Related papers: Coronal magnetic field evolution over the cycle 24
We estimate the temporal change of magnetic flux perpendicular to the solar surface in a decaying active region by using a time series of the spatial distribution of vector magnetic fields in the photosphere. The vector magnetic fields are…
The solar active region photospheric magnetic field evolves rapidly during major eruptive events, suggesting appreciable feedback from the corona. Previous studies of these "magnetic imprints" are mostly based on line-of-sight only or…
This work examines the relation between the fractal properties of the photospheric magnetic patterns and those of the coronal magnetic fields in solar active regions.Our results show no correlation between the fractal dimensions of the…
Normal modes of oscillation of the Sun are useful probes of the solar interior. In this work, we use the even-order splitting coefficients to study the evolution of magnetic fields in the convection zone over solar cycle 23, assuming that…
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…
Magnetoseismology, a technique of magnetic field diagnostics based on observations of magnetohydrodynamic (MHD) waves, has been widely used to estimate the field strengths of oscillating structures in the solar corona. However, previously…
Coronal magnetic flux ropes are closely related to large-scale solar activities. Using a 2.5-dimensional time-dependent ideal magnetohydrodynamic (MHD) model in Cartesian coordinates, we carry out numerical simulations to investigate the…
We investigate spatio-temporal evolution of high-degree acoustic mode frequencies of the Sun and the surface magnetic activity, over the course of multiple solar cycles, to improve our understanding of the connection between the solar…
After decades of effort, the solar activity cycle is exceptionally well characterized but it remains poorly understood. Pioneering work at the Mount Wilson Observatory demonstrated that other sun-like stars also show regular activity…
The solar coronal magnetic field is a pivotal element in the study of eruptive phenomena, and understanding its dynamic evolution has long been a focal point in solar physics. Numerical models, driven directly by observation data, serve as…
We present a comprehensive radiative magnetohydrodynamic simulation of the quiet Sun and large solar active regions. The 197 Mm wide simulation domain spans from 18 (10) Mm beneath the photosphere to 113 Mm in the solar corona. Radiative…
The heating of the solar corona is likely to be due to reconnection of the highly complex magnetic field that threads throughout its volume. We have run a numerical experiment of an elementary interaction between the magnetic field of two…
Extrapolation codes for modelling the magnetic field in the corona in cartesian geometry do not take the curvature of the Sun's surface into account and can only be applied to relatively small areas, \textit{e.g.}, a single active region.…
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…
Over the solar-activity cycle, there are extended periods where significant discrepancies occur between the spacecraft-observed total (unsigned) open magnetic flux and that determined from coronal models. In this article, the total open…
Our understanding of the structure and dynamics of stellar coronae has changed dramatically with the availability of surface maps of both star spots and also magnetic field vectors. Magnetic field extrapolations from these surface maps…
In addition to sunspots, which represent the most easily visualized manifestation of solar magnetism, cutting-edge observations of the solar atmosphere have uncovered a plethora of magnetic flux tubes, down to the resolving power of modern…
We report on the dynamical interaction of quiet-Sun magnetic fields and granular convection in the solar photosphere as seen by \textsc{Sunrise}. We use high spatial resolution (0\farcs 15--0\farcs 18) and temporal cadence (33 s)…
We examine the temporal changes in both solar polar magnetic field (PMF) at latitudes $\ge$ $45^{\circ}$ and heliospheric magnetic field (HMF) at 1 AU during solar cycles 21--24 with emphasis on the recent activity changes after July 2015,…
We have measured the meridional motions of the magnetic elements in the Sun's surface layers since 1996 and find systematic and substantial variations. In general the meridional flow speed is fast at cycle minima and slow at cycle maxima.…