ON THE ASYMMETRICAL EFFECT OF FLARE POSITION UPON GEOMAGNETIC ACTIVETY
ZHANG GONG-LIANG(Institute of Geophysics and Meteorology, Academia Sinica)
Flares of importance≥Ⅱ~+ are grouped according to their heliographic position and magnetic class of the active regions. By means of superposed-epoch method, we have calculated the mean daily frequency of Kp≥6 under different conditions. It is found that, for the magnetic group βγ+γ+β_f solar flares in northern hemisphere produce stronger corpulscular effect than those in southern hemisphere, but for the flares in β_p+β regions no such hemispheric asymmetry is found. Also, in southern hemisphere the western flares have stronger effect than the central and eastern ones, but in northern hemisphere only those flares in β_p+β regions have this E—W asymmetry. Those asymmetrical relations appear in all of the last three solar cycles, and it is especially conspicuous during equinoxes.