Numerical modeling of magnetohydrodynamic convection in a rapidly rotating spherical shell: Weak and strong field dynamo action. (English) Zbl 0957.76096
From the summary: We describe a numerical model for magnetohydrodynamic convective flow of Boussinesq fluid in a rapidly rotating spherical shell, driven by the buoyancy forces arising from incoming buoyant flux at the inner core boundary. The model is designed to investigate the generation of magnetic field in the Earth’s fluid outer core. We use an axisymmetric inertial force to balance the axial magnetic torque arising from the Lorentz force, and we use a mixed spectral-finite difference algorithm for the parallelization of the code. We test our numerical model by examining purely thermal convection in a rapidly rotating fluid shell, and by examining Kumar-Roberts kinematic dynamos (modified for the spherical shell). Our results agree well with previous studies. We also present a weak-field dynamo solution in a very simplified system, and strong-field dynamo solutions in a more realistic system.
MSC:
| 76W05 | Magnetohydrodynamics and electrohydrodynamics |
| 76U05 | General theory of rotating fluids |
| 76M22 | Spectral methods applied to problems in fluid mechanics |
| 76M20 | Finite difference methods applied to problems in fluid mechanics |
| 86A25 | Geo-electricity and geomagnetism |
| 65Y05 | Parallel numerical computation |
Keywords:
geomagnetism; magnetohydrodynamic convective flow; Boussinesq fluid; rapidly rotating spherical shell; buoyancy forces; axisymmetric inertial force; mixed spectral-finite difference algorithm; parallelization; purely thermal convection; Kumar-Roberts kinematic dynamos; weak-field dynamo solution; strong-field dynamo solutionsReferences:
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