An objective technique based on two measured parameters has been developed to determine the probability of occurrence of a solar flare near a sunspot group. The parameters utilized were the size of each sunspot group and the magnitude of an associated radio brightness temperature. Flare, sunspot, and radio data measured daily during the period from April 1962 through October 1966 were used in the study. These data were associated objectively and analyzed statistically. The size of a sunspot group is a significant predictor in itself. This analysis shows that consideration of radio brightness temperature significantly improves the accuracy of solar flare prediction beyond the accuracy that can be achieved by considering only the size of the sunspot group. (Author).

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A flare event list that is consistent with flare patrol times is prerequisite to a reliable, unbiased estimate of flare occurrence per unit patrol time. A comparison of the flare occurrence times and flare patrol times reported by 52 solar observatories during the period of 1955 to 1964 discloses that 12.3 percent of the flare reports (Importance = or > 1) have no reported patrol coverage. Elimination of these 'unpatrolled' flare reports reduces the number of individual flare events in the data sample by 9.7 percent. This means that flare occurrence per unit patrol time computed from the raw flare and flare patrol data is overestimated by this same percentage. In addition to eliminating 'unpatrolled' flare reports, appropriate adjustments are made in the 'patrolled' flare data so as to make each observatory's reported flare times completely consistent with its reported patrol times.

The solar radio sweep-frequency observations and hours of patrol from five rad radio observatories for the period 1955 through 1964 have been compiled, edited, and put onto two magnetic tapes. One tape contains the hours of radio patrol from the observatories at Ann Arbor, Bigpine, Boulder, Sydney and Fort Davis. Another tape contains the sweep-frequency observations in the meter and dekameter wavelengths of the radio spectrum from these observatories. The sources, methods of reduction, and the format and content of the data on tape are described. Statistics related to various distributions of the radio spectral activity reported by each station are discussed and demonstrate an urgent need for standard policies in detecting, scaling, classifying, and reporting these data.

A computer program has been developed which processes and groups individual observations of solar flares which describe the same feature. From each group of observations a consolidated description of the flare 'event' is produced. The report details the methods by which these groups are formed and the subsequent consolidated descriptions achieved. (Author).