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Related papers: A Practical Approach to Coronal Magnetic Field Ext…

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Solar filament are commonly thought to be supported in magnetic dips, in particular, of magnetic flux ropes (FRs). In this Letter, from the observed photospheric vector magnetogram, we implement a nonlinear force-free field (NLFFF)…

Solar and Stellar Astrophysics · Physics 2015-06-19 Chaowei Jiang , S. T. Wu , Xueshang Feng , Qiang Hu

The solar magnetic field is key to understanding the physical processes in the solar atmosphere. Nonlinear force-free codes have been shown to be useful in extrapolating the coronal field upward from underlying vector boundary data.…

Astrophysics · Physics 2008-02-29 T. Wiegelmann , J. K. Thalmann , C. J. Schrijver , M. L. Derosa , T. R. Metcalf

The SDO/HMI instruments provide photospheric vector magnetograms with a high spatial and temporal resolution. Our intention is to model the coronal magnetic field above active regions with the help of a nonlinear force-free extrapolation…

Solar and Stellar Astrophysics · Physics 2015-06-04 T. Wiegelmann , J. K. Thalmann , B. Inhester , T. Tadesse , X. Sun , J. T. Hoeksema

A nonlinear force-free field (NLFFF) extrapolation is widely used to reconstruct the three-dimensional magnetic field in the solar corona from the observed photospheric magnetic field. However, the pressure gradient and gravitational forces…

Solar and Stellar Astrophysics · Physics 2020-03-04 Takahiro Miyoshi , Kanya Kusano , Satoshi Inoue

In the solar corona, magnetic flux rope is believed to be a fundamental structure accounts for magnetic free energy storage and solar eruptions. Up to the present, the extrapolation of magnetic field from boundary data is the primary way to…

Solar and Stellar Astrophysics · Physics 2016-01-20 Chaowei Jiang , Xueshang Feng

The photospheric magnetic field vector is continuously derived from measurements, while reconstruction of the three-dimensional (3D) coronal magnetic field requires modelling with photospheric measurements as a boundary condition. For…

Solar and Stellar Astrophysics · Physics 2022-03-23 I. Chifu , B. Inhester , T. Wiegelmann

For the extrapolation of magnetic fields into the solar corona from measurements taken in the photosphere (or chromosphere) force-free magnetic fields are typically used. This does not take into account that the lower layers of the solar…

Solar and Stellar Astrophysics · Physics 2020-01-08 Thomas Neukirch , Thomas Wiegelmann

CONTEXT: As the coronal magnetic field can usually not be measured directly, it has to be extrapolated from photospheric measurements into the corona. AIMS: We test the quality of a non-linear force-free coronal magnetic field extrapolation…

Extrapolations of solar photospheric vector magnetograms into three-dimensional magnetic fields in the chromosphere and corona are usually done under the assumption that the fields are force-free. The field calculations can be improved by…

Solar and Stellar Astrophysics · Physics 2015-05-20 M. Fuhrmann , N. Seehafer , G. Valori , T. Wiegelmann

This paper is concerned with the Laplace boundary-value problem with the directional derivative, corresponding to the specific nature of measurements of the longitudinal component of the photospheric magnetic field. Boundary conditions are…

Astrophysics · Physics 2015-06-24 G. V. Rudenko

Given a known radial magnetic field distribution on the Sun's photospheric surface, there exist well-established methods for computing a potential magnetic field in the corona above. Such potential fields are routinely used as input to…

Solar and Stellar Astrophysics · Physics 2021-12-22 Oliver E. K. Rice , Anthony R. Yeates

Force-free extrapolations are widely used to study the magnetic field in the solar corona based on surface measurements. The extrapolations assume that the ratio of internal energy of the plasma to magnetic energy, the plasma-beta is…

Solar and Stellar Astrophysics · Physics 2015-11-25 H. Peter , J. Warnecke , L. P. Chitta , R. H. Cameron

The Potential Field Source Surface (PFSS) model is the most used approach for extrapolating the global coronal magnetic field, offering efficiency and strong performance at large scales. However, PFSS assumes a potential coronal field, so…

Solar and Stellar Astrophysics · Physics 2026-03-23 C. Antonio , I. Chifu , R. Gafeira , J. J. G. Lima

The magnetic fields in the solar atmosphere structure the plasma, store free magnetic energy and produce a wide variety of active solar phenomena, like flare and coronal mass ejections(CMEs). The distribution and strength of magnetic fields…

Solar and Stellar Astrophysics · Physics 2015-06-12 Tilaye Tadesse , T. Wiegelmann , K. Olson , P. J. MacNeice

We develop a nonlinear force-free field (NLFFF) extrapolation code based on the magnetohydrodynamic (MHD) relaxation method. We extend the classical MHD relaxation method in two important ways. First, we introduce an algorithm initially…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. Inoue , T. Magara , V. S. Pandey , D. Shiota. , K. Kusano , G. S. Choe , K. S. Kim

Coronal heating through the explosive release of magnetic energy remains an open problem in solar physics. Recent hydrodynamical models attempt an investigation by placing swarms of 'nanoflares' at random sites and times in modeled…

Solar and Stellar Astrophysics · Physics 2016-11-30 K. Moraitis , A. Toutountzi , H. Isliker , M. Georgoulis , L. Vlahos , G. Chintzoglou

The minimum-energy configuration for the magnetic field above the solar photosphere is curl-free (hence, by Ampere's law, also current-free), so can be represented as the gradient of a scalar potential. Since magnetic fields are divergence…

Solar and Stellar Astrophysics · Physics 2016-06-20 Brian T. Welsch , George H. Fisher

Solar eruptive phenomena, like flares and coronal mass ejections(CMEs) are governed by magnetic fields. To describe the structure of these phenomena one needs information on the magnetic flux density and the electric current density vector…

Solar and Stellar Astrophysics · Physics 2015-06-17 Tilaye Tadesse , T. Wiegelmann , Pevtsov A Alexei , P. Macneice , S. Gosain

Magnetic field plays an important role in various solar eruptions like flares, coronal mass ejections, etc. The formation and evolution of characteristic magnetic field topology in solar eruptions are critical problems that will ultimately…

Solar and Stellar Astrophysics · Physics 2023-06-07 Wen He , Qiang Hu , Ju Jing , Haimin Wang , Chaowei Jiang , Sushree S. Nayak , Avijeet Prasad

Three-dimensional (3D) magnetic field in the solar atmosphere provides crucial information to understand the explosive phenomenon such as solar flares and coronal mass ejections. Since it is still hard that we determine the 3D magnetic…

Solar and Stellar Astrophysics · Physics 2026-01-07 Daiki Yamasaki , Takahiro Miyoshi , Satoshi Inoue