The LDE Flares in the 20th Solar Cycle 1. Comparison of the Time Behaviour of H-alpha Grouped and LDE Flares
Abstract
The numerical series of H-alpha and LDE flares are tested and compared for the years 1969-1976, using methods of statistical analysis. The results show that the occurrence of H-alpha flares can be expressed by an exponential function. The analytical expression of the LDE (M - X) flare occurrence (their SXR duration exceeds 2 hours) is a parabola or a set of spline functions. Time intervals with increased flare activities were observed in the years 1970, 1972 and 1974, whereas decreased flare activity was found in 1971 and 1975.
- Publication:
-
Bulletin of the Astronomical Institutes of Czechoslovakia
- Pub Date:
- June 1991
- Bibcode:
- 1991BAICz..42..133A
- Keywords:
-
- Solar Cycles;
- Solar Flares;
- Solar X-Rays;
- H Alpha Line;
- Solar Magnetic Field;
- Time Series Analysis;
- Solar Physics