Recovery phase of magnetospheric substorms and its association with morning‐sector aurora
Recovery phase of magnetospheric substorms and its association with morning‐sector aurora
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磁层亚暴的恢复阶段及其与晨区极光的关系
DOI：
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发表时间：
1994
期刊：
影响因子：
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通讯作者：
R. Pellinen
中科院分区：
文献类型：
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作者：
H. Opgenoorth;M. Persson;T. Pulkkinen;R. Pellinen
与被广泛研究的磁层亚暴的增长和扩展阶段相比，亚暴恢复阶段在已发表的文献中没有得到太多的关注。它通常被认为是由前两个阶段引起的所有扰动都衰变，磁层“恢复”到再次达到平静状态的时期。主要使用地面数据，我们表明“恢复阶段”包含许多与扩张阶段性质不同的特征，也就是说，不仅仅是先前激发的能量释放形式的衰减。典型的恢复相现象包括上午区强烈的电喷流活动、高能粒子降水、大尺度极光涡旋街的发展(所谓的Ω带和相关的磁Ps6脉动)，以及经常新的向东扩展的活动极光现象，与晚间部分的扩展阶段特征相似，但集中在极光椭圆形的上午部分。这些特征必须与亚风暴机制本身相关联。我们认为，我们在亚暴恢复阶段的观测结果可以用等离子体抛射后的磁层重组来解释。我们发现，对亚暴后期特征的更详细的研究可以加深我们对导致磁层能量释放的完整周期的物理过程的理解。
In contrast to the extensively studied growth and expansion phases of magnetospheric substorms, the substorm recovery phase has not received much attention in the published literature. It has generally been considered as a period in which all disturbances caused by the previous two phases decay, the magnetosphere “recovers” to reach a quiet state again. Using mainly ground-based data, we show that the “recovery phase” contains a number of features which are qualitatively different from the expansion phase, that is, not just a decay of previously excited forms of energy release. Typical recovery phase phenomena include intense electrojet activity in the morning sector, high-energy particle precipitation, the development of large-scale auroral vortex streets (so-called Ω bands and associated magnetic Ps 6 pulsations), and very often new eastward expanding active auroral phenomena, not unlike evening-sector expansion phase features but concentrated to the morning sector of the auroral oval. Such features must be associated with the substorm mechanism itself. We suggest that our observations during the substorm recovery phase are explained by the magnetospheric reorganization after the ejection of a plasmoid. We show that a more detailed investigation of the late substorm features can increase our understanding of the physical processes leading to the complete cycle of magnetospheric energy release.