• Cox, M. D., 1987: Isopycnal diffusion in a z-coordinate ocean model. Ocean Modelling (unpublished manuscripts), 74, 1–5.

  • Danabasoglu, G., and J. C. McWilliams, 1995: Sensitivity of the global ocean circulation to parameterizations of mesoscale tracer transports. J. Climate,8, 2967–2987.

  • ——, ——, and P. R. Gent, 1994: The role of mesoscale tracer transports in the global ocean circulation. Science,264, 1123–1126.

  • Döös, K., and D. J. Webb, 1994: The Deacon cell and the other meridional cells of the Southern Ocean. J. Phys. Oceanogr.,24, 429–442.

  • Duffy, P. B., K. Caldeira, J. Selvaggi, and M. I. Hoffert, 1997: Effects of subgrid-scale mixing parameterizations on simulated distributions of natural 14C, temperature, and salinity in a three-dimensional ocean general circulation model. J. Phys. Oceanogr.,27, 498–523.

  • England, M. H., and G. Holloway, 1998: Simulation of CFC content and water mass age in the deep North Atlantic. J. Geophys. Res.,103, 15 885–15 901.

  • Gent, P. R., and J. C. McWilliams, 1990: Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr.,20, 150–155.

  • ——, J. Willebrand, T. J. McDougall, and J. C. McWilliams, 1995: Parameterizing eddy-induced tracer transports in ocean circulation models. J. Phys. Oceanogr.,25, 463–474.

  • ——, F. O. Bryan, G. Danabasoglu, S. C. Doney, W. R. Holland, W. G. Large, and J. C. McWilliams, 1998: The NCAR climate system model ocean component. J. Climate,11, 1278–1306.

  • Gerdes, R., C. Köberle, and J. Willebrand, 1991: The influence of numerical advection schemes on the results of ocean general circulation models. Climate Dyn.,5, 211–226.

  • Gordon, C., C. Cooper, C. A. Senior, H. Banks, J. M. Gregory, T. C. Johns, J. F. B. Mitchell, and R. A. Wood, 2000: The simulation of SST, sea ice extents and ocean heat transports in a version of the Hadley Centre coupled model without flux adjustments. Climate Dyn.,16, 147–168.

  • Greatbatch, R. J., 1998: Exploring the relationship between eddy-induced transport velocity, vertical momentum transfer, and the isopycnal flux of potential vorticity. J. Phys. Oceanogr.,28, 422–432.

  • Griffies, S. M., 1998: The Gent–McWilliams skew flux. J. Phys. Oceanogr.,28, 831–841.

  • Hall, M. M., and H. L. Bryden, 1982: Direct estimates and mechanisms of ocean heat transport. Deep-Sea Res.,29, 339–359.

  • Han, Y. J., and S. W. Lee, 1983: An analysis of monthly mean windstress over the global ocean. Mon. Wea. Rev.,111, 1554–1566.

  • Harvey, L. D. D., 1995: Impact of isopycnal diffusion on heat fluxes and the transient response of a two-dimensional ocean model. J. Phys. Oceanogr.,25, 2166–2176.

  • Hirst, A. C., 1999: The Southern Ocean response to global warming in the CSIRO coupled ocean–atmosphere model. Environ. Model. Software,14, 227–241.

  • ——, and W. Cai, 1994: Sensitivity of a World Ocean GCM to changes in subsurface mixing parameterization. J. Phys. Oceanogr.,24, 1256–1279.

  • ——, and T. J. McDougall, 1996: Deep-water properties and surface buoyancy flux as simulated by a z-coordinate model including eddy-induced advection. J. Phys. Oceanogr.,26, 1320–1343.

  • ——, and ——, 1998: Meridional overturning and dianeutral transport in a z-coordinate ocean model including eddy-induced advection. J. Phys. Oceanogr.,28, 1205–1223.

  • ——, H. B. Gordon, and S. P. O’Farell, 1996: Global warming in a coupled climate model including oceanic eddy-induced advection. Geophys. Res. Lett.,23, 3361–3364.

  • Iselin, C. O., 1939: The influence of vertical and lateral turbulence on the characteristics of the waters at mid-depths. Trans. Amer. Geophys. Union,20, 414–417.

  • Knutti, R., 1999: Parametrisierungen von sub-skaligen Mischungsprozessen in einem zonal gemittelten Ozean-Modell. M.S. thesis, Dept. of Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland, 143 pp. [Available from Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrasse 5, CH-3012 Bern, Switzerland.].

