Time-Distance Seismology of the Solar Corona with CoMP

TL;DR

This paper uses CoMP Doppler imaging to perform time-distance seismology of the solar corona, revealing wave propagation characteristics and turbulence effects.

Contribution

It presents the first k-omega diagrams of the solar corona, enabling separation of wave directions and analysis of wave power and attenuation.

Findings

Outward and inward wave powers are distinguishable.

Low-frequency Alfvenic motions are significantly attenuated.

Wave power spectrum follows a power law indicating turbulence.

Abstract

We employ a sequence of Doppler images obtained with the Coronal Multi-channel Polarimeter (CoMP) instrument to perform time-distance seismology of the solar corona. We construct the first k-omega diagrams of the region. These allow us to separate outward and inward propagating waves and estimate the spatial variation of the plane-of-sky projected phase speed, and the relative amount of outward and inward directed wave power. The disparity between outward and inward wave power and the slope of the observed power law spectrum indicate that low-frequency Alfvenic motions suffer significant attenuation as they propagate, consistent with isotropic MHD turbulence.