DOI: 10.1038/ngeo2859
论文题名: An accelerating high-latitude jet in Earth's core
作者: Livermore P.W. ; Hollerbach R. ; Finlay C.C.
刊名: Nature Geoscience
ISSN: 17520894
出版年: 2017
卷: 10, 期: 1 起始页码: 62
结束页码: 68
语种: 英语
Scopus关键词: core (planetary)
; Earth structure
; latitude
; magnetic field
; movement
; satellite mission
; secular variation
; torsion
; wave action
英文摘要: Observations of the change in Earth's magnetic field - the secular variation - provide information about the motion of liquid metal within the core that is responsible for the magnetic field's generation. High-resolution observations from the European Space Agency's Swarm satellite mission show intense field change at high latitude, localized in a distinctive circular daisy-chain configuration centred on the north geographic pole. Here we show that this feature can be explained by a localized, non-axisymmetric, westward jet of 420 km width on the tangent cylinder, the cylinder of fluid within the core that is aligned with the rotation axis and tangent to the solid inner core. We find that the jet has increased in magnitude by a factor of three over the period 2000-2016 to about 40 km yr-1, and is now much stronger than typical large-scale flows inferred for the core. We suggest that the current accelerating phase may be part of a longer-term fluctuation of the jet causing both eastward and westward movement of magnetic features over historical periods, and may contribute to recent changes in torsional-wave activity and the rotation direction of the inner core. © 2017 Macmillan Publishers Limited, part of Springer Nature. All rights reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/105865
Appears in Collections: 气候减缓与适应 科学计划与规划
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作者单位: School of Earth and Environment, University of Leeds, Leeds, United Kingdom; School of Mathematics, University of Leeds, Leeds, United Kingdom; DTU Space, Technical University of Denmark, 2800 Kongens Lyngby, Copenhagen, Denmark
Recommended Citation:
Livermore P.W.,Hollerbach R.,Finlay C.C.. An accelerating high-latitude jet in Earth's core[J]. Nature Geoscience,2017-01-01,10(1)