A catastrophe mechanism for coronal mass ejections

• Published in: The Astrophysical journal Vol. 373; no. 1; pp. 294 - 301
• Main Authors: Forbes, T. G., Isenberg, P. A.
• Format: Journal Article
• Language: English
• Published: Legacy CDMS University of Chicago Press 20.05.1991
• Subjects: 640104 - Astrophysics & Cosmology- Solar Phenomena; Astronomy; ATMOSPHERES; CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; Corona. Coronal loops, streamers, and holes; CURRENTS; Earth, ocean, space; ELECTRIC CURRENTS; Exact sciences and technology; FLUID MECHANICS; HYDRODYNAMICS; MAGNETIC RECONNECTION; MAGNETOHYDRODYNAMICS; MASS TRANSFER; MECHANICS; PHOTOSPHERE; RADIATIONS; SOLAR ACTIVITY; SOLAR ATMOSPHERE; SOLAR CORONA; Solar Physics; SOLAR PROMINENCES; SOLAR RADIATION; Solar system; STELLAR ATMOSPHERES; STELLAR CORONAE; STELLAR RADIATION; Solar corona; MHD model; Current sheet; Filament; Stability; Coronal mass ejection; Particle emission; Digital simulation; Data table; Two dimensional model; Sun; Solar photosphere
• ISSN: 0004-637X; 1538-4357
• DOI: 10.1086/170051

The ideal-MHD equations are used to show that a coronal current filament can suddenly lose equilibrium if its magnetic energy exceeds a critical value. The loss of equilibrium in the configuration results from an imbalance between magnetic tension and compression, and this imbalance ejects the filament upwards. Near the critical value, the equilibrium configuration develops a vertical current sheet attached to the photosphere at the point directly below the filament. When equilibrium is lost, field lines anchored to the photosphere are stretched upwards, and the current sheet rapidly grows longer. Without reconnection in the current sheet, the filament travels only a short distance before reaching a new equilibrium, and the net magnetic energy released is less than 1 percent of the stored magnetic energy. However, with reconnection, the filament travels upwards indefinitely, and all of the stored energy is released.