Resonantly Damped Propagating Kink Waves in Longitudinally Stratified Solar Waveguides

TL;DR

This paper investigates how longitudinal and transverse plasma inhomogeneity affect propagating kink waves in solar waveguides, enhancing understanding of wave damping and aiding solar atmospheric magnetoseismology.

Contribution

It is the first study to analyze propagating kink waves considering both longitudinal and transverse plasma inhomogeneity effects.

Findings

Wavelength depends only on longitudinal stratification.

Amplitude is a product of longitudinal and transverse effects.

Results facilitate plasma inhomogeneity scale determination in the solar atmosphere.

Abstract

It has been shown that resonant absorption is a robust physical mechanism to explain the observed damping of magnetohydrodynamic (MHD) kink waves in the solar atmosphere due to naturally occurring plasma inhomogeneity in the direction transverse to the direction of the magnetic field. Theoretical studies of this damping mechanism were greatly inspired by the first observations of post-flare standing kink modes in coronal loops using the Transition Region And Coronal Explorer (TRACE). More recently, these studies have been extended to explain the attenuation of propagating coronal kink waves observed by the Coronal Multi-Channel Polarimeter (CoMP). In the present study, for the first time we investigate the properties of propagating kink waves in solar waveguides including the effects of both longitudinal and transverse plasma inhomogeneity. Importantly, it is found that the wavelength is only dependent on the longitudinal stratification and the amplitude is simply a product of the two effects. In light of these results the advancement of solar atmospheric magnetoseismology by exploiting high spatial/temporal resolution observations of propagating kink waves in magnetic waveguides to determine the length scales of the plasma inhomogeneity along and transverse to the direction of the magnetic field is discussed.