Solar Flares 2012:
What is a coronal mass ejection?
A coronal mass ejection (CME) is a massive burst of solar
wind, other light isotope plasma, and magnetic fields rising above the solar
corona or being released into space.
Coronal mass ejections are often associated with other forms of solar activity, most notably solar flares, but a causal relationship has not been established. Most ejections originate from active regions on Sun's surface, such as groupings of sunspots associated with frequent flares. Near solar maxima the Sun produces about three CMEs every day, whereas near solar minima there is about one CME every five days.