OBSERVATIONAL EVIDENCE OF RESONANTLY DAMPED PROPAGATING KINK WAVES IN THE SOLAR CORONA

Abstract

In this Letter we establish clear evidence for the resonant absorption\ndamping mechanism by analyzing observational data from the novel Coronal\nMulti-Channel Polarimeter (CoMP). This instrument has established that in the\nsolar corona there are ubiquitous propagating low amplitude ($\\approx$1 km\ns$^{-1}$) Alfv\\'{e}nic waves with a wide range of frequencies. Realistically\ninterpreting these waves as the kink mode from magnetohydrodynamic (MHD) wave\ntheory, they should exhibit a frequency dependent damping length due to\nresonant absorption, governed by the TGV relation showing that transversal\nplasma inhomogeneity in coronal magnetic flux tubes causes them to act as\nnatural low-pass filters. It is found that observed frequency dependence on\ndamping length (up to about 8 mHz) can be explained by the kink wave\ninterpretation and furthermore, the spatially averaged equilibrium parameter\ndescribing the length scale of transverse plasma density inhomogeneity over a\nsystem of coronal loops is consistent with the range of values estimated from\nTRACE observations of standing kink modes.\n