The MHD of Compact Structures in the Solar Corona

Michael A. Raadu

Royal Institute of Technology, Alfvén Laboratory, Division of Plasma Physics, SE-100 44 Stockholm, Sweden

Abstract : Simplified MHD Models for the equilibrium and motion of localised structures in the solar corona are considered. Attention is focussed on models for the support and dynamics of filaments and quiescent prominences. Mirror currents due to line tying in the photosphere can make an important contribution to the magnetic forces. Comparisons are made with work on the melon seed effect for a magnetised plasma blob (plasmoid). An important question is whether there is a net current through the structure (e.g. simple current filaments) or alternatively the currents are isolated (e.g. plasmoids). A filament, even with no net axial current, will be subject to a force, analogous to that for a plasmoid, in a nonuniform ambient external field.

Key Words : prominences, filaments, plasmoids, currents

Information : Contribution (May 31, 2002) to the Festschrift for Max Kuperus on the occasion of his retirement.
Published as an Alfvén Laboratory report (December 2002)
TRITA-ALP-2002-03 (ISRN KTH/ALP/R-02/3-SE)