Abstract
A two-dimensional, three-basin ocean model suitable for long-term climate studies is developed. The model is based on the zonally averaged form of the primitive equations written in spherical coordinates. The east-west density difference which arises upon averaging the momentum equations is taken to be proportional to the meridional density gradient. Lateral exchanges of heat and salt between the basins are explicitly resolved. Moreover, the model includes bottom topography and has representations of the Arctic Ocean and of the Weddell and Ross seas. Under realistic restoring boundary conditions, the model reproduces the global conveyor belt: deep water is formed in the Atlantic between 60 and 70°N at a rate of about 17 Sv (1 Sv=106 m3 s−1) and in the vicinity of the Antarctic continent, while the Indian and Pacific basins show broad upwelling. Superimposed on this thermohaline circulation are vigorous wind-driven cells in the upper thermocline. The simulated temperature and salinity fields and the computed meridional heat transport compare reasonably well with the observational estimates. When mixed boundary conditions (i.e., a restoring condition on sea-surface temperature and flux condition on sea-surface salinity) are applied, the model exhibits an irregular behavior before reaching a steady state characterized by self-sustained oscillations of 8.5-y period. The conveyor-belt circulation always results at this stage. A series of perturbation experiments illustrates the ability of the model to reproduce different steady-state circulations under mixed boundary conditions. Finally, the model sensitivity to various factors is examined. This sensitivity study reveals that the bottom topography and the presence of a submarine meridional ridge in the zone of the Drake Passage play a crucial role in determining the properties of the model bottom-water masses. The importance of the seasonality of the surface forcing is also stressed.
Similar content being viewed by others
References
Asselin R (1972) Frequency filter for time integrations. Mon Weather Rev 6:487–490
Boyle EA, Keigwin LD (1987) North Atlantic thermohaline circulation during the last 20000 years linked to high-latitude surface temperature. Nature 330:35–40
Broecker WS (1987) Unpleasant surprise in the greenhouse? Nature 328:123–127
Broecker WS (1991) The great ocean conveyor. Oceanography 4:79–89
Broecker WS, Peteet D, Rind D (1985) Does the ocean-atmosphere have more than one stable mode of operation? Nature 315:21–25
Broecker WS, Bond G, Klas M, Bonani G, Wolfi W (1990) A salt oscillator in the glacial North Atlantic? I. The concept. Paleoceanography 5:469–477
Bryan F (1986) High-latitude salinity effects and interhemispheric thermohaline circulations. Nature 323:301–304
Bryan F (1987) Parameter sensitivity of primitive equation ocean general circulation models. J Phys Oceanogr 17:970–985
Bryan K (1969) A numerical method for the study of the circulation of the World Ocean. J Comput Phys 4:347–376
Bryan K (1982) Seasonal variation in meridional overturning and poleward heat transport in the Atlantic and Pacific oceans: a model study. J Mar Res 40:39–53
Bryan K (1984) Accelerating the convergence to equilibrium of ocean-climate models. J Phys Oceanogr 14:666–673
Bryan K, Lewis LJ (1979) A water mass model of the World Ocean. J Geophys Res 67:3403–3414
Bryden HL, Hall MM (1980) Heat transport by currents across 25°N latitude in the Atlantic Ocean. Science 207:884–885
Carissimo BC, Oort AH, Vonder Haar TH (1985) Estimating the meridional energy transports in the atmosphere and ocean. J Phys Oceanogr 15:82–91
Colin de Verdière A (1988) Buoyancy driven planetary flows. J Mar Res 46:215–265
Covey C (1992) Behavior of an ocean general circulation model at four different horizontal resolutions. Program for Climate Model Diagnosis and Intercomparison Report No 4, University of California and Lawrence Livermore National Laboratory, Livermore
Cox MD (1989) An idealized model of the World Ocean. Part I: the global-scale water masses. J Phys Oceanogr 19:1730–1752
Duplessy J-C, Shackleton NJ, Fairbanks RG, Labeyrie LD, Oppo D, Kallel N (1988) Deep-water source variations during the last climatic cycle and their impact on the global deepwater circulation. Paleoceanography 3:343–360
England MH (1992) On the formation of Antarctic Intermediate and Bottom Water in ocean general circulation models. J Phys Oceanogr 22:918–926
Esbensen SK, Kushnir Y (1981) The heat budget of the global ocean: an atlas based on estimates from surface marine observations. Climate Research Institute Report 29, Oregon State University, Corvallis
Friedrich H, Levitus S (1972) An approximation equation of state for numerical models of ocean circulation. J Phys Oceanogr 2:514–517
Fu LL (1986) Mass, heat and freshwater fluxes in the South Indian Ocean. J Phys Oceanogr 16:1683–1693
Gallée H, van Ypersele J-P, Fichefet Th, Tricot Ch, Berger A (1991) Simulation of the last glacial cycle by a coupled, sectorially averaged climate-ice sheet model. I. The climate model. J Geophys Res 96:13139–13161
Gallée H, van Ypersele J-P, Fichefet Th, Marsiat I, Tricot Ch, Berger A (1992) Simulation of the last glacial cycle by a coupled, sectorially averaged climate-ice sheet model. 11. Response to insolation and CO2 variations. J Geophys Res 97:15713–15740
