English
Related papers

Related papers: Coronal magnetic field evolution over the cycle 24

200 papers

Observations of surface magnetic fields are now within reach for many stellar types thanks to the development of Zeeman-Doppler Imaging. These observations are extremely useful for constraining rotational evolution models of stars, as well…

Solar and Stellar Astrophysics · Physics 2015-09-24 Victor Réville , Allan Sacha Brun , Antoine Strugarek , Sean P. Matt , Jérôme Bouvier , Colin P. Folsom , Pascal Petit

We describe, test, and apply a technique to incorporate full-sun, surface flux evolution into an MHD model of the global solar corona. Requiring only maps of the evolving surface flux, our method is similar to that of Lionello et al.…

Solar and Stellar Astrophysics · Physics 2023-10-12 Roberto Lionello , Cooper Downs , Emily I. Mason , Jon A. Linker , Ronald M. Caplan , Pete Riley , Viacheslav S. Titov , Marc L. DeRosa

The Sun's polar magnetic fields are directly related to solar cycle variability. The strength of the polar fields at the start (minimum) of a cycle determine the subsequent amplitude of that cycle. In addition, the polar field reversals at…

Solar and Stellar Astrophysics · Physics 2014-08-01 Lisa Upton , David H. Hathaway

It is widely believed that loops observed in the solar atmosphere trace out magnetic field lines. However, the degree to which magnetic field extrapolations yield field lines that actually do follow loops has yet to be studied…

Solar and Stellar Astrophysics · Physics 2018-06-27 Harry P. Warren , Nicholas A. Crump , Ignacio Ugarte-Urra , Xudong Sun , Markus J. Aschwanden , Thomas Wiegelmann

[..] 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…

Solar and Stellar Astrophysics · Physics 2015-05-28 S. Regnier

It is an indisputable fact that solar magnetic fields are force-free in the corona, where force free fields means that current and magnetic fields are parallel and there is no Lorentz force in the fields. While the force-free extent of…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. Liu , J. T. Su , H. Q. Zhang , Y. Y. Deng , Y. Gao , X. Yang , X. J. Mao

The origin of the heliospheric magnetic flux on the Sun, and hence the origin of the solar wind, is a topic of hot debate.While the prevailing view is that the solar wind originates from outside coronal streamer helmets, there also exists…

Solar and Stellar Astrophysics · Physics 2015-06-05 Bo Li , Xing Li , Hui Yu

Photospheric magnetic vector maps from two different instruments are used to model the nonlinear force-free coronal magnetic field above an active region. We use vector maps inferred from polarization measurements of the Solar Dynamics…

Solar and Stellar Astrophysics · Physics 2015-06-15 J. K. Thalmann , S. K. Tiwari , T. Wiegelmann

The presence of magnetic field is crucial in the transport of energy through the solar atmosphere. Recent ground-based and space-borne observations of the quiet Sun have revealed that magnetic field accumulates at photospheric heights, via…

Solar and Stellar Astrophysics · Physics 2019-06-19 Juan Martínez-Sykora , Viggo H. Hansteen , Boris Gudiksen , Mats Carlsson , Bart De Pontieu , Milan Gosic

The solar surface magnetic field is fundamental for modeling the coronal magnetic field, studying the solar dynamo, and predicting solar cycle strength. We perform a continuous simulation of the surface magnetic field from 2010 to 2024,…

Solar and Stellar Astrophysics · Physics 2025-06-03 Ruihui Wang , Jie Jiang , Yukun Luo

This paper is the third in a series of papers working towards the construction of a realistic, evolving, non-linear force-free coronal field model for the solar magnetic carpet. Here, we present preliminary results of 3D time-dependent…

Solar and Stellar Astrophysics · Physics 2013-03-07 K. A. Meyer , D. H. Mackay , A. A. van Ballegooijen , C. E. Parnell

Solar flares are driven by release of free magnetic energy and often associated with restructurization of the magnetic field topology. Yet, observations of evolving magnetic field in the flaring volume are limited to very few cases…

Solar and Stellar Astrophysics · Physics 2026-02-18 Gregory D. Fleishman , Tatyana Kaltman , Sijie Yu

The heliospheric magnetic field is of pivotal importance in solar and space physics. The field is rooted in the Sun's photosphere, where it has been observed for many years. Global maps of the solar magnetic field based on full disk…

Solar and Stellar Astrophysics · Physics 2017-10-18 J. A. Linker , R. M. Caplan , C. Downs , P Riley , Z Mikic , R. Lionello , C. J. Henney , C. N. Arge , Y. Liu , M. L. Derosa , A. Yeates , M. J. Owens

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

The structure and dynamics of the solar corona is dominated by the magnetic field. In most areas in the corona magnetic forces are so dominant that all non-magnetic forces like plasma pressure gradient and gravity can be neglected in the…

Solar and Stellar Astrophysics · Physics 2021-03-24 Thomas Wiegelmann , Takashi Sakurai

The magnetic fields in the solar corona are generally neither force-free nor axisymmetric and have complex dynamics that are difficult to characterize. Here we simulate the topological evolution of solar coronal magnetic field lines (MFLs)…

Solar and Stellar Astrophysics · Physics 2017-05-09 A. Prasad , R. Bhattacharyya , Sanjay Kumar

We present a newly developed approach to solar coronal magnetic field extrapolation from vector magnetograms, based on the Principle of Minimum Dissipation Rate (MDR). The MDR system was derived from a variational problem that is more…

Astrophysics · Physics 2009-11-13 Q. Hu , B. Dasgupta , D. P. Choudhary , J. Büchner

We present a three-dimensional numerical model for the generation and evolution of the magnetic field in the solar convection zone, in which sunspots are produced and contribute to the cyclic reversal of the large-scale magnetic field. We…

Solar and Stellar Astrophysics · Physics 2018-01-30 Rohit Kumar , Laurène Jouve , Rui F. Pinto , Alexis P. Rouillard

The solar magnetic structure changes over the solar cycle. It has a dipole structure during solar minimum, where the open flux extends mainly from the polar regions into the interplanetary space. During maximum, a complex structure is…

Solar and Stellar Astrophysics · Physics 2023-06-28 Minami Yoshida , Toshifumi Shimizu , Shin Toriumi

The Sun is replete with magnetic fields, with sunspots, pores and plage regions being their most prominent representatives on the solar surface. But even far away from these active regions, magnetic fields are ubiquitous. To a large extent,…

Solar and Stellar Astrophysics · Physics 2015-11-05 Andreas Lagg , Bruce Lites , Jack Harvey , Sanjay Gosain , Rebecca Centeno
‹ Prev 1 3 4 5 6 7 10 Next ›