Statistical analysis of the X-ray flares (M >= 1) during the maximum period of solar cycle 22
Abstract
The data of the X-ray flare events of class M>= 1 during the interval of 1987 to 1992 corresponding to the maximum period of the 22nd solar cycle have been investigated to study the North-South (N-S) and West-East (W-E) asymmetries. During that period it has been shown the existence of a real N-S asymmetry. That confirms recent studies done by using other indicators, such as sunspot areas \cite[(Oliver & Ballester 1994)]{oliv94}. The E-W asymmetry during that period is not significant but a non uniform flare distribution in longitude has been evidenced. That result is also in good agreement with the work made by \cite[Joshi (1995)]{josh95} using Hα flares for the same time period. We have shown that the behaviour of the reverse tendency of Solar Cycle 21 to exhibit a predominance of the southern hemisphere in the N-S asymmetry compared to the previous Solar Cycles (19 and 20) is maintained for Solar Cycle 22. A long period cycle of the N-S asymmetry could be suspected.
- Publication:
-
Astronomy and Astrophysics Supplement Series
- Pub Date:
- July 1998
- DOI:
- 10.1051/aas:1998254
- Bibcode:
- 1998A&AS..131...99L
- Keywords:
-
- SUN: ACTIVITY;
- SUN: FLARES;
- SUN: X-RAYS