| Evidence of kinetic Alfven eigenmode in the near-Earth magnetotail during substorm expansion phase | |
| Duan, S. P.; Dai, Lei; Wang, Chi; Liang, J.; Lui, A. T. Y.; Chen, L. J.; He, Z. H.; Zhang, Y. C.; Angelopoulos, V.; Duan, SP; Dai, L (reprint author), Chinese Acad Sci, Natl Space Sci Ctr, State Key Lab Space Weather, Beijing, Peoples R China. | |
| Department | 空间科学部 |
| Source Publication | JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
 |
| 2016 | |
| Volume | 121Issue:5Pages:4316-4330 |
| ISSN | 2169-9380 |
| Language | 英语 |
| Keyword | Kinetic Alfven Wave Substorm Hall Current Aurora Brightening Hall Fields |
| Abstract | Unipolar pulses of kinetic Alfven waves (KAW) are first observed in the near-Earth plasma sheet (NEPS) associated with dipolarizations during substorm expansion phases. Two similar events are studied with Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations during substorms on 3 February 2008 and 7 February 2008. The unipolar pulses were located at a trough-like Alfven speed profile in the northern plasma sheet at a distance of 10-11R(E) from Earth. The dominant wave components consist of a southward E-z toward the neutral plane and a +B-y toward the dusk. The |E-z|/|B-y| ratio was in the range of a few times the local Alfven speed, a strong indication of KAW nature. The wave Poynting flux was earthward and nearly parallel to the background magnetic field. The pulse was associated with an earthward field-aligned current carried by electrons. These observational facts strongly indicate a KAW eigenmode that is confined by the plasma sheet but propagates earthward along the field line. The KAW eigenmode was accompanied by short timescale (1min) dipolarizations likely generated by transient magnetotail reconnection. The observed polarity of the KAW field/current is consistent with that of the Hall field/current in magnetic reconnection, supporting the scenario that the Hall fields/current propagate out from reconnection site as KAW eigenmodes. Aurora images on the footprint of THEMIS spacecraft suggest that KAW eigenmode may power aurora brightening during substorm expansion phase. |
| Indexed By | SCI |
| Document Type | 期刊论文 |
| Identifier | http://ir.nssc.ac.cn/handle/122/5593 |
| Collection | 空间科学部 |
| Corresponding Author | Duan, SP; Dai, L (reprint author), Chinese Acad Sci, Natl Space Sci Ctr, State Key Lab Space Weather, Beijing, Peoples R China. |
| Recommended Citation GB/T 7714 | Duan, S. P.,Dai, Lei,Wang, Chi,et al. Evidence of kinetic Alfven eigenmode in the near-Earth magnetotail during substorm expansion phase[J]. JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,2016,121(5):4316-4330. |
| APA | Duan, S. P..,Dai, Lei.,Wang, Chi.,Liang, J..,Lui, A. T. Y..,...&Dai, L .(2016).Evidence of kinetic Alfven eigenmode in the near-Earth magnetotail during substorm expansion phase.JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS,121(5),4316-4330. |
| MLA | Duan, S. P.,et al."Evidence of kinetic Alfven eigenmode in the near-Earth magnetotail during substorm expansion phase".JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS 121.5(2016):4316-4330. |
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| 2016jgra52602.pdf（5458KB） | 期刊论文 | 作者接受稿 | 开放获取 | CC BY-NC-SA | View Download | |
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