The Effect of Shear on Numerical Models of Quiescent Normal Polarity Prominences
Abstract
The equilibrium structure of normal-polarity, quiescent prominences is investigated and the influence of magnetic shear in response to a slow, shearing, photospheric velocity discussed. The results show that the overall field structure predicted by Fiedler and Hood (1992) is largely unaffected but that magnetic shear reduces the plasma beta and lengthens and flattens the magnetic field when viewed from the side. The flatness of the field suggests that the initial condensation can form and, when the mass is sufficient, deform the field slightly into the equilibrium structure calculated here. Thus, it is postulated that the field must be highly sheared for the radiation (or condensation) time to be less than the free-fall time along the field. A simple estimate predicts that the field must lie close to the polarity inversion line with an angle in agreement with observations. Hence, it is apparent that normal polarity prominences will always be observed with a highly sheared field.
- Publication:
-
Solar Physics
- Pub Date:
- August 1993
- DOI:
- 10.1007/BF00662015
- Bibcode:
- 1993SoPh..146..297F
- Keywords:
-
- Magnetic Field Configurations;
- Mathematical Models;
- Polarity;
- Solar Magnetic Field;
- Solar Prominences;
- Dense Plasmas;
- Line Of Sight;
- Solar Corona;
- Solar Physics;
- Radiation;
- Magnetic Field;
- Numerical Model;
- Field Component;
- Simple Estimate