North Atlantic surface ocean warming and salinization in response to middle Eocene greenhouse warming
van der Ploeg, Robin; Cramwinckel, Margot J.; Kocken, Ilja J.; Leutert, Thomas J.; Bohaty, Steven M.; Fokkema, Chris D.; Hull, Pincelli M.; Meckler, A. Nele; Middelburg, Jack J.; Müller, Inigo A.; Penman, Donald E.; Peterse, Francien; Reichart, Gert Jan; Sexton, Philip F.; Vahlenkamp, Maximilian; De Vleeschouwer, David; Wilson, Paul A.; Ziegler, Martin; Sluijs, Appy
(2023) Science advances, volume 9, issue 4, pp. 1 - 16
(Article)
Abstract
Quantitative reconstructions of hydrological change during ancient greenhouse warming events provide valuable insight into warmer-than-modern hydrological cycles but are limited by paleoclimate proxy uncertainties. We present sea surface temperature (SST) records and seawater oxygen isotope (δ18Osw) estimates for the Middle Eocene Climatic Optimum (MECO), using coupled carbonate clumped isotope (Δ47)
... read more
and oxygen isotope (δ18Oc) data of well-preserved planktonic foraminifera from the North Atlantic Newfoundland Drifts. These indicate a transient ~3°C warming across the MECO, with absolute temperatures generally in accordance with trace element (Mg/Ca)–based SSTs but lower than biomarker-based SSTs for the same interval. We find a transient ~0.5 ‰ shift toward higher δ18Osw, which implies increased salinity in the North Atlantic subtropical gyre and potentially a poleward expansion of its northern boundary in response to greenhouse warming. These observations provide constraints on dynamic ocean response to warming events, which are consistent with theory and model simulations predicting an enhanced hydrological cycle under global warming.
show less
Download/Full Text
Keywords: Climatic optimum meco, Planktic foraminifera, Thermal maximum, Proxy data, Temperature-gradient, Isotope analysis, Membrane-lipids, Atmospheric co2, Carbon-cycle, Global ocean, General
ISSN: 2375-2548
Publisher: American Association for the Advancement of Science
Note: Funding Information: We thank P. Pearson (Cardiff University) for discussions on foraminiferal taxonomy. We further acknowledge A. Roepert (UU), A. van Dijk (Utrecht Geolab), W. Boer (NIOZ), M. van der Meer (NIOZ), and W. Strojie (Yale University) for laboratory assistance and analytical support. We are grateful to two anonymous reviewers for constructive feedback. This research used samples provided by the IODP. This work was carried out under the program of the Netherlands Earth System Science Centre (NESSC), which is financially supported by the Ministry of Education, Culture and Science (OCW) of the Netherlands. A.N.M. and T.J.L. acknowledge European Research Council grant no. 638467 and Trond Mohn Foundation grant no. BFS2015REK01 for funding the clumped isotope analyses at UiB. P.M.H. and D.E.P. acknowledge support from NSF award no. 133526. A.S. thanks the European Research Council for consolidator grant no. 771497 (SPANC), and R.v.d.P. and A.S. thank the Ammodo Foundation for funding unfettered research of laureate A.S. Publisher Copyright: Copyright © 2023 The Authors, some rights reserved.
(Peer reviewed)
