MAGNETIC HELICITY REVERSALS IN A CYCLIC CONVECTIVE DYNAMO

doi:10.3847/2041-8205/824/1/L15

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	MAGNETIC HELICITY REVERSALS IN A CYCLIC CONVECTIVE DYNAMO
	Miesch,Mark S.1; Zhang,Mei 2; Augustson,Kyle C.3
刊名	The Astrophysical Journal Letters
	2016-06-10
卷号	824 期号:1
关键词	dynamo magnetohydrodynamics (MHD) stars: activity Sun: activity Sun: interior Sun: magnetic fields
ISSN号	2041-8205
DOI	10.3847/2041-8205/824/1/L15
英文摘要	ABSTRACT We investigate the role of magnetic helicity in promoting cyclic magnetic activity in a global, 3D, magnetohydrodynamic (MHD) simulation of a convective dynamo. This simulation is characterized by coherent bands of toroidal field that exist within the convection zone, with opposite polarities in the northern hemisphere (NH) and southern hemisphere (SH). Throughout most of the cycle, the magnetic helicity in these bands is negative in the NH and positive in the SH. However, during the declining phase of each cycle, this hemispheric rule reverses. We attribute this to a global restructuring of the magnetic topology that is induced by the interaction of the bands across the equator. This band interaction appears to be ultimately responsible for, or at least associated with, the decay and subsequent reversal of both the toroidal bands and the polar fields. We briefly discuss the implications of these results within the context of solar observations, which also show some potential evidence for toroidal band interactions and helicity reversals.
语种	英语
出版者	The American Astronomical Society
WOS记录号	IOP:2041-8205-824-1-L15
内容类型	期刊论文
源URL	[http://ir.bao.ac.cn/handle/114a11/36294]
专题	中国科学院国家天文台
作者单位	1.High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO 80307-3000, USA; miesch@ucar.edu 2.Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Datun Road A20, Chaoyang District, Beijing 100012, China 3.CEA/DRF/IRFU Service d’Astrophysique, CEA-Saclay, Batiment 709, F-91191 Gif-sur-Yvette Cedex, France
推荐引用方式 GB/T 7714	Miesch,Mark S.,Zhang,Mei,Augustson,Kyle C.. MAGNETIC HELICITY REVERSALS IN A CYCLIC CONVECTIVE DYNAMO[J]. The Astrophysical Journal Letters,2016,824(1).
APA	Miesch,Mark S.,Zhang,Mei,&Augustson,Kyle C..(2016).MAGNETIC HELICITY REVERSALS IN A CYCLIC CONVECTIVE DYNAMO.The Astrophysical Journal Letters,824(1).
MLA	Miesch,Mark S.,et al."MAGNETIC HELICITY REVERSALS IN A CYCLIC CONVECTIVE DYNAMO".The Astrophysical Journal Letters 824.1(2016).