相关论文: Scaling laws for magnetic fields on the quiet Sun
Although the magnetic fields in the quiet Sun account for the majority of the magnetic energy in the solar photosphere, inferring their exact spatial distribution, origin, and evolution poses an important challenge because the signals lie…
In this paper we investigate the dynamics of magnetic helicity in magnetohydrodynamic (MHD) turbulent flows focusing at scales larger than the forcing scale. Our results show a nonlocal inverse cascade of magnetic helicity, which occurs…
Rapid magnetic upflows in the quiet-Sun photosphere were recently uncovered from both SUNRISE/IMaX and Hinode/SOT observations. Here, we study magnetic upflow events (MUEs) from high-quality, high- (spatial, temporal, and spectral)…
Small bipolar magnetic features are observed to appear in the interior of individual granules in the quiet Sun, signaling the emergence of tiny magnetic loops from the solar interior. We study the origin of those features as part of the…
Magnetic flux is continuously being removed and replenished on the solar surface. To understand the removal process we carried out 3D radiative MHD simulations of the evolution of patches of photospheric magnetic field with equal amounts of…
In turbulence, for neutral or conducting fluids, a large ratio of scales is excited because of the possible occurrence of inverse cascades to large, global scales together with direct cascades to small, dissipative scales, as observed in…
Hydrodynamic simulations of granular convection predict the existence of supersonic flows covering ~3-4% of the solar surface at any time, but these flows have not been detected unambigously as yet. Using data from the spectropolarimeter…
We use direct numerical simulations of forced MHD turbulence with a forcing function that produces two different signs of kinetic helicity in the upper and lower parts of the domain. We show that the mean flux of magnetic helicity from the…
The nature of solar wind turbulence at large scale is rather well understood in the theoretical framework of magnetohydrodynamics. The situation is quite different at sub-proton scales where the magnetic energy spectrum measured by…
The multi-scale structure of the solar surface magnetic field is essential for understanding both the Sun's internal dynamo processes and its external magnetic activity. The surface flux transport (SFT) model has been successful in…
We explore the nature of the small-scale solar dynamo by tracking magnetic features. We investigate two previously-explored categories of the small-scale solar dynamo: shallow and deep. Recent modeling work on the shallow dynamo has…
Recent observations have shown that the photometric and dynamic properties of granulation and of small-scale magnetic features depend on the amount of magnetic flux of the region they are embedded in. We analyze results from numerical Hydro…
A system of multiple open magnetic flux tubes spanning the solar photosphere and lower corona is modelled analytically, within a realistic stratified atmosphere subject to solar gravity. This extends results for a single magnetic flux tube…
We investigate vortex dynamics in three magnetic regions, viz., Quiet Sun, Weak Plage, and Strong Plage, using realistic three-dimensional simulations from a comprehensive radiation-MHD code, MURaM. We find that the spatial extents and…
Inspired by observations of sunspots embedded in active regions, it is often assumed that large-scale, strong magnetic flux emerges from the Sun's deep interior in the form of arched, cylindrical structures, colloquially known as flux…
The aim of this work is to identify the physical processes that occur in the network and contribute to its dynamics and heating. We model the network as consisting of individual flux tubes with a non-potential field structure that are…
The dynamic properties of the quiet Sun photosphere can be investigated by analyzing the pair dispersion of small-scale magnetic fields (i.e., magnetic elements). By using $25$ hr-long Hinode magnetograms at high spatial resolution…
A key question in understanding the observed magnetic field topologies of cool stars is the link between the small- and the large-scale magnetic field and the influence of the stellar parameters on the magnetic field topology. We examine…
We study the growth of small fluctuations of magnetic field in supersonic turbulence, the small-scale dynamo. The growth is due to the fastest turbulent eddies above the resistive scale. We observe that for supersonic turbulence these…
A recent study carried out on high sensitivity SUNRISE/IMAX data has reported about the existence of areas of limited flux emergence in the quiet Sun. By exploiting an independent and longer (4 hours) data set acquired by HINODE/SOT, we…