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
Citations
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Journal ArticleDOI
Data Constraints on Glacial Atlantic Water Mass Geometry and Properties
Delia W Oppo,Geoffrey Gebbie,Kuo-Fang Huang,Kuo-Fang Huang,William B Curry,William B Curry,Thomas M Marchitto,Kathryn R. Pietro +7 more
Journal ArticleDOI
Deep circulation changes in the central South Atlantic during the past 145 kyrs reflected in a combined231Pa/230Th, Neodymium isotope and benthic δ13C record
Lukas Jonkers,Lukas Jonkers,Rainer Zahn,Rainer Zahn,Alexander L. Thomas,Gideon M. Henderson,Wafa Abouchami,Roger Francois,Pere Masqué,Ian R Hall,Torsten Bickert +10 more
TL;DR: In this paper, the authors used a single sediment core from the South Atlantic subtropical gyre to investigate the influence of local productivity changes on sedimentary 231Pa/230Th records.
Journal ArticleDOI
Ba/Ca in benthic foraminifera: Thermocline and middepth circulation in the North Atlantic during the last glaciation
TL;DR: Foraminiferal Ba/Ca data suggest a 38% contribution from southern component water to a depth as shallow as 1475 m and a 14% contribution at 1123 m during deglaciation.
Journal ArticleDOI
Carbon isotope offsets between benthic foraminifer species of the genus Cibicides (Cibicidoides) in the glacial sub-Antarctic Atlantic
Julia Gottschalk,Julia Gottschalk,Natalia Vázquez Riveiros,Natalia Vázquez Riveiros,Claire Waelbroeck,Luke C Skinner,Elisabeth Michel,Jean-Claude Duplessy,David A. Hodell,Andreas Mackensen +9 more
TL;DR: In this paper, the authors compare the δ13C of two benthic foraminifer species, Cibicides kullenbergi and cibicides wuellerstorfi, and their morphotypes, in three sub-Antarctic Atlantic sediment cores over several glacial-interglacial transitions.
Journal ArticleDOI
True to Milankovitch: Glacial Inception in the New Community Climate System Model
Markus Jochum,Alexandra Jahn,Synte Peacock,David A. Bailey,John T. Fasullo,Jennifer E. Kay,Samuel Levis,Bette L. Otto-Bliesner +7 more
TL;DR: In this paper, the authors compared the equilibrium solution of a fully coupled general circulation model with present-day orbital forcing, compared to the solution of the same model with the orbital forcing from 115 000 years ago.
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.
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North Atlantic thermohaline circulation during the past 20,000 years linked to high-latitude surface temperature
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