Geomagnetic Storms on Earth

At one time, it was thought that flares were responsible for the sudden bursts in the solar wind responsible for geomagnetic storms and auroras on the Earth. It is now thought that these bursts are due more to violent events higher in the corona (coronal mass ejections), which will be discussed when we consider the corona. The issue is clouded by the fact that coronal mass ejections may occur over regions that also exhibit flare or eruptive prominence activity.