Differential Rotation in Solar Convective Dynamo Simulations

TL;DR

This paper presents advanced MHD simulations of the solar convective dynamo that successfully reproduce solar-like differential rotation and magnetic cycle behaviors, with improved physical realism due to reduced viscosity and magnetic diffusion.

Contribution

It demonstrates that reducing viscosity and magnetic diffusion in simulations enhances the solar-like differential rotation and magnetic cycle features.

Findings

Reproduces solar-like differential rotation with faster equator

Shows cyclic magnetic polarity reversals

Enhanced angular momentum transport with lower diffusion

Abstract

We carry out a magneto-hydrodynamic (MHD) simulation of convective dynamo in the rotating solar convective envelope driven by the solar radiative diffusive heat flux. The simulation is similar to that reported in Fan & Fang (2014) but with further reduced viscosity and magnetic diffusion. The resulting convective dynamo produces a large scale mean field that exhibits similar 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 we found that this transport is enhanced with reduced viscosity and magnetic diffusion.