Observational evidence for buffeting induced kink waves in solar magnetic elements

Abstract

The role of diffuse photospheric magnetic elements in the energy budget of the upper layers of the Sun's atmosphere has been the recent subject of many studies. This was made possible by the availability of high temporal and spatial resolution observations of the solar photosphere, allowing large numbers of magnetic elements to be tracked to study their dynamics. In this work we exploit a long temporal series of seeing-free magnetograms of the solar photosphere to study the effect of the turbulent convection in the excitation of kink oscillations in magnetic elements. We make use of the empirical mode decomposition technique (EMD) in order to study the transverse oscillations of several magnetic flux tubes. This technique permits the analysis of non-stationary time series like those associated to the horizontal velocities of these flux tubes which are continuously advected and dispersed by granular flows. Our primary findings reveal the excitation of low frequency modes of kink oscillations, which are sub-harmonics of a fundamental mode with a $7.6\pm 0.2$ minute periodicity. These results constitute a strong case for observational proof of the excitation of kink waves by the buffeting of the convection cells in the solar photosphere, and are discussed in light of their possible role in the energy budget of the upper Sun's atmosphere.

A&A accepted

References in corpus (9)

• The Solar Optical Telescope for the Hinode Mission: An Overview
• Alfven Waves in the Lower Solar Atmosphere
• Solar Magnetic Tracking. I. Software Comparison and Recommended Practices
• Channeling 5-min photospheric oscillations into the solar outer atmosphere through small-scale vertical magnetic flux tubes
• Non-linear numerical simulations of magneto-acoustic wave propagation in small-scale flux tubes
• Dynamics of the Solar Magnetic Network. II. Heating the Magnetized Chromosphere
• Dynamics of the solar magnetic bright points derived from their horizontal motions
• Structure and Dynamics of Isolated Internetwork Ca II H Bright Points Observed by Sunrise
• Diffusion of magnetic elements in a supergranular cell

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• The small-scale structure of photospheric convection retrieved by a deconvolution technique applied to Hinode/SP data
• Analysis of Pseudo-Lyapunov Exponents of Solar Convection Using State-of-the-Art Observations
• The Sun at millimeter wavelengths IV. Magnetohydrodynamic waves in small-scale bright features