Dynamics of flux tubes in the solar atmosphere: Observations

2008 ◽  
pp. 49-73 ◽  
Author(s):  
S. K. Solanki
Keyword(s):  
Solar Atmosphere ◽  
Flux Tubes

The Characteristics of Thin Magnetic Flux Tubes in the Lower Solar Atmosphere Observed byHinode/SOT in the G band and in Ca ii H Bright Points

2017 ◽  
Vol 851 (1) ◽  
pp. 42 ◽  
Author(s):  
Jianping Xiong ◽  
Yunfei Yang ◽  
Chunlan Jin ◽  
Kaifan Ji ◽  
Song Feng ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Solar Atmosphere ◽  
Flux Tubes ◽  
Magnetic Flux Tubes ◽  
Lower Solar Atmosphere

scholarly journals Modelling 3D magnetic networks in a realistic solar atmosphere

2019 ◽  
Vol 489 (1) ◽  
pp. 28-35
Author(s):  
Frederick A Gent ◽  
Ben Snow ◽  
Viktor Fedun ◽  
Robertus Erdélyi
Keyword(s):  
Magnetic Field ◽  
Magnetic Flux ◽  
Solar Atmosphere ◽  
Energy Transport ◽  
Solar Dynamics Observatory ◽  
Lower Corona ◽  
Flux Tubes ◽  
Background Magnetic Field ◽  
Magnetic Flux Tubes ◽  
Open Magnetic Flux

ABSTRACT The magnetic network extending from the photosphere (solar radius ≃ R⊙) to the lower corona ($\mathrm{ R}_\odot +10\, {\rm Mm}$) plays an important role in the heating mechanisms of the solar atmosphere. Here we develop further the models of the authors with realistic open magnetic flux tubes, in order to model more complicated configurations. Closed magnetic loops and combinations of closed and open magnetic flux tubes are modelled. These are embedded within a stratified atmosphere, derived from observationally motivated semi-empirical and data-driven models subject to solar gravity and capable of spanning from the photosphere up into the chromosphere and lower corona. Constructing a magnetic field comprising self-similar magnetic flux tubes, an analytic solution for the kinetic pressure and plasma density is derived. Combining flux tubes of opposite polarity, it is possible to create a steady background magnetic field configuration, modelling a solar atmosphere exhibiting realistic stratification. The result can be applied to the Solar and Heliospheric Observatory Michelson Doppler Imager (SOHO/MDI), Solar Dynamics Observatory Helioseismic and Magnetic Imager (SDO/HMI) and other magnetograms from the solar surface, for which photospheric motions can be simulated to explore the mechanism of energy transport. We demonstrate this powerful and versatile method with an application to HMI data.

Induced mass and wave motions in the lower solar atmosphere. I - Effects of shear motion of flux tubes

1983 ◽  
Vol 266 ◽  
pp. 866 ◽  
Author(s):  
S. T. Wu ◽  
Y. Q. Hu ◽  
Y. Nakagawa ◽  
E. Tandberg-Hanssen
Keyword(s):  
Solar Atmosphere ◽  
Flux Tubes ◽  
Shear Motion ◽  
Lower Solar Atmosphere

Three-Dimensional MHD Simulations of the Emergence of Twisted Magnetic Flux Tubes in the Solar Atmosphere

1999 ◽  
pp. 343-344
Author(s):  
H. Tonooka ◽  
R. Matsumoto ◽  
W. Chou ◽  
T. Tajima ◽  
K. Shibata
Keyword(s):  
Magnetic Flux ◽  
Solar Atmosphere ◽  
Three Dimensional ◽  
Flux Tubes ◽  
Mhd Simulations ◽  
Magnetic Flux Tubes

scholarly journals Are the umbral dots, penumbral grains, and G band bright points formed by the same type of magnetic flux tubes?

2010 ◽  
Vol 6 (S273) ◽  
pp. 426-429
Author(s):  
Isroil Sattarov
Keyword(s):  
Magnetic Flux ◽  
Solar Atmosphere ◽  
Solar Physics ◽  
Common Type ◽  
Present Evidence ◽  
Flux Tubes ◽  
Quiet Sun ◽  
Magnetic Flux Tubes ◽  
Fine Structures ◽  
Umbral Dots

AbstractToday's Solar Physics comes across of different type of fine structures in solar atmosphere including umbral dots and penumbral grains in sunspots, and G-band bright points in quiet Sun. In this report, we present evidence that umbral dots, penumbral grains, and, possibly, G band bright points are related to a common type of features in solar atmosphere magnetic flux tubes.

scholarly journals Flux tube model in the solar atmosphere

2018 ◽  
Vol 13 (S340) ◽  
pp. 55-56
Author(s):  
S. Sen ◽  
A. Mangalam
Keyword(s):  
Open Field ◽  
Solar Atmosphere ◽  
Flux Tube ◽  
Field Model ◽  
Gas Pressure ◽  
Tube Model ◽  
Shape Functions ◽  
Flux Tubes ◽  
Shafranov Equation ◽  
Self Similar

