Temporal variation of hemispheric solar rotation

	Temporal variation of hemispheric solar rotation
	Xie JL(谢婧岚)1,2 ; Shi XJ(石祥军)1,2 ; Xu JC(徐景晨)1,2
刊名	RESEARCH IN ASTRONOMY AND ASTROPHYSICS
	2012-02
卷号	12 期号:2 页码:187-200
关键词	Sun: activity Sun: rotation Sun: sunspot
ISSN号	1674-4527
通讯作者	Xie, JL (reprint author), Chinese Acad Sci, Natl Astron Observ, Yunnan Observ, Kunming 650011, Peoples R China.
产权排序	第一完成单位
英文摘要	The daily sunspot numbers of the whole disk as well as the northern and southern hemispheres from 1945 January 1 to 2010 December 31 are used to investigate the temporal variation of rotational cycle length through the continuous wavelet transformation analysis method. Auto-correlation function analysis of daily hemispheric sunspot numbers shows that the southern hemisphere rotates faster than the northern hemisphere. The results obtained from the wavelet transformation analysis are that no direct relationship exists between the variation trend of the rotational cycle length and the solar activity in the two hemispheres and that the rotational cycle length of both hemispheres has no significant period appearing at 11 yr, but has a significant period of about 7.6 yr. Analysis concerning the solar cycle dependence of the rotational cycle length shows that acceleration seems to appear before the minimum time of solar activity in the whole disk and the northern hemisphere, respectively. Furthermore, the cross-correlation study indicates that the rotational cycle length of the two hemispheres has different phases, and that the rotational cycle length of the whole disk as well as the northern and southern hemispheres, also has phase shifts with corresponding solar activity. In addition, the temporal variation of the north-south (NS) asymmetry of the rotational cycle length is also studied. This displays the same variation trend as the N-S asymmetry of solar activity in a solar cycle, as well as in the considered time interval, and has two significant periods of 7.7 and 17.5 yr. Moreover, the rotational cycle length and the N-S asymmetry of solar activity are highly correlated. It is inferred that the northern hemisphere should rotate faster at the beginning of solar cycle 24.
学科主题	Astronomy & Astrophysics
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	NORTH-SOUTH ASYMMETRY ; N-S ASYMMETRY ; NUMBERS R-N ; DIFFERENTIAL ROTATION ; SUNSPOT NUMBERS ; WAVELET ANALYSIS ; ACTIVITY CYCLES ; PERIODICITIES ; SUN ; VELOCITY
收录类别	SCI
原文出处	http://iopscience.iop.org/article/10.1088/1674-4527/12/2/007/meta
语种	英语
WOS记录号	WOS:000300762600007
内容类型	期刊论文
源URL	[http://ir.ynao.ac.cn/handle/114a53/6211]
专题	云南天文台_太阳物理研究组
作者单位	1.National Astronomical Observatories/ Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011, China 2.Graduate University of Chinese Academy of Sciences, Beijing 100049, China
推荐引用方式 GB/T 7714	Xie JL,Shi XJ,Xu JC. Temporal variation of hemispheric solar rotation[J]. RESEARCH IN ASTRONOMY AND ASTROPHYSICS,2012,12(2):187-200.
APA	Xie JL,Shi XJ,&Xu JC.(2012).Temporal variation of hemispheric solar rotation.RESEARCH IN ASTRONOMY AND ASTROPHYSICS,12(2),187-200.
MLA	Xie JL,et al."Temporal variation of hemispheric solar rotation".RESEARCH IN ASTRONOMY AND ASTROPHYSICS 12.2(2012):187-200.