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Title: A search for the 154 day periodicity in the occurrence rate of solar flares using Ottawa 2. 8 GHz burst data, 1955-1990

Journal Article · · Astrophysical Journal; (USA)
DOI:https://doi.org/10.1086/169831· OSTI ID:5701894
;  [1]
  1. Tufts Univ., Medford, MA (USA) USAF, Geophysics Laboratory, Hanscom AFB, MA (USA)

The Ottawa 2.8 GHz burst record from 1955 January to 1990 February has been examined for evidence of a periodicity near 154 days in the occurrence rate of solar flares. This periodicity is found to be statistically significant, at the 1-percent level, only for the years from 1978 to 1983, corresponding to the activity maximum of solar cycle 21. Through 1990 February, the Ottawa data show no evidence for a 154 day period in the current 22d solar cycle that began in 1986 September. A spectral peak near 51 days is found in solar cycle 19 (1955-1964), as had been previously reported based on an examination of CFI data, but its significance is low, at the 33-percent level. It is concluded that, other than for the period in cycle 21 in which it was first discovered, the evidence for the 154 day periodicity from flare-related data sets is contradictory and not compelling. Stronger evidence for the occurrence of the 154 day periodicity outside cycle 21 can be found in recent studies that examine parameters such as sunspot counts and areas that characterize solar active regions. 29 refs.

OSTI ID:
5701894
Journal Information:
Astrophysical Journal; (USA), Vol. 370; ISSN 0004-637X
Country of Publication:
United States
Language:
English