气候变化领域集成服务门户(CCPortal): Geomagnetic jerks and rapid hydromagnetic waves focusing at Earth’s core surface

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DOI	10.1038/s41561-019-0355-1
	Geomagnetic jerks and rapid hydromagnetic waves focusing at Earth’s core surface
	Aubert J.; Finlay C.C.
发表日期	2019
ISSN	17520894
卷号	12 期号:5
英文摘要	Geomagnetic jerks are abrupt changes in the second time derivative—the secular acceleration—of Earth’s magnetic field that punctuate ground observatory records. As their dynamical origin has not yet been established, they represent a major obstacle to the prediction of geomagnetic field behaviour for years to decades ahead. Recent jerks have been linked to short-lived, temporally alternating and equatorially localized pulses of secular acceleration observed in satellite data, associated with rapidly alternating flows at Earth’s core surface. Here we show that these signatures can be reproduced in numerical simulations of the geodynamo that realistically account for the interaction between slow core convection and rapid hydromagnetic waves. In these simulations, jerks are caused by the arrival of localized Alfvén wave packets radiated from sudden buoyancy releases inside the core. As they reach the core surface, the waves focus their energy towards the equatorial plane and along lines of strong magnetic flux, creating sharp interannual changes in core flow and producing geomagnetic jerks through the induced variations in magnetic field acceleration. The ability to numerically reproduce jerks offers a new way to probe the physical properties of Earth’s deep interior. © 2019, The Author(s), under exclusive licence to Springer Nature Limited.
语种	英语
scopus关键词	acceleration; buoyancy; core analysis; geodynamo; geomagnetic field; numerical model; satellite data
来源期刊	Nature Geoscience
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/124669
作者单位	Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France; Division of Geomagnetism, National Space Institute, Technical University of Denmark, Lyngby, Denmark
推荐引用方式 GB/T 7714	Aubert J.,Finlay C.C.. Geomagnetic jerks and rapid hydromagnetic waves focusing at Earth’s core surface[J],2019,12(5).
APA	Aubert J.,&Finlay C.C..(2019).Geomagnetic jerks and rapid hydromagnetic waves focusing at Earth’s core surface.Nature Geoscience,12(5).
MLA	Aubert J.,et al."Geomagnetic jerks and rapid hydromagnetic waves focusing at Earth’s core surface".Nature Geoscience 12.5(2019).