Large-scale magnetic fields at high Reynolds numbers in magnetohydrodynamic simulations.
Science
; 351(6280): 1427-30, 2016 Mar 25.
Article
em En
| MEDLINE
| ID: mdl-27013727
ABSTRACT
The 11-year solar magnetic cycle shows a high degree of coherence in spite of the turbulent nature of the solar convection zone. It has been found in recent high-resolution magnetohydrodynamics simulations that the maintenance of a large-scale coherent magnetic field is difficult with small viscosity and magnetic diffusivity (â²10 (12) square centimenters per second). We reproduced previous findings that indicate a reduction of the energy in the large-scale magnetic field for lower diffusivities and demonstrate the recovery of the global-scale magnetic field using unprecedentedly high resolution. We found an efficient small-scale dynamo that suppresses small-scale flows, which mimics the properties of large diffusivity. As a result, the global-scale magnetic field is maintained even in the regime of small diffusivities-that is, large Reynolds numbers.
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01-internacional
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MEDLINE
Idioma:
En
Ano de publicação:
2016
Tipo de documento:
Article