On Current Sheet Approximations in Models of Eruptive Flares
Abstract
We consider an approximation sometimes used for current sheets in flux-rope models of eruptive flares. This approximation is based on a linear expansion of the background field in the vicinity of the current sheet, and it is valid when the length of the current sheet is small compared to the scale length of the coronal magnetic field. However, we find that flux-rope models which use this approximation predict the occurrence of an eruption due to a loss of ideal-MHD equilibrium even when the corresponding exact solution shows that no such eruption occurs. Determination of whether a loss of equilibrium exists can only be obtained by including higher order terms in the expansion of the field or by using the exact solution.
- Publication:
-
Solar Physics
- Pub Date:
- January 1994
- DOI:
- 10.1007/BF00645190
- Bibcode:
- 1994SoPh..149..205B
- Keywords:
-
- Approximation;
- Current Sheets;
- Magnetohydrodynamics;
- Solar Corona;
- Solar Flares;
- Solar Prominences;
- Stellar Models;
- Equilibrium Equations;
- Expansion;
- Flux Density;
- Photosphere;
- Solar Magnetic Field;
- Solar Physics;
- Magnetic Field;
- Flare;
- Exact Solution;
- Order Term;
- Current Sheet