Shear-Induced Inflation of Coronal Magnetic Fields
Abstract
Using numerical models of force-free magnetic fields, we have examined how the shearing of footpoints in arcade geometries leads to an inflation of the coronal magnetic field. For each of the shear profiles considered, all of the field lines become elevated compared with the potential field. This includes cases where the shear is concentrated well away from the arcade axis, such that Bz, the component of field parallel to the axis, increases outward to produce an inward Bz2/8 pi magnetic pressure gradient force. These results contrast with an earlier claim, shown to be incorrect, that field lines can sometimes become depressed as a result of shear. We conjecture that an inflation of the entire field will always result from the shearing of simple arcade configurations. These results have implications for prominence formation, the interplanetary magnetic flux, and possibly also coronal holes.
Document Details
- Document Type
- Technical Report
- Publication Date
- Aug 05, 1989
- Accession Number
- ADA216204
Entities
People
- James A. Klimchuk
Organizations
- Stanford University