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| Titel |
Instability Interplay at the Low Latitude Magnetopause: Pairing and Decay of Large-Scale Vortices |
| VerfasserIn |
Matteo Faganello, Anna Tenerani, Francesco Pegoraro, Francesco Califano |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250037812
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| Zusammenfassung |
| Kelvin-Helmholtz vortices provides an efficient mechanism for the formation of a mixing
layer along the flank Magnetopause at low latitude. The transport properties of these vortices
depend on the interplay between their large-scale evolution and the development of
secondary, small-scale instabilities inside the vortices. In particular density inhomogeneities,
centrifugal acceleration and plasma current inhomogeneities, created by the vortex
motion, drive local Rayleigh-Taylor and Magnetic Reconnection instabilities. The
interplay between the large-scale vortex evolution and these secondary instabilities in a
magnetized inhomogeneous plasma with a sheared velocity field is investigated
within the framework of a two-dimensional, two fluid model. It is found that the
combined role of the density inhomogeneity and of the in-plane magnetic field
during the development of the Kelvin Helmholtz vortices is multi faceted. It leads
to small scale density bubbles and magnetic islands through the development of
Rayleigh-Taylor instability and induced magnetic reconnection but, at the same time,
the in-plane magnetic field preserves the global coherence of the vortex merging
process. |
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