Large-scale Waves and Shocks in the Solar Corona

Abstract

Large-scale waves and shocks in the solar corona are reviewed. The emphasis is on globally propagating wave-like disturbances that are observed in the low corona which have become known as ‘‘coronal transient waves’’ or ‘‘coronal Moreton waves’’. These phenomena have recently come back into focus prompted by the observation of wave-like perturbations in several spectral ranges, particularly in the extreme ultraviolet (with the SOHO/EIT instrument). The different observational signatures of coronal waves are discussed with the aim of providing a coherent physical explanation of the phenomena. In addition to imaging observations, radiospectral data are considered in order to point out the relation between coronal waves and metric type II radio bursts. Briefly, potential generation mechanisms of coronal waves are examined. Finally, the relevance of coronal waves to other areas of solar physics is reviewed.