Coronal Magnetic Fields Produced by Photospheric Shear,
Abstract
The magneto-frictional method for computing force-free fields examines the evolution of the magnetic field of a line dipole, when there is relative shearing motion between the two polarities. The energy of the sheared field can be arbitrarily large compared with the potential field. It is possible to fit the magnetic energy, as a function of shear amplitude, by a simple functional form. The fit parameters depend only on the distribution of normal field in the photosphere and the form of the shearing displacement. The energy is relatively more enhanced if the shear occurs: (1) where the normal field is strongest; (2) in the inner region of the dipole, near the axis; or (3) over a large fraction of the dipole area.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1988
- Accession Number
- ADA194591
Entities
People
- J. A. Klimchuk
- Peter A. Sturrock
- W. -h. Yang
Organizations
- Stanford University