Toward a fast and consistent approach to model solar magnetic fields in multiple layers

TL;DR

This paper introduces a novel combined extrapolation method that efficiently models magnetic fields across multiple layers of the solar atmosphere, improving accuracy over existing methods.

Contribution

The paper presents a new combined magnetohydrostatic and nonlinear force-free field extrapolation approach for multi-layer solar magnetic field modeling, optimized for speed and accuracy.

Findings

The combined method achieves accuracy comparable to MHS extrapolation.

It outperforms NLFFF extrapolation in multi-layer magnetic field reconstruction.

The approach is moderately efficient for high-resolution magnetograms.

Abstract

Aims. We aim to develop a fast and consistent extrapolation method to model multiple layers of the solar atmosphere. Methods. The new approach combines the magnetohydrostatic (MHS) extrapolation which models the solar low atmosphere in a flat box and the nonlinear force-free field (NLFFF) extrapolation which models the solar corona with a chromospheric vector magnetogram deduced from the MHS extrapolation. We test our code with a snapshot of a radiative magnetohydrodynamic simulation of a solar flare. Comparisons are conducted by several metrics quantitatively. Results. Based on a number of test runs, we find out the optimized configuration for the combination of two extrapolations with a 5.8-Mm-high box for the MHS extrapolation and a magnetogram at a height of 1 Mm for the NLFFF extrapolation. The new approach under this configuration is able to reconstruct the magnetic fields in multi-layers accurately and efficiently. Based on figures of merit that are used to assess the performance of different extrapolations (NLFFF extrapolation, MHS extrapolation, and the combined one), we find the combined extrapolation reaches accuracy of the MHS extrapolation which is better than the NLFFF extrapolation. The combined extrapolation is moderately efficient for application to magnetograms with high resolution.