Abstract
We report an instance of localized chromospheric polarity reversal in a rapidly-formed sunspot which appears to be part of new emerging flux. The chromospheric polarity reversal is preceded by extraordinarily fast growth of the transverse magnetic field and an increase in the line-of-sight magnetic flux of the newly formed sunspot in the photosphere. The strength of this reversal is more than 350 G at maximum, in contrast to approximately - 1300 G for the line-of-sight field and 400 G for the transverse field in the photosphere. Continued flare activity takes place around the site of the reversal with progressively increasing flare size and extent. It is suggested that a kinked or knotted flux loop, or a self-closed flux system developed above the fast-forming sunspot. So far, this phenomenon has been revealed in several active regions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ai, G.: 1989, presented at the STP Workshop, Sydney.
Ai, G. and Hu, Y.: 1986, Publ. Beijing Astron. Obs. 8, 1.
Chen, J., Ai, G., Zhang, H., and Jiang, S.: 1989, Publ. Yunnan Observatory, Special Issue 1, p. 108.
Tsap, T. T.: in R. Howard (ed.), ‘Solar Magnetic Fields’, IAU Symp. 43.
Zirin, H.: 1988, Astrophysics of the Sun, Cambridge University Press, Cambridge.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Jingxiu, W., Zhongxian, S. Flare-associated magnetic changes in an active region. Sol Phys 140, 67–84 (1992). https://doi.org/10.1007/BF00148430
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00148430