| GEOPHYSICS, ASTRONOMY, AND ASTROPHYSICS |
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An Island Coalescence Scenario for Near-Earth Current Disruption in the Magnetotail |
| MA Zhi-Wei1,2, LU Xing-Qiang1 |
| 1Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 2300312Institute for Fusion Theory and Simulation, Zhejiang University, Hangzhou 310027 |
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| Cite this article: |
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MA Zhi-Wei, LU Xing-Qiang 2009 Chin. Phys. Lett. 26 089401 |
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Abstract A current disruption and dipolarization scenario associated with island coalescences in the near-Earth region is proposed. The thin and elongated current-sheet built up during the growth phase is unstable due to a tearing mode instability that leads to formation of multiple magnetic islands (or magnetic flux ropes in the three dimensional case) in the near-Earth region. The growth rate of the tearing mode should be different in different locations because the rate is in general determined by the external driving force and the local plasma sheet properties. When the rate of the magnetic reconnection in the mid-tail region around 20RE is much larger than that in other locations, the strong bulk earthward flows resulting from the fast reconnection in the mid-tail drive the earthward convection and the coalescence of the magnetic islands. Consequently, the cross-tail current in the near-Earth region is suddenly disrupted and the geometry of the magnetic field changes from tail-like to dipolar-like in the ideal time scale. This proposed scenario is tested by Hall MHD simulation and is compared with the observations.
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| Keywords:
94.30.Cp
94.30.Cl
52.30.Cv
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Received: 17 April 2009
Published: 30 July 2009
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| PACS: |
94.30.cp
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(Magnetic reconnection)
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94.30.cl
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(Magnetotail)
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52.30.Cv
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(Magnetohydrodynamics (including electron magnetohydrodynamics))
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[1] Rostoker G et al 1980 J. Geophys. Res.: Space Phys. 85 1663
[2] Angelopoulos V et al 2008 Science. 321 931
[3] Lui A T Y 1996 J. Geophys. Res.: Space Phys. 101 13067
[4] Petrukovich A A 2008 Science. 321 920
[5] Cao J B et al 2006 J. Geophys. Res.: Space Phys. 111 A04206
[6] Fairfield D H et al 1998 J. Geophys. Res.: SpacePhys. 103 103
[7] Lui A T Y 1991 J. Geophys. Res.: Space Phys. 96 1849
[8] Baker D N et al 1996 J. Geophys. Res.: Space Phys. 101 12975
[9] Kan J R, Zhu L and Akasofu S I 1988 J. Geophys. Res.:Space Phys. 93 5624
[10] Goertz C K and Smith R A 1989 J. Geophys. Res.:Space Phys. 94 6581
[11] Pu Z Y et al 1997 J. Geophys. Res.: Space Phys. 102 14397
[12] Parks G K, Pellat R and Laval G 1972 Planetary andSpace Science 20 1391
[13] Ohtani S, Kokubun S and Russell C T 1992 J. Geophys.Res.: Space Phys. 97 3129
[14] Jacquey C, Sauvaud J A and Dandouras J 1991 Geophys.Res. Lett. 18 389
[15] Jacquey C et al 1993 Geophys. Res. Lett. 20983
[16] Baker D N et al 2002 Geophys. Res. Lett. 292190
[17] Miyashita Y et al 2009 J. Geophys. Res.: SpacePhys. 114 A01211
[18] Sergeev V A et al 1993 J. Geophys. Res.: SpacePhys. 98 17345
[19] Asano Y et al 2003 J. Geophys. Res.: Space Phys. 108 1189
[20] Ma Z W 2008 Phys. Plasmas 15 032906
[21] Ma Z W and Bhattacharjee A 1998 Geophys. Res. Lett. 25 3277
[22] Ma Z W and Feng S L 2008 Chin. Phys. Lett. 252934
[23] Lu X Q and Ma Z W 2009 Chin. Phys. Lett. 26059401
[24] Eastwood J P et al 2005 Geophys. Res. Lett. 32 L11105
[25] Lin N G et al 1991 J. Geophys. Res.: Space Phys. 96 19427
[26] Zong Q G et al 2004 Geophys. Res. Lett. 31L18803
[27] Smets R et al 1999 J. Geophys. Res.: Space Phys. 104 14571
[28] Perraut S et al 2003 J. Geophys. Res.: Space Phys. 108 1159
[29] Eastwood J P et al 2007 J. Geophys. Res.: SpacePhys. 112 A06235
[30] Pritchett P L 2008 Phys. Plasmas 15 102105
[31] Chen L J et al 2008 J. Geophys. Res.: Space Phys. 113 A12213
[32] Zhang H et al 2007 Geophys. Res. Lett. 34L03104
[33] Pritchett P L 2007 Phys. Plasmas. 14 052102
[34] Wu P et al 2006 Geophys. Res. Lett. 33 L17101
[35] Fu X R, Lu Q M and Wang S 2006 Phys. Plasmas. 13 012309
[36] Xiao C J et al 2007 Geophys. Res. Lett. 34L01101
[37] Xiao C J et al 2007 Nature Phys. 3 609 |
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