scholarly journals Free Magnetic Energy in Solar Active Regions above the Minimum-Energy Relaxed State

2007 ◽  
Vol 669 (1) ◽  
pp. L53-L56 ◽  
Author(s):  
S. Régnier ◽  
E. R. Priest
Keyword(s):  
Magnetic Energy ◽  
Minimum Energy ◽  
Active Regions ◽  
Solar Active Regions ◽  
Free Magnetic Energy

scholarly journals STATISTICAL STUDY OF FREE MAGNETIC ENERGY AND FLARE PRODUCTIVITY OF SOLAR ACTIVE REGIONS

2014 ◽  
Vol 788 (2) ◽  
pp. 150 ◽  
Author(s):  
J. T. Su ◽  
J. Jing ◽  
S. Wang ◽  
T. Wiegelmann ◽  
H. M. Wang
Keyword(s):  
Statistical Study ◽  
Magnetic Energy ◽  
Active Regions ◽  
Solar Active Regions ◽  
Free Magnetic Energy ◽  
Flare Productivity

Numerical Short-Term Solar Activity Forecasting

2017 ◽  
Vol 13 (S335) ◽  
pp. 243-249 ◽  
Author(s):  
Huaning Wang ◽  
Yihua Yan ◽  
Han He ◽  
Xin Huang ◽  
Xinghua Dai ◽  
...  
Keyword(s):  
Solar Activity ◽  
Magnetic Fields ◽  
Solar Atmosphere ◽  
Magnetic Energy ◽  
Three Dimensional ◽  
Active Regions ◽  
Short Term ◽  
Solar Active Regions ◽  
Solar Eruptions ◽  
Dimensional Reconstruction

AbstractIt is well known that the energy for solar eruptions comes from magnetic fields in solar active regions. Magnetic energy storage and dissipation are regarded as important physical processes in the solar corona. With incomplete theoretical modeling for eruptions in the solar atmosphere, activity forecasting is mainly supported with statistical models. Solar observations with high temporal and spatial resolution continuously from space well describe the evolution of activities in the solar atmosphere, and combined with three dimensional reconstruction of solar magnetic fields, makes numerical short-term (within hours to days) solar activity forecasting possible. In the current report, we propose the erupting frequency and main attack direction of solar eruptions as new forecasts and present the prospects for numerical short-term solar activity forecasting based on the magnetic topological framework in solar active regions.

On heating of solar active regions by magnetic energy dissipation

Solar Physics ◽  
1985 ◽  
Vol 95 (1) ◽  
pp. 69-72 ◽  
Author(s):  
Mukul Kumar ◽  
Udit Narain
Keyword(s):  
Energy Dissipation ◽  
Magnetic Energy ◽  
Active Regions ◽  
Solar Active Regions

scholarly journals Magnetic Field Topology in Solar Active Regions

1993 ◽  
Vol 141 ◽  
pp. 435-438
Author(s):  
N. Seehafer
Keyword(s):  
Magnetic Field ◽  
Magnetic Energy ◽  
Mean Field ◽  
Active Regions ◽  
Field Configuration ◽  
Relaxation Processes ◽  
Magnetic Field Topology ◽  
Solar Active Regions ◽  
Global Magnetic Field ◽  
Slow Evolution

AbstractIn solar active regions, over extended periods of time the plasma-magnetic field configuration evolves quasistatically through a sequence of nearly force-free equilibrium states. This evolution may be understood as the continual distortion of an existing equilibrium by wavelike disturbances propagating upward from the photosphere and subsequent fast relaxation to a new, neighbouring equilibrium. In the present paper the build-up of magnetic energy, which is presumably necessary for flares and other explosive events, during a quasistatic evolution is considered. If during the slow evolution the magnetic energy is increased, then the relaxation processes represent inverse cascades of energy. We study the conditions under which such cascades are possible within the framework of mean-field MHD. In contrast to the convection zone, where the dynamo for the global magnetic field of the Sun works, the solar atmosphere is convectively stable and the first order smoothing approximation justified. It turns out then that current helicity (B.∇ × B) is an important quantity decisive for whether magnetic energy can be built up.

scholarly journals Difference of source regions between fast and slow coronal mass ejections

2019 ◽  
Vol 36 ◽  
Author(s):  
B. Filippov
Keyword(s):  
Magnetic Field ◽  
Coronal Mass Ejections ◽  
Solar Flares ◽  
Magnetic Energy ◽  
Active Regions ◽  
Coronal Magnetic Field ◽  
Source Regions ◽  
Free Magnetic Energy ◽  
The Difference ◽  
Sunspot Groups

Abstract Coronal mass ejections (CMEs) are tightly related to filament eruptions and usually are their continuation in the upper solar corona. It is common practice to divide all observed CMEs into fast and slow ones. Fast CMEs usually follow eruptive events in active regions near big sunspot groups and associated with major solar flares. Slow CMEs are more related to eruptions of quiescent prominences located far from active regions. We analyse 10 eruptive events with particular attention to the events on 2013 September 29 and on 2016 January 26, one of which was associated with a fast CME, while another was followed by a slow CME. We estimated the initial store of free magnetic energy in the two regions and show the resemblance of pre-eruptive situations. The difference of late behaviour of the two eruptive prominences is a consequence of the different structure of magnetic field above the filaments. We estimated this structure on the basis of potential magnetic field calculations. Analysis of other eight events confirmed that all fast CMEs originate in regions with rapidly changing with height value and direction of coronal magnetic field.

scholarly journals THE MAGNETIC ENERGY-HELICITY DIAGRAM OF SOLAR ACTIVE REGIONS

2012 ◽  
Vol 759 (1) ◽  
pp. L4 ◽  
Author(s):  
Kostas Tziotziou ◽  
Manolis K. Georgoulis ◽  
Nour-Eddine Raouafi
Keyword(s):  
Magnetic Energy ◽  
Active Regions ◽  
Solar Active Regions

scholarly journals MAGNETIC ENERGY SPECTRA IN SOLAR ACTIVE REGIONS

2010 ◽  
Vol 720 (1) ◽  
pp. 717-722 ◽  
Author(s):  
Valentyna Abramenko ◽  
Vasyl Yurchyshyn
Keyword(s):  
Magnetic Energy ◽  
Active Regions ◽  
Energy Spectra ◽  
Solar Active Regions
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