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
Effect of drake and panamanian gateways on the circulation of an Ocean model
TL;DR: In this article, the effect of the breaching of the Drake barrier has been examined in an ocean general circulation model, with the net effect being decreased transport of the Antarctic Current and an approximate fourfold increase in outflow of Antarctic deep-bottom waters.
Journal ArticleDOI
Suborbital timescale variability of North Atlantic Deep Water during the past 200,000 years
Delia W Oppo,Scott J. Lehman +1 more
TL;DR: Oppo et al. as mentioned in this paper used a benthic δ13C record to evaluate the deep water response to Dansgaard-Oeschger temperature oscillations and to Heinrich events, times of massive iceberg delivery to the North Atlantic.
Journal ArticleDOI
The role of deep ocean circulation in setting glacial climates
TL;DR: In this paper, the authors examine the data for biogeochemical, circulation rate, and conservative tracers during glacial climates and combine these observations into a new idea for how ocean-atmosphere system moves from interglacial to glacial periods across a single cycle.
Book ChapterDOI
Glacial to Interglacial Changes in the Isotopic Gradients of Southern Ocean Surface Water
TL;DR: In this paper, core top values of δ 18O and δ 13C in the planktic foraminiferal species Neoghboquadrina pachyderma l.c. follow those expected for calcite precipitated in equilibrium with surface waters.
Journal ArticleDOI
Late Quaternary CaCO3 production and preservation in the Southern Ocean: Implications for oceanic and atmospheric carbon cycling
William R Howard,Warren L. Prell +1 more
TL;DR: In this paper, the authors use cores from the Southeast Indian Ridge and from the deep Cape Basin in the South Atlantic to show that carbonate dissolution was enhanced during glacial stages in areas now bathed by Circumpolar Deep Water.
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
Edward A. Boyle,Lloyd D Keigwin +1 more