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

V. I. Abramenko, Tongjiang Wang, V. B. Yurchishin

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29 Scopus citations


Using vector magnetograms of 40 active regions (ARs) of the maximum of solar cycle 22, we calculated the imbalance ρh (over the AR area) of the current helicity hc ≡ Bz(▽ × B)z in the photosphere. In 82.5% of the cases the predominant current helicity was negative (ρh < 0) in the northern hemisphere and positive (ρh > 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.

Original languageEnglish (US)
Pages (from-to)291-296
Number of pages6
JournalSolar Physics
Issue number1-2
StatePublished - 1997
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


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