THE NORTH-SOUTH ASYMMETRY OF SOFT X-RAY SOLAR FLARES

We analyse the North-South (N-S) asymmetry of soft X-ray (SXR) solar flares during the 11-year solar cycle (SC). After reviewing the literature on flare dominance in the northern and southern hemispheres of the solar disk for SCs 17-23, we analyse the SXR flare distribution in the two hemispheres during the period 1976- 2001. The analysis was made using the number of flares (N) and the Qx index, which evaluates the energy emitted by flares in soft X-ray. The monthly and annual N-S asymmetry values computed by us for the mentioned period are in agreement with the results from the literature. The degree of the N-S asymmetry for both N and Qx indices confirmed the antiphase of SXR flare emergence for spectral classes M and X, and class C, respectively, noted by Maris et al. (2000). Finally, we consider that the detailed study of the descending and minimum phases of the SCs, at the stage when magnetic phenomena from both the old and the new cycle interact in the solar atmosphere, would be useful for inferring information about the activity level of the next cycle.