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| Titel |
Forced current sheet structure, formation and evolution: application to magnetic reconnection in the magnetosphere |
| VerfasserIn |
V. I. Domrin, A. P. Kropotkin |
| 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 ; 22, no. 7 ; Nr. 22, no. 7 (2004-07-14), S.2547-2553 |
| Datensatznummer |
250014944
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| Publikation (Nr.) |
 copernicus.org/angeo-22-2547-2004.pdf |
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| Zusammenfassung |
| By means of a simulation model, the earlier predicted nonlinear kinetic
structure, a Forced Kinetic Current Sheet (FKCS), with extremely anisotropic
ion distributions, is shown to appear as a result of a fast nonlinear
process of transition from a previously existing equilibrium. This occurs
under triggering action of a weak MHD disturbance that is applied at the
boundary of the simulation box. In the FKCS, current is carried by initially
cold ions which are brought into the CS by convection from both sides, and
accelerated inside the CS. The process then appears to be spontaneously
self-sustained, as a MHD disturbance of a rarefaction wave type propagates
over the background plasma outside the CS. Comparable to the Alfvénic
discontinuity in MHD, transformation of electromagnetic energy into the
energy of plasma flows occurs at the FKCS. But unlike the MHD case, ``free"
energy is produced here: dissipation should occur later, through particle
interaction with turbulent waves generated by unstable ion distribution
being formed by the FKCS action. In this way, an effect of magnetic field
``annihilation" appears, required for fast magnetic reconnection.
Application of the theory to observations at the magnetopause and in the
magnetotail is considered. |
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