THEMIS observations of electron acceleration associated with the evolution of substorm dipolarization in the near-Earth tail
文献类型:期刊论文
作者 | Tang, C. L.; Lu, L.; Zhou, M.; Yao, Z. H. |
刊名 | JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
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出版日期 | 2013 |
卷号 | 118期号:7页码:81961H |
关键词 | dipolarization electron acceleration substorm onset auroral breakup |
ISSN号 | 2169-9380 |
通讯作者 | Tang, CL (reprint author), Shandong Univ, Shandong Prov Key Lab Opt Astron & Solar Terr Env, Sch Space Sci & Phys, Weihai 264209, Shandong, Peoples R China. |
英文摘要 | We present the evolution of dipolarizations in the near-Earth tail during a substorm on 15 March 2009, based on the two-point measurements in the nightside plasma sheet at X similar to-8.0 R-E. The earthward-moving dipolarization, the magnetic flux pileup, and the tailward-moving dipolarization were observed. For the 30-200 keV electrons, betatron acceleration was the dominant process, which was caused by the much larger gradient of the magnetic field there during the earthward-moving dipolarization or by a local compression of the magnetic field during the magnetic flux pileup and tailward-moving dipolarization. These near-perpendicular distributions for the 30-200 keV electrons are interpreted as produced by a two-step acceleration: Electrons were first accelerated in the dipolarization fronts in the midtail or the near-Earth tail and then were further accelerated near the tail current disruption region. For the more than 200 keV electrons, Fermi acceleration was the dominant process, which was caused by the shrinking length of magnetic field line during the tailward-moving dipolarization. The source region of the more than 200 keV electrons may be near the tail current disruption region, but these electrons were accelerated locally. These field-aligned electrons can precipitate into the ionosphere and form the discrete auroral arcs. Two parallel arcs were clearly observed around the substorm onset: one propagated equatorward, another propagated poleward. We suggest that the earthward-moving dipolarization, the magnetic flux pileup, and the tailward-moving dipolarization near the tail current disruption region can well explain the auroral evolution around the substorm onset. |
收录类别 | SCI |
语种 | 英语 |
源URL | [http://ir.nssc.ac.cn/handle/122/5054] ![]() |
专题 | 国家空间科学中心_空间科学部 |
推荐引用方式 GB/T 7714 | Tang, C. L.,Lu, L.,Zhou, M.,et al. THEMIS observations of electron acceleration associated with the evolution of substorm dipolarization in the near-Earth tail[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2013,118(7):81961H. |
APA | Tang, C. L.,Lu, L.,Zhou, M.,&Yao, Z. H..(2013).THEMIS observations of electron acceleration associated with the evolution of substorm dipolarization in the near-Earth tail.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,118(7),81961H. |
MLA | Tang, C. L.,et al."THEMIS observations of electron acceleration associated with the evolution of substorm dipolarization in the near-Earth tail".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 118.7(2013):81961H. |
入库方式: OAI收割
来源:国家空间科学中心
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