Modeling Solar Atmosphere Dynamics with MAGEC

TL;DR

This paper introduces and validates MAGEC, a new radiative MHD code for simulating the solar atmosphere's complex dynamics, demonstrating its accuracy and efficiency through 2D magneto-convection simulations.

Contribution

The paper presents MAGEC, a novel radiative MHD code combining existing tools with improvements for coronal modeling, validated via comprehensive 2D simulations of the solar atmosphere.

Findings

MAGEC accurately reproduces temperature stratification and reaches thermal equilibrium.

Open magnetic fields produce higher coronal temperatures than closed fields.

Perpendicular thermal conduction influences plasma dynamics and average coronal temperature.

Abstract

Modeling the solar atmosphere is challenging due to its layered structure and multi-scale dynamics. We aim to validate the new radiative MHD code MAGEC, which combines the MANCHA and MAGNUS codes into a finite-volume, shock-capturing framework, and to test its performance through 2D simulations of magneto-convection. MAGEC is MPI-parallelized and includes improvements for coronal modeling, such as LTE radiative losses and a hyperbolic treatment of thermal conduction that mitigates restrictive time steps. We also estimated its numerical viscosity and resistivity. To assess robustness, we performed 2D simulations covering a domain from 2 Mm below the surface to 18.16 Mm into the corona, using both open and closed magnetic-field configurations. For each case, we analyzed steady-state temperature profiles and the contributions to the internal-energy balance at different heights. A separate experiment examined the role of perpendicular thermal conduction. MAGEC reproduced the expected temperature stratification set by boundary conditions and magnetic geometry, and all simulations reached thermal equilibrium. Open-field cases produced higher coronal temperatures than closed, arcade-like fields. Analysis of the explicit and implicit energy terms clarified their relative effects on heating and cooling. Perpendicular thermal conduction, often neglected in coronal models, was found to influence plasma dynamics near reconnection; although local effects are small, they can cumulatively modify the average coronal temperature. These results show that MAGEC is a reliable and efficient tool for radiative MHD simulations, well suited to capturing the shocks and dynamic processes of the solar atmosphere.