（CPS）的等离子体团，这是活跃时期两个区域之间界面处波活动增强的结果。我们表明，CPS 极光结构的特征几何形状是通过跟踪注入等离子体团中粒子向地球对流时的漂移路径得出的，并在此过程中绝热加热。我们还概述了与该提案有关的突出问题，作为继续研究的动力。
During the development of large-scale magnetospheric substorm expansive phase activity, the auroral oval may become very wide. During such episodes, clear discrete arc structures appear from time to time in the equatorward portion of the evening sector oval in a region of space normally thought to feature structureless diffuse auroras. On occasion, these discrete auroral forms acquire a north-south orientation and remain as identifiable forms for up to several minutes. Most auroral theories attempt to describe the origin of the normally east-west aligned features. In this paper we propose that the particles responsible for north-south aligned arc structures originate as plasma blobs injected into the central plasma sheet (CPS) from the adjacent low-latitude boundary layer, as a result of enhanced wave activity at the interface between the two regions during active times. We show that the characteristic geometric forms of the CPS auroral structures follow from tracking the drift paths of the particles in the injected plasma blob as they convect earthward, heating adiabatically in the process. We also outline outstanding issues pertaining to the proposal as motivation for a continued study.