CP Climate of the Past CP Clim. Past 1814-9332 Copernicus Publications Göttingen, Germany 10.5194/cp-9-1495-2013 Mid-pliocene Atlantic Meridional Overturning Circulation not unlike modern Zhang Z.-S. 3 2 1 Nisancioglu K. H. https://orcid.org/0000-0002-5737-5765 4 2 1 Chandler M. A. https://orcid.org/0000-0002-6548-227X 5 Haywood A. M. 6 Otto-Bliesner B. L. https://orcid.org/0000-0003-1911-1598 7 Ramstein G. 8 Stepanek C. 9 Abe-Ouchi A. https://orcid.org/0000-0003-1745-5952 10 11 Chan W.-L. https://orcid.org/0000-0002-5646-6104 10 Bragg F. J. https://orcid.org/0000-0002-8179-4214 12 Contoux C. https://orcid.org/0000-0001-8487-9275 9 13 Dolan A. M. 6 Hill D. J. https://orcid.org/0000-0001-5492-3925 6 14 Jost A. 13 Kamae Y. https://orcid.org/0000-0003-0461-5718 15 Lohmann G. https://orcid.org/0000-0003-2089-733X 9 16 Lunt D. J. https://orcid.org/0000-0003-3585-6928 11 Rosenbloom N. A. https://orcid.org/0000-0001-7389-3346 7 Sohl L. E. 5 Ueda H. 15 UNI Research, Allegaten 55, 5007 Bergen, Norway Bjerknes Centre for Climate Research, Allegaten 55, 5007 Bergen, Norway Nansen-Zhu International Research Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, 100029, Beijing, China Department of Earth Science, University of Bergen, Allegaten 41, 5007 Bergen, Norway CCSR/GISS, Columbia University, Columbia, New York, USA School of Earth and Environment, University of Leeds, Woodhouse Lane, Leeds, S29JT, UK National Center for Atmospheric Research, Boulder, Colorado, USA LSCE/IPSL, CNRS-CEA-UVSQ, Saclay, France Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwa, Japan Research Institute for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan BRIDGE, School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK Sisyphe, CNRS/UPMC Univ Paris 06, Paris, France British Geological Survey, Keyworth, Nottingham, NG12 5GG, UK Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan Institute for Environmental Physics, University of Bremen, Bremen, Germany 15 07 2013 9 4 1495 1504 Copyright: © 2013 Z.-S. Zhang et al. 2013 This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/3.0/ This article is available from https://cp.copernicus.org/articles/9/1495/2013/cp-9-1495-2013.html The full text article is available as a PDF file from https://cp.copernicus.org/articles/9/1495/2013/cp-9-1495-2013.pdf

In the Pliocene Model Intercomparison Project (PlioMIP), eight state-of-the-art coupled climate models have simulated the mid-Pliocene warm period (mPWP, 3.264 to 3.025 Ma). Here, we compare the Atlantic Meridional Overturning Circulation (AMOC), northward ocean heat transport and ocean stratification simulated with these models. None of the models participating in PlioMIP simulates a strong mid-Pliocene AMOC as suggested by earlier proxy studies. Rather, there is no consistent increase in AMOC maximum among the PlioMIP models. The only consistent change in AMOC is a shoaling of the overturning cell in the Atlantic, and a reduced influence of North Atlantic Deep Water (NADW) at depth in the basin. Furthermore, the simulated mid-Pliocene Atlantic northward heat transport is similar to the pre-industrial. These simulations demonstrate that the reconstructed high-latitude mid-Pliocene warming can not be explained as a direct response to an intensification of AMOC and concomitant increase in northward ocean heat transport by the Atlantic.

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