scholarly journals Trend of photospheric magnetic helicity flux in active regions generating halo coronal mass ejections

2010 ◽  
Vol 521 ◽  
pp. A56 ◽  
Author(s):  
A. Smyrli ◽  
F. Zuccarello ◽  
P. Romano ◽  
F. P. Zuccarello ◽  
S. L. Guglielmino ◽  
...  
Keyword(s):  
Coronal Mass Ejections ◽  
Active Regions ◽  
Magnetic Helicity

scholarly journals Magnetic helicity ejections and coronal activity

2012 ◽  
Vol 8 (S294) ◽  
pp. 519-530 ◽  
Author(s):  
A. Nindos
Keyword(s):  
Magnetic Field ◽  
Physical Quantity ◽  
Coronal Mass Ejections ◽  
Active Regions ◽  
Magnetic Helicity ◽  
The Sun ◽  
Coronal Activity ◽  
Solar Eruptions ◽  
Ideal Tool ◽  
The Magnetic Field

AbstractMagnetic helicity quantifies the degree of linkage and/or twistedness in the magnetic field. It is probably the only physical quantity which is approximately conserved even in resistive MHD. This makes it an ideal tool for the exploration of the physics of solar eruptions. In this article, I discuss the sources of magnetic helicity injected into active regions and I point out that coronal mass ejections (CMEs) are probably necessary to remove at least part of the excess helicity produced in the Sun. I also discuss the importance of magnetic helicity in the overall coronal evolution that may lead to eruptions.

scholarly journals Helicity Pattern of CME Source Active Regions

2005 ◽  
Vol 13 ◽  
pp. 125-125
Author(s):  
Jingxiu Wang ◽  
Guiping Zhou ◽  
Jun Zhang
Keyword(s):  
Coronal Mass Ejections ◽  
Active Regions ◽  
The Other ◽  
Magnetic Helicity ◽  
Other Hand

Coronal mass ejections are thought to originate from the over accumulation of magnetic helicity (Rust & Kumar, 1994). While recent studies revealed the incompetence of CME associated active regions in creating enough helicity for CMEs (Nindos, Zhang, & Zhang, 2003 and references therein), we have tried to seek, on the other hand, if particular helicity patterns are retained by CME-associated active regions.

Solar Filaments as Tracers of Subsurface Processes

2000 ◽  
Vol 179 ◽  
pp. 177-183
Author(s):  
D. M. Rust
Keyword(s):  
Magnetic Fields ◽  
Magnetic Flux ◽  
Coronal Mass Ejections ◽  
Interplanetary Space ◽  
Intermediate Stage ◽  
Coronal Plasma ◽  
Magnetic Helicity ◽  
The Sun ◽  
New Paradigm ◽  
Solar Filaments

AbstractSolar filaments are discussed in terms of two contrasting paradigms. The standard paradigm is that filaments are formed by condensation of coronal plasma into magnetic fields that are twisted or dimpled as a consequence of motions of the fields’ sources in the photosphere. According to a new paradigm, filaments form in rising, twisted flux ropes and are a necessary intermediate stage in the transfer to interplanetary space of dynamo-generated magnetic flux. It is argued that the accumulation of magnetic helicity in filaments and their coronal surroundings leads to filament eruptions and coronal mass ejections. These ejections relieve the Sun of the flux generated by the dynamo and make way for the flux of the next cycle.

scholarly journals Observations of magnetic and kinetic helicity proxies

2012 ◽  
Vol 8 (S294) ◽  
pp. 13-24
Author(s):  
Hongqi Zhang
Keyword(s):  
Magnetic Field ◽  
Velocity Field ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
Active Regions ◽  
Solar Dynamo ◽  
Magnetic Helicity ◽  
Vector Magnetograms ◽  
Topological Configuration ◽  
The Relationship

AbstractThe helicity is important to present the basic topological configuration of magnetic field in solar atmosphere. The distribution of magnetic helicity in solar atmosphere is presented by means of the observational (vector) magnetograms. As the kinetic helicity in the solar subatmosphere can be inferred from the velocity field based on the technique of the helioseismology and used to compare with the magnetic helicity in the solar atmosphere, the observational helicities provide the important chance for the confirmation on the generation of magnetic fields in the subatmosphere and solar dynamo models also. In this paper, we present the observational magnetic and kinetic helicity in solar active regions and corresponding questions, except the relationship with solar eruptive phenomena.

scholarly journals Observations of flux rope formation prior to coronal mass ejections

2013 ◽  
Vol 8 (S300) ◽  
pp. 209-214 ◽  
Author(s):  
Lucie M. Green ◽  
Bernhard Kliem
Keyword(s):  
Magnetic Flux ◽  
Magnetic Structure ◽  
Solar Atmosphere ◽  
Coronal Mass Ejections ◽  
Flux Rope ◽  
Active Regions ◽  
Magnetic Configuration ◽  
Magnetic Flux Rope ◽  
Source Regions ◽  
Flux Ropes

AbstractUnderstanding the magnetic configuration of the source regions of coronal mass ejections (CMEs) is vital in order to determine the trigger and driver of these events. Observations of four CME productive active regions are presented here, which indicate that the pre-eruption magnetic configuration is that of a magnetic flux rope. The flux ropes are formed in the solar atmosphere by the process known as flux cancellation and are stable for several hours before the eruption. The observations also indicate that the magnetic structure that erupts is not the entire flux rope as initially formed, raising the question of whether the flux rope is able to undergo a partial eruption or whether it undergoes a transition in specific flux rope configuration shortly before the CME.

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