On the singular Cauchy problem for operators with variable involutive characteristics
On the singular Cauchy problem for operators with variable involutive characteristics
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具有变对合特性算子的奇异柯西问题
DOI：
10.1029/2005ja011204
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发表时间：
1982
期刊：
影响因子：
--
通讯作者：
Takao Kobayashi
中科院分区：
文献类型：
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作者：
Takao Kobayashi
研究了磁静期极光千米辐射（AKR）的特性。明显的AKR发作有时没有任何典型的亚暴特征，其特征是地面上的极光电喷流增强，近地等离子体片的尾电流中断，以及等离子体片的高能粒子注入。然而，它的开始伴随着收缩的椭圆上的极光变亮，地面上的Pi2脉动，以及等离子体片中的快速等离子体流动。静时AKR的这些特征似乎与收缩的椭圆形亚暴相一致，表明AKR的开始是收缩亚暴的基本组成部分之一。研究还发现，AKR的谱并不总是依赖于亚暴的强度：①在磁场平静期，AKR的强度有时与通常的亚暴AKR相当；②AKR的频率带宽扩展，被认为与亚暴期间场对准势的垂直发展有关，在安静期和扰动期AKR之间有时具有可比性。
The behavior of auroral kilometric radiation (AKR) during magnetically quiet periods is investigated. A clear AKR onset sometimes occurs without any typical substorm signatures characterized by auroral electrojet enhancement on the ground, tail current disruption in the near‐Earth plasma sheet, and energetic particle injection from the plasma sheet. However, the onset is accompanied by auroral brightening on the contracted oval, Pi2 pulsation on the ground, and fast plasma flow in the plasma sheet. These features of quiet‐time AKR seem consistent with a contracted oval substorm, indicating that the onset of AKR is one of the elementary components of the contracted substorm. Unexpected features showing that AKR spectra do not always depend on the substorm magnitude are also presented: (1) the AKR intensity during the magnetically quiet period was sometimes comparable with the usual substorm AKR, and (2) the frequency‐bandwidth expansion of AKR at the time of onset, which is considered to be related with the vertical development of the field‐aligned potential during the substorm, was sometimes comparable between quiet‐ and disturbed‐period AKR.