Auroral Activities and Long-Period Geomagnetic Pulsations
Auroral Activities and Long-Period Geomagnetic Pulsations
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极光活动和长周期地磁脉动
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
J. S. Kim
中科院分区：
文献类型：
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作者：
Tatsundo Yamamoto;K. Hayashi;S. Kokubun;T. Oguti;T. Ogawa;N. Iwagami;T. Kitamura;O. Saka;T. Araki;K. Makita;N. Sato;T. Watanabe;R. Horita;J. S. Kim
在极光分裂后的午夜前，人们会反复观察到空间范围达数百公里的明亮极光形态（周期性为数至约 15 分钟）。极光形态向西北或西南方向漂移，与地面同期范围内的磁场波动有关。漂流极光形态的前缘具有离散极光（涡链）特征。在离散形式通过后，出现脉动极光。通过与地球同步轨道卫星GOES 5和GOES 6的磁场扰动比较，这些极光形式很可能对应于磁总强度的减弱。这些明亮的极光形式的可能来源是从等离子体片注入的热等离子体。并发的磁脉动（这里称为 Ps5）将由电离层中由于电子沉淀到极光形式而产生的波动电场和电导率产生。在亚暴过程中准周期性注入的热等离子体云与极光和磁场脉动有关。磁层中热等离子体的陡峭注入前沿可能与电离层中离散的极光有关。
Bright auroral forms several hundreds of km in spatial extent were observed repeatedly (a few to about 15min, periodicity) in the premidnight hours, following auroral breakups. The auroral forms drifted towards the northwest or the southwest, and were related to the magnetic field fluctuations on the ground in a similar period range. The leading front of the drifting auroral form has a discrete auroral (vortexchain) feature. After the passage of discrete forms pulsating aurora appears. From the comparison with magnetic field perturbations at the geosynchronous orbit satellites GOES 5 and GOES 6, these auroral forms are likely to correspond to the depression of the magnetic total intensity. A possible source of these bright auroral forms is hot plasmas injected from the plasma sheet. The concurrent magnetic pulsations, here called Ps5, would be produced by the fluctuating electric field and conductivity in the ionosphere due to the electron precipitation into the auroral forms. Hot plasma clouds, quasi-periodically injected during the course of a substorm, are related to the auroral and magnetic field pulsations. A steep injection front of hot plasma in the magnetosphere is likely related to discrete auroras at the ionosphere.