Trajectories of Chromospheric Disk Surges

Abstract

As a result of the use of rapid sequence H-alpha cinematography, Lockheed Solar Observatory has collected a large quantity of data on disk surges during 1959 and 1960. Since January 1960, the band pass of the birefringent filter has been displaced 0.5 Å. to the blue or red of H-alpha. The increased contrast between active absorption features and the background in the wings of H-alpha has resulted in a greater ability to detect disk surges. The percentage of flares of all classes associated with observed surges increased from 11.4 per cent in 1959 to 20.4 per cent in 1960. Approximately 94 per cent of the total flares were sub-flares. During the two years, a total of 953 flare surge events were photographed at the Observatory.