Electric current helicity in 40 active regions in the maximum of solar cycle 22

Using vector magnetograms of 40 active regions (ARs) of the maximum of solar cycle 22, we calculated the imbalance ρ_h (over the AR area) of the current helicity h_c ≡ B_z(▽ × B)_z in the photosphere. In 82.5% of the cases the predominant current helicity was negative (ρ_h < 0) in the northern hemisphere and positive (ρ_h > 0) in the southern hemisphere. Thus, the predominance of counter-clockwise (clockwise) vortices in the northern (southern) hemisphere seems to be valid not only for unipolar spots with obvious vortex structure (Hale, 1927; Richardson, 1941; McIntosh, 1979; Ding, Hong, and Wang, 1987) but also for ARs of different types. The forces of rotation of the Sun (Coriolis force and/or differential rotation) seem to take effect in the twisting of various magnetic structures.