Interpretation of the power spectrum of the quiet Sun photospheric turbulence

TL;DR

This paper interprets the observed power spectrum of quiet Sun photospheric turbulence, revealing a transition in spectral indices and estimating the turbulent layer depth as comparable to the photosphere's depth.

Contribution

It provides a novel interpretation of the power spectrum transition and estimates the turbulent layer width from observational data.

Findings

Power spectrum transitions from -1.2 to -2.2 index at smaller scales

Effective turbulent layer width is approximately equal to the photosphere depth

Interpretation links spectral change to physical properties of the turbulent layer

Abstract

Observational power spectra of the photospheric magnetic field turbulence, of the quiet-sun, were presented in a recent paper by Abramenko and Yurchyshyn. Here I focus on the power spectrum derived from the observations of the Near InfraRed Imaging Spectrapolarimeter (NIRIS) operating at the Goode Solar Telescope. The latter exhibits a transition from a power law with index $-1.2$ to a steeper power law with index $-2.2$, for smaller spatial scales. The present paper presents an interpretation of this change. Furthermore, this interpretation provides an estimate for the effective width of the turbulent layer probed by the observations. The latter turns out to be practically equal to the depth of the photosphere.