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| Titel |
Thin current sheets caused by plasma flow gradients in space and astrophysical plasma |
| VerfasserIn |
D. H. Nickeler, T. Wiegelmann |
| 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 ; 28, no. 8 ; Nr. 28, no. 8 (2010-08-13), S.1523-1532 |
| Datensatznummer |
250016867
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| Publikation (Nr.) |
 copernicus.org/angeo-28-1523-2010.pdf |
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| Zusammenfassung |
| Strong gradients in plasma flows play a major role in space and astrophysical plasmas.
A typical situation is that a static plasma equilibrium is surrounded by a
plasma flow, which can lead to strong plasma flow gradients at the separatrices
between field lines with different magnetic topologies, e.g.,
planetary magnetospheres, helmet streamers in the solar corona,
or at the boundary between the heliosphere
and interstellar medium. Within this work we make a first step to understand
the influence of these flows towards the occurrence of current sheets in a
stationary state situation. We concentrate here on incompressible
plasma flows and 2-D equilibria, which allow us to find analytic solutions
of the stationary magnetohydrodynamics equations (SMHD).
First we solve
the magnetohydrostatic (MHS) equations with the help of a
Grad-Shafranov equation and then we transform these static equilibria into
a stationary state with plasma flow. We are in particular interested
to study SMHD-equilibria with strong plasma flow gradients
perpendicular to separatrices.
We find that induced thin current sheets occur naturally in
such situations. The strength of the induced currents
depend on the Alfvén Mach number and its gradient, and on the magnetic
field. |
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