Bremen 2017 – wissenschaftliches Programm
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EP: Fachverband Extraterrestrische Physik
EP 4: Sonne und Heliosphäre I
EP 4.5: Vortrag
Dienstag, 14. März 2017, 15:15–15:30, GW2 B2880
Current filamentation induced by 3D plasma flows in the solar corona — •Dieter Nickeler1, Thomas Wiegelmann2, Marian Karlicky1, and Michaela Kraus1,3 — 1Astronomical Institute AVCR, Ondrejov, Czech Republic — 2Max-Planck Institut fuer Sonnensystemforschung, Goettingen, Deutschland — 3Tartu Observatory, Toravere, Estonia
Many magnetic structures in the solar atmosphere evolve rather slowly so that they can be assumed as (quasi-)static or (quasi-)steady and represented via magneto-hydrostatic (MHS) or magneto-hydrodynamic (MHD) equilibria, respectively. While exact 3D solutions would be desired, they are extremely difficult to find in steady MHD. We construct solutions with magnetic and flow vector fields that have three components depending on all three coordinates. We show that the non-canonical transformation method produces quasi-3D solutions of steady MHD by mapping 2D or 2.5D MHS equilibria to strongly related steady-MHD states. These steady-MHD states exist on magnetic flux surfaces of the original 2D MHS-states. Although the flux surfaces and therefore also the equilibria have a 2D character, these steady MHD-states depend on all three coordinates and display highly complex currents. The existence of geometrically complex 3D currents within symmetric field-line structures provide the base for efficient dissipation of the magnetic energy in the solar corona by Ohmic heating. We also discuss the possibility of achieving force-free fields, and find that they only arise under severe restrictions of the field-line geometry and of the magnetic flux density distribution.