Evolution of Magnetic Helicity in Magnetic Reconnection
Abstract
This paper presents a definition of magnetic helicity specifically for two-dimensional magnetic fields and derives the associated helicity equation. The newly defined helicity is closely related to its three-dimensional counterpart and serves as a measure of the shear of magnetic field. Based on this, a numerical simulation is carried out on magnetic reconnection occurring in the lower solar atmosphere. It is found that the helicity dissipation due to magnetic reconnection is very small. A large amount of helicity is transferred upward and escapes from the domain of the solution, and the total helicity is approximately conserved during the magnetic reconnection and helicity transfer. This is in support of the applicability of a postulate, which was proposed by Taylor (1974, 1986) concerning the approximate conservation of magnetic helicity in the presence of resistive dissipation and magnetic reconnection in a highly conductive laboratory plasma, to the solar atmosphere.
- Publication:
-
Solar Physics
- Pub Date:
- February 1997
- DOI:
- 10.1023/A:1004905230866
- Bibcode:
- 1997SoPh..170..283H
- Keywords:
-
- Atmosphere;
- Magnetic Field;
- Magnetic Reconnection;
- Solar Atmosphere;
- Magnetic Helicity