Mid-Holocene NAO: A PMIP2 model intercomparison

• Published in: Geophysical Research Letters
• Main Authors: Gladstone, R., Ross, I., Valdes, P.J., Abe-Ouchi, A., Braconnot, P., Brewer, S., Kageyama, M., Kitoh, A., Legrande, A., Marti, O., Ohgaito, R., Otto-Bliesner, B., Peltier, W. R., Vettoretti, G.
• Other Authors: School of Geographical Sciences Bristol, University of Bristol Bristol, Center for Climate System Research Kashiwa (CCSR), The University of Tokyo (UTokyo), Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Modélisation du climat (CLIM), Meteorological Research Institute Tsukuba (MRI), Japan Meteorological Agency (JMA), NASA Goddard Institute for Space Studies (GISS), NASA Goddard Space Flight Center (GSFC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), National Center for Atmospheric Research Boulder (NCAR), Department of Physics Toronto, University of Toronto
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2005
• Subjects: [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology; North Atlantic; North Atlantic oscillation
• Online Access: https://hal.science/hal-02931809; https://hal.science/hal-02931809/document; https://hal.science/hal-02931809/file/2005GL023596.pdf; https://doi.org/10.1029/2005GL023596

International audience The mid‐Holocene (6000 years before present) North Atlantic Oscillation (NAO) from nine models in the Paleoclimate Modeling Intercomparison Project Phase 2 is studied, primarily through principal component analysis of winter time North Atlantic sea level pressure (SLP). Modeled mid‐Holocene NAO and mean SLP show small changes compared to pre‐industrial control runs, with a shift in mean state towards a more positive NAO regime for three of the models. Modeled NAO variability shows little change, with a small increase for some models in the fraction of time spent in the NAO‐negative phase during the mid‐Holocene. Proxy based reconstructions of the NAO indicate a more positive NAO regime compared to present day during the mid‐ Holocene. We hypothesise that there was a small NAO+ like shift in mean state during the mid‐Holocene.