Rapid global ocean-atmosphere response to Southern Ocean freshening during the last glacial

Chris S. M. Turney, Richard Jones, Steven J. Phipps, Zoë Thomas, Alan Hogg, Peter Kershaw, Christopher Fogwill, Jonathan Palmer, Christopher Bronk Ramsey, Florian Adolphi, Raimund Muscheler, Konrad Hughen, Richard A. Staff, Mark Grosvenor, Nicholas R Golledge, Sune Olander Rasmussen, David K. Hutchinson, Simon Haberle, Andrew Lorrey, Gretel BoswijkAlan Cooper

11 Citationer (Scopus)
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Abstract

Contrasting Greenland and Antarctic temperatures during the last glacial period (115,000 to 11,650 years ago) are thought to have been driven by imbalances in the rates of formation of North Atlantic and Antarctic Deep Water (the 'bipolar seesaw'). Here we exploit a bidecadally resolved 14C data set obtained from New Zealand kauri (Agathis australis) to undertake high-precision alignment of key climate data sets spanning iceberg-rafted debris event Heinrich 3 and Greenland Interstadial (GI) 5.1 in the North Atlantic (~30,400 to 28,400 years ago). We observe no divergence between the kauri and Atlantic marine sediment 14C data sets, implying limited changes in deep water formation. However, a Southern Ocean (Atlantic-sector) iceberg rafted debris event appears to have occurred synchronously with GI-5.1 warming and decreased precipitation over the western equatorial Pacific and Atlantic. An ensemble of transient meltwater simulations shows that Antarctic-sourced salinity anomalies can generate climate changes that are propagated globally via an atmospheric Rossby wave train.

OriginalsprogEngelsk
Artikelnummer520
TidsskriftNature Communications
Vol/bind8
ISSN2041-1723
DOI
StatusUdgivet - 1 dec. 2017

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