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Due to the absence of direct measurement, the magnetic field in the solar corona is usually extrapolated from the photosphere in numerical way. At the moment, the nonlinear force-free field (NLFFF) model dominates the physical models for…

Solar and Stellar Astrophysics · Physics 2015-06-15 Chaowei Jiang , Xueshang Feng

The magnetic field plays a crucial role in heating the solar corona, but the exact energy release mechanism(s) is(are) still unknown. Here, we investigate in detail, the process of magnetic energy release in a situation where two initially…

Astrophysics · Physics 2009-11-10 K. Galsgaard , C. E. Parnell

Observations of the upper chromosphere shows an enormous amount of intricate fine structure. Much of this comes in the form of linear features which are most often assumed to be well aligned with the direction of the magnetic field in the…

Solar and Stellar Astrophysics · Physics 2017-10-23 Juan Martínez-Sykora , Bart De Pontieu , Mats Carlsson , Viggo Hansteen

In situ measurements of kinetic scale current sheets in the solar wind show that they are often approximately force-free although the plasma beta is of order one. They frequently display systematic asymmetric and anti-correlated spatial…

Solar and Stellar Astrophysics · Physics 2025-09-30 Sophie Boswell , Thomas Neukirch , Anton Artemyev , Ivan Vasko , Oliver Allanson

Estimating the magnetic field strength in the solar corona is crucial for understanding different physical processes happening over diverse spatio-temporal scales. However, the high temperatures and low density of the solar corona make this…

Solar and Stellar Astrophysics · Physics 2024-03-07 Upasna Baweja , Vaibhav Pant , Iñigo Arregui

Presently, many models of the coronal magnetic field rely on photospheric vector magnetograms but these data have been shown to be problematic as the sole boundary information for nonlinear force-free field (NLFFF) extrapolations. Magnetic…

Solar and Stellar Astrophysics · Physics 2021-06-29 A. Malanushenko , C. J. Schrijver , M. L. DeRosa , M. S. Wheatland , S. A. Gilchrist

We estimate the energy input into the solar corona from photospheric footpoint motions, using observations of a plage region by the Hinode Solar Optical Telescope. Assuming a perfectly ideal coronal evolution, two alternative lower bounds…

Solar and Stellar Astrophysics · Physics 2014-05-08 A. R. Yeates , F. Bianchi , B. T. Welsch , P. J. Bushby

Solar magnetic fields are closely related to various physical phenomena on the sun, which can be extrapolated with different models from photospheric magnetograms. However, the Open Flux Problem (OFP), the underestimation of the magnetic…

Solar and Stellar Astrophysics · Physics 2024-05-30 Guanglu Shi , Li Feng , Beili Ying , Shuting Li , Weiqun Gan

Many questions remain about the compressibility of solar wind turbulence with respect to its origins and properties. Low plasma beta (ratio of thermal to magnetic pressure) environments allow for the easier generation of compressible…

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

Reliable measurements of the solar magnetic field are still restricted to the photosphere, and our present knowledge of the three-dimensional coronal magnetic field is largely based on extrapolation from photospheric magnetogram using…

Solar and Stellar Astrophysics · Physics 2015-06-05 Chaowei Jiang , Xueshang Feng , Changqing Xiang

Faraday rotation of the polarization plane in magnetized thermal plasma provides one of the most efficient methods to deduce regular magnetic fields from radio astronomical observations. Since the Faraday rotation measure RM is proportional…

Astrophysics · Physics 2009-11-10 Rainer Beck , Anvar Shukurov , Dmitry Sokoloff , Richard Wielebinski

The coupling between small and large scale structures and processes on the Sun and in the heliosphere is important in the relation to the global magnetic configuration. Thin heliospheric current sheets play the leading role in this respect.…

Solar and Stellar Astrophysics · Physics 2012-12-24 Igor Veselovsky , Olga Panasenco

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

The plasma-$\beta$ is an important fundamental physical quantity in solar plasma physics, which determines the dominating process in the solar atmosphere, i.e., magnetic or thermodynamic processes. Here, for the first time, we provide…

Solar and Stellar Astrophysics · Physics 2025-07-23 Ananya Rawat , Girjesh Gupta , Tom Van Doorsselaere , S. Krishna Prasad , Robertus Erdélyi

This paper follows up on a previous study showing that in an open atmosphere such as the solar corona the total magnetic helicity of a force-free field must be bounded and the accumulation of magnetic helicity in excess of its upper bound…

Astrophysics · Physics 2009-11-13 Mei Zhang , Natasha Flyer

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

Relative magnetic helicity is commonly used in solar physics to avoid the well known gauge ambiguity of standard magnetic helicity in magnetically open domains. But its physical interpretation is difficult owing to the invocation of a…

Solar and Stellar Astrophysics · Physics 2026-01-12 Anthony R. Yeates , Gunnar Hornig

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

The coronal magnetic field, despite its overwhelming importance to the physics and dynamics of the corona, has only rarely been measured. Here, the electron density maps derived from images acquired during the total solar eclipse of August…

Solar and Stellar Astrophysics · Physics 2023-03-29 Alessandro Bemporad
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