Solar Coronal Brightness Changes and Mass Ejections during Solar Cycle 22

Abstract
Observations of the brightness of the outer solar corona from the Solar Maximum Mission (SMM) coronagraph during solar cycle 22 (1980, then 1984-1989) are compared with the occurrence rate and the mass of coronal mass ejections (CMEs) observed during this period. We find that the brightness and, hence, mass of the outer corona increased by more than a factor of 4 from solar minimum (1986) to late 1989, when the SMM ceased operation. The peak brightness (mass) in 1989 was roughly equivalent to that observed in the latter part of 1980. Accompanying a sharp increase in brightness (mass) of the corona in early 1989 was a concomitant increase in both the occurrence rate and the average mass of CMEs.