THEMIS observations of the near-Earth plasma sheet during a substorm
文献类型:期刊论文
作者 | Tang, C. L. ; Li, Z. Y. ; Angelopoulos, V. ; Mende, S. B. ; Glassmeier, K. H. ; Donovan, E. ; Russell, C. T. ; Lu, L. |
刊名 | Journal of Geophysical Research-Space Physics
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出版日期 | 2009 |
卷号 | 114页码:A09211 |
关键词 | current disruption tail reconnection growth-phase current wedge ion flow onset dipolarization expansion signatures model |
ISSN号 | 0148-0227 |
通讯作者 | 北京8701信箱 |
英文摘要 | We present observations of a substorm on 13 March 2008 by Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft in the near-Earth tail during the plasma sheet expansion evidenced by increase in the plasma density and temperature. The main features of the event are as follows: (1) Cross-tail current reduction or current disruption (CD) was observed in the near-Earth tail at X similar to -8.0 R-E and Y similar to 2.0 R-E, marked by a sharp drop of vertical bar B-x vertical bar and accompanied by sharp increases in the plasma density and temperature, manifesting a rapid expansion (recovery) of the local plasma sheet. During the course of the plasma sheet expansion, the propagation speed of the dipolarization is similar to 48 km/s in tailward direction and similar to 35 km/s in azimuthal direction. ( 2) In the inner edge of the plasma sheet, slow flux pileup is observed. The magnetic flux pileup is characterized by continuous enhancement of B-z and B-t and a reduction of the plasma density, pressure P-th, and beta in the flow-braking region. The tailward moving plasma sheet expansion (CD) is also passing across the flow-braking region. In short, the dipolarization in the inner edge of the plasma sheet can be attributed to CD, while the tailward progression of dipolarization in the flow-braking region can be attributed to magnetic flux pileup. (3) A sharp decrease in the magnitude of B-x at P1 (-13.1 R-E, 2.5 R-E, -0.56 R-E) prior to the dipolarization at P5 is difficult to explain as part of the outward evolution of the CD. The rapid change in the magnetic field topology, and signatures of earthward flows and dipolarization observed at P1 prior to Pi2 onset may be caused by inward motion of flux from magnetic reconnection in the midtail (20-30 R-E). Tail reconnection prior to substorm expansion can result in a sudden change of the near-Earth configuration, which may result in instabilities related to the onset of CD. |
收录类别 | SCI |
原文出处 | http://www.agu.org/pubs/crossref/2009/2008JA013729.shtml |
语种 | 英语 |
源URL | [http://ir.cssar.ac.cn/handle/122/1693] ![]() |
专题 | 国家空间科学中心_其他部室 |
推荐引用方式 GB/T 7714 | Tang, C. L.,Li, Z. Y.,Angelopoulos, V.,et al. THEMIS observations of the near-Earth plasma sheet during a substorm[J]. Journal of Geophysical Research-Space Physics,2009,114:A09211. |
APA | Tang, C. L..,Li, Z. Y..,Angelopoulos, V..,Mende, S. B..,Glassmeier, K. H..,...&Lu, L..(2009).THEMIS observations of the near-Earth plasma sheet during a substorm.Journal of Geophysical Research-Space Physics,114,A09211. |
MLA | Tang, C. L.,et al."THEMIS observations of the near-Earth plasma sheet during a substorm".Journal of Geophysical Research-Space Physics 114(2009):A09211. |
入库方式: OAI收割
来源:国家空间科学中心
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