Altitude dependence of plasma density in the auroral zone
Altitude dependence of plasma density in the auroral zone
复制标题
极光区等离子体密度的高度依赖性
DOI：
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发表时间：
2002
期刊：
影响因子：
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通讯作者：
H. Laakso
中科院分区：
文献类型：
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作者：
P. Janhunen;A. Olsson;H. Laakso
抽象的。我们研究了等离子体耗尽的高度依赖性极光区以上的5000-30 000公里的高度范围内使用五年的极地航天器的潜在数据。我们发现，等离子体密度除了随高度的增加而降低外，在2-4 RE径向距离处（RE为地球半径），还经常存在附加的密度贫化。与黑暗相比，当电离层足点被阳光照射时，耗尽的位置倾向于移动到更高的高度。除了2-4 RE径向距离处的空洞外，4 RE以上的空洞也出现在午夜区，而在早晨区，高K p的空洞也出现在午夜区。在晚上部门，我们的数据在这方面仍然没有结论。这适用于ILAT范围68-74。这些额外的消耗可能与亚暴有关。我们的研究表明，极光现象修改等离子体密度在极光区的一种方式，一个非平凡的和有趣的高度变化的结果，这反映了极光加速过程的性质。关键词。磁层物理学（极光现象;磁层-电离层相互作用）
Abstract. We study the altitude dependence of plasma depletions above the auroral region in the 5000–30 000 km altitude range using five years of Polar spacecraft potential data. We find that besides a general decrease of plasma density with altitude, there frequently exist additional density depletions at 2–4 R E radial distance, where R E is the Earth radius. The position of the depletions tends to move to higher altitude when the ionospheric footpoint is sunlit as compared to darkness. Apart from these cavities at 2–4 R E radial distance, separate cavities above 4 R E occur in the midnight sector for all K p and also in the morning sector for high K p . In the evening sector our data remain inconclusive in this respect. This holds for the ILAT range 68–74. These additional depletions may be substorm-related. Our study shows that auroral phenomena modify the plasma density in the auroral region in such a way that a nontrivial and interesting altitude variation results, which reflects the nature of the auroral acceleration processes. Key words. Magnetospheric physics (auroral phenomena; magnetosphere–ionosphere interactions)