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
Variability of Upwelling Off NW Africa During the Latest Quaternary: Diatom Evidence
TL;DR: Sarnthein et al. as mentioned in this paper quantitatively studied diatom abundance and species composition in two latest Quaternary (≃130 ka to the Present) sequences from the continental margin of northwest Africa.
Journal ArticleDOI
Atmospheric CO2 forcing on glacial thermohaline circulation and climate
TL;DR: In this article, a coupled climate model study indicates the paleoclimate record of glacial thermohaline circulation and reversed deep-sea temperature-salinity distribution in the Atlantic can be explained largely by lower glacial atmospheric CO2 alone.
Journal ArticleDOI
Field examination of the oceanic carbonate ion effect on stable isotopes in planktonic foraminifera
Ann D. Russell,Howard J. Spero +1 more
TL;DR: In this paper, the authors determined the shell offsets of Globigerinoides ruber and Pulleniatina obliquiloculata from sediment traps located from 5°N to 12°S along 140°W in the Pacific Ocean.
Journal ArticleDOI
Terrestrial biosphere changes over the last 120 kyr
Babette A A Hoogakker,Robin S. Smith,Joy S. Singarayer,Joy S. Singarayer,Rob Marchant,Iain Colin Prentice,Iain Colin Prentice,Judy R M Allen,R. S. Anderson,Shonil A. Bhagwat,Hermann Behling,Olga K. Borisova,Mark B. Bush,Alexander Correa-Metrio,A. de Vernal,Jemma M. Finch,Bianca Fréchette,Socorro Lozano-García,William D. Gosling,Wojciech Granoszewski,Eric C. Grimm,Eberhard Grüger,Jennifer A. Hanselman,Sandy P. Harrison,Sandy P. Harrison,Trevor Hill,Brian Huntley,Gonzalo Jiménez-Moreno,Peter Kershaw,M.-P. Ledru,Donatella Magri,Merna McKenzie,Ulrich C Müller,Takeshi Nakagawa,Elena Novenko,Dan Penny,Laura Sadori,Louis Scott,Janelle Stevenson,Paul J. Valdes,M. Vandergoes,A.A. Velichko,Cathy Whitlock,C. Tzedakis +43 more
TL;DR: In this paper, a new global synthesis and biomization of long (>40kyr) pollen-data records is presented and used with simulations from the HadCM3 and FAMOUS climate models and the BIOME4 vegetation model to analyse the dynamics of the global terrestrial biosphere and carbon storage over the last glacial-interglacial cycle.
Journal ArticleDOI
Extratropical forcing of Sahel aridity during Heinrich stadials
Eva M Niedermeyer,Matthias Prange,Stefan Mulitza,Gesine Mollenhauer,Enno Schefuß,Michael Schulz +5 more
TL;DR: In this article, the authors investigated a possible link between tropical NE Atlantic sea-surface temperature (SST), Atlantic meridional overturning circulation (AMOC), and drought in the Sahel during the past 44 thousand years (kyr) using alkenone paleothermometry and δ13C of C. wuellerstorfi.
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