Solar Mass Emission

Russell A. Howard

U.S. Naval Research Laboratory, Washington, DC 20375, USA

With the advent of the orbiting white light coronagraph, observations of mass expulsions from the Sun were routinely observed. Initially these were large eruptions called Coronal Transients and later the term, Coronal Mass Ejections or CMEs became generally applied to these eruptions. With the much greater sensitivity of the LASCO experiment on SOHO, small scale eruptions were observed to be leaving the Sun almost continually. Both of these episodic processes contribute to the variability of the slow solar wind, ranging from 1012 grams of material up to 1017 grams. This variability has been observed by the SECCHI instruments on the STEREO mission. The mass emissions certainly arise from different mechanisms, but an outstanding question is to determine the mechanism, or mechanisms, for the initiation of CMEs. Examples of these observations will be shown.