Heating of coronal holes by the resonant absorption and dissipation of Alfven waves

Journal Article · Sat Jul 20 04:00:00 EDT 1996 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.51375· OSTI ID:21163467

Ofman, L; Davila, J M ^[1]

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1. Laboratory for Astronomy and Solar Physics, NASA-Goddard Space Flight Center, Greenbelt, Maryland (United States)

Coronal hole regions are well known sources of high-speed solar wind, however to account for the observed properties of the solar wind a source of energy must be included in addition to heat conduction. Alfven waves were suggested as the possible source of heating that accelerates the solar wind. We investigate the heating and propagation of Alfven waves in coronal holes via 2-D MHD simulation in slab geometry. Resonance heating layers are found to occur when shear Alfven waves are driven at the coronal boundary and a continuous density profile is assumed for the coronal hole. The heating is enhanced by phase mixing when coronal hole inhomogeneities (i.e., plumes) are included. We investigate the dependence of the heating rate on the driver frequency and the Lundquist number S and find a good agreement with the analytical S{sup 1/3} scaling of the dissipation length for uniform background magnetic field. We find that when S=10{sup 4} the low frequency Alfven waves can be a significant source of heating of coronal holes at several solar radii. At larger values of S nonlinear effects may reduce the effective dissipation length. We also find that the radial dependence of the heating rate has the same form as the observed scale height temperature radial profiles observed by SPARTAN 201-01.

• OSTI ID: 21163467
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 382; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
ABSORPTION
ALFVEN WAVES
ASTROPHYSICS
HEAT LOSSES
HEATING RATE
MAGNETIC FIELDS
MAGNETOHYDRODYNAMICS
NONLINEAR PROBLEMS
PLASMA DENSITY
PLASMA SIMULATION
SCALE HEIGHT
SHEAR
SOLAR CORONA
SOLAR WIND
THERMAL CONDUCTION
TWO-DIMENSIONAL CALCULATIONS
VELOCITY
WAVE PROPAGATION