Millennial scale evolution of the Southern Ocean chemical divide

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doi: 10.1016/j.quascirev.2009.09.021
Author(s): Charles, Christopher D.; Pahnke, Katharina; Zahn, Rainer; Mortyn, P. G.; Ninnemann, Ulysses; Hodell, D. A.
Author Affiliation(s): Primary:
Scripps Institute of Oceanography, La Jolla, CA, United States
University of Hawaii at Manoa, United States
Institució Catalana de Recerca i Estudis Ancats, Spain
Universitat Autonoma de Barcelona, Spain
University of Bergen, Norway
University of Cambridge, United Kingdom
Volume Title: Quaternary Science Reviews
Source: Quaternary Science Reviews, 29(3-4), p.399-409. Publisher: Elsevier, International. ISSN: 0277-3791
Note: In English. 52 refs.; illus.
Summary: The chemical properties of the mid-depth and deep Southern Ocean are diagnostic of the mechanisms of abrupt changes in the global ocean throughout the late Pleistocene, because the regional water mass conversion and mixing help determine global ocean gradients. Here we define continuous time series of Southern Ocean vertical gradients by differencing the records from two high deposition rate deep sea sedimentary sequences that span the last several ice age cycles. The inferred changes in vertical carbon and oxygen isotopic gradients were dominated by variability on the millennial scale, and they followed closely the abrupt climate events of the high latitude Northern Hemisphere. In particular, the stadial events of at least the last 200 kyr were characterized by enhanced mid-deep gradients in both δ13C (dissolved inorganic carbon) and δ18O (temperature). Interstadial events, conversely, featured reduced vertical gradients in both properties. The glacial terminations represented exceptions to this pattern of variability, as the vertical carbon isotopic gradient flattened dramatically at times of peak warmth in the Southern Ocean surface waters and with little or no corresponding change δ18O gradient. The available evidence suggests that properties of the upper layer of the Southern Ocean (Antarctic Intermediate Water) were influenced by an atmospherically mediated teleconnection to high latitude Northern Hemisphere. Abstract Copyright (2010) Elsevier, B.V.
Year of Publication: 2010
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 24 Surficial Geology, Quaternary Geology; Atlantic Ocean; C-13/C-12; Cape Basin; Carbon; Cenozoic; Foraminifera; Glaciation; Globigerina; Globigerina bulloides; Globigerinacea; Globigerinidae; Invertebrata; Isotope ratios; Isotopes; Leg 177; Marine environment; Microfossils; O-18/O-16; ODP Site 1089; Ocean Drilling Program; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleoenvironment; Pleistocene; Protista; Quaternary; Rotaliina; South Atlantic; South Pacific; Southern Ocean; Stable isotopes; Upper Pleistocene
Coordinates: S405611 S405611 E0095338 E0095338
Record ID: 2011049207
Copyright Information: GeoRef, Copyright 2017 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands