Coronal Heating by Means of Helical Magnetohydrodynamic Turbulence.
Abstract
Numerical simulations are used to investigate the relaxation of an unconfined, helically turbulent, fully three-dimensional magnetofluid, with conditions similar to those which are thought to result in the heating of the solar corona. In these simulations, the system evolves through a succession of force free states. After a relatively quiescent period of Ohmic decay, a phase of accelerated magnetic energy dissipation occurs. Some magnetic energy is transformed into kinetic energy, and the magnitude of entrophy created is a nontrival fraction of the mean square electric current. Concentrated vorticity structures are seen to play almost as important a role as electric current sheets in the heating process. Coincident with this accelerated dissipation process , a reorganization of the magnetic fields occurs, with transfer of magnetic energy to both shorter and longer wavelength modes than are initially present. The ratio of the magnetic field to the electric current density, alpha does not in general tend to assume a constant value in the force free regions during the evolution of the magnetofluid. Keywords: Coronal heating; Helical magnetohydrodynamic Turbulence; Direct numerical simulation.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 17, 1987
- Accession Number
- ADA187084
Entities
People
- J. P. Dahlburg
- J. T. Mariska
- R. B. Dahlburg
Organizations
- United States Naval Research Laboratory