Asymmetric development of auroral surges in northern and southern hemispheres
Asymmetric development of auroral surges in northern and southern hemispheres
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北半球和南半球极光涌的不对称发展
DOI：
10.1029/2020gl088750
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
et al.
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文献类型：
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作者：
Uchida H. A;R. Kataoka;A. Kadokura;K. Murase;A. S. Yukimatu;Y. Miyoshi;K. Shiokawa;Y. Ebihara;K. Hosokawa;A. Matsuoka;et al.
冰岛Tjörnes站和南极洲Syowa站同时观测到东向浪涌和西向浪涌。发现了几个显著的差异。(1)初始亮点的位置在两个半球之间移动了1.7 ~ 2.3 MLT。(2)东向浪涌（6.5 km s−1）和西向浪涌（1.3 km s−1）的速度不同。(3) Arase卫星位于连接两个地面站的地磁力线上，观测到磁场西向分量明显过剩，这与两个半球初始亮斑的大位移一致。(4)背景霍尔电流向东（北半球）和向西（南半球）流动。观测到的南北向传播波的不对称性表明，电离层在控制两个半球极光的基本时空发展中发挥了重要作用。
Simultaneous eastward and westward traveling surges were observed at Tjörnes, Iceland, and Syowa station, Antarctica, respectively. Several remarkable differences were identified. (1) The position of the initial bright spot was shifted by 1.7 to 2.3 MLT between both hemispheres. (2) The surges differ in traveling speed between the eastward traveling surge (6.5 km s−1) and the westward traveling surge (1.3 km s−1). (3) The Arase satellite was located on a geomagnetic field line connecting both ground stations and observed a significant excess in westward component of the magnetic field, which is consistent with the large shifts of the initial bright spots in both hemispheres. (4) The background Hall current flows eastward (Northern Hemisphere) and westward (Southern Hemisphere). The observed north‐south asymmetry of the traveling surges suggests that the ionosphere can play an essential role in controlling the fundamental spatiotemporal development of auroras in both hemispheres.