On the Nature and Genesis of EUV Waves: A Synthesis of Observations from SOHO, STEREO, SDO, and Hinode

TL;DR

This paper reviews and synthesizes observations from multiple solar missions to clarify the nature of EUV waves, proposing they are driven by CME expansion, which reconciles wave and pseudo-wave interpretations.

Contribution

It provides a comprehensive synthesis of recent EUV wave observations, proposing a unified model that explains their dual wave and pseudo-wave characteristics.

Findings

EUV waves are driven by CME lateral expansion.

The observations reconcile wave and pseudo-wave interpretations.

Remaining open questions about EUV wave physics.

Abstract

A major, albeit serendipitous, discovery of the SOlar and Heliospheric Observatory mission was the observation by the Extreme Ultraviolet Telescope (EIT) of large-scale Extreme Ultraviolet (EUV) intensity fronts propagating over a significant fraction of the Sun's surface. These so-called EIT or EUV waves are associated with eruptive phenomena and have been studied intensely. However, their wave nature has been challenged by non-wave (or pseudo-wave) interpretations and the subject remains under debate. A string of recent solar missions has provided a wealth of detailed EUV observations of these waves bringing us closer to resolving their nature. With this review, we gather the current state-of-art knowledge in the field and synthesize it into a picture of an EUV wave driven by the lateral expansion of the CME. This picture can account for both wave and pseudo-wave interpretations of the observations, thus resolving the controversy over the nature of EUV waves to a large degree but not completely. We close with a discussion of several remaining open questions in the field of EUV waves research.