  • Latif, M., E. Roeckner, U. Mikolajewicz, and R. Voss, 2000: Tropical stabilization of the thermohaline circulation in a greenhouse warming simulation. J. Climate,13, 1809–1813.

  • Ledwell, J. R., A. J. Watson, and C. S. Law, 1993: Evidence for slow mixing across the pycnocline from an open-ocean tracer-release experiment. Nature,364, 701–703.

  • Levitus, S., and T. P. Boyer, 1994: World Ocean Atlas 1994, Vol. 4:Temperature. NOAA Atlas NESDIS 4, NOAA, U.S. Dept. of Commerce, 117 pp.

  • ——, S. R. Burgett, and T. P. Boyer, 1994: World Ocean Atlas 1994, Vol. 3: Salinity. NOAA Atlas NESDIS 3, NOAA U.S. Dept. of Commerce, 99 pp.

  • Lin, C. A., 1988: A mechanistic model of isopycnal diffusion in the ocean. Climate Dyn.,2, 165–171.

  • Manabe, S., and R. J. Stouffer, 1994: Multiple-century response of a coupled ocean–atmosphere model to an increase of atmospheric carbon dioxide. J. Climate,7, 5–23.

  • Marotzke, J., and P. Stone, 1995: Atmospheric transports, the thermohaline circulation, and flux adjustments in a simple coupled model. J. Phys. Oceanogr.,25, 1350–1364.

  • McDougall, T. J., 1987: Neutral surfaces. J. Phys. Oceanogr.,17, 1950–1964.

  • ——, and J. A. Church, 1986: Pitfalls with the numerical representation of isopycnal and diapycnal mixing. J. Phys. Oceanogr.,16, 196–199.

  • Montgomery, R. B., 1940: The present evidence on the importance of lateral mixing processes in the ocean. Bull. Amer. Meteor. Soc.,21, 87–94.

  • Power, S. B., and A. C. Hirst, 1997: Eddy parameterization and the oceanic response to global warming. Climate Dyn.,13, 417–428.

  • Redi, M. H., 1982: Oceanic isopycnal mixing by coordinate rotation. J. Phys. Oceanogr.,12, 1154–1158.

  • Robitaille, D. Y., and A. J. Weaver, 1995: Validation of sub-grid-scale mixing schemes using CFCs in a global ocean model. Geophys. Res. Lett.,22, 2917–2920.

  • Sausen, R., R. Barthels, and K. Hasselman, 1988: Coupled ocean–atmosphere models with flux correction. Climate Dyn.,2, 154–163.

  • Schmittner, A., and T. F. Stocker, 1999: The stability of the thermohaline circulation in global warming experiments. J. Climate,12, 1117–1133.

  • ——, C. Appenzeller, and T. F. Stocker, 2000a: Enhanced Atlantic freshwater export during El Niño. Geophys. Res. Lett.,27, 1163–1166.

  • ——, ——, and ——, 2000b: Validation of parameterizations of the hydrological cycle used in zonally averaged climate models. Climate Dyn.,16, 63–77.

  • Shine, K. P., R. G. Derwent, D. J. Wuebbles, and J.-J. Morcrette, 1995: Radiative forcing of climate. Climate Change, The IPCC Scientific Assessment, J. T. Houghton, G. J. Jenkins, and J. J. Ephraums, Eds., Cambridge University Press, 41–68.

  • Stocker, T. F., and D. G. Wright, 1996: Rapid changes in ocean circulation and atmospheric radiocarbon. Paleoceanography,11, 773–796.

  • ——, and A. Schmittner, 1997: Influence of CO2 emission rates on the stability of the thermohaline circulation. Nature,388, 862–865.

  • ——, D. G. Wright, and W. S. Broecker, 1992a: The influence of high-latitude surface forcing on the global thermohaline circulation. Paleoceanography,7, 529–541.

  • ——, ——, and L. A. Mysak, 1992b: A zonally averaged, coupled ocean–atmosphere model for paleoclimate studies. J. Climate,5, 773–797.

  • Toole, J. M., K. L. Polzin, and R. W. Schmitt, 1994: Estimates of diapycnal mixing in the abyssal ocean. Science,264, 1120–1123.

  • Trenberth, K. E., and A. Solomon, 1994: The global heat balance: Heat transport in the atmosphere and ocean. Climate Dyn.,10, 107–134.

  • Tziperman, E., 1997: Inherently unstable climate behaviour due to weak thermohaline ocean circulation. Nature,386, 592–595.

