相关论文: Topology of Coronal Magnetic Fields: Extending the…
The topology of the coronal magnetic field produces a strong impact on the properties of the solar corona and presumably on the origin of the slow solar wind. To advance our understanding of this impact, we revisit the concept of so-called…
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 polar magnetism near an activity maximum when these regions change their polarity, from which it is expected that its magnetism should be less affected by the global field. To fully characterise the magnetic field vector, we…
Non-linear force-free extrapolations are a common approach to estimate the 3D topology of coronal magnetic fields based on photospheric vector magnetograms. The force-free assumption is a valid approximation at coronal heights, but for the…
Recent advances in spectropolarimetry have allowed the reconstruction of stellar coronal magnetic fields. This uses Zeeman-Doppler magnetograms of the surface magnetic field as a lower boundary condition. The ZDI maps, however, suffer from…
Solar flares are accessible to a broad variety of observational methods to see and investigate the {\em magnetic reconnection} phenomenon in high-temperature strongly-magnetized plasma of the solar corona. An analysis of the topological…
The role of null-point reconnection in a 3D numerical MHD model of solar emerging flux is investigated. The model consists of a twisted magnetic flux tube rising through a stratified convection zone and atmosphere to interact and reconnect…
The solar magnetic fields emerging from the photosphere into the chromosphere and corona are comprised of a combination of "closed" and "open" fields. The closed magnetic field lines are defined as those having both ends rooted in the solar…
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)…
Contrary to the electric charge that generates the electric field, magnetic charge (namely magnetic monopoles) does not exist in the elementary electromagnetism. Consequently, magnetic flux lines only form loops and cannot have a source or…
There is an increasing theoretical and observational evidence that the external magnetic field of magnetars may contain a toroidal component, likely of the same order of the poloidal one. Such "twisted magnetospheres" are threaded by…
Although the analysis of observational data indicates that quasi-separatrix layers (QSLs) have to play an important role in magnetic configurations of solar flares, the corresponding theory is only at an initial stage so far. In particular,…
By comparing a magneto-frictional model of the low coronal magnetic field to a potential-field source-surface model, we investigate the possible impact of non-potential magnetic structure on empirical solar-wind models. These empirical…
We investigate sharp structures visible in solar magnetic field tracers. It is shown that the sunspot magnetic boundaries do not coincide with the photometric ones. Moreover, there is no clear boundary of the magnetic field in the vicinity…
The solar atmosphere being magnetic in nature, the understanding of the structure and evolution of the magnetic field in different regions of the solar atmosphere has been an important task over the past decades. This task has been made…
We investigate sharply outlined features recorded in solar magnetic field tracers. It is shown that the magnetic boundaries of a sunspot do not coincide with the photometric ones. Moreover, there is no clear magnetic boundary around…
The high spatial, temporal and spectral resolution achieved by Hinode instruments give much better understanding of the behavior of some elusive solar features, such as pores and naked sunspots. Their fast evolution and, in some cases,…
We study the topology associated with physical vector and scalar fields. A mathematical object, e.g., a ball, can be continuously deformed, without tearing or gluing, to make other topologically equivalent objects, e.g., a cube or a solid…
[..] 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…
We study the effect of photospheric footpoint motions on magnetic field structures containing magnetic nulls. The footpoint motions are prescribed on the photospheric boundary as a velocity field which entangles the magnetic field. We…