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Bibliographic Details
Main Authors: Nadol, Lilli, Neukirch, Thomas
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2504.16619
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author Nadol, Lilli
Neukirch, Thomas
author_facet Nadol, Lilli
Neukirch, Thomas
contents With current observational methods it is not possible to directly measure the magnetic field in the solar corona with sufficient accuracy. Therefore, coronal magnetic field models have to rely on extrapolation methods using photospheric magnetograms as boundary conditions. In recent years, due to the increased resolution of observations and the need to resolve non-force-free lower regions of the solar atmosphere, there have been increased efforts to use magnetohydrostatic (MHS) field models instead of force-free extrapolation methods. Although numerical methods to calculateMHS solutions can deal with non-linear problems and hence provide more accurate models, analytical three-dimensional MHS equilibria can also be used as a numerically relatively "cheap" complementary method. In this paper, we present an extrapolation method based on a family of analytical MHS equilibria that allows for a transition from a non-force-free region to a force-free region. We demonstrate how asymptotic forms of the solutions can help to increase the numerical efficiency of the method. Through both artificial boundary condition testing and a first application to observational
format Preprint
id arxiv_https___arxiv_org_abs_2504_16619
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle An efficient method for magnetic field extrapolation based on a family of analytical three-dimensional magnetohydrostatic equilibria
Nadol, Lilli
Neukirch, Thomas
Solar and Stellar Astrophysics
With current observational methods it is not possible to directly measure the magnetic field in the solar corona with sufficient accuracy. Therefore, coronal magnetic field models have to rely on extrapolation methods using photospheric magnetograms as boundary conditions. In recent years, due to the increased resolution of observations and the need to resolve non-force-free lower regions of the solar atmosphere, there have been increased efforts to use magnetohydrostatic (MHS) field models instead of force-free extrapolation methods. Although numerical methods to calculateMHS solutions can deal with non-linear problems and hence provide more accurate models, analytical three-dimensional MHS equilibria can also be used as a numerically relatively "cheap" complementary method. In this paper, we present an extrapolation method based on a family of analytical MHS equilibria that allows for a transition from a non-force-free region to a force-free region. We demonstrate how asymptotic forms of the solutions can help to increase the numerical efficiency of the method. Through both artificial boundary condition testing and a first application to observational
title An efficient method for magnetic field extrapolation based on a family of analytical three-dimensional magnetohydrostatic equilibria
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2504.16619