Effects in the Solarp‐Mode Power Spectrum from Scattering on a Turbulent Background Flow with Stochastic Wave Sources

Abstract

This work demonstrates how the scattered wave field, in combination with stochastic wave sources, influences the p-mode power spectrum. I adopt a zone with random fluctuations in sound speed and velocity (characterized by the respective correlation functions). I present a general formalism (for plane-parallel conditions) to calculate the expectation value of the p-mode power spectrum. The power due to the direct field from the sources dominates, and depends only on the source correlation function. Smaller, but significant, are due to scattered wave field components. These corrections depend in general on the correlation functions of the fluctuations in the medium. I adopt a simple waveguide for the purpose of clear demonstration, and show that the corrections generate three important effects: (1) the line profiles are shifted along the wavenumber (frequency) axis, with varying effects depending on which turbulent physical quantity we consider; (2) the shapes and widths of the line profiles are altered; and (3) the troughs between the line profiles are to some extent filled in, contributing to the solar background power. It is demonstrated that boundary zones can generate important contributions to the power spectrum.