Gill AE, Bryan K (1971) Effects of geometry on the circulation of a three-dimensional Southern-Hemisphere ocean model. Deep-Sea Res 91:685–721
Gordon AL (1986) Interocean exchange of thermocline water. J Geophys Res 91:5037–5046
Gordon AL, Molinelli EJ (1986) Thermohaline and chemical distributions and the atlas data set. In: Southern Ocean atlas. Amerind Publishing Company, New Delhi, India
Haney RL (1971) Surface thermal boundary condition for ocean circulation models. J Phys Oceanogr 1:241–248
Harvey LDD (1992) A two-dimensional ocean model for longterm climatic simulations: stability and coupling to atmospheric and sea ice models. J Geophys Res 97:9435–9453
Hastenrath S (1982) On meridional heat transports in the World Ocean. J Phys Oceanogr 12:922–927
Hellerman S, Rosenstein M (1983) Normal monthly wind stress over the World Ocean with error estimates. J Phys Oceanogr 13:1093–1104
Hsiung J (1985) Estimates of global oceanic meridional heat transport. J Phys Oceanogr 15:1405–1413
Keigwin LD, Jones GA, Lehman SJ, Boyle EA (1991) Deglacial meltwater discharge, North Atlantic deep circulation, and abrupt climate change. J Geophys Res 96:16811–16826
Kiliworth PD (1983) Deep convection in the World Ocean. Rev Geophys Space Phys 21:1–26
Lehman SJ, Keigwin LD (1992) Sudden changes in North Atlantic circulation during the last deglaciation. Nature 356:757–762
Levitus S (1982) Climatological atlas of the World Ocean. NOAA Prof Pap 13, US Government Printing Office, Washington, DC
Marotzke J, Willebrand J (1991) Multiple equilibria of the global thermohaline circulation. J Phys Oceanogr 21:1372–1385
Marotzke J, Welander P, Willebrand J (1988) Instability and multiple steady states in a meridional-plane model of the thermohaline circulation. Tellus 40A:162–172
Meehl GA, Washington WM, Semtner AJ (1982) Experiments with a global ocean model driven by observed atmospheric forcing. J Phys Oceanogr 2:301–312
Oberhuber JM (1988) An atlas based on the COADS data set: the budget of heat buoyancy and turbulent kinetic energy at the surface of the global ocean. Max-Planck-Institut fur Meteorologie Rep 15, Hamburg, Germany
Oort AH, Vonder Haar TH (1976) On the observed annual cycle in the ocean-atmosphere heat balance over the Northern Hemisphere. J Phys Oceanogr 6:781–800
Power SB, Kleeman R (1993) Multiple equilibria in a global ocean general circulation model. J Phys Oceanogr 23:1670–1681
Rago TA, Rossby HT (1987) Heat transport into the North Atlantic Ocean north of 32°N latitude. J Phys Oceanogr 17:854–871
Roemmich D (1980) Estimates of meridional heat flux in the North Atlantic by inverse methods. J Phys Oceanogr 10:1972–1983
Semtner AJ (1986) Finite-difference formulation of a World Ocean model. In: O'Brien (ed) Advanced physical oceanographic numerical modelling. D Reidel, Dordrecht, pp 187–202
Stocker TF, Wright DG (1991a) A zonally averaged ocean model for the thermohaline circulation. Part 11: Interocean circulation in the Pacific-Atlantic basin system. J Phys Oceanogr 21:1725–1739
Stocker TF, Wright DG (1991b) Rapid transitions of the ocean's deep circulation induced by changes in surface water fluxes. Nature 351:729–732
Stocker TF, Wright DG, Mysak LA (1992a) A zonally averaged coupled ocean-atmosphere model for paleoclimate studies. J Clim 5:773–797
Stocker TF, Wright DG, Broecker WS (1992b) The influence of high-latitude surface forcing on the global thermohaline circulation. Paleoceanography 7:529–541
Stommel H (1961) Thermohaline convection with two stable regimes of flow. Tellus 13:224–230
Talley LD (1984) Meridional heat transport in the Pacific Ocean. J Phys Oceanogr 14:231–241
Veum T, Jansen E, Arnold M, Beyer I, Duplessy J-C (1992) Water mass exchange between the North Atlantic and the Norwegian Sea during the past 28000 years. Nature 356:783–785
Warren BA (1981) Deep circulation of the World Ocean. In: Warren BA, Wunsch C (eds) Evolution of physical oceanography, scientific surveys in honor of Henry Stommel. MIT Press, Cambridge, pp 6–41
Weaver AJ, Sarachik ES (1991a) The role of mixed boundary conditions in numerical models of the ocean's climate. J Geophys Res 21:1470–1493
Weaver AJ, Sarachik ES (1991b) Evidence for decadal variability in an ocean general circulation model: an advective mechanism. Atmos-Ocean 29:197–231
Whitworth T, Peterson RG (1985) Volume transport of the Antarctic Circumpolar Current from bottom pressure measurements. J Phys Oceanogr 15:810–816
Wright DG, Stocker TF (1991) A zonally averaged ocean model for the thermohaline circulation. Part 1: model development and flow dynamics. J Phys Oceanogr 21:1713–1724
Wright DG, Stocker TF (1992) Sensitivities of a zonally averaged global ocean circulation model. J Geophys Res 97:12707–12730
Wunsch C (1984) An eclectic Atlantic Ocean circulation model. Part I: the meridional flux of heat. J Phys Oceanogr 14:1712–1733
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hovine, S., Fichefet, T. A zonally averaged, three-basin ocean circulation model for climate studies. Climate Dynamics 10, 313–331 (1994). https://doi.org/10.1007/BF00228030
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00228030