Evidence for northward expansion of Antarctic Bottom Water mass in the Southern Ocean during the last glacial inception

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doi: 10.1029/2008PA001603
Author(s): Govin, Aline; Michel, Elisabeth; Labeyrie, Laurent; Waelbroeck, Claire; Dewilde, Fabien; Jansen, Eystein
Author Affiliation(s): Primary:
Université de Versailles Saint-Quentin-en-Yvelines, Laboratoire des Sciences du Climat et de l'Environnement, Gif sur Yvette, France
Other:
University of Bergen, Norway
Volume Title: Paleoceanography
Source: Paleoceanography, 24(1). Publisher: American Geophysical Union, Washington, DC, United States. ISSN: 0883-8305 CODEN: POCGEP
Note: In English. 70 refs.; illus., incl. 2 tables, sketch map
Summary: We investigated deep water changes in the Southern Ocean during the last glacial inception, in relationship to surface hydrology and global climatology, to better understand the mechanisms of the establishment of a glacial ocean circulation. Changes in benthic foraminiferal δ13C from three high-resolution cores are compared and indicate decoupled intermediate and deep water changes in the Southern Ocean. From the comparison with records from the North Atlantic, South Atlantic, and the Southern Ocean, we show that the early southern deep water δ13C drop observed at the MIS 5.5-5.4 transition occurred before any significant reduction of North Atlantic Deep Water ventilation. We propose that this drop is linked to the northward expansion of poorly ventilated Antarctic Bottom Water (AABW) mass in the Southern Ocean. Associated with an early cooling in the high southern latitudes, the westerly winds and surface oceanic fronts would migrate equatorward, thus weakening the upwelling of Circumpolar Deep Waters. Reduced heat brought to Antarctic surface waters would enhance sea ice formation during winters and the deep convection of cold and poorly ventilated AABW.
Year of Publication: 2009
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Antarctic Bottom Water; Antarctica; Atlantic Ocean; Benthic taxa; C-13/C-12; Cape Basin; Carbon; Cenozoic; Cores; Dome C; EPICA; Foraminifera; Glaciation; Invertebrata; Isotope ratios; Isotopes; Leg 177; Marine environment; Marine sediments; O-18/O-16; ODP Site 1089; Ocean Drilling Program; Oxygen; Paleo-oceanography; Paleoclimatology; Paleocurrents; Paleoenvironment; Paleotemperature; Pleistocene; Protista; Quaternary; Sediments; South Atlantic; Southern Ocean; Stable isotopes; Upper Pleistocene; Wilkes Land
Coordinates: S405611 S405611 E0095338 E0095338
Record ID: 2010010121
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