Buoyancy-driven perturbations in a rapidly rotating,electrically conducting fluid: part II – dynamo action

The helicity, electromotive force and α-effect produced in a homogeneous, rapidly rotating, electrically conducting fluid by an isolated source of buoyancy at small Elsasser number are calculated, visualized and analyzed. Due to physical symmetries of the system, the integrals of helicity and electromotive force over all space are zero. However, each has a significant non-zero value when integrated over the cross section of the Taylor column. The local α-effect is found to be significantly anisotropic; it is strongest when the applied magnetic field is toroidal and the resulting EMF is parallel to the applied field.