Manifestation of pulsation instability in solar radio emission preceding proton flares

✍ Scribed by M. M. Kobrin; A. I. Korshunov; S. I. Arbuzov; V. V. Pakhomov; V. M. Fridman; Yu. V. Tikhomirov

• Publisher: Springer
• Year: 1978
• Tongue: English
• Weight: 728 KB
• Volume: 56
• Category: Article
• ISSN: 0038-0938
• DOI: 10.1007/bf00152477

✦ Synopsis

The investigation of solar radio emission fluctuations at the wavelength ~t = 3 cm led to the discovery of a visible increase in pulsations with periods of about 30-120 min prior to proton flares. These pulsations were observed before all (seven) proton flares included in our cycle of observations from 1969 to 1974. The phenomenon was not found to occur before non-proton flares. The assumption is made that the observed pulsations are a manifestation of pre-flare instability in coronal structures. Estimations have been made for fluctuations of the gyro-resonance radiation from the regions above spots associated with the magnetic field variations when a groove instability of a coronal condensation is developed. They are in good agreement with the observational data. The discovered manifestation of the pre-flare instability in fluctuations of the solar radio emission open new ways to study the flare development and to predict geo-effective phenomena on the Sun.