A simulation of convective dynamo in the solar convective envelope: maintenance of the solar-like differential rotation and emerging flux

TL;DR

This paper presents a magneto-hydrodynamic simulation of the solar convective envelope that demonstrates the self-consistent generation of a solar-like differential rotation and the emergence of flux bundles resembling active regions.

Contribution

It introduces a novel MHD simulation capturing the cyclic magnetic behavior and flux emergence in a solar-like convective dynamo model.

Findings

Magnetic fields sustain solar-like differential rotation.

The dynamo exhibits irregular magnetic cycles with polarity reversals.

Emergence of flux bundles similar to solar active regions.

Abstract

We report the results of a magneto-hydrodynamic (MHD) simulation of a convective dynamo in a model solar convective envelope driven by the solar radiative diffusive heat flux. The convective dynamo produces a large-scale mean magnetic field that exhibits irregular cyclic behavior with oscillation time scales ranging from about 5 to 15 years and undergoes irregular polarity reversals. The mean axisymmetric toroidal magnetic field is of opposite signs in the two hemispheres and is concentrated at the bottom of the convection zone. The presence of the magnetic fields is found to play an important role in the self-consistent maintenance of a solar-like differential rotation in the convective dynamo model. Without the magnetic fields, the convective flows drive a differential rotation with a faster rotating polar region. In the midst of magneto-convection, we found emergence of strong super-equipartition flux bundles at the surface, exhibiting properties that are similar to emerging solar active regions.