AbstractWe construct two classes of the magnetohydrostatic equilibria of the axisymmetric flux tubes with twisted magnetic fields in the stratified solar atmosphere that span from the photosphere to the transition region. We built the models by incorporating specific forms of the gas pressure and poloidal current in the Grad-Shafranov equation. This model gives both closed and open field structure of the flux tube. The other open field model we construct is based on the self-similar formulation, where we have incorporated specific forms of the gas pressure, poloidal current and two different shape functions. We study the homology of the parameter space that is consistent with the solar atmosphere and find that the estimation of the magnetic structure inside the flux tubes is consistent with the observation and simulation results of the magnetic bright points.

scholarly journals Waves in Magnetic Flux Tubes

1990 ◽  
Vol 142 ◽  
pp. 159-174
Author(s):  
B Roberts
Keyword(s):  
Wave Propagation ◽  
Magnetic Flux ◽  
Solar Atmosphere ◽  
Flux Tube ◽  
Seismic Waves ◽  
Wave Guide ◽  
Magnetic Flux Tube ◽  
Flux Tubes ◽  
Ocean Layer ◽  
Magnetic Flux Tubes

The basic aspects of wave propagation in a magnetic flux tube are reviewed, with particular emphasis on the types of flux tube that occur in the solar atmosphere. Two fundamental speeds arise naturally in a description of wave propagation in a flux tube: the slow magnetoacoustic (cusp) speed cT, which is both subsonic and sub-Alfvénic, and a mean Alfvén speed ck. Both surface and body modes are supported by a tube. It is stressed that a flux tube may act as a wave guide, similar to the guidance of light by a fibre optic, or sound in an ocean layer, or seismic waves in the Earth's crust.

scholarly journals Cosmic ray interactions in the solar atmosphere

2019 ◽  
Vol 491 (4) ◽  
pp. 4852-4856 ◽  
Author(s):  
Hugh S Hudson ◽  
Alec MacKinnon ◽  
Mikolaj Szydlarski ◽  
Mats Carlsson
Keyword(s):  
Magnetic Field ◽  
Open Field ◽  
Solar Atmosphere ◽  
Cosmic Ray ◽  
High Energy ◽  
Emission Anisotropy ◽  
Flux Tubes ◽  
Wide Range ◽  
High Energy Particles ◽  
The Magnetic Field

ABSTRACT High-energy particles enter the solar atmosphere from Galactic or solar coronal sources, and produce ‘albedo’ emission from the quiet Sun that is now observable across a wide range of photon energies. The interaction of high-energy particles in a stellar atmosphere depends essentially upon the joint variation of the magnetic field and plasma density, which heretofore has been characterized parametrically as P ∝ Bα with P the gas pressure and B the magnitude of the magnetic field. We re-examine that parametrization by using a self-consistent 3D MHD model (Bifrost) and show that this relationship tends to P ∝ B3.5 ± 0.1 based on the visible portions of the sample of open-field flux tubes in such a model, but with large variations from point to point. This scatter corresponds to the strong meandering of the open-field flux tubes in the lower atmosphere, which will have a strong effect on the prediction of the emission anisotropy (limb brightening). The simulations show that much of the open flux in coronal holes originates in weak-field regions within the granular pattern of the convective motions seen in the simulations.

scholarly journals Vortex flow properties in simulations of solar plage region: Evidence for their role in chromospheric heating

2020 ◽  
Vol 645 ◽  
pp. A3
Author(s):  
N. Yadav ◽  
R. H. Cameron ◽  
S. K. Solanki
Keyword(s):  
Magnetic Flux ◽  
Physical Properties ◽  
Numerical Simulations ◽  
Solar Atmosphere ◽  
Small Scale ◽  
Flux Tubes ◽  
Current Sheets ◽  
Plage Region ◽  
Magnetic Flux Tubes ◽  
Chromospheric Heating

Context. Vortex flows exist across a broad range of spatial and temporal scales in the solar atmosphere. Small-scale vortices are thought to play an important role in energy transport in the solar atmosphere. However, their physical properties remain poorly understood due to the limited spatial resolution of the observations. Aims. We explore and analyze the physical properties of small-scale vortices inside magnetic flux tubes using numerical simulations, and investigate whether they contribute to heating the chromosphere in a plage region. Methods. Using the three-dimensional radiative magnetohydrodynamic simulation code MURaM, we perform numerical simulations of a unipolar solar plage region. To detect and isolate vortices we use the swirling strength criterion and select the locations where the fluid is rotating with an angular velocity greater than a certain threshold. We concentrate on small-scale vortices as they are the strongest and carry most of the energy. We explore the spatial profiles of physical quantities such as density and horizontal velocity inside these vortices. Moreover, to learn their general characteristics, a statistical investigation is performed. Results. Magnetic flux tubes have a complex filamentary substructure harboring an abundance of small-scale vortices. At the interfaces between vortices strong current sheets are formed that may dissipate and heat the solar chromosphere. Statistically, vortices have higher densities and higher temperatures than the average values at the same geometrical height in the chromosphere. Conclusions. We conclude that small-scale vortices are ubiquitous in solar plage regions; they are denser and hotter structures that contribute to chromospheric heating, possibly by dissipation of the current sheets formed at their interfaces.

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