Meridional Circulation and Global Solar Oscillations

TL;DR

This paper studies how large-scale meridional circulation affects solar p-modes using perturbation theory, revealing shifts in mode frequencies that could be observed.

Contribution

It applies quasi-degenerate perturbation theory to model the impact of meridional circulation on solar oscillation frequencies, providing new insights into solar dynamics.

Findings

Meridional circulation causes negative frequency shifts in solar p-mode multiplets.

The study derives observable signatures of meridional flow in solar oscillation data.

Potential effects on solar oscillation measurements are discussed.

Abstract

We investigate the influence of large-scale meridional circulation on solar p-modes by quasi-degenerate perturbation theory, as proposed by \cite{lavely92}. As an input flow we use various models of stationary meridional circulation obeying the continuity equation. This flow perturbs the eigenmodes of an equilibrium model of the Sun. We derive the signatures of the meridional circulation in the frequency multiplets of solar p-modes. In most cases the meridional circulation leads to negative average frequency shifts of the multiplets. Further possible observable effects are briefly discussed.