• Adkins, J. F., 2013: The role of deep ocean circulation in setting glacial climates. Paleoceanography, 28, 539561, https://doi.org/10.1002/palo.20046.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Baker, J. A., A. J. Watson, and G. K. Vallis, 2020: Meridional overturning circulation in a multi-basin model. Part I: Dependence on southern ocean buoyancy forcing. J. Phys. Oceanogr., 50, 11591178, https://doi.org/10.1175/JPO-D-19-0135.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Broecker, W. S., 1991: The great ocean conveyor. Oceanography, 4, 7989, https://doi.org/10.5670/oceanog.1991.07.

  • Brovkin, V., A. Ganopolski, D. Archer, and S. Rahmstorf, 2007: Lowering of glacial atmospheric CO2 in response to changes in oceanic circulation and marine biogeochemistry. Paleoceanography, 22, PA4202, https://doi.org/10.1029/2006PA001380.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Burke, A., A. L. Stewart, J. F. Adkins, R. Ferrari, M. F. Jansen, and A. F. Thompson, 2015: The glacial mid-depth radiocarbon bulge and its implications for the overturning circulation. Paleoceanography, 30, 10211039, https://doi.org/10.1002/2015PA002778.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cessi, P., 2019: The global overturning circulation. Annu. Rev. Mar. Sci., 11, 249270, https://doi.org/10.1146/annurev-marine-010318-095241.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Cessi, P., and C. S. Jones, 2017: Warm-route versus cold-route interbasin exchange in the meridional overturning circulation. J. Phys. Oceanogr., 47, 19811997, https://doi.org/10.1175/JPO-D-16-0249.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Curry, W. B., and D. W. Oppo, 2005: Glacial water mass geometry and the distribution of δ13C of ΣCO2 in the western Atlantic Ocean. Paleoceanography, 20, PA1017, https://doi.org/10.1029/2004PA001021.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ferrari, R., M. F. Jansen, J. F. Adkins, A. Burke, A. L. Stewart, and A. F. Thompson, 2014: Antarctic sea ice control on ocean circulation in present and glacial climates. Proc. Natl. Acad. Sci. USA, 111, 87538758, https://doi.org/10.1073/pnas.1323922111.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Ferrari, R., L.-P. Nadeau, D. P. Marshall, L. C. Allison, and H. L. Johnson, 2017: A model of the ocean overturning circulation with two closed basins and a reentrant channel. J. Phys. Oceanogr., 47, 28872906, https://doi.org/10.1175/JPO-D-16-0223.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Gnanadesikan, A., 1999: A simple predictive model for the structure of the oceanic pycnocline. Science, 283, 20772079, https://doi.org/10.1126/science.283.5410.2077.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jansen, M. F., 2017: Glacial ocean circulation and stratification explained by reduced atmospheric temperature. Proc. Natl. Acad. Sci. USA, 114, 4550, https://doi.org/10.1073/pnas.1610438113.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jansen, M. F., and L.-P. Nadeau, 2016: The effect of Southern Ocean surface buoyancy loss on the deep ocean circulation and stratification. J. Phys. Oceanogr., 46, 34553470, https://doi.org/10.1175/JPO-D-16-0084.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jansen, M. F., and L.-P. Nadeau, 2019: A toy model for the response of the residual overturning circulation to surface warming. J. Phys. Oceanogr., 49, 12491268, https://doi.org/10.1175/JPO-D-18-0187.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jones, C. S., and P. Cessi, 2016: Interbasin transport of the meridional overturning circulation. J. Phys. Oceanogr., 46, 11571169, https://doi.org/10.1175/JPO-D-15-0197.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Jones, C. S., and R. P. Abernathey, 2019: Isopycnal mixing controls deep ocean ventilation. Geophys. Res. Lett., 46, 13 14413 151, https://doi.org/10.1029/2019GL085208.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Lumpkin, R., and K. Speer, 2007: Global ocean meridional overturning. J. Phys. Oceanogr., 37, 25502562, https://doi.org/10.1175/JPO3130.1.

