History and Development of Coronal Mass Ejections as a Key Player in Solar Terrestrial Relationship

TL;DR

This paper reviews the history and development of coronal mass ejections (CMEs), highlighting their discovery, significance in space weather, and recent advances in understanding their role in solar-terrestrial interactions.

Contribution

It provides a comprehensive overview of CME research history, key discoveries, and the progress made since the launch of major solar observation missions.

Findings

CMEs are major drivers of space weather phenomena.

The understanding of CMEs has significantly advanced since 1995.

CMEs are now recognized as critical factors in geomagnetic storms.

Abstract

Coronal mass ejections (CMEs) are relatively a recently-discovered phenomenon, in 1971, some fifteen years into the Space Era. It took another two decades to realize that CMEs are the most important players in solar terrestrial relationship as the root cause of severe weather in Earth's space environment. CMEs are now counted among the major natural hazards because they cause large solar energetic particle (SEP) events and major geomagnetic storms, both of which pose danger to humans and their technology in space and ground. Geomagnetic storms discovered in the 1700s, solar flares discovered in the 1800s, and SEP events discovered in the1900s are all now found to be closely related to CMEs via various physical processes occurring at various locations in and around CMEs, when they interact with the ambient medium. This article identifies a number of key developments that preceded the discovery of white-light CMEs suggesting that CMEs were waiting to be discovered. The last two decades witnessed an explosion of CME research following the launch of the Solar and Heliospheric Observatory mission in 1995, resulting in the establishment of a full picture of CMEs.