2017/12/21 by Yu Gao, Gao, Yu
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Astro and Planetary Science #FOS: Physical sciences #Geomagnetism and Paleomagnetism Studies #Solar and Space Plasma Dynamics #Solar and Stellar Astrophysics (astro-ph.SR)
paper · pdf · doi:10.48550/arxiv.1712.07833
openalex publication_date 2017/12/21 · openalex created_date 2018/01/05 · openalex updated_date 2026/07/28
An alternative parameter RJz is introduced as the ratio of one of two kinds of opposite-sign current to the total current and investigate the relationship between the quantity and the hemispheric sign rule of helicity (HSR) that is established by a series of previous statistical studies. The classification of current in each hemisphere is according to the following rule: If the product of the current and the corresponding longitudinal field component contributes a consistent sign with reference to the HSR, it is called "HSR-compliant" current, or else it is called "HSR-noncompliant" current. Firstly, the consistence between the butterfly diagram of the RJz and the current helicity was obtained in a statistical study. Active regions with RJz smaller than 0.5 tend to obey the HSR whereas those with RJz greater than 0.5 tend to disobey the HSR. The "HSR-compliant" current systems have 60% probability of realization compared to 40% of "HSR-noncompliant" current systems. Overall, the HSR is violated for active regions in which the "HSR-noncompliant" current is greater than the "HSR-compliant" current. Secondly, the RJz parameter was subsequently used to study the evolution of current systems in the case analyses of flare-productive active regions NOAA AR 11158 and 11283. It is found that there were "RJz-quasi-stationary" phase that is relatively flare quiescent and "RJz-dynamic" phase that is covered by the occurrence of large flares.