  • Marshall, D. P., and L. Zanna, 2014: A conceptual model of ocean heat uptake under climate change. J. Climate, 27, 84448465, https://doi.org/10.1175/JCLI-D-13-00344.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marshall, J., and T. Radko, 2003: Residual-mean solutions for the Antarctic circumpolar current and its associated overturning circulation. J. Phys. Oceanogr., 33, 23412354, https://doi.org/10.1175/1520-0485(2003)033<2341:RSFTAC>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marshall, J., C. Hill, L. Perelman, and A. Adcroft, 1997: A finite-volume, incompressible navier stokes model for studies of the ocean on parallel computers. J. Geophys. Res., 102, 57535766, https://doi.org/10.1029/96JC02775.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marzocchi, A., and M. F. Jansen, 2017: Connecting Antarctic sea ice to deep-ocean circulation in modern and glacial climate simulations. Geophys. Res. Lett., 44, 62866295, https://doi.org/10.1002/2017GL073936.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Marzocchi, A., and M. F. Jansen, 2019: Global cooling linked to increased glacial carbon storage via changes in Antarctic sea ice. Nat. Geosci., 12, 10011005, https://doi.org/10.1038/s41561-019-0466-8.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nadeau, L.-P., R. Ferrari, and M. F. Jansen, 2019: Antarctic sea ice control on the depth of North Atlantic deep water. J. Climate, 32, 25372551, https://doi.org/10.1175/JCLI-D-18-0519.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Newsom, E. R., and A. F. Thompson, 2018: Reassessing the role of the Indo-Pacific in the ocean’s global overturning circulation. Geophys. Res. Lett., 45, 12 42212 431, https://doi.org/10.1029/2018GL080350.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nikurashin, M., and G. Vallis, 2011: A theory of deep stratification and overturning circulation in the ocean. J. Phys. Oceanogr., 41, 485502, https://doi.org/10.1175/2010JPO4529.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Nikurashin, M., and G. Vallis, 2012: A theory of the interhemispheric meridional overturning circulation and associated stratification. J. Phys. Oceanogr., 42, 16521667, https://doi.org/10.1175/JPO-D-11-0189.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Schmittner, A., J. Green, and S.-B. Wilmes, 2015: Glacial ocean overturning intensified by tidal mixing in a global circulation model. Geophys. Res. Lett., 42, 40144022, https://doi.org/10.1002/2015GL063561.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Shin, S.-I., Z. Liu, B. L. Otto-Bliesner, J. E. Kutzbach, and S. J. Vavrus, 2003: Southern Ocean sea-ice control of the glacial North Atlantic thermohaline circulation. Geophys. Res. Lett., 30, 1096, https://doi.org/10.1029/2002GL015513.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sigman, D. M., and E. A. Boyle, 2000: Glacial/interglacial variations in atmospheric carbon dioxide. Nature, 407, 859869, https://doi.org/10.1038/35038000.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Stephens, B. B., and R. F. Keeling, 2000: The influence of Antarctic sea ice on glacial-interglacial CO2 variations. Nature, 404, 171174, https://doi.org/10.1038/35004556.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sun, S., I. Eisenman, and A. L. Stewart, 2018: Does southern ocean surface forcing shape the global ocean overturning circulation? Geophys. Res. Lett., 45, 24132423, https://doi.org/10.1002/2017GL076437.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Sun, S., I. Eisenman, L. Zanna, and A. L. Stewart, 2020: Surface constraints on the depth of the Atlantic meridional overturning circulation: Southern Ocean versus North Atlantic. J. Climate, 33, 31253149, https://doi.org/10.1175/JCLI-D-19-0546.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Talley, L. D., 2013: Closure of the global overturning circulation through the Indian, Pacific, and Southern Oceans: Schematics and transports. Oceanography, 26, 8097, https://doi.org/10.5670/oceanog.2013.07.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Thompson, A. F., A. L. Stewart, and T. Bischoff, 2016: A multibasin residual-mean model for the global overturning circulation. J. Phys. Oceanogr., 46, 25832604, https://doi.org/10.1175/JPO-D-15-0204.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Toggweiler, J. R., and B. Samuels, 1998: On the ocean’s large-scale circulation near the limit of no vertical mixing. J. Phys. Oceanogr., 28, 18321852, https://doi.org/10.1175/1520-0485(1998)028<1832:OTOSLS>2.0.CO;2.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Watson, A. J., G. K. Vallis, and M. Nikurashin, 2015: Southern ocean buoyancy forcing of ocean ventilation and glacial atmospheric CO2. Nat. Geosci., 8, 861864, https://doi.org/10.1038/ngeo2538.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wolfe, C. L., and P. Cessi, 2009: Overturning circulation in an eddy-resolving model: The effect of the pole-to-pole temperature gradient. J. Phys. Oceanogr., 39, 125142, https://doi.org/10.1175/2008JPO3991.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wolfe, C. L., and P. Cessi, 2011: The adiabatic pole-to-pole overturning circulation. J. Phys. Oceanogr., 41, 17951810, https://doi.org/10.1175/2011JPO4570.1.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • Wunsch, C., and R. Ferrari, 2004: Vertical mixing, energy, and the general circulation of the oceans. Annu. Rev. Fluid Mech., 36, 281314, https://doi.org/10.1146/annurev.fluid.36.050802.122121.

