LATITUDINAL DISTRIBUTION OF PHOTOSPHERIC CURRENT HELICITY AND SOLAR ACTIVITIES

In this paper, we analyze the latitudinal distribution of the photosph eric current helicity for 422 active regions, including most of the la rge ones observed in the last ten years. Observations show that most a ctive regions in the northern hemisphere have negative helicities and in the southern hemisphere have positive ones. The negative maximum va lues of current helicity occurred in 1989 and 1991, while these positi ve around 1992. It is evident that the observational current helicity of active regions is normally brought up by emerging magnetic flux fro m the subatmosphere and probably acted by the moving mass. The result observed shows that less than 20 % of active regions have the sign opp osite to that of most ones in the same hemisphere. These reversed sign regions of the current helicity are obviously related to abnormal dis tribution of the vector magnetic field in the active regions, due to e mergence of new magnetic flux of opposite polarities.