The dynamo bifurcation in rotating spherical shells
arXiv:1006.1144 · doi:10.1142/S021797920906378X
Abstract
We investigate the nature of the dynamo bifurcation in a configuration applicable to the Earth's liquid outer core, i.e. in a rotating spherical shell with thermally driven motions. We show that the nature of the bifurcation, which can be either supercritical or subcritical or even take the form of isola (or detached lobes) strongly depends on the parameters. This dependence is described in a range of parameters numerically accessible (which unfortunately remains remote from geophysical application), and we show how the magnetic Prandtl number and the Ekman number control these transitions.
16 pages, 14 figures
Cited by in corpus (18)
- Dynamo theories
- Shell Models of Magnetohydrodynamic Turbulence
- Dipolar versus multipolar dynamos: the influence of the background density stratification
- Strong-Field Spherical Dynamos
- Subcritical convection of liquid metals in a rotating sphere using a quasi-geostrophic model
- Predictive Scaling Laws for Spherical Rotating Dynamos
- Three Branches of Dynamo Action
- Bistability and chaos in Taylor-Green dynamo
- Supercriticality to subcriticality in dynamo transitions
- Study on the large scale dynamo transition
- Systematic parameter study of dynamo bifurcations in geodynamo simulations
- Confinement of rotating convection by a laterally varying magnetic field
- Rotational threshold in global numerical dynamo simulations
- Can Core Flows inferred from Geomagnetic Field Models explain the Earth's Dynamo?
- Magnetic structure, dipole reversals, and 1/f noise in resistive MHD spherical dynamos
- Mechanisms of Planetary and Stellar Dynamos
- Stochastic bistable systems, and competing hysteresis and phase coexistence
- Dynamo transition in a five-mode helical model