A Decade of Coronagraphic and Spectroscopic Studies of CME-Driven Shocks

TL;DR

This paper reviews a decade of advances in imaging and analyzing CME-driven shocks using coronagraphic and spectroscopic methods, enhancing understanding of shock physics near the Sun.

Contribution

It highlights the integration of coronagraphic and spectroscopic observations as a novel approach to study CME-driven shocks.

Findings

Imaging of shocks from the low corona to Earth has improved understanding.

Spectroscopic methods provide detailed shock property measurements.

Joint observations are crucial for understanding shock physics near the Sun.

Abstract

Shocks driven by Coronal Mass Ejections (CMEs) are primary agents of space weather. They can accelerate particles to high energies and can compress the magnetosphere thus setting in motion geomagnetic storms. For many years, these shocks were studied only in-situ when they crossed over spacecraft or remotely through their radio emission spectra. Neither of these two methods provides information on the spatial structure of the shock nor on its relationship to its driver, the CME. In the last decade, we have been able to not only image shocks with coronagraphs but also measure their properties remotely through the use of spectroscopic and image analysis methods. Thanks to instrumentation on STEREO and SOHO we can now image shocks (and waves) from the low corona, through the inner heliosphere, to Earth. Here, we review the progress made in imaging and analyzing CME-driven shocks and show that joint coronagraphic and spectrscopic observations are our best means to understand shock physics close to the Sun.