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| Titel |
Fluid simulations of Alfvenic turbulence at ion scales |
| VerfasserIn |
Thierry Passot, Dimitri Laveder, Pierre-Louis Sulem |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250109796
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| Publikation (Nr.) |
 EGU/EGU2015-9734.pdf |
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| Zusammenfassung |
| We present three-dimensional simulations of Alfvenic turbulence in collisionless plasmas,
using a Landau fluid model that retains ion and electron Landau damping and finite Larmor
radius corrections. Low frequency oblique Alfvén waves are driven at scales roughly five
times larger than the ion Larmor radius, and small hyperviscosity terms are supplemented in
the velocity and magnetic field equations in order to ensure the presence of a numerical
dissipation range. Two runs corresponding to different amplitude levels of the magnetic field
fluctuations are presented. In the small amplitude regime, the spectral properties compare
well with Solar Wind observational data, with e.g. a slope close to -2.8 for the magnetic-field
perpendicular spectrum. At larger amplitude, corresponding to situations actually beyond
the validity range of the model, shallower spectra are obtained, suggesting that
additional kinetic processes could provide in this case other channels for turbulence
dissipation. |
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