气候变化领域集成服务门户(CCPortal): New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length-Of-Day Variation

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DOI	10.1029/2020JB020990
	New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length-Of-Day Variation
	Ding H.; An Y.; Shen W.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	The intradecadal fluctuations in the length-of-day variation (∆LOD) are considered likely to play an important role in core motions. Two intradecadal oscillations, with ∼5.9 and ∼8.5 years periods (referred to as SYO and EYO, respectively), have been detected in previous studies. However, whether the SYO and the EYO have exhibited stable damping trends since 1962 and whether geomagnetic jerks are possible excitation sources for the SYO/EYO are still debated. In this study, based on different methods and different ∆LOD records with different time spans, we showed robust evidence to prove that the SYO and the EYO have had no stable damping trends since 1962. We also found that there may be a ∼7.6 years signal, but given that its average amplitude is too small, further confirmations are needed in the future. After confirming that the jerks have no special consistency with the peaks/valleys of the EYO/SYO, we further used a deconvolution process and confirmed that the geomagnetic jerks seem to be related to sudden changes in the SYO/EYO time series and their excitation series. Thus we finally suggest that jerks are possible excitation sources of the SYO/EYO. After using a deconvolution process, we estimate that the period P and quality factor Q of the SYO and the EYO are [P = 5.85 ± 0.06 years, Q ≥ 180] and [P = 8.45 ± 0.17 years, Q ≥ 350], respectively. © 2021. American Geophysical Union. All Rights Reserved.
英文关键词	damping trends; geomagnetic jerks; intradecadal fluctuations; length-of-day variations
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187364
作者单位	Department of Geophysics, School of Geodesy and Geomatics, Key Laboratory of Geospace Environment and Geodesy of the Ministry of Education, Wuhan University, Wuhan, China
推荐引用方式 GB/T 7714	Ding H.,An Y.,Shen W.. New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length-Of-Day Variation[J],2021,126(2).
APA	Ding H.,An Y.,&Shen W..(2021).New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length-Of-Day Variation.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Ding H.,et al."New Evidence for the Fluctuation Characteristics of Intradecadal Periodic Signals in Length-Of-Day Variation".Journal of Geophysical Research: Solid Earth 126.2(2021).