English
Related papers

Related papers: A comparison of preprocessing methods for solar fo…

200 papers

The finite-element analysis of three-dimensional magnetostatic problems in terms of magnetic vector potential has proven to be one of the most efficient tools capable of providing the excellent quality results but becoming computationally…

Computational Physics · Physics 2023-07-25 Alexander Chervyakov

Determination of solar magnetic fields with a spatial resolution set by the diffraction limit of a telescope is difficult because the time required to measure the Stokes vector with sufficient signal-to-noise is long compared to the solar…

Solar and Stellar Astrophysics · Physics 2024-05-08 Jaime de la Cruz Rodríguez , Jorrit Leenaarts

Based on several magnetic nonpotentiality parameters obtained from the vector photospheric active region magnetograms obtained with the Solar Magnetic Field Telescope at the Huairou Solar Observing Station over two solar cycles, a machine…

Solar and Stellar Astrophysics · Physics 2013-08-29 Xiao Yang , GangHua Lin , HongQi Zhang , XinJie Mao

We examine the nonlinear magnetofrictional extrapolation scheme using the solar active region model by Titov and D\'emoulin as test field. This model consists of an arched, line-tied current channel held in force-free equilibrium by the…

Solar and Stellar Astrophysics · Physics 2015-05-18 G. Valori , B. Kliem , T. Török , V. S. Titov

Kilogauss-strength magnetic fields are often observed in intergranular lanes at the photosphere in the quiet Sun. Such fields are stronger than the equipartition field $B_e$, corresponding to a magnetic energy density that matches the…

Astrophysics · Physics 2009-11-13 P. J. Bushby , S. M. Houghton , M. R. E. Proctor , N. O. Weiss

Fringe fields in multipole magnets can have a variety of effects on the linear and nonlinear dynamics of particles moving along an accelerator beamline. An accurate model of an accelerator must include realistic models of the magnet fringe…

Accelerator Physics · Physics 2015-06-10 B. D. Muratori , J. K. Jones , A. Wolski

We investigate the generation mechanisms of MHD Poynting flux in the magnetised solar photosphere. Using radiative MHD modelling of the solar photosphere with initial magnetic configurations that differ in their field strength and geometry,…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. Shelyag , M. Mathioudakis , F. P. Keenan

Electric currents in solar active regions are thought to provide the energy released via magnetic reconnection in solar flares. Vertical electric current densities $J_z$ at the photosphere may be estimated from vector magnetogram data,…

Solar and Stellar Astrophysics · Physics 2015-06-24 M. S. Wheatland

It was recently proposed that the intensity ratios of several extreme ultraviolet spectral lines from the Fe X ion can be used to measure the solar coronal magnetic field based on the magnetic-field-inducedtransition (MIT) theory. To verify…

Solar and Stellar Astrophysics · Physics 2021-10-27 Yajie Chen , Wenxian Li , Hui Tian , Feng Chen , Xianyong Bai , Yang Yang , Zihao Yang , Xianyu Liu , Yuanyong Deng

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

Observations of quiet Sun from the Solar Optical Telescope/Spectro-Polarimeter (SOT/SP) aboard the Hinode spacecraft would reveal the magnetic characters of the solar photosphere. By making use of the deep mode observations of three quiet…

Astrophysics · Physics 2008-12-18 Chunlan Jin , Jingxiu Wang , Meng Zhao

We address the problem of calculating the transverse magnetic field in the solar wind outside of the hypothetical sphere called the source surface where the solar wind originates. This calculation must overcome a widely used fundamental…

Solar and Stellar Astrophysics · Physics 2016-04-27 Roger K. Ulrich , Tham Tran

In earlier works we introduced and tested a nonlinear force-free (NLFF) method designed to self-consistently calculate the free magnetic energy and the relative magnetic helicity budgets of the corona of observed solar magnetic structures.…

Solar and Stellar Astrophysics · Physics 2015-06-22 K. Moraitis , K. Tziotziou , M. K. Georgoulis , V. Archontis

The solar coronal magnetic field produces solar activity, including extremely energetic solar flares and coronal mass ejections (CMEs). Knowledge of the structure and evolution of the magnetic field of the solar corona is important for…

Solar and Stellar Astrophysics · Physics 2015-06-22 Tilaye Tadesse , Thomas Wiegelmann , Peter MacNeice

We show that a Maxwell-like system of equations for spatial gravitational fields $\bf g$ and $\bf B$ (latter being the analogy of a magnetic field), modified to include an extra term for the $\bf B$ field in the expression for force, leads…

General Relativity and Quantum Cosmology · Physics 2009-11-10 W. D. Flanders , G. S. Japaridze

First, we describe a general procedure to produce high quality vector magnetograms using the Imaging Vector Magnetograph (IVM) at Mees Solar Observatory. At the spatial resolution 2"x2", the Stokes Q,U,V uncertainty reaches 0.001-0.0005 in…

Astrophysics · Physics 2011-02-11 Jing Li , A. A. van Ballegooijen , Don Mickey

Measurements of the interplanetary magnetic field (IMF) over several solar cycles do not agree with computed values of open magnetic flux from potential field extrapolations. The discrepancy becomes greater around solar maximum in each…

Solar and Stellar Astrophysics · Physics 2015-05-19 A. R. Yeates , D. H. Mackay , A. A. van Ballegooijen , J. A. Constable

Magnetic field is the key physical quantity in solar physics as it controls all kinds of solar activity, ranging from nanoflares to big flares and coronal mass ejections (CMEs). However, so far only the magnetic field on the solar surface…

Solar and Stellar Astrophysics · Physics 2025-11-21 P. F. Chen

We outline a general methodology to infer the inductive velocity field vector in solar active regions. For the first time, both the field-aligned and the cross-field velocity components are reconstructed. The cross-field velocity solution…

Astrophysics · Physics 2009-11-13 Manolis K. Georgoulis , Barry J. LaBonte

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