当前位置: X-MOL 学术J. Geophys. Res. Space Phys. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Formation and Release of the Harang Reversal Relating With the Substorm Onset Process
Journal of Geophysical Research: Space Physics ( IF 2.8 ) Pub Date : 2020-12-14 , DOI: 10.1029/2020ja028170
T. Tanaka 1 , Y. Ebihara 2 , M. Watanabe 1 , M. Den 3 , S. Fujita 4, 5 , T. Kikuchi 6 , K. K. Hashimoto 7 , R. Kataoka 5
Affiliation  

With the interplanetary magnetic field (IMF) that turns from northward to southward, the global simulation successively reproduces the growth phase, the onset, and the expansion phase of the substorm. The calculated ionospheric convection for the growth phase reproduces the development of the Harang reversal (HR), the upward field‐aligned current (FAC), and the upcoming onset point as observed. Magnetic field lines traced from the center of the nightside upward FAC are open, while the magnetic field line traced from the onset point is closed. These open magnetic field lines map to flow shear just outside the O/C boundary. Seen from the magnetic configuration, the growth phase proceeds as the replacement process of nulls. Two new nulls appear on the dayside under the southward IMF, while two old nulls under the northward IMF retreat tailward forming two bifurcation regions on the dawn and dusk flanks. Flow shear around the O/C boundary forms by magnetospheric convection that returns to the dayside via bifurcation regions. The expansion phase proceeds through a topological change by the near‐earth neutral line (NENL). The NENL occurs inside the thinned structure of the northward IMF remnant, on the low‐latitude side of the flow shear, and projects down to the low‐latitude edge of the upward FAC. Associated with the NENL, the convection return path changes to the center of the plasma sheet and reveals in the ionosphere as the release of the HR. By the shrinkage of projecting magnetic field line, the O/C boundary migrates poleward in the ionosphere.

中文翻译:

与亚暴爆发过程有关的哈朗逆转的形成和释放

利用从北到南的行星际磁场(IMF),全局模拟依次再现了亚暴的生长阶段,开始和扩展阶段。计算出的生长期电离层对流再现了哈朗反转(HR),向上场对准电流(FAC)和即将到来的起始点的发展。从夜间向上FAC的中心跟踪的磁场线是打开的,而从发病点跟踪的磁场线是关闭的。这些开放的磁场线映射到O / C边界外的流动剪切。从磁性构造看,生长阶段作为零位的替换过程而进行。在IMF南下,白天出现两个新的空值,而在IMF北下的两个旧零点向后退,在黎明和黄昏的侧面形成两个分叉区域。O / C边界周围的流动剪切是由磁层对流形成的,该磁对流通过分叉区返回到白天。扩展阶段通过近地中性线(NENL)进行拓扑变化。NENL发生在北向IMF残余物的变薄结构内部,在流动剪的低纬度一侧,向下突出到向上FAC的低纬度边缘。与NENL关联,对流返回路径改变为等离子片的中心,并随着HR的释放而在电离层中显示出来。通过投射磁场线的收缩,O / C边界在电离层中向极点迁移。O / C边界周围的流动剪切是由磁层对流形成的,该磁对流通过分叉区返回到白天。扩展阶段通过近地中性线(NENL)进行拓扑变化。NENL发生在北向IMF残余物的变薄结构内部,在流动剪的低纬度一侧,向下突出到向上FAC的低纬度边缘。与NENL关联,对流返回路径改变为等离子片的中心,并随着HR的释放而在电离层中显示出来。通过投射磁场线的收缩,O / C边界在电离层中向极点迁移。O / C边界周围的流动剪切是由磁层对流形成的,该磁对流通过分叉区返回到白天。扩展阶段通过近地中性线(NENL)进行拓扑变化。NENL发生在北向IMF残余物的变薄结构内部,在流动剪的低纬度一侧,向下突出到向上FAC的低纬度边缘。与NENL关联,对流返回路径改变为等离子片的中心,并随着HR的释放而在电离层中显示出来。通过投射磁场线的收缩,O / C边界在电离层中向极点迁移。NENL发生在北向IMF残余物的变薄结构内部,在流动剪的低纬度一侧,向下突出到向上FAC的低纬度边缘。与NENL关联,对流返回路径改变为等离子片的中心,并随着HR的释放而在电离层中显示出来。通过投射磁场线的收缩,O / C边界在电离层中向极点迁移。NENL发生在北向IMF残余物的变薄结构内部,在流动剪的低纬度一侧,向下突出到向上FAC的低纬度边缘。与NENL关联,对流返回路径改变为等离子片的中心,并随着HR的释放而在电离层中显示出来。通过投射磁场线的收缩,O / C边界在电离层中向极点迁移。
更新日期:2021-01-19
down
wechat
bug