Modeling a modern-like p CO2 warm period (Marine Isotope Stage KM5c) with two versions of an Institut Pierre Simon Laplace atmosphere-ocean coupled general circulation model

• Published in: Climate of the Past
• Main Authors: Tan, Ning, Contoux, Camille, Ramstein, Gilles, Sun, Yong, Dumas, Christophe, Sepulchre, Pierre, Guo, Zhengtang
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute of Geology and Geophysics Beijing (IGG), Chinese Academy of Sciences Beijing (CAS), Modélisation du climat (CLIM), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institute of Atmospheric Physics Beijing (IAP), College of Earth Sciences Beijing (CES), University of Chinese Academy of Sciences Beijing (UCAS), 2019-A0050102212 ANR-17-CE31-0010 National Natural Science Foundation of China, NSFC: 41888101, Acknowledgements. We thank Oliver Marti and Jean Baptiste Ladant for their help on the model setup. Many thanks to editor Aisling Dolan and two anonymous reviewers for their useful comments, which improved the quality of the manuscript. This study was performed using HPC resources from GENCI-TGCC under the allocation 2019-A0050102212., Financial support. This research has been supported by the French State Program Investissements d’Avenir (managed by ANR), the ANR HADOC project (grant no. ANR-17-CE31-0010), the Basic Science Center Project of the National Science Foundation of China (grant no. 41888101), and the Strategic Priority Research Program (grant no. XDB 26000000)., ANR-17-CE31-0010,HADoC,Rôle du Climat dans la dispersion des ancêtres de l'Homme(2017)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Greenland; Laplace; Ice Sheet; Sea ice
• Online Access: https://hal.archives-ouvertes.fr/hal-02861696; https://hal.archives-ouvertes.fr/hal-02861696/document; https://hal.archives-ouvertes.fr/hal-02861696/file/cp-16-1-2020.pdf; https://doi.org/10.5194/cp-16-1-2020

International audience The mid-Piacenzian warm period (3.264 to3.025 Ma) is the most recent geological period with present-like atmosphericpCO2and is thus expected to have exhib-ited a warm climate similar to or warmer than the present day.On the basis of understanding that has been gathered on theclimate variability of this interval, a specific interglacial (Ma-rine Isotope Stage KM5c, MIS KM5c; 3.205 Ma) has beenselected for the Pliocene Model Intercomparison Projectphase 2 (PlioMIP 2). We carried out a series of experimentsaccording to the design of PlioMIP2 with two versions ofthe Institut Pierre Simon Laplace (IPSL) atmosphere–oceancoupled general circulation model (AOGCM): IPSL-CM5Aand IPSL-CM5A2. Compared to the PlioMIP 1 experiment,run with IPSL-CM5A, our results show that the simulatedMIS KM5c climate presents enhanced warming in mid- tohigh latitudes, especially over oceanic regions. This warmingcan be largely attributed to the enhanced Atlantic MeridionalOverturning Circulation caused by the high-latitude seawaychanges. The sensitivity experiments, conducted with IPSL-CM5A2, show that besides the increasedpCO2, both mod-ified orography and reduced ice sheets contribute substan-tially to mid- to high latitude warming in MIS KM5c. Whenconsidering thepCO2uncertainties (+/−50 ppmv) duringthe Pliocene, the response of the modeled mean annual sur-face air temperature to changes topCO2(+/−50 ppmv) isnot symmetric, which is likely due to the nonlinear responseof the cryosphere (snow cover and sea ice extent). By an-alyzing the Greenland Ice Sheet surface mass balance, wealso demonstrate its vulnerability under both MIS KM5c andmodern warm climate