Coronal mass ejection transients observed with the white light coronagraph on Skylab are found to be associated with several other forms of solar activity. There is a strong correlation between such mass ejection transients and chromospheric Ha activity, with three-quarters of the transients apparently ...... o/ originating m or near active regions. We infer that 4(1~ of transients are associated with flares, 30 ,o are associated with eruptive prominences solely (without flares), and more than 70~ are associated with eruptive prominences or filament disappearances (with or without flares). Nine of ten flares which displayed apparent mass ejections of Ha-emitting material from the flare site could be associated with coronal transients. Within each class of activity, the more energetic events are more likely to be associated with an observable mass ejection.

More than 30 instances of sudden mass ejections from the sun were observed with the white light coronagraph experiment aboard Skylab during the first 118 days of the mission. Typically, these ejections appear as large magnetic loops rooted at the sun, yet expanding outward through the solar corona at speeds of the order of 400 km s−1. The loops always appear to retain their magnetic connection to the sun. Eighteen of these ejections were associated with active and eruptive prominences and surges; only three ejections appear to have been flare initiated. Associations with ground‐detected metric wavelength type 2 and 4 radio bursts occur for about 30% of these events; however, ground‐detected type 2 and 4 radio bursts originating near the limb are almost invariably accompanied by coronagraph‐observed ejections. Pressure or MHD waves run out ahead of the transient material ejecta; at times these waves can be detected by their effects on nearby coronal structures. For one event, that of August 10, 1973, we make the following estimates: (1) mass content, 4 × 1015 grams; (2) mass flow rate, 1.1 × 1012 grams s−1; (3) energy content, 8.4 × 1030 ergs; and (4) energy flow rate, 7.7 × 1026 ergs s−1. Locally, this represents a significant mass and energy input to the solar wind; we suggest that the ejections are the coronal counterparts of nonrecurrent (including shocks) solar wind disturbances detected near the orbit of the earth.

The outward speeds of mass ejection events observed with the white light coronagraph experiment on Skylab varied over a range extending from less than 100kms -I to greater than 1200 km s -1. For all events the average speed within the field of view of the experiment (1.75 to 6 solar radii) was 470 km s -I. Typically, flare associated events (Importance 1 or greater) traveled faster (775 km s -j) than events associated with eruptive prominences (330 km s 1); no flare associated event had a speed less than 360 km s 1, and only one eruptive prominence associated event had a speed greater than 600 km s 1. Speeds versus height profiles for a limited number of events indicate that the leading edges of the ejecta move outward with constant or increasing speeds.Metric wavelength type II and IV radio bursts are associated only with events moving faster than' about 400kms t; all but two events moving faster than 500kms i produced either a type II or IV radio burst or both. This suggests that the characteristic speed with which MHD signals propagate in the lower (1.1 to 3 solar radii) corona, where metric wavelength bursts are generated, is about 400 to 500 km s -t. The fact that the fastest mass ejection events are almost always associated with flares and with metric wavelength type II and IV radio bursts explains why major shock wave disturbances in the solar wind at 1 AU are most often associated with these forms of solar activity rather than with eruptive prominences.