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Titel |
Kinetic structure and wave properties associated with sharp dipolarization front observed by Cluster |
VerfasserIn |
S. Y. Huang, M. Zhou, X. H. Deng, Z. G. Yuan, Y. Pang, Q. Wei, W. Su, H. M. Li, Q. Q. Wang |
Medientyp |
Artikel
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Sprache |
Englisch
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ISSN |
0992-7689
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Digitales Dokument |
URL |
Erschienen |
In: Annales Geophysicae ; 30, no. 1 ; Nr. 30, no. 1 (2012-01-09), S.97-107 |
Datensatznummer |
250017166
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Publikation (Nr.) |
copernicus.org/angeo-30-97-2012.pdf |
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Zusammenfassung |
Multiple dipolarization fronts (DFs) were observed by Cluster spacecraft in
the magnetotail during a substorm. These DFs were kinetic structures,
embedded in the bursty plasma flow, and moved earthward (mainly) and
dawnward. Intense electric field, parallel and perpendicular currents were
detected in the DF layer. These front layers were energy dissipation region
(load region) where the energy of electromagnetic fields were transferred to
the plasma thermal and kinetic energy. This dissipation was dominated by
electrons. There were enhancements of plasma waves around the DF region:
wavelet results show that wave activities around the ion cyclotron frequency
in the front layer were generated by Alfvén ion cyclotron instability;
whistler waves were also detected before, during and after the DFs, which
are triggered by electron temperature anisotropy and coincident with
enhancement of energetic electron fluxes. The observation of these waves
could be important for the understanding of evolution of DF and electron
energization during the substorm. We discuss the generation mechanism of the
DFs and suggest that these DFs were generated in the process of transient
reconnection, and then traveled toward the Earth. |
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