Magnetic reconnection: A problem of general physical and astrophysical interest, with special implications in solar physics

1983 ◽  
Vol 2 (9) ◽  
pp. 21-26 ◽  
Author(s):  
J. Heyvaerts
Keyword(s):  
Magnetic Reconnection ◽  
Solar Physics ◽  
Astrophysical Interest ◽  
General Physical

scholarly journals Quasi-separatrix Layers Induced by Ballooning Instability in Near-Earth Magnetotail

2019 ◽  
Author(s):  
Ping Zhu ◽  
Zechen Wang ◽  
Jun Chen ◽  
Xingting Yan ◽  
Rui Liu
Keyword(s):  
Numerical Simulations ◽  
Magnetic Reconnection ◽  
Solar Physics ◽  
Close Correlation ◽  
Satellite Observations ◽  
Two Dimensional ◽  
3 Dimensional ◽  
Ballooning Instability ◽  
3D Geometry ◽  
Alternative Means

Abstract. Magnetic reconnection processes in the near-Earth magnetotail can be highly 3-dimensional (3D) in geometry and dynamics, even though the magnetotail configuration itself is nearly two dimensional due to the symmetry in the dusk-dawn direction. Such reconnection processes can be induced by the 3D dynamics of nonlinear ballooning instability. In this work, we explore the global 3D geometry of the reconnection process induced by ballooning instability in the near-Earth magnetotail by examining the distribution of quasi-separatrix layers associated with plasmoid formation in the entire 3D domain of magnetotail configuration, using an algorithm previously developed in context of solar physics. The 3D distribution of quasi-separatrix layers (QSLs) as well as their evolution directly follows the plasmoid formation during the nonlinear development of ballooning instability in both time and space. Such a close correlation demonstrates a strong coupling between the ballooning and the corresponding reconnection processes. It further confirms the intrinsic 3D nature of the ballooning-induced plasmoid formation and reconnection processes, in both geometry and dynamics. In addition, the reconstruction of the 3D QSL geometry may provide an alternative means for identifying the location and timing of 3D reconnection sites in magnetotail from both numerical simulations and satellite observations.

Recent progress made in numerical experiments on magnetic reconnection and the related solar activities 

2021 ◽  
Author(s):  
Jun Lin ◽  
Jing Ye
Keyword(s):  
Magnetic Reconnection ◽  
Solar Flares ◽  
Numerical Experiments ◽  
Recent Progress ◽  
Magnetic Energy ◽  
Solar Physics ◽  
Plasma Heating ◽  
Mhd Turbulence ◽  
2D And 3D ◽  
Made In

<p>Magnetic reconnection plays a crucial role in the process of solar flares and coronal mass ejections, in which large amounts of magnetic energy (10^29-10^32 ergs) are converted into kinetic energy and thermal energy, even allowing for particle acceleration. On the platform of the Computational Solar Physics Laboratory of Yunnan Observatories, we have performed a series of numerical experiments on magnetic reconnection related to solar eruption events as well as numerical method developments both in 2D and 3D. In this talk, we will present some recent studies on the topic of plasma heating by reconnection, MHD turbulence, wave structures and complicate structures of CMEs, etc. Our numerical results have great potentials to explain and predict many related solar activities in the corona. </p>

scholarly journals How eruptions of a small filament feed materials to a nearby larger-scaled filament

2020 ◽  
Vol 498 (1) ◽  
pp. L104-L108 ◽  
Author(s):  
H Wei ◽  
Z Huang ◽  
Z Hou ◽  
Y Qi ◽  
H Fu ◽  
...  
Keyword(s):  
Magnetic Reconnection ◽  
Solar Physics ◽  
Solar Telescope ◽  
Solar Dynamics Observatory ◽  
Plasma Flows ◽  
Laboratory Plasma ◽  
Common Features ◽  
Multi Wavelength ◽  
Magnetic Channel ◽  
Solar Dynamics

ABSTRACT As one of the most common features in the solar atmosphere, filaments are significant not only in solar physics but also in stellar and laboratory plasma physics. With the New Vacuum Solar Telescope and the Solar Dynamics Observatory, here we report on multi-wavelength observations of eruptions of a small (30 arcsec) filament (SF) and its consequences while interacting with ambient magnetic features including a large (300 arcsec) filament (LF). The eruptions of the SF drive a two-side-loop jet that is a result of magnetic reconnection between the SF threads and an overlying magnetic channel. As a consequence of the eruption, the heating in the footpoints of the SF destabilizes the barbs of the LF rooted nearby. Supersonic chromospheric plasma flows along the barbs of the LF are then observed in the H α passband and they apparently feed materials to the LF. We suggest that they are shock-driven plasma flows or chromospheric evaporations, which can both be the consequences of heating in the chromosphere by non-thermal particles generated in the magnetic reconnection associated with the two-side-loop jet. Our observations demonstrate that the destabilization in the vicinity of the footpoints of a barb can drive chromospheric plasma feeding to the filament.

