Rapid reductions in North Atlantic Deep Water during the peak of the last interglacial period
|Author(s)||Galaasen Eirik Vinje1, Ninnemann Ulysses S1, 2, Irvali Nil2, Kleiven Helga (kikki) F1, 2, Rosenthal Yair3, Kissel Catherine4, Hodell David A5|
|Affiliation(s)||1 : Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Allégaten 41, 5007 Bergen, Norway.
2 : Uni Climate, Uni Research and Bjerknes Centre for Climate Research, Bergen, Norway.
3 : Institute of Marine and Coastal Sciences and Department of Earth and Planetary Sciences, Rutgers University, New Brunswick, NJ, USA.
4 : Laboratorie des Sciences du Climat et de l’Environnement/Institut Pierre Simon Laplace, CEA/CNRS/UVSQ, Gif-sur-Yvette, France.
5 : Godwin Laboratory for Paleoclimate Research, Department of Earth Sciences, University of Cambridge, Cambridge, UK.
|Keyword(s)||paleoceanography, NADW, AMOC, last interglacial period, MIS 5e, Eem, North Atlantic, Eirik Drift, benthic foraminifera d13C|
Deep ocean circulation has been considered relatively stable during interglacial periods, yet little is known about its behavior on submillennial time scales. Using a subcentennially resolved epibenthic foraminiferal d13C record, we show that the influence of North Atlantic Deep Water (NADW) was strong at the onset of the last interglacial period and was then interrupted by several prominent centennial-scale reductions. These NADW transients occurred during periods of increased ice rafting and southward expansions of polar water influence, suggesting that a buoyancy threshold for convective instability was triggered by freshwater and circum-Arctic cryosphere changes. The deep Atlantic chemical changes were similar in magnitude to those associated with glaciations, implying that the canonical view of a relatively stable interglacial circulation may not hold for conditions warmer and fresher than at present.