Axial and equatorial magnetic dipoles generated in a rotating spherical shell

Two types of magnetic dipole fields are generated by thermal convection in a rotating spherical shell. The axial (or equatorial) dipole in which the m agnetic dipole moment is parallel (or perpendicular) to the rotation axis i s realized at a larger (or smaller) value of the Rayleigh number. Their str ucture is robust and persists over the entire simulation period, that is, e ight (or two) magnetic diffusion times.