Evaluation of ocean model ventilation with CFC-11: comparison of 13 global ocean models

• Published in: Ocean Modelling
• Main Authors: Dutay, Jean-Claude, Bullister, John L., Doney, Scott C., Orr, James C., Najjar, Raymond G., Caldeira, K., Campin, J.-M., Drange, Helge, Follows, Michael J., Gao, Y., Gruber, Nicolas, Hecht, M.W, Ishida, Akio, Joos, Fortunat, Lindsay, Keith, Madec, Gurvan, Maier-Reimer, Ernst, Marshall, J.C., Matear, Richard J., Monfray, Patrick, Mouchet, Anne, Plattner, Gian-Kasper, Sarmiento, Jorge L., Schlitzer, Reiner, Slater, Richard D., Totterdell, Ian J., Weirig, Marie-France, Yamanaka, Yasuhiro, Yool, Andrew
• Other Authors: 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), Modélisation du climat (CLIM), 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)), NOAA Pacific Marine Environmental Laboratory Seattle (PMEL), National Oceanic and Atmospheric Administration (NOAA), National Center for Atmospheric Research Boulder (NCAR), Pennsylvania State University (Penn State), Penn State System, Lawrence Livermore National Laboratory (LLNL), Institut d'Astronomie et de Géophysique Georges Lemaître (UCL-ASTR), Université Catholique de Louvain = Catholic University of Louvain (UCL), Nansen Environmental and Remote Sensing Center Bergen (NERSC), Massachusetts Institute of Technology (MIT), Atmospheric and Oceanic Sciences Program Princeton (AOS Program), NOAA Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-Princeton University, Research Institute for Global Change (RIGC), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Climate and Environmental Physics Bern (CEP), Physikalisches Institut Bern, Universität Bern / University of Bern (UNIBE)-Universität Bern / University of Bern (UNIBE), Oeschger Centre for Climate Change Research (OCCR), Universität Bern / University of Bern (UNIBE), Climate and Global Dynamics Division Boulder (CGD), Laboratoire d'océanographie dynamique et de climatologie (LODYC), Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Max Planck Institute for Meteorology (MPI-M), Max-Planck-Gesellschaft, Commonwealth Scientific and Industrial Research Organisation Canberra (CSIRO), Astrophysics and Geophysics Institute Liège, Université de Liège, Institute of Applied Physics Bern (IAP), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung = Alfred Wegener Institute for Polar and Marine Research = Institut Alfred-Wegener pour la recherche polaire et marine (AWI), Helmholtz-Gemeinschaft = Helmholtz Association, National Oceanography Centre Southampton (NOC), University of Southampton
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2002
• Subjects: Models; Ocean ventilation; Transient tracers; CFC; [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]; [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]; Southern Ocean; Pacific; NADW; North Atlantic Deep Water; North Atlantic; Sea ice
• Online Access: https://hal.science/hal-00772133; https://doi.org/10.1016/S1463-5003(01)00013-0

International audience We compared the 13 models participating in the Ocean Carbon Model Intercomparison Project (OCMIP) with regards to their skill in matching observed distributions of CFC-11. This analysis characterizes the abilities of these models to ventilate the ocean on timescales relevant for anthropogenic CO2 uptake. We found a large range in the modeled global inventory (±30%), mainly due to differences in ventilation from the high latitudes. In the Southern Ocean, models differ particularly in the longitudinal distribution of the CFC uptake in the intermediate water, whereas the latitudinal distribution is mainly controlled by the subgrid-scale parameterization. Models with isopycnal diffusion and eddy-induced velocity parameterization produce more realistic intermediate water ventilation. Deep and bottom water ventilation also varies substantially between the models. Models coupled to a sea-ice model systematically provide more realistic AABW formation source region; however these same models also largely overestimate AABW ventilation if no specific parameterization of brine rejection during sea-ice formation is included. In the North Pacific Ocean, all models exhibit a systematic large underestimation of the CFC uptake in the thermocline of the subtropical gyre, while no systematic difference toward the observations is found in the subpolar gyre. In the North Atlantic Ocean, the CFC uptake is globally underestimated in subsurface. In the deep ocean, all but the adjoint model, failed to produce the two recently ventilated branches observed in the North Atlantic Deep Water (NADW). Furthermore, simulated transport in the Deep Western Boundary Current (DWBC) is too sluggish in all but the isopycnal model, where it is too rapid.