气候变化领域集成服务门户(CCPortal): Detection of significant climatic precession variability in early Pleistocene glacial cycles

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DOI	10.1016/j.epsl.2020.116137
	Detection of significant climatic precession variability in early Pleistocene glacial cycles
	Liautaud P.R.; Hodell D.A.; Huybers P.J.
发表日期	2020
ISSN	0012821X
卷号	536
英文摘要	Despite having a large influence on summer insolation, climatic precession is thought to account for little variance in early Pleistocene proxies of ice volume and deep-water temperature. Various mechanisms have been suggested to account for the dearth of precession variability, including meridional insolation gradients, interhemispheric cancellation of ice-volume changes, and antiphasing between the duration and intensity of summer insolation. We employ a method termed Empirical Nonlinear Orbital Fitting (ENOF) to estimate the amplitudes of obliquity and precession forcing in early Pleistocene proxies and their respective leads or lags relative to the timing of orbital variations. Analysis of a high-resolution North Atlantic benthic δ18O record, comprising data from IODP sites U1308 and U1313, indicates a larger precession contribution than previously recognized, with an average precession-to-obliquity amplitude ratio of 0.51 (0.30-0.76 95% confidence interval) in the rate-of-change of δ18O between 3 and 1 Ma. Averaged when eccentricity exceeds 0.05, this ratio rises to 1.18 (0.84-1.53). Additional support for precession's importance in the early Pleistocene comes from its estimated amplitude covarying with eccentricity, analyses of other benthic δ18O records yielding similar orbital amplitude ratios, and use of an orbitally-independent timescale also showing significant precession. Precession in phase with Northern Hemisphere summer intensity steadily intensifies throughout the Pleistocene, in agreement with its more common identification during the late Pleistocene. A Northern Hemisphere ice sheet and energy balance model run over the early Pleistocene predicts orbital amplitudes consistent with observations when a cooling commensurate with North Atlantic sea surface temperatures is imposed. These results provide strong evidence that glaciation is influenced by climatic precession during the late Pliocene and early Pleistocene, and are consistent with hypotheses that glaciation is controlled by Northern Hemisphere summer insolation. © 2020 Elsevier B.V.
关键词	glacial cycle Milankovitch orbital forcing Pleistocene precession spectral analysis
英文关键词	Ice; Incident solar radiation; Oceanography; Spectrum analysis; Surface waters; Glacial cycles; Milankovitch; Orbital forcing; Pleistocene; precession; Glacial geology; detection method; Milankovitch cycle; Northern Hemisphere; orbital forcing; paleoclimate; Pleistocene; precession; spectral analysis; summer; Atlantic Ocean; Atlantic Ocean (North)
语种	英语
来源期刊	Earth and Planetary Science Letters
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/202737
作者单位	Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA 02138, United States; Godwin Laboratory for Palaeoclimate Research, Department of Earth Sciences, University of Cambridge, Cambridge, CB2 3EQ, United Kingdom
推荐引用方式 GB/T 7714	Liautaud P.R.,Hodell D.A.,Huybers P.J.. Detection of significant climatic precession variability in early Pleistocene glacial cycles[J],2020,536.
APA	Liautaud P.R.,Hodell D.A.,&Huybers P.J..(2020).Detection of significant climatic precession variability in early Pleistocene glacial cycles.Earth and Planetary Science Letters,536.
MLA	Liautaud P.R.,et al."Detection of significant climatic precession variability in early Pleistocene glacial cycles".Earth and Planetary Science Letters 536(2020).