Articles | Volume 10, issue 11
Geosci. Model Dev., 10, 4035–4055, 2017

Special issue: Paleoclimate Modelling Intercomparison Project phase 4 (PMIP4)...

Geosci. Model Dev., 10, 4035–4055, 2017
Model experiment description paper
07 Nov 2017
Model experiment description paper | 07 Nov 2017

The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experiments

Masa Kageyama1, Samuel Albani1, Pascale Braconnot1, Sandy P. Harrison2, Peter O. Hopcroft3, Ruza F. Ivanovic4, Fabrice Lambert5, Olivier Marti1, W. Richard Peltier6, Jean-Yves Peterschmitt1, Didier M. Roche1,7, Lev Tarasov8, Xu Zhang9, Esther C. Brady10, Alan M. Haywood4, Allegra N. LeGrande11, Daniel J. Lunt3, Natalie M. Mahowald12, Uwe Mikolajewicz13, Kerim H. Nisancioglu14,15, Bette L. Otto-Bliesner10, Hans Renssen7,16, Robert A. Tomas10, Qiong Zhang17, Ayako Abe-Ouchi18, Patrick J. Bartlein19, Jian Cao20, Qiang Li17, Gerrit Lohmann9, Rumi Ohgaito18,21, Xiaoxu Shi9, Evgeny Volodin22, Kohei Yoshida23, Xiao Zhang24,25, and Weipeng Zheng26 Masa Kageyama et al.
  • 1Laboratoire des Sciences du Climat et de l'Environnement, LSCE/IPSL, CEA-CNRS-UVSQ, Université Paris-Saclay, 91191 Gif-sur-Yvette, France
  • 2Centre for Past Climate Change and School of Archaeology, Geography and Environmental Science (SAGES) University of Reading, Whiteknights, Reading, RG6 6AH, UK
  • 3School of Geographical Sciences, University of Bristol, Bristol, BS8 1SS, UK
  • 4School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK
  • 5Department of Physical Geography, Pontifical Catholic University of Chile, Santiago, Chile
  • 6Department of Physics, University of Toronto, 60 St. George Street, Toronto, Ontario M5S 1A7, Canada
  • 7Earth and Climate Cluster, Faculty of Earth and Life Sciences, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
  • 8Department of Physics and Physical Oceanography, Memorial University of Newfoundland and Labrador, St. John's, NL, A1B 3X7, Canada
  • 9Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bussestrasse 24, 27570, Bremerhaven, Germany
  • 10National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, CO 80305, USA
  • 11NASA Goddard Institute for Space Studies, 2880 Broadway, New York, NY 10025, USA
  • 12Department of Earth and Atmospheric Sciences, Bradfield 1112, Cornell University, Ithaca, NY 14850, USA
  • 13Max Planck Institute for Meteorology, Bundesstrasse 53, 20146 Hamburg, Germany
  • 14Department of Earth Science, University of Bergen and the Bjerknes Centre for Climate Research, Allégaten 41, 5007 Bergen, Norway
  • 15Department of Geosciences and the Centre for Earth Evolution and Dynamics, University of Oslo, Sem Sælands vei 2A, 0371 Oslo, Norway
  • 16Department of Natural Sciences and Environmental Health, University College of Southeast Norway, Bø, Norway
  • 17Department of Physical Geography, Stockholm University and Bolin Centre for Climate Research, Stockholm, Sweden
  • 18Atmosphere Ocean Research Institute, University of Tokyo, 5-1-5, Kashiwanoha, Kashiwa-shi, Chiba 277-8564, Japan
  • 19Department of Geography, University of Oregon, Eugene, OR 97403-1251, USA
  • 20Earth System Modeling Center, Nanjing University of Information Science and Technology, Nanjing, China
  • 21Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan
  • 22Institute of Numerical Mathematics, Russian Academy of Sciences, Moscow, Russia
  • 23Meteorological Research Institute, Tsukuba, Japan
  • 24School of Atmospheric Science, Nanjing University of Information sciences and Technology, Nanjing, 210044, China
  • 25International Pacific Research Center, University of Hawaii at Manoa, Honolulu, HI 96822, USA
  • 26State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of China, 100029, Beijing, China

Abstract. The Last Glacial Maximum (LGM, 21 000 years ago) is one of the suite of paleoclimate simulations included in the current phase of the Coupled Model Intercomparison Project (CMIP6). It is an interval when insolation was similar to the present, but global ice volume was at a maximum, eustatic sea level was at or close to a minimum, greenhouse gas concentrations were lower, atmospheric aerosol loadings were higher than today, and vegetation and land-surface characteristics were different from today. The LGM has been a focus for the Paleoclimate Modelling Intercomparison Project (PMIP) since its inception, and thus many of the problems that might be associated with simulating such a radically different climate are well documented. The LGM state provides an ideal case study for evaluating climate model performance because the changes in forcing and temperature between the LGM and pre-industrial are of the same order of magnitude as those projected for the end of the 21st century. Thus, the CMIP6 LGM experiment could provide additional information that can be used to constrain estimates of climate sensitivity. The design of the Tier 1 LGM experiment (lgm) includes an assessment of uncertainties in boundary conditions, in particular through the use of different reconstructions of the ice sheets and of the change in dust forcing. Additional (Tier 2) sensitivity experiments have been designed to quantify feedbacks associated with land-surface changes and aerosol loadings, and to isolate the role of individual forcings. Model analysis and evaluation will capitalize on the relative abundance of paleoenvironmental observations and quantitative climate reconstructions already available for the LGM.

Short summary
The Last Glacial Maximum (LGM, 21000 years ago) is an interval when global ice volume was at a maximum, eustatic sea level close to a minimum, greenhouse gas concentrations were lower, atmospheric aerosol loadings were higher than today, and vegetation and land-surface characteristics were different from today. This paper describes the implementation of the LGM numerical experiment for the PMIP4-CMIP6 modelling intercomparison projects and the associated sensitivity experiments.