Solar Flares and Associated 200 Mc/sec Radiation.

Abstract

view Abstract Citations (28) References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Solar Flares and Associated 200 Mc/sec Radiation. Dodson, Helen W. ; Hedeman, E. Ruth ; Owren, Leif Abstract Study of 200 Mc/sec solar radiation for the times of 194 flares indicates distinctive radio events associated with 78 per cent of the flares. The flare-associated distinctive events can be divided into ten descriptive types or categories: major burst, major burst with second part, minor burst, minor burst with econd part, micro burst, group of bursts, series of bursts, noise storm in progress, onset of noise storm, and rise in base level. In addition, there is the designation "null," or no distinctive event. Consideration of the time relationships between flares and 200 Mc/sec events suggests that two quite different types of phenomena may be represented in the flare-associated 200 Mc/sec radiation. The first or "early" phenomenon includes very sudden, relatively isolated, burstlike features which occur close to the time of start of the . The second or "late" phenomenon includes the more gradual rises in base level and onsets of noise storms. These usually start at or after the time of flare maximum. The "early" and "late" phenomena can occur in conjunction with each other, or either of the two can occur separately. The importance of the flare, position on the solar disk, and accompanying ionospheric disturbances are considered with respect to the form and energy excess of the flare-associated 200 Mc/sec events. The various aspects of the complex flare phenomenon, as observed photographically and visually, are discussed. An association is suggested between the high-velocity ejections observed at the onset of certain flares and the occurrence of a major burst at 200 Mc/sec. From the point of view of the parameters considered in this paper, the flares for which there were no distinctive events on the 200 Mc/sec records constitute a random sample from the entire set of 194 flares. Publication: The Astrophysical Journal Pub Date: September 1953 DOI: 10.1086/145740 Bibcode: 1953ApJ...118..169D full text sources ADS |