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Climate of the Past An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/cp-2017-103
© Author(s) 2017. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
24 Aug 2017
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Climate of the Past (CP).
A spatio-temporal reconstruction of sea-surface temperatures in the North Atlantic during Dansgaard-Oeschger events 5–8
Mari F. Jensen1, Aleksi Nummelin2, Søren B. Nielsen3, Henrik Sadatzki1, Evangeline Sessford1, Bjørg Risebrobakken4, Carin Andersson4, Antje Voelker5, William H. G. Roberts6, and Andreas Born7 1Department of Earth Science, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway
2Geophysical Institute, University of Bergen and Bjerknes Centre for Climate Research, Bergen, Norway and Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, USA
3Climate and Geophysics, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
4Uni Research Climate, Bjerknes Centre for Climate Research, Bergen, Norway
5Instituto Português do Mar e da Atmosfera, Lisbon, and Centre of Marine Sciences (CCMAR), University of Algarve, Faro, Portugal
6University of Bristol, Bristol, England
7Institute of Physics and Oeschger Centre for Climate Research, University of Bern, Bern, Switzerland
Abstract. Here we establish a spatio-temporal evolution of the sea-surface temperatures in the North Atlantic over Dansgaard Oeschger (DO) events 5–8 (c. 30–40 ka) using the proxy surrogate reconstruction method. Proxy data suggest a large variability in North Atlantic sea-surface temperatures during the DO-events of the last glacial period. However, proxy data availability is limited and cannot provide a full spatial picture of the oceanic changes. Therefore, we combine fully coupled, general circulation model simulations with planktic foraminifera based sea-surface temperature reconstructions to obtain a broader spatial picture of the ocean state during DO-events 5–8. The resulting spatial sea-surface temperature patterns agree over a number of different general circulation models and simulations. We find that sea-surface temperature variability over the DO-events is characterized by colder conditions in the subpolar North Atlantic during stadials than during interstadials, and the variability is linked to changes in the Atlantic Meridional Overturning circulation, and in the sea-ice cover. Forced simulations are needed to capture the strength of the temperature variability and to reconstruct the variability in other climatic records not directly linked to the sea-surface temperature reconstructions. Our results are robust to uncertainties in the age models of the proxy data, the number of available temperature reconstructions, and over a range of climate models.

Citation: Jensen, M. F., Nummelin, A., Nielsen, S. B., Sadatzki, H., Sessford, E., Risebrobakken, B., Andersson, C., Voelker, A., Roberts, W. H. G., and Born, A.: A spatio-temporal reconstruction of sea-surface temperatures in the North Atlantic during Dansgaard-Oeschger events 5–8, Clim. Past Discuss., https://doi.org/10.5194/cp-2017-103, in review, 2017.
Mari F. Jensen et al.
Mari F. Jensen et al.
Mari F. Jensen et al.

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Short summary
We combine North Atlantic sea-surface temperature reconstructions and global climate model simulations to study the rapid glacial climate shifts (30–40 thousand years ago). Interestingly, the pre-industrial climate boosts similar, albeit weaker, sea-surface temperature variability as the glacial period. However, in order to reproduce the amplitude of this variability, and to see temperature variability on Greenland similar to the ice core record, we need forced simulations.
We combine North Atlantic sea-surface temperature reconstructions and global climate model...
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