THE DYNAMO BIFURCATION IN ROTATING SPHERICAL SHELLS

Convection in Rotating Spherical Fluid Shells

Convection driven by thermal buoyancy in rotating spherical bodies of fluid has long been recognized as a fundamental process in the understanding of the properties of planets and stars. Since these objects are rotating in general and since their evolution is associated with the transport of heat from their interiors convection influenced by the Coriolis force does indeed play a dominant role i...

“Unusual Properties of Convection and Dynamos in Rotating Spherical Shells”

On the onset of low-Prandtl-number convection in rotating spherical shells: non-slip boundary conditions

Accurate numerical computations of the onset of thermal convection in wide rotating spherical shells are presented. Low-Prandtl-number (σ ) fluids, and non-slip boundary conditions are considered. It is shown that at small Ekman numbers (E), and very low σ values, the well-known equatorially trapped patterns of convection are superseded by multicellular outer-equatorially-attached modes. As a r...

Two computational approaches for the simulation of fluid problems in rotating spherical shells

Many geophysical and astrophysical phenomena such as magnetic fields generation, or the differential rotation observed in the atmospheres of the major planets are studied by means of numerical simulations of the Navier-Stokes equations in rotating spherical shells. Two different computational codes, spatially discretized using spherical harmonics in the angular variables, are presented. The fir...

The oscillation and stability of differentially rotating spherical shells: The normal-mode problem

An understanding of the dynamics of differentially rotating systems is key to many areas of astrophysics. We investigate the oscillations of a simple system exhibiting differential rotation, and discuss issues concerning the role of corotation points and the emergence of dynamical instabilities. This problem is of particular relevance to the emission of gravitational waves from oscillating neut...