气候变化领域集成服务门户(CCPortal): Evolution of the Global Overturning Circulation since the Last Glacial Maximum based on marine authigenic neodymium isotopes

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DOI	10.1016/j.quascirev.2020.106396
	Evolution of the Global Overturning Circulation since the Last Glacial Maximum based on marine authigenic neodymium isotopes
	Du J.; Haley B.A.; Mix A.C.
发表日期	2020
ISSN	0277-3791
卷号	241
英文摘要	The Global Overturning Circulation is linked to climate change on glacial-interglacial and multi-millennial timescales. The understanding of past climate-circulation links remains hindered by apparent conflicts among proxy measures of circulation. Here we reconstruct circulation changes since the Last Glacial Maximum (LGM) based on a global synthesis of authigenic neodymium isotope records (εNd). We propose the bottom-up framework of interpreting seawater and authigenic εNd considering not only conservative watermass mixing, but also the preformed properties and the non-conservative behavior of εNd, both subject to sedimentary influences. We extract the major spatial-temporal modes of authigenic εNd using Principal Component Analysis, and make a first-order circulation reconstruction with budget-constrained box model simulations. We show that during the LGM, the source region of North Atlantic overturning shifted southward, which led to more radiogenic preformed εNd of glacial Northern Source Water (NSW). Considering this preformed effect, we infer that glacial deep Atlantic had a similar proportion of NSW as today, although the overall strength of glacial circulation appears reduced from both North Atlantic and Southern Ocean sources, which increased the relative importance of non-conservative behavior of εNd and may have facilitated accumulation of respired carbon in the deep ocean. During the deglaciation, we find that Southern Ocean overturning increased, which offset suppressed North Atlantic overturning and resulted in a net stronger global abyssal circulation. Faster global scale deglacial circulation reduced the relative importance of non-conservative effects, resulting in Atlantic-Pacific convergence of abyssal εNd signatures. Variations of Southern Ocean overturning likely drove a significant fraction of deglacial changes in atmospheric CO2 and oceanic heat budget. © 2020 The Author(s)
英文关键词	Authigenic phase; Detrital sediments; Last deglaciation; Last glacial maximum; Marine Nd Cycle; Neodymium isotopes; Ocean circulation; Paleoceanography; Paleoclimate
语种	英语
scopus关键词	Budget control; Climate change; Glacial geology; Isotopes; Neodymium; Principal component analysis; Abyssal circulation; Bottom-up frameworks; Circulation changes; Last Glacial Maximum; Neodymium isotopes; Non-conservative effects; Overturning circulation; Spatial temporals; Oceanography; abyssal circulation; authigenesis; climate change; convergence; glacial-interglacial cycle; global perspective; Last Glacial Maximum; marine environment; neodymium isotope; oceanic circulation; overturn; reconstruction; timescale; Atlantic Ocean; Atlantic Ocean (North); Southern Ocean
来源期刊	Quaternary Science Reviews
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/151413
作者单位	College of Earth, Ocean and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, United States; Department of Earth Sciences, Institute of Geochemistry and Petrology, ETH Zürich, Clausiusstrasse 25, Zürich, 8092, Switzerland
推荐引用方式 GB/T 7714	Du J.,Haley B.A.,Mix A.C.. Evolution of the Global Overturning Circulation since the Last Glacial Maximum based on marine authigenic neodymium isotopes[J],2020,241.
APA	Du J.,Haley B.A.,&Mix A.C..(2020).Evolution of the Global Overturning Circulation since the Last Glacial Maximum based on marine authigenic neodymium isotopes.Quaternary Science Reviews,241.
MLA	Du J.,et al."Evolution of the Global Overturning Circulation since the Last Glacial Maximum based on marine authigenic neodymium isotopes".Quaternary Science Reviews 241(2020).