Global distribution of equatorial magnetosonic waves observed by THEMIS
Global distribution of equatorial magnetosonic waves observed by THEMIS
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DOI：
10.1002/grl.50434
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发表时间：
2013-05
影响因子：
5.2
通讯作者：
Q. Ma;Wen Li;R. Thorne;V. Angelopoulos
中科院分区：
文献类型：
--
作者：
Q. Ma;Wen Li;R. Thorne;V. Angelopoulos
我们调查了三个THEMIS航天器近31个月的波磁场数据，对赤道磁声(MS)波的特性和空间分布进行了统计研究。THEMIS航天器在赤道附近的主要MS波区和2≤L≤8提供了良好的数据覆盖。我们的全球调查表明，在地磁扰动期间，MS波通常在赤道附近、等离子体顶层外、黎明侧观察到强振幅和高发生率。此外，地磁活动的增加使MS波的分布向较早的地磁本地时移动。强MS波在等离子体顶外的黎明面上通常具有均方根波幅∼50pT和出现率∼20%，因此可能对地球辐射带中的环流离子和高能电子动力学产生重要影响。
We investigate the wave magnetic field data from three THEMIS spacecraft over the recent 31 months to perform a statistical study of equatorial magnetosonic (MS) wave properties and spatial distribution. The THEMIS spacecraft provide good data coverage in the dominant MS wave region near the equator and at 2≤L≤8. Our global survey shows that strong amplitudes and high occurrence of MS waves are generally observed near the equator, outside the plasmapause, on the dawnside during geomagnetically disturbed periods. In addition, increase of geomagnetic activity shifts the MS wave distribution toward earlier magnetic local time. Strong MS waves generally have RMS wave amplitudes ∼50 pT and an occurrence rate ∼20% on the dawnside outside the plasmapause and could therefore have an important influence on both ring current ion and energetic electron dynamics in the Earth's radiation belts.