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      Oceanographic dynamics and the end of the last interglacial in the subpolar North Atlantic

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      Proceedings of the National Academy of Sciences
      Proceedings of the National Academy of Sciences

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          Abstract

          The last interglacial interval was terminated by the inception of a long, progressive glaciation that is attributed to astronomically influenced changes in the seasonal distribution of sunlight over the earth. However, the feedbacks, internal dynamics, and global teleconnections associated with declining northern summer insolation remain incompletely understood. Here we show that a crucial early step in glacial inception involves the weakening of the subpolar gyre (SPG) circulation of the North Atlantic Ocean. Detailed new records of microfossil foraminifera abundance and stable isotope ratios in deep sea sediments from Ocean Drilling Program site 984 south of Iceland reveal repeated, progressive cold water-mass expansions into subpolar latitudes during the last peak interglacial interval, marine isotope substage 5e. These movements are expressed as a sequence of progressively extensive southward advances and subsequent retreats of a hydrographic boundary that may have been analogous to the modern Arctic front, and associated with rapid changes in the strength of the SPG. This persistent millennial-scale oceanographic oscillation accompanied a long-term cooling trend at a time of slowly declining northern summer insolation, providing an early link in the propagation of those insolation changes globally, and resulting in a rapid transition from extensive regional warmth to the dramatic instability of the subsequent ∼ 100 ka.

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          Most cited references46

          • Record: found
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          Origin and consequences of cyclic ice rafting in the Northeast Atlantic Ocean during the past 130,000 years

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            Climate and atmospheric history of the past 420,000 years from the Vostok ice core, Antarctica

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              • Record: found
              • Abstract: not found
              • Article: not found

              On the Structure and Origin of Major Glaciation Cycles 1. Linear Responses to Milankovitch Forcing

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                Author and article information

                Journal
                Proceedings of the National Academy of Sciences
                Proceedings of the National Academy of Sciences
                Proceedings of the National Academy of Sciences
                0027-8424
                1091-6490
                August 05 2014
                August 05 2014
                July 21 2014
                August 05 2014
                : 111
                : 31
                : 11263-11268
                Article
                10.1073/pnas.1322103111
                4128163
                25049405
                7231fe52-6d8b-48ca-b08c-822294442a73
                © 2014
                History

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