Estimates of anthropogenic carbon uptake from four three-dimensional global ocean models

• Published in: Global Biogeochemical Cycles
• Main Authors: Orr, James C., Maier-Reimer, Ernst, Mikolajewicz, U., Monfray, Patrick, Sarmiento, Jorge L., Toggweiler, J. R., Taylor, N. K., Palmer, J., Gruber, Nicolas, Sabine, Christopher L., Le Quéré, Corinne, Key, Robert M., Boutin, Jacqueline
• 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), Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics (MERMAID), 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), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-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)-École polytechnique (X)-Centre National d'Études Spatiales Toulouse (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Max-Planck-Institut für Meteorologie (MPI-M), Max-Planck-Gesellschaft, 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, National Oceanic and Atmospheric Administration (NOAA), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office Exeter, University of Bern, Princeton University, 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)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2001
• Subjects: [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]; [SDE.MCG]Environmental Sciences/Global Changes; Southern Ocean
• Online Access: https://hal.science/hal-00153888; https://hal.science/hal-00153888/document; https://hal.science/hal-00153888/file/2000GB001273.pdf; https://doi.org/10.1029/2000GB001273

We have compared simulations of anthropogenic CO$_2$ in the four threedimensional ocean models that participated in the first phase of the Ocean Carbon-Cycle Model Intercomparison Project (OCMIP), as a means to identify their major differences.Simulated global uptake agrees to within $\pm$19%, giving a range of 1.85$\pm$0.35 PgC yr$^{-1}$ for the 1980-1989 average. Regionally, the Southern Ocean dominates the present-day air-sea flux of anthropogenic CO$_2$ in all models, with one third to one half of the global uptake occurring south of 30°S. The highest simulated total uptake in the Southern Ocean was 70% larger than the lowest. Comparison with recent data-based estimates of anthropogenic CO$_2$ suggesthat most of the models substantially overestimate storage in the Southern Ocean; elsewhere they generally underestimate storage by less than 20%. Globally, the OCMIP models appear to bracket the real ocean's present uptake, based on comparison of regional data-basedstimates of anthropogenic CO$_2$ and bomb $^{14}$C. Column inventories of bomb $^{14}$C have become more similar to those for anthropogenic CO$_2$ with the time that has elapsed between the Geochemical Ocean Sections Study (1970s) and Word Ocean Circulation Experiment (1990s) global sampling campaigns. Our ability to evaluate simulated anthropogenic CO$_2$ would improve if systematic errors associated with the data-based estimates could be provided regionally.