Differential Rotation in solar convective dynamo simulations

Monday, February 22, 2016

Fan and Fang's recent publication shows significant advances in global-scale fully dynamic 3D convective dynamo simulations of the solar convective envelope. These simulations demonstrate the role magnetic field plays in the self-consistent maintenance of the solar differential rotation.

3D views of iso-surfaces image
Figure: 3D isosurfaces of the strong magnetic field concentrations (where the magnetic energy density exceeds that of the kinetic energy density of convection) in the convective envelope produced by two convective dynamo simulations with different magnetic diffusivities (lower magnetic diffusivity in panel (a) compared to panel (b)).

HAO scientist Yuhong Fan and LASP/CU scientist Fang have carry out magnetohydrodynamic (MHD) simulations of convective dynamo in the rotating solar convective envelope driven by the solar radiative diffusive heat flux. The resulting convective dynamo produces a large-scale mean field that exhibits irregular cyclic behavior and polarity reversals, and self-consistently maintains a solar-like differential rotation. The main driver for the solar-like differential rotation (with faster rotating equator) is a net outward transport of angular momentum away from the rotation axis by the Reynolds stress, and it is found that this transport is enhanced with reduced viscosity and magnetic diffusion. See full article at http://www.sciencedirect.com/science/article/pii/S0273117715009138.