Two-dimensional non-linear simulations of the magnetostrophic magnetorotational instability
| Autor: | Ludovic Petitdemange |
|---|---|
| Přispěvatelé: | Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique (LERMA), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Centre National de la Recherche Scientifique (CNRS), Dynamique des milieux interstellaires et plasmas stellaires, Laboratoire d'Etude du Rayonnement et de la Matière en Astrophysique et Atmosphères = Laboratory for Studies of Radiation and Matter in Astrophysics and Atmospheres (LERMA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-CY Cergy Paris Université (CY) |
| Rok vydání: | 2010 |
| Předmět: |
Physics
Angular momentum Physics::Medical Physics Computational Mechanics Rotational symmetry Astronomy and Astrophysics Instability Outer core Spherical geometry Nonlinear system Geophysics Classical mechanics Geochemistry and Petrology Mechanics of Materials Magnetorotational instability Differential rotation Astrophysics::Earth and Planetary Astrophysics [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph] |
| Zdroj: | Geophysical and Astrophysical Fluid Dynamics Geophysical and Astrophysical Fluid Dynamics, 2010, 104, pp.287-299. ⟨10.1080/03091921003636496⟩ |
| ISSN: | 1029-0419 0309-1929 |
| DOI: | 10.1080/03091921003636496 |
| Popis: | International audience; We have shown that a simple, modified version of the Magnetorotational Instability (MRI) can, in principle, develop in the Earth's outer liquid core in the presence of a background shear (see Petitdemange, Dormy and Balbus, MagnetoStrophic MRI in the Earth's outer core. Geophys. Res. Lett. 2008, 35 15305). We refer to this instability as the Magnetostrophic MRI (MS-MRI). In this article, we extend our investigations to the nonlinear regime and present results from global axisymmetric simulations in spherical geometry. We show that as the angular momentum is transported outward, the MS-MRI saturates by rapidly changing the initial shear profile. Therefore, the saturation process differs substantially from traditional MRI applications (e.g. accretion disks) in which the background shear is essentially fixed. We show that the MS-MRI appears as a new constraint which limits the maximum differential rotation. To illustrate this mechanism, we apply this work to a Jupiter-like planet, and argue that the magnetic field eventually destabilises the conducting zone of this planet. According to these results, purely hydrodynamic models for the deep origin of the banded structure of Jupiter may need to be modified. |
| Databáze: | OpenAIRE |
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