Accession Number:

ADA065261

Title:

Study of Geomagnetic Storms and Solar Flares in the Years of Increasing Solar Activity, Cycles 19 and 20 (1955-1957, 1965-1968),

Descriptive Note:

Corporate Author:

MCMATH-HULBERT OBSERVATORY PONTIAC MICH

Report Date:

1978-10-31

Pagination or Media Count:

39.0

Abstract:

Solar circumstances prior to the 245 geomagnetic storms with maximum values of 3-hourly K sub p greater than or equal to 5 in the years 1955-1957 and 1965-1968 have been evaluated. The years studied were those of increasing activity in solar cycles 19 and 20. To assist in this study, a Comprehensive Flare Index based on the flares H-alpha, ionizing, and radio frequency radiation has been used. Of the 245 storms in the seven years studied 62 were considered to be flare-associated, 30 were primarily sequential, and only 8 remained as problem cases. Most of the severe storms were associated with flares. Sequential storms were primarily of moderate severity. The most important flares tended to be associated with the most severe storms. Flare criteria that include ionizing and radio frequency emissions as well as optical data apparently assist in the recognition of flares associated with subsequent geomagnetic storms.

Subject Categories:

  • Astrophysics
  • Radiofrequency Wave Propagation

Distribution Statement:

APPROVED FOR PUBLIC RELEASE