Journal ArticleDOI
Deepwater source variations during the last climatic cycle and their impact on the global deepwater circulation
J.-C. Duplessy,N.J. Shackleton,Richard G. Fairbanks,Laurent Labeyrie,Delia W Oppo,Nejib Kallel +5 more
TLDR
In this paper, a detailed reconstruction of the geographic distribution of ∂13C in benthic foraminifera in the Atlantic Ocean during the last glacial maximum was presented.Abstract:
The degree of similarity of the ∂13C records of the planktonic foraminiferal species N. pachyderma and of the benthic foraminiferal genus Cibicides in the high-latitude basins of the world ocean is used as an indicator of the presence of deepwater sources during the last climatic cycle. Whereas continuous formation of deep water is recognized in the southern ocean, the Norwegian Sea stopped acting as a sink for surface water during isotope stage 4 and the remainder of the last glaciation. However, deep water formed in the north Atlantic south of the Norwegian Sea during the last climatic cycle as early as isotope substage 5d, and this area was also the only active northern source during stages 4–2. A detailed reconstruction of the geographic distribution of ∂13C in benthic foraminifera in the Atlantic Ocean during the last glacial maximum shows that the most important deepwater mass originated from the southern ocean, whereas the Glacial North Atlantic Deep Water cannot be traced south of 40°N. At shallower depth an oxygenated 13C rich Intermediate Water mass extended from 45°N to 15°S. In the Pacific Ocean a ventilation higher than the modern one was also found in open ocean in the depth range 700–2600 m and is best explained by stronger formation of Intermediate Water in high northern latitudes.read more
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Book ChapterDOI
Glacial-Holocene Paleoproductivity off Western Australia: A Comparison of Proxy Records
TL;DR: In this paper, the authors compare paleoproductivity proxy records from a set of gravity cores from the Exmouth Plateau (≈ 19°S, 113°E, 950 to 2250 m) and the Perth Basin in the southeastern Indian Ocean.
Journal ArticleDOI
Meridional overturning circulation in the South Atlantic at the last glacial maximum
Jean Lynch-Stieglitz,William B Curry,Delia W Oppo,Ulysses S. Ninneman,Christopher D. Charles,Jenna Munson +5 more
TL;DR: In this article, the authors examined how the density difference across 30°S in the upper 2 km of the Atlantic Ocean (and thus the magnitude of the shear associated with the overturning circulation) has changed between the last glacial maximum and the present.
Journal ArticleDOI
AMOC response to global warming: dependence on the background climate and response timescale
TL;DR: In this article, the authors investigated the response of the Atlantic meridional overturning circulation (AMOC) to a sudden doubling of atmospheric CO2 in the National Center for Atmospheric Research Community Climate System Model version 3, with a focus on differences under different background climates.
Journal ArticleDOI
Glacial-interglacial Nd isotope variability of North Atlantic Deep Water modulated by North American ice sheet.
Ning Zhao,Ning Zhao,Delia W Oppo,Kuo-Fang Huang,Kuo-Fang Huang,Jacob N W Howe,Jerzy S. Blusztajn,Lloyd D Keigwin +7 more
TL;DR: It is shown that deep water produced in the North Atlantic had a significantly more radiogenic Nd signature during the Last Glacial Maximum compared to today.
Journal ArticleDOI
Variation of Labrador Sea Water formation over the Last Glacial cycle in a climate model of intermediate complexity
Melanie Cottet-Puinel,Andrew J. Weaver,Claude Hillaire-Marcel,Anne de Vernal,Peter U. Clark,Michael Eby +5 more
TL;DR: In this paper, the variation of North Atlantic Deep Water (NADW) formation over the last Glacial cycle, from Oxygen Isotopic Substage 5e (OIS-5e; the Eemian) to future global warming projections, is investigated using the UVic Earth System Climate Model.
References
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Journal ArticleDOI
Smoothing and Differentiation of Data by Simplified Least Squares Procedures.
Journal ArticleDOI
The distribution of 13C of ΣCO2 in the world oceans
TL;DR: In this article, the results from 2252 samples from 107 hydrographic stations are presented as north-south vertical (depth) sections with δ13C contoured at intervals of 0.5−0.0075·AOU.
Journal ArticleDOI
North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature
Edward A. Boyle,Lloyd D Keigwin +1 more
TL;DR: In this paper, the authors show that during a surface cooling event 10,000 to 12,000 years ago, higher Cd/Ca and lower 13C/12C ratios are observed in benthic foraminifera shells from rapidly accumulating western North Atlantic sediments.
Journal ArticleDOI
Comparison of Atlantic and Pacific paleochemical records for the last 215,000 years : changes in deep ocean circulation and chemical inventories
Edward A. Boyle,Lloyd D Keigwin +1 more
TL;DR: In this article, detailed Cd/Ca and δ 13 C data have been obtained for benthic foraminifera from western North Atlantic and Equatorial Pacific sediment cores, which indicate that bottom waters overlying the Atlantic site have been nutrient depleted relative to those at the Pacific site over the last 215,000 years.
Related Papers (5)
North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature
Edward A. Boyle,Lloyd D Keigwin +1 more