On the Origin of Differences in Helicity Parameters Derived from Data of Two Solar Magnetographs

	On the Origin of Differences in Helicity Parameters Derived from Data of Two Solar Magnetographs
	Xu, Haiqing1 ; Zhang, Hongqi1 ; Kuzanyan, K.1,2,3; Sakurai, T.3,4
刊名	SOLAR PHYSICS
	2016-10-01
卷号	291 期号:8 页码:2253-2267
关键词	Active regions Dynamo mechanism Helicity Magnetic fields
英文摘要	We analyzed how sensitivity and accuracy in solar magnetic field measurements may affect the values of mean current helicity density and twist parameter by comparing these values obtained from two magnetographs (SMFT at Beijing and SFT at Mitaka, Tokyo). When we computed the helicity parameters from the SFT data, we replaced the values of the longitudinal field component, transverse field strength, and transverse field azimuth angle with those from the SMFT data and examined the differences. The results show that the correlation coefficient and the fraction of the data that agree in signs of or increase when an SFT parameter is substituted by the corresponding SMFT parameter because one source of discrepancy is removed. The increase in correlation coefficient is largest when the azimuthal angles and transverse field strengths are set identical in the two instruments; the correlation coefficient of () increases from 0.74 (0.56) to 0.86 (0.78), respectively, indicating that the differences in the transverse field strength and its azimuthal angle are the largest source of discrepancy in the values of or . We found a nonlinear relationship in the components of the magnetic field between the two instruments for some data samples; we conclude that this is due to the discrepancy in the calibration procedure between the two instruments. This nonlinearity can be another source of difference in determining helical parameters between the two instruments.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	VECTOR MAGNETIC-FIELDS ; ELECTRIC-CURRENT HELICITY ; ACTIVE REGIONS ; CYCLE VARIATION ; RULE ; HUAIROU ; MITAKA
收录类别	SCI
语种	英语
WOS记录号	WOS:000385207200004
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/6866]
专题	国家天文台_太阳物理研究部
作者单位	1.Chinese Acad Sci, Key Lab Solar Act, Natl Astron Observ, Beijing 100012, Peoples R China 2.IZMIRAN, Troitsk 142190, Moscow Region, Russia 3.Natl Astron Observ Japan, Mitaka, Tokyo 1818588, Japan 4.Grad Univ Adv Studies, Dept Astron Sci, Mitaka, Tokyo 1818588, Japan
推荐引用方式 GB/T 7714	Xu, Haiqing,Zhang, Hongqi,Kuzanyan, K.,et al. On the Origin of Differences in Helicity Parameters Derived from Data of Two Solar Magnetographs[J]. SOLAR PHYSICS,2016,291(8):2253-2267.
APA	Xu, Haiqing,Zhang, Hongqi,Kuzanyan, K.,&Sakurai, T..(2016).On the Origin of Differences in Helicity Parameters Derived from Data of Two Solar Magnetographs.SOLAR PHYSICS,291(8),2253-2267.
MLA	Xu, Haiqing,et al."On the Origin of Differences in Helicity Parameters Derived from Data of Two Solar Magnetographs".SOLAR PHYSICS 291.8(2016):2253-2267.