Interglacial instability of North Atlantic Deep Water ventilation

Disrupting North Atlantic Deep Water (NADW) ventilation is a key concern in climate projections. We use (sub)centennially resolved bottom water d13C records that span the interglacials of the last 0.5 million years to assess the frequency of and the climatic backgrounds capable of triggering large NADW reductions. Episodes of reduced NADW in the deep Atlantic, similar in magnitude to glacial events, have been relatively common and occasionally long-lasting features of interglacials. NADW reductions were triggered across the range of recent interglacial climate backgrounds, which demonstrates that catastrophic freshwater outburst floods were not a prerequisite for large perturbations. Our results argue that large NADW disruptions are more easily achieved than previously appreciated and that they occurred in past climate conditions similar to those we may soon face.

Disrupting North Atlantic Deep Water (NADW) ventilation is a key concern in climate projections. We use (sub)centennially resolved bottom water d13C records that span the interglacials of the last 0.5 million years to assess the frequency of and the climatic backgrounds capable of triggering large NADW reductions. Episodes of reduced NADW in the deep Atlantic, similar in magnitude to glacial events, have been relatively common and occasionally long-lasting features of interglacials. NADW reductions were triggered across the range of recent interglacial climate backgrounds, which demonstrates that catastrophic freshwater outburst floods were not a prerequisite for large perturbations. Our results argue that large NADW disruptions are more easily achieved than previously appreciated and that they occurred in past climate conditions similar to those we may soon face.

Disciplines

Marine geology

Keywords

paleoceanography, NADW, AMOC, interglacial, North Atlantic, Eirik Drift

Location

63.763414N, 52.025944S, -31.781194E, -60.785101W

Data

FileSizeFormatProcessingAccess
Galaasen et al. (2020) supplementary data.
181 KoXLS, XLSXProcessed data
How to cite
Galaasen Eirik Vinje, Ninnemann Ulysses, Kessler Augustin, Irvali Nil, Rosenthal Yair, Tjiputra Jerry, Bouttes Nathaëlle, Roche Didier M., Kleiven Helga (Kikki) F., Hodell David A. (2020). Interglacial instability of North Atlantic Deep Water ventilation. SEANOE. https://doi.org/10.17882/77657

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