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| Titel |
The role of the bow shock in solar wind-magnetosphere coupling |
| VerfasserIn |
R. E. Lopez, V. G. Merkin, J. G. Lyon |
| 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 ; 29, no. 6 ; Nr. 29, no. 6 (2011-06-25), S.1129-1135 |
| Datensatznummer |
250017047
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| Publikation (Nr.) |
 copernicus.org/angeo-29-1129-2011.pdf |
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| Zusammenfassung |
| In this paper we examine the role of the bow shock in coupling solar wind
energy to the magnetosphere using global magnetohydrodynamic simulations of
the solar wind-magnetosphere interaction with southward IMF. During typical
solar wind conditions, there are two significant dynamo currents in the
magnetospheric system, one in the high-latitude mantle region tailward of
the cusp and the other in the bow shock. As the magnitude of the (southward)
IMF increases and the solar wind becomes a low Mach number flow, there is a
significant change in solar wind-magnetosphere coupling. The high-latitude
magnetopause dynamo becomes insignificant compared to the bow shock and a
large load appears right outside the magnetopause. This leaves the bow shock
current as the only substantial dynamo current in the system, and the only
place where a significant amount of mechanical energy is extracted from the
solar wind. That energy appears primarily as electromagnetic energy, and the
Poynting flux generated at the bow shock feeds energy back into the plasma,
reaccelerating it to solar wind speeds. Some small fraction of that Poynting
flux is directed into the magnetosphere, supplying the energy needed for
magnetospheric dynamics. Thus during periods when the solar wind flow has a
low Mach number, the main dynamo in the solar wind-magnetosphere system is
the bow shock. |
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