Non-linear propagation of kink waves to the solar chromosphere

TL;DR

This study investigates how kink waves propagate non-linearly from the photosphere to the chromosphere in small magnetic elements, revealing upward wave propagation with significant energy transfer in the solar atmosphere.

Contribution

It provides observational evidence of non-linear kink wave propagation in the solar atmosphere and quantifies energy transfer from the photosphere to the chromosphere.

Findings

Upward propagation of kink waves observed above 2.6 mHz.

Non-linear propagation signatures detected.

No evidence of energy dissipation at analyzed heights.

Abstract

Small-scale magnetic field concentrations (magnetic elements) in the quiet Sun are believed to contribute to the energy budget of the upper layers of the Sun's atmosphere, as they are observed to support a large number of MHD modes. In recent years, kink waves in magnetic elements were observed at different heights in the solar atmosphere, from the photosphere to the corona. However, the propagation of these waves has not been fully evaluated. Our aim is to investigate the propagation of kink waves in small magnetic elements in the solar atmosphere. We analysed spectropolarimetric data of high-quality and long duration of a photospheric quiet Sun region observed near the disk center with the spectropolarimeter CRISP at the Swedish Solar Telescope (SST), and complemented by simultaneous and co-spatial broad-band chromospheric observations of the same region. Our findings reveal a clear upward propagation of kink waves with frequency above $~2.6$ mHz. Moreover, the signature of a non-linear propagation process is also observed. By comparing photospheric to chromospheric power spectra, no signature of an energy dissipation is found at least at the atmospheric heights at which the data analysed originate. This implies that most of the energy carried by the kink waves (within the frequency range under study $< 17$ mHz) flows to upper layers in the Sun's atmosphere.