DEMETER observations of high‐latitude chorus waves penetrating the plasmasphere during a geomagnetic storm
DEMETER observations of high‐latitude chorus waves penetrating the plasmasphere during a geomagnetic storm
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DOI：
10.1002/2013gl058089
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发表时间：
2013-11
影响因子：
5.2
通讯作者：
Z. Zhima;Jinbin Cao;Wenlong Liu;H. Fu;Junying Yang;Xuemin Zhang;X. Shen
中科院分区：
文献类型：
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作者：
Z. Zhima;Jinbin Cao;Wenlong Liu;H. Fu;Junying Yang;Xuemin Zhang;X. Shen
利用2006年4月14日磁暴期间的DEMTER卫星资料，研究了磁暴时的VLF电磁波，首次发现了高纬合唱团穿透等离子体层的观测证据。在这场磁暴期间，观测到几赫兹到20 kHz的“带状”发射被加强，并在磁纬约40°和约60°之间的高纬度地区在0.1-0.5fce（赤道电子回旋频率）的频率范围内组织起来。波功率谱中的特征表明，这些发射可能是较低波段的合唱。所观察到的合唱波一般在等离子体束之外。然而，有趣的是，这些波在主相和早期恢复相期间在低L值的区域内观察到，这在以前的低纬度地区合唱研究中从未报道过。
Using the data of the DEMTER satellite during the magnetic storm on 14 April 2006, we study the storm time VLF electromagnetic waves, and find the first observational evidence of penetration of high‐latitude chorus into the plasmasphere. During this geomagnetic storm, “banded” emissions of a few hertz to 20 kHz are observed to be intensified and to be organized in the frequency range of 0.1–0.5fce (equatorial electron cyclotron frequency) in high‐latitude region of magnetic latitude between ~40°and ~60°. The signatures in the wave power spectra suggest that these emissions are likely lower‐band chorus. The observed chorus waves are generally outside the plasmasphere. However, interestingly, these waves are observed inside the plasmasphere at regions with low L value during the main phase and early recover phase, which has never been reported in previous studies of chorus in low‐latitude regions.