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| Titel |
Diffusion at the Earth magnetopause: enhancement by Kelvin-Helmholtz instability |
| VerfasserIn |
R. Smets, G. Belmont, D. Delcourt, L. Rezeau |
| 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 ; 25, no. 1 ; Nr. 25, no. 1 (2007-02-01), S.271-282 |
| Datensatznummer |
250015776
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| Publikation (Nr.) |
 copernicus.org/angeo-25-271-2007.pdf |
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| Zusammenfassung |
| Using hybrid simulations, we examine how particles can diffuse across the
Earth's magnetopause because of finite Larmor radius effects. We focus on
tangential discontinuities and consider a reversal of the magnetic field that
closely models the magnetopause under southward interplanetary magnetic
field. When the Larmor radius is on the order of the field reversal
thickness, we show that particles can cross the discontinuity. We also show
that with a realistic initial shear flow, a Kelvin-Helmholtz instability
develops that increases the efficiency of the crossing process. We
investigate the distribution functions of the transmitted ions and
demonstrate that they are structured according to a D-shape. It accordingly
appears that magnetic reconnection at the magnetopause is not the only
process that leads to such specific distribution functions. A simple
analytical model that describes the built-up of these functions is proposed. |
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