波浪的全球形态波恩廷流动:为极光提供动力
A Keiling1, J R Wygant, C A Cattell
1Department of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55144, USA. akeiling@ham.space.umn.edu
概括
全球阿尔弗文波是一种电磁波,为地球的极地极光贡献了大量的能量. 这一发现扩大了我们对为这些令人惊叹的灯光显示器提供动力的能源的理解.
科学领域:
- 空间物理 空间物理
- 等离子体物理学的物理学
- 大气科学 大气科学
背景情况:
- 极光主要归因于沿磁场线流向地球极地的电流.
- 正确的能量转移机制为电离层极光提供动力仍在调查中.
研究的目的:
- 调查电磁波,特别是阿尔弗文波对极光能量潜在的全球贡献.
- 为了确定高海拔的阿尔弗文波是否能够足够为极光加速过程提供动力.
主要方法:
- 对极地航天器在一年时间内收集的数据进行分析.
- 测量Poynting流 (波电磁能量流) 在25,000至38,000公里的高度.
- 能量流与统计极光圆的相关性.
主要成果:
- 发现了来自电磁波 (阿尔夫文波) 的全球贡献的证据.
- 高海拔的电磁波能量流量划定了统计上的极光圆形.
- 个别事件的Poynting流量超过5ergs/cm2/s,足以实现极光加速.
结论:
- 阿尔夫恩波是白天和夜晚极光的重要全球能源.
- 这些发现表明极光的能量来源是双重的:与磁场对齐的电流和高海拔的阿尔夫文波.
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