气候变化领域集成服务门户(CCPortal): Decomposition of Geomagnetic Secular Acceleration Into Traveling Waves Using Complex Empirical Orthogonal Functions

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DOI	10.1029/2020GL087940
	Decomposition of Geomagnetic Secular Acceleration Into Traveling Waves Using Complex Empirical Orthogonal Functions
	Chi-Durán R.; Avery M.S.; Knezek N.; Buffett B.A.
发表日期	2020
ISSN	0094-8276
卷号	47 期号:17
英文摘要	Satellite observations reveal short pulses in the second time derivative of the geomagnetic field. We seek to interpret these signals using complex empirical orthogonal functions (CEOFs). This methodology decomposes the signal into traveling waves, permitting estimates for the period, angular wave number, and phase velocity. We recover CEOFs from the CHAOS-6 model, focusing on three geographic regions with strong secular acceleration. Two regions are confined to the equator, while the third is located under Alaska. We find evidence for both eastward and westward traveling waves with periods between 7 and 20 years. There is also evidence for weaker standing waves with complex spatial patterns. Two of the three regions have waves that are compatible with predictions for waves in a stratified fluid. Our results yield estimates for the structure of fluid stratification at the top of the core. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	Geomagnetism; Signal processing; Complex empirical orthogonal functions; Fluid stratification; Geomagnetic fields; Satellite observations; Secular accelerations; Spatial patterns; Stratified fluid; Time derivative; Orthogonal functions; acceleration; decomposition analysis; geographical variation; geomagnetic field; methodology; stratification; Alaska; United States
语种	英语
来源期刊	Geophysical Research Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/169773
作者单位	Department of Earth and Planetary Science, University of California, Berkeley, CA, United States
推荐引用方式 GB/T 7714	Chi-Durán R.,Avery M.S.,Knezek N.,et al. Decomposition of Geomagnetic Secular Acceleration Into Traveling Waves Using Complex Empirical Orthogonal Functions[J],2020,47(17).
APA	Chi-Durán R.,Avery M.S.,Knezek N.,&Buffett B.A..(2020).Decomposition of Geomagnetic Secular Acceleration Into Traveling Waves Using Complex Empirical Orthogonal Functions.Geophysical Research Letters,47(17).
MLA	Chi-Durán R.,et al."Decomposition of Geomagnetic Secular Acceleration Into Traveling Waves Using Complex Empirical Orthogonal Functions".Geophysical Research Letters 47.17(2020).