scholarly journals Magnetic Reconnection: Phantom Theory

2020 ◽  
Vol 3 (2) ◽  
pp. p66
Author(s):  
Syun-Ichi Akasofu
Keyword(s):  
Global Warming ◽  
Magnetic Reconnection ◽  
Solar Flares ◽  
Solar Physics ◽  
Scientific Field ◽  
Half Century ◽  
Auroral Physics ◽  
Unusual Situation

In any scientific field, there is always a possibility, in which a particular theory dominates for many years. In this paper, the theory of magnetic reconnection in solar physics and auroral physics is reviewed as an example. It has prevailed for more than a half century in both fields as the “only one” without a concrete progress in understanding the source of energy for solar flares and auroral activities. This unusual situation is analyzed why and how it occurred. Since such a situation could occur in any scientific field, it may be useful to analyze how this situation happened. Actually, it is pointed out that a study of global warming may also be in a similar situation.

scholarly journals Quasi-separatrix layers induced by ballooning instability in the near-Earth magnetotail

2019 ◽  
Vol 37 (3) ◽  
pp. 325-335
Author(s):  
Ping Zhu ◽  
Zechen Wang ◽  
Jun Chen ◽  
Xingting Yan ◽  
Rui Liu
Keyword(s):  
Numerical Simulations ◽  
Magnetic Reconnection ◽  
Strong Coupling ◽  
Solar Physics ◽  
Three Dimensional ◽  
Close Correlation ◽  
Satellite Observations ◽  
Two Dimensional ◽  
Ballooning Instability ◽  
Alternative Means

Abstract. Magnetic reconnection processes in the near-Earth magnetotail can be highly three-dimensional (3-D) in geometry and dynamics, even though the magnetotail configuration itself is nearly two-dimensional due to the symmetry in the dusk–dawn direction. Such reconnection processes can be induced by the 3-D dynamics of nonlinear ballooning instability. In this work, we explore the global 3-D geometry of the reconnection process induced by ballooning instability in the near-Earth magnetotail by examining the distribution of quasi-separatrix layers associated with plasmoid formation in the entire 3-D domain of magnetotail configuration, using an algorithm previously developed in the context of solar physics. The 3-D distribution of quasi-separatrix layers (QSLs) as well as their evolution directly follow the plasmoid formation during the nonlinear development of ballooning instability in both time and space. Such a close correlation demonstrates a strong coupling between the ballooning and the corresponding reconnection processes. It further confirms the intrinsic 3-D nature of the ballooning-induced plasmoid formation and reconnection processes, in both geometry and dynamics. In addition, the reconstruction of the 3-D QSL geometry may provide an alternative means of identifying the location and timing of 3-D reconnection sites in the magnetotail from both numerical simulations and satellite observations.

Recent Radiative and Collisional Atomic Data of Astrophysical Interest

1988 ◽  
Vol 102 ◽  
pp. 129-132
Author(s):  
K.L. Baluja ◽  
K. Butler ◽  
J. Le Bourlot ◽  
C.J. Zeippen
Keyword(s):  
Mass Production ◽  
Bound States ◽  
Physical Models ◽  
Impact Excitation ◽  
Electron Impact Excitation ◽  
Atomic Data ◽  
Isoelectronic Sequence ◽  
Astrophysical Interest ◽  
Radiative Transitions ◽  
Forbidden Transitions

SummaryUsing sophisticated computer programs and elaborate physical models, accurate radiative and collisional atomic data of astrophysical interest have been or are being calculated. The cases treated include radiative transitions between bound states in the 2p4and 2s2p5configurations of many ions in the oxygen isoelectronic sequence, the photoionisation of the ground state of neutral iron, the electron impact excitation of the fine-structure forbidden transitions within the 3p3ground configuration of CℓIII, Ar IV and K V, and the mass-production of radiative data for ions in the oxygen and fluorine isoelectronic sequences, as part of the international Opacity Project.

A large rotating structure around AB Doradus A at VLBI scale

2019 ◽  
Vol 15 (S354) ◽  
pp. 189-194
Author(s):  
J. B. Climent ◽  
J. C. Guirado ◽  
R. Azulay ◽  
J. M. Marcaide
Keyword(s):  
Magnetic Reconnection ◽  
Main Sequence ◽  
Complex Structure ◽  
Main Sequence Star ◽  
Polar Cap ◽  
Vlbi Observations ◽  
Rotating Structure ◽  
Source Structure ◽  
Expected Position

AbstractWe report the results of three VLBI observations of the pre-main-sequence star AB Doradus A at 8.4 GHz. With almost three years between consecutive observations, we found a complex structure at the expected position of this star for all epochs. Maps at epochs 2007 and 2010 show a double core-halo morphology while the 2013 map reveals three emission peaks with separations between 5 and 18 stellar radii. Furthermore, all maps show a clear variation of the source structure within the observing time. We consider a number of hypothesis in order to explain such observations, mainly: magnetic reconnection in loops on the polar cap, a more general loop scenario and a close companion to AB Dor A.

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