H-alpha flare associated microwave emissions
Abstract
The author has carried out a statistical association of 321 two-ribbon and 1564 non two-ribbon (normal) H-alpha flares which occurred during 1976 to 1980 with microwave bursts in the frequency range 3 - 35 GHz. Results obtained are as follows: (1) the two-ribbon (TR) flares show 1.5 to 3 times higher correlation as compared to normal (N) flares, indicating that TR flares are strong emitter of microwave emissions; (2) the TR flares show 2 to 4 times better association as compared to N flares with impulsive microwave bursts; (3) the higher correlation of TR flares with impulsive microwave bursts is perhaps due to their occurrence in complex magnetic configurations; (4) the strong and weak correlation of TR flares and N flares respectively, with impulsive microwave bursts at higher frequencies (10 - 35 GHz) indicates that the source of the TR flares is near the photosphere or the lower chromosphere (strong magnetic fields) and that of the normal flare is the upper chromosphere (weak magnetic fields).
- Publication:
-
Bulletin of the Astronomical Society of India
- Pub Date:
- September 1985
- Bibcode:
- 1985BASI...13..253J
- Keywords:
-
- H Alpha Line;
- Microwave Emission;
- Solar Flares;
- Solar Radio Bursts;
- Chromosphere;
- Solar Magnetic Field;
- Statistical Correlation;
- Solar Physics