相关论文: Validating Coronal Magnetic Field Models Using Gau…
Deriving the strength and direction of the three-dimensional (3D) magnetic field in the solar atmosphere is fundamental for understanding its dynamics. Volume information on the magnetic field mostly relies on coupling 3D reconstruction…
Solar image analysis relies on the detection of coronal holes for predicting disruptions to earth's magnetic field. The coronal holes act as sources of solar wind that can reach the earth. Thus, coronal holes are used in physical models for…
Seven different models are applied to the same problem of simulating the Sun's coronal magnetic field during the solar eclipse on 2015 March 20. All of the models are non-potential, allowing for free magnetic energy, but the associated…
[..] The change in the magnetic configuration due to the increase/decrease of electric current for different force-free models (potential, linear and nonlinear force-free fields) has never been studied in detail before. Here we focus…
The coronal magnetic field directly or indirectly affects a majority of the phenomena studied in space physics. It provides energy for coronal heating, controls the release of coronal mass ejections (CMEs), and drives heliospheric and…
Recently, it has been proposed that the magnetic-field-induced transition (MIT) in Fe X can be used to measure coronal magnetic field strengths. Several techniques, the direct line ratio technique and the weak and strong magnetic field…
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…
Context: In this paper we present a validation scheme to investigate the quality of coronal magnetic field models, which is based upon comparisons with observational data from multiple sources. Aims: Many of these coronal models may use a…
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…
Current sheets are essential for energy dissipation in the solar corona, in particular by enabling magnetic reconnection. Unfortunately, sufficiently thin current sheets cannot be resolved observationally and the theory of their formation…
We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. We analyse a 3D MHD…
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…
Context. On the sun, the magnetic field vector is measured routinely only in the photosphere. By using these photospheric measurements as boundary condition, we developed the magnetohydrostatic (MHS) extrapolation to model the solar…
Coronal and chromospheric magnetic fields are derived from polarization and spectral observations of the thermal free-free emission using the Nobeyama Radioheliograph (NoRH). In magnetized plasma, the ordinary and extraordinary modes of…
A 3-D coronal magnetic field is reconstructed for NOAA 11158 on Feb 14, 2011. A GPU-accelerated direct boundary integral equation (DBIE) method is implemented. This is about 1000 times faster than the original DBIE used on solar NLFFF…
Previous work utilising NASA's High-resolution Coronal Imager (Hi-C 2.1) 17.2 nm observations revealed that, even at the increased spatial scales available in the data-set, there may be evidence for coronal structures that are still not…
Measurements of the magnetic field in the stellar coronae are extremely difficult. Recently, it was proposed that the magnetic-field-induced transition (MIT) of the Fe X 257 {\AA} line can be used to measure the coronal magnetic field of…
All three components of the current density are required to compute the heating rate due to free magnetic energy dissipation. Here we present a first test of a new model developed to determine if the times of increases in the resistive…
The potential field (PF) solution of the solar corona is a vital modeling tool for a wide range of applications, including minimum energy estimates, coronal magnetic field modeling, and empirical solar wind solutions. Given its popularity,…
The variation of the vector magnetic field along structures in the solar corona remains unmeasured. Using a unique combination of spectropolarimetry and stereoscopy, we infer and compare the vector magnetic field structure and…