The effect of the environment on the P1/P2 period ratio for kink oscillations of coronal loops

TL;DR

This paper investigates how environmental temperature differences affect the P1/P2 period ratio in kink oscillations of coronal loops, enhancing plasma diagnostic techniques in solar physics.

Contribution

It extends existing models by analyzing environmental temperature effects on the P1/P2 ratio using a variational principle, providing new insights for plasma diagnostics.

Findings

Temperature differences influence the P1/P2 ratio significantly.

Results improve the accuracy of coronal loop diagnostics.

Method applicable to various magnetic structures.

Abstract

The P1/P2 period ratio of transversal loop oscillations is currently used for the diagnostics of longitudinal structuring of coronal loops as its deviation from 2 is intrinsically connected to the density scale-height along coronal loops and/or the sub-resolution structure of the magnetic field. The same technique can be applied not only to coronal structures, but also to other oscillating magnetic structures. The oscillations in magnetic structures are described by differential equations whose coefficients depend on the longitudinal structure of the plasma. Using a variational principle written for the transversal component of the velocity vector, developed earlier by McEwan et al. (2008), we investigate how the different temperature of the environment compared to the temperature of the magnetic structure will influence the P1/P2 ratio for typical coronal and prominence conditions. The possible changes are translated into quantities that are used in the process of remote plasma diagnostics in the solar atmosphere.