Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic Ocean
William B Curry,Delia W Oppo +1 more
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In this article, oxygen and carbon isotopic data were produced on the benthic foraminiferal taxa Cibicidoides and Planulina from 25 new piston cores, gravity cores, and multicores from the Brazil margin.Abstract:
[1] Oxygen and carbon isotopic data were produced on the benthic foraminiferal taxa Cibicidoides and Planulina from 25 new piston cores, gravity cores, and multicores from the Brazil margin. The cores span water depths from about 400 to 3000 m and intersect the major water masses in this region. These new data fill a critical gap in the South Atlantic Ocean and provide the motivation for updating the classic glacial western Atlantic δ13C transect of Duplessy et al. (1988). The distribution of δ13C of ΣCO2 requires the presence of three distinct water masses in the glacial Atlantic Ocean: a shallow (∼1000 m), southern source water mass with an end-member δ13C value of about 0.3–0.5‰ VPDB, a middepth (∼1500 m), northern source water mass with an end-member value of about 1.5‰, and a deep (>2000 m), southern source water with an end-member value of less than −0.2‰, and perhaps as low as the −0.9‰ values observed in the South Atlantic sector of the Southern Ocean (Ninnemann and Charles, 2002). The origins of the water masses are supported by the meridional gradients in benthic foraminiferal δ18O. A revised glacial section of deep water δ13C documents the positions and gradients among these end-member intermediate and deep water masses. The large property gradients in the presence of strong vertical mixing can only be maintained by a vigorous overturning circulation.read more
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Global climate evolution during the last deglaciation
Peter U. Clark,Jeremy D. Shakun,Paul A. Baker,Patrick J. Bartlein,Simon Brewer,Edward J. Brook,Anders E. Carlson,Hai Cheng,Darrell S. Kaufman,Zhengyu Liu,Zhengyu Liu,Thomas M Marchitto,Alan C. Mix,Carrie Morrill,Bette L. Otto-Bliesner,Katharina Pahnke,James M. Russell,Cathy Whitlock,Jess F. Adkins,Jessica L. Blois,Jorie Clark,Steven M. Colman,William B Curry,Ben P. Flower,Feng He,Thomas C. Johnson,Jean Lynch-Stieglitz,Vera Markgraf,Jerry F. McManus,Jerry X. Mitrovica,Patricio I. Moreno,John W. Williams +31 more
TL;DR: A major effort by the paleoclimate research community to characterize changes through the development of well-dated, high-resolution records of the deep and intermediate ocean as well as surface climate indicates that the superposition of two modes explains much of the variability in regional and global climate during the last deglaciation.
Journal ArticleDOI
Atlantic meridional overturning circulation during the Last Glacial Maximum.
Jean Lynch-Stieglitz,Jess F. Adkins,William B Curry,Trond Dokken,Ian Hall,Juan Carlos Herguera,Joël J.-M. Hirschi,Elena Ivanova,Catherine Kissel,Olivier Marchal,Thomas M Marchitto,I. Nicholas McCave,Jerry F. McManus,Stefan Mulitza,Ulysses S Ninnemann,Frank Peeters,Ein-Fen Yu,Rainer Zahn +17 more
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Journal ArticleDOI
Onset of “Hudson Strait” Heinrich events in the eastern North Atlantic at the end of the middle Pleistocene transition (∼640 ka)?
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Journal ArticleDOI
Antarctic sea ice control on ocean circulation in present and glacial climates.
Raffaele Ferrari,Malte F. Jansen,Jess F. Adkins,Andrea Burke,Andrew L. Stewart,Andrew F. Thompson +5 more
TL;DR: This study shows that this rearrangement of deep water masses is dynamically linked to the expansion of summer sea ice around Antarctica, and may help quantify the ocean’s role in regulating atmospheric carbon dioxide on glacial–interglacial timescales.
Journal ArticleDOI
Radiocarbon Variability in the Western North Atlantic During the Last Deglaciation
Laura F. Robinson,Jess F. Adkins,Lloyd D Keigwin,John Southon,Diego P. Fernandez,S.-L. Wang,Daniel S. Scheirer +6 more
TL;DR: The deep-ocean record supports the notion of a bipolar seesaw with increased Northern-source deep-water formation linked to Northern Hemisphere warming and the reverse, and the more frequent radiocarbon variations in the intermediate/deep ocean are associated with roughly synchronous changes at the poles.
References
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Journal ArticleDOI
Collapse and rapid resumption of Atlantic meridional circulation linked to deglacial climate changes
TL;DR: It is found that the meridional overturning was nearly, or completely, eliminated during the coldest deglacial interval in the North Atlantic region, beginning with the catastrophic iceberg discharge Heinrich event H1, 17,500’yr ago, and declined sharply but briefly into the Younger Dryas cold event, about 12,700 yr ago.
Journal ArticleDOI
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J.-C. Duplessy,N.J. Shackleton,Richard G. Fairbanks,Laurent Labeyrie,Delia W Oppo,Nejib Kallel +5 more
TL;DR: 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.
Journal ArticleDOI
Spatial variability of turbulent mixing in the Abyssal Ocean
TL;DR: Ocean microstructure data show that turbulent mixing in the deep Brazil Basin of the South Atlantic Ocean is weak at all depths above smooth abyssal plains and the South American Continental Rise, which implies that abyssal circulations have complex spatial structures that are linked to the underlying bathymetry.
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.
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