气候变化领域集成服务门户(CCPortal): Variation of Earth's Oblateness J2 on Interannual-to-Decadal Timescales

CCPortal

DOI	10.1029/2020JB019421
	Variation of Earth's Oblateness J2 on Interannual-to-Decadal Timescales
	Chao B.F.; Yu Y.; Chung C.H.
发表日期	2020
ISSN	21699313
卷号	125 期号:6
英文摘要	The Earth's oblateness varies slightly due to a host of physical processes that involve large-scale meridional N-S mass redistributions in the Earth. We analyze these minute, broadband signals in the observed ΔJ2 data series for 1976–2019 (43 years). We first remove the near-quadratic variation (due to the glacial isostatic adjustment plus the accelerating land ice melting) and the seasonal terms (due to seasonality of the surface geophysical fluids) by least squares regression. Then we examine via cross-correlation function and cross-coherence spectrum the relationships of the remaining interannual-to-decadal ΔJ2 with various climate oscillations in terms of their respective indices. We elucidate the contributions of the Antarctic Oscillation and Arctic Oscillation (for timescales shorter than 5 years), Pacific Decadal Oscillation (for timescales longer than 5 years), and the absence thereof in El Niño–Southern Oscillation and Atlantic Multidecadal Oscillation. Removal of their contributions from ΔJ2 reveals two remaining, nonclimatic long-period signals: An 18.61-year tidal signal calls for an augmentation in the in-phase value and a reduction of the out-of-phase value in the theoretical models per International Earth rotation and Reference systems Service (IERS), while a more detailed quantitative study awaits future, longer data. An additional 10.5-year signal is found to be correlated with the solar cycle, but the origin of this apparent correlation is uncertain presently. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	18.6-year tide; climatic oscillations; cross correlation; Earth oblateness; interannual-decadal
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/187829
作者单位	Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan; Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA, United States; Department of Geosciences, National Taiwan University, Taipei, Taiwan
推荐引用方式 GB/T 7714	Chao B.F.,Yu Y.,Chung C.H.. Variation of Earth's Oblateness J2 on Interannual-to-Decadal Timescales[J],2020,125(6).
APA	Chao B.F.,Yu Y.,&Chung C.H..(2020).Variation of Earth's Oblateness J2 on Interannual-to-Decadal Timescales.Journal of Geophysical Research: Solid Earth,125(6).
MLA	Chao B.F.,et al."Variation of Earth's Oblateness J2 on Interannual-to-Decadal Timescales".Journal of Geophysical Research: Solid Earth 125.6(2020).