Intradecadal variations in length of day and their correspondence with geomagnetic jerks

Earth’s core oscillations and magnetic field inside the liquid outer core cannot be observed directly from the surface, we can infer these information from the intradecadal variations in Earth’s rotation rate defined by length of day. However, the fine time-varying characteristics as well as relevan...

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Bibliographic Details
Published in:Nature communications 2020-05, Vol.11 (1), p.2273-2273, Article 2273
Main Authors: Duan, Pengshuo, Huang, Chengli
Format: Article
Language:English
Subjects:
639/33/445/210
704/2151/2809
Earth core
Earth rotation
Earth surface
Geomagnetic field
Geomagnetism
Humanities and Social Sciences
Magnetic fields
multidisciplinary
Oscillations
Science
Science (multidisciplinary)
Variation
Wave propagation
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Summary:Earth’s core oscillations and magnetic field inside the liquid outer core cannot be observed directly from the surface, we can infer these information from the intradecadal variations in Earth’s rotation rate defined by length of day. However, the fine time-varying characteristics as well as relevant mechanisms of the intradecadal variations are still unclear. Here we report that the intradecadal variations present a significant 8.6-year harmonic component with an unexpected increasing phenomenon, besides a 6-year decreasing oscillation. More importantly, we find that there is a very good correspondence between the extremes of the 8.6-year oscillation with geomagnetic jerks. The fast equatorial waves with subdecadal periods propagating at Earth’s core surface may explain the origin of this 8.6-year oscillation. Earth rotation variation reflects the physics, dynamics and the magnetic field changes of Earth’s interior. The authors find a significant ~8.6 year periodic increasing oscillation in length of day and its good link to geomagnetic jerks related to Earth’s core oscillations, which may be used to predict the future jerk timings.
ISSN:2041-1723
2041-1723
DOI:10.1038/s41467-020-16109-8