The effect of a twisted magnetic field on the phase mixing of the kink magnetohydrodynamic waves in coronal loops

Abstract

There are observational evidences for the existence of twisted magnetic field in the solar corona. This inspires us to investigate the effect of a twisted magnetic field on the evolution of magnetohydrodynamic (MHD) kink waves in coronal loops. To this aim, we solve the incompressible linearized MHD equations in a magnetically twisted nonuniform coronal flux tube in the limit of long wavelengths. Our results show that a twisted magnetic field can enhance or diminish the rate of phase-mixing of the Alfvén continuum modes and the decay rate of the global kink oscillation depending on the twist model and the sign of the longitudinal ($k_z$) and azimuthal ($m$) wavenumbers. Also our results confirm that in the presence of a twisted magnetic field, when the sign of one of the two wavenumbers $m$ and $k_z$ is changed, the symmetry with respect to the propagation direction is broken. Even a small amount of twist can have an important impact on the process of energy cascade to small scales.

25 pages, 22 figures

References in corpus (5)

• Magnetohydrodynamic kink waves in nonuniform solar flux tubes: phase mixing and energy cascade to small scales
• Current driven rotating kink mode in a plasma column with a non-line-tied free end
• The effect of twisted magnetic field on the resonant absorption of MHD waves in coronal loops
• Resonant Absorption of Axisymmetric Modes in Twisted Magnetic Flux Tubes
• The effects of twisted magnetic field on coronal loops oscillations and dissipation

Cited by in corpus (2)

• Phase Mixing of Kink MHD Waves in the Solar Corona: Viscous Dissipation and Heating
• Resonant Absorption of Kink MHD Waves in Inclined and Asymmetric Coronal Loops