Fragmentation of electric currents in the solar corona by plasma flows

0399164 - ASÚ 2014 RIV FR eng J - Journal Article
Nickeler, Dieter Horst - Karlický, Marian - Wiegelmann, T. - Kraus, Michaela
Fragmentation of electric currents in the solar corona by plasma flows.
Astronomy & Astrophysics. Roč. 556, August (2013), A61/1-A61/12. ISSN 0004-6361. E-ISSN 1432-0746
R&D Projects: GA ČR GAP209/12/0103; GA ČR GA13-24782S
Institutional support: RVO:67985815
Keywords : magnetohydrodynamics * Sun flares * Sun corona
Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics
Impact factor: 4.479, year: 2013

We consider a magnetic configuration consisting of an arcade structure and a detached plasmoid, resulting from a magnetic reconnection process, as is typically found in connection with solar flares. We study spontaneous current fragmentation caused by shear and vortex plasma flows. We find that current fragmentation takes place at different locations within our configuration. Steep gradients of the Alfven Mach number are required, implying the strong influence of shear flows on current amplification and filamentation of the magnetohydrostatic current sheets. Crescent-or ring-like structures appear along the outer separatrix, butterfly structures between the upper and lower plasmoids, and strong current peaks close the lower boundary (photosphere). Furthermore, impressing an intrinsic small-scale structure on the upper plasmoid results in strong fragmentation of the plasmoid. Hence fragmentation of current sheets and plasmoids is an inherent property of magnetohydrodynamic theory.
Permanent Link: http://hdl.handle.net/11104/0226550