  • Visbeck, M., J. Marshall, and T. Haine, 1997: Specification of eddy transfer coefficients in coarse-resolution ocean circulation models. J. Phys. Oceanogr.,27, 381–402.

  • Weaver, A. J., and M. Eby, 1997: On the numerical implementation of advection schemes for use in conjunction with various mixing parameterizations in the GFDL ocean model. J. Phys. Oceanogr.,27, 369–377.

  • Wiebe, E. C., and A. J. Weaver, 1999: On the sensitivity of global warming experiments to the parameterisation of sub-grid scale ocean mixing. Climate Dyn.,15, 875–893.

  • Wright, D. G., 1996: An equation of state for use in ocean models: Eckart’s formula revisited. J. Atmos. Oceanic Technol.,14, 735–740.

  • ——, and T. F. Stocker, 1991: A zonally averaged ocean model for the thermohaline circulation. Part I: Model development and flow dynamics. J. Phys. Oceanogr.,21, 1713–1724.

  • ——, and ——, 1992: Sensitivities of a zonally averaged global ocean circulation model. J. Geophys. Res.,97, 12 707–12 730.

  • ——, and ——, 1993: Younger Dryas experiments. Ice in the Climate System, W. R. Peltier, Ed., NATO ASI Series, Vol. I 12, Springer-Verlag, 395–416.

  • ——, C. B. Vreugdenhil, and T. M. Hughes, 1995: Vorticity dynamics and zonally averaged ocean circulation models. J. Phys. Oceanogr.,25, 2141–2154.

  • ——, T. F. Stocker, and D. Mercer, 1998: Closures used in zonally averaged ocean models. J. Phys. Oceanogr.,28, 791–804.

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The Effects of Subgrid-Scale Parameterizations in a Zonally Averaged Ocean Model

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  • 1 Climate and Environmental Physics, Physics Institute, University of Bern, Bern, Switzerland
  • | 2 Ocean Science Division, Bedford Institute of Oceanography, Dartmouth, Nova Scotia, Canada
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Abstract

Isopycnal diffusion and an additional transport velocity parameterizing the effect of mesoscale eddies are implemented in the ocean component of a 2.5-dimensional zonally averaged coupled ocean–atmosphere model. The equilibrium states of the coupled ocean–atmosphere model, resulting from the different mixing parameterizations, are compared, and extensive parameter sensitivity studies are presented. For the equilibrium base states, the new mixing schemes result in changes in the distributions of temperature and salinity that are significant in the Southern Ocean, where the isopycnal surfaces are steep and the eddy-induced transport velocity approximately cancels the Deacon cell. The temperature and salinity changes are relatively small in the rest of the ocean. Furthermore, the implementation of the new mixing schemes results in significant changes in the strength and the pattern of the thermohaline circulation. Transient responses of the coupled ocean–atmosphere system in global warming scenarios are compared for the different mixing parameterizations. It is demonstrated that large changes in the stability of the thermohaline circulation occur and that the observed changes in stability are highly parameter dependent.

Corresponding author address: Dr. Thomas F. Stocker, Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrase 5, CH-3012 Bern, Switzerland.

Email: stocker@climate.unibe.ch

Abstract

Isopycnal diffusion and an additional transport velocity parameterizing the effect of mesoscale eddies are implemented in the ocean component of a 2.5-dimensional zonally averaged coupled ocean–atmosphere model. The equilibrium states of the coupled ocean–atmosphere model, resulting from the different mixing parameterizations, are compared, and extensive parameter sensitivity studies are presented. For the equilibrium base states, the new mixing schemes result in changes in the distributions of temperature and salinity that are significant in the Southern Ocean, where the isopycnal surfaces are steep and the eddy-induced transport velocity approximately cancels the Deacon cell. The temperature and salinity changes are relatively small in the rest of the ocean. Furthermore, the implementation of the new mixing schemes results in significant changes in the strength and the pattern of the thermohaline circulation. Transient responses of the coupled ocean–atmosphere system in global warming scenarios are compared for the different mixing parameterizations. It is demonstrated that large changes in the stability of the thermohaline circulation occur and that the observed changes in stability are highly parameter dependent.

Corresponding author address: Dr. Thomas F. Stocker, Climate and Environmental Physics, Physics Institute, University of Bern, Sidlerstrase 5, CH-3012 Bern, Switzerland.

Email: stocker@climate.unibe.ch

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