On the 152-Day Periodicity of the Solar Flare Occurrence Rate,

Abstract

The occurrence rate of solar flares exhibits a periodicity of about 152 days. This periodicity was discovered from analyses of flares observed with the Solar Maximum Mission (SMM), and confirmed with flares observed by other observatories. This periodicity was also discovered from the flare rate of solar cycle 20 (1965-1975). The cause of the 152 day periodicity still remains a mystery. But answers to the following questions will enhance our understanding of it. (1) Is the periodicity a local or global phenomenon? (2) Is the periodicity due to interactions of hot spots rotating at different rates such that they aligh with one another once in every 152-day period? (3) Is the periodicity due to interactions of rotating features originating from g-mode oscillations? Analyzing major flares observed with the Hard X Ray Burst Spectrometer (HXRBS) aboard SMM concludes that the 152 day periodicity is a global phenomenon.

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1986
Accession Number
ADA176920

Entities

People

  • Peter A. Sturrock
  • Taeil Bai

Organizations

  • Stanford University

Tags

DTIC Thesaurus Topics

  • Cycles
  • Hard X Rays
  • Hot Spots
  • Observatories
  • Oscillation
  • Periodic Variations
  • Solar Cycle
  • Solar Flares
  • Spectrometers
  • X Rays

Readers

  • Solar Physics