Three-dimensional simulations of solar magneto-convection including effects of partial ionization

TL;DR

This paper presents the first 3D realistic simulations of solar magneto-convection that incorporate partial ionization effects, revealing significant impacts on wave amplitudes, energy flux absorption, and chromospheric structure formation.

Contribution

It introduces a novel 3D simulation approach including ambipolar diffusion and battery effects, advancing the modeling of partially ionized solar plasma.

Findings

Ambipolar diffusion affects wave amplitudes and energy transfer.

It influences chromospheric structure formation.

The simulations set a lower limit on temperature increase due to ambipolar effects.

Abstract

Over the last decades, realistic 3D radiative-MHD simulations have become the dominant theoretical tool for understanding the complex interactions between the plasma and the magnetic field on the Sun. Most of such simulations are based on approximations of magnetohydrodynamics, without directly considering the consequences of the very low degree of ionization of the solar plasma in the photosphere and bottom chromosphere. The presence of large amount of neutrals leads to a partial decoupling of the plasma and the magnetic field. As a consequence of that, a series of non-ideal effects (ambipolar diffusion, Hall effect and battery effect) arises. The ambipolar effect is the dominant one in the solar chromosphere. Here we report on the first three-dimensional realistic simulations of magneto-convection including ambipolar diffusion and battery effects. The simulations are done using the newly developed Mancha3D code. Our results reveal that ambipolar diffusion causes measurable effects on the amplitudes of waves excited by convection in the simulations, on the absorption of Poynting flux and heating and on the formation of chromospheric structures. We provide a low limit on the chromospheric temperature increase due to the ambipolar effect using the simulations with battery-excited dynamo fields.