    • Crossref
    • Search Google Scholar
    • Export Citation
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Overturning Circulation Pathways in a Two-Basin Ocean Model

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  • 1 Institut des Sciences de la Mer de Rimouski, Université du Québec à Rimouski, Rimouski, Quebec, Canada
  • 2 Department of the Geophysical Sciences, University of Chicago, Chicago, Illinois
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Abstract

A toy model for the deep ocean overturning circulation in multiple basins is presented and applied to study the role of buoyancy forcing and basin geometry in the ocean’s global overturning. The model reproduces the results from idealized general circulation model simulations and provides theoretical insights into the mechanisms that govern the structure of the overturning circulation. The results highlight the importance of the diabatic component of the meridional overturning circulation (MOC) for the depth of North Atlantic Deep Water (NADW) and for the interbasin exchange of deep ocean water masses. This diabatic component, which extends the upper cell in the Atlantic below the depth of adiabatic upwelling in the Southern Ocean, is shown to be sensitive to the global area-integrated diapycnal mixing rate and the density contrast between NADW and Antarctic Bottom Water (AABW). The model also shows that the zonally averaged global overturning circulation is to zeroth-order independent of whether the ocean consists of one or multiple connected basins, but depends on the total length of the southern reentrant channel region (representing the Southern Ocean) and the global ocean area integrated diapycnal mixing. Common biases in single-basin simulations can thus be understood as a direct result of the reduced domain size.

Corresponding author: Louis-Philippe Nadeau, louis-philippe_nadeau@uqar.ca

Both authors contributed equally to this work.

Abstract

A toy model for the deep ocean overturning circulation in multiple basins is presented and applied to study the role of buoyancy forcing and basin geometry in the ocean’s global overturning. The model reproduces the results from idealized general circulation model simulations and provides theoretical insights into the mechanisms that govern the structure of the overturning circulation. The results highlight the importance of the diabatic component of the meridional overturning circulation (MOC) for the depth of North Atlantic Deep Water (NADW) and for the interbasin exchange of deep ocean water masses. This diabatic component, which extends the upper cell in the Atlantic below the depth of adiabatic upwelling in the Southern Ocean, is shown to be sensitive to the global area-integrated diapycnal mixing rate and the density contrast between NADW and Antarctic Bottom Water (AABW). The model also shows that the zonally averaged global overturning circulation is to zeroth-order independent of whether the ocean consists of one or multiple connected basins, but depends on the total length of the southern reentrant channel region (representing the Southern Ocean) and the global ocean area integrated diapycnal mixing. Common biases in single-basin simulations can thus be understood as a direct result of the reduced domain size.

Corresponding author: Louis-Philippe Nadeau, louis-philippe_nadeau@uqar.ca

Both authors contributed equally to this work.

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