• Adcroft, A., , J-M. Campin, , P. Heimbach, , C. Hill, , and J. Marshall, cited. 2002: Mitgcm release 1 manual. MIT/EAPS, Cambridge, MA. [Available online at http://mitgcm.org/sealion/online_documents/manual.html.].

  • Alley, R. B., 2000: Ice-core evidence of abrupt climate changes. Proc. Natl. Acad. Sci. USA, 97 , 13311334.

  • Alley, R., , S. Anandakrishnan, , and P. Jung, 2001: Stochastic resonance in the North Atlantic. Paleoceanography, 16 , 190198.

  • Bice, K. L., , and J. Marotzke, 2001: Numerical evidence against reversed thermohaline circulation in the warm Paleocene/Eocene ocean. J. Geophys. Res., 106 , 1152911542.

    • Search Google Scholar
    • Export Citation
  • Bryan, F., 1986: High latitude salinity effects and interhemispheric thermohaline circulation. Nature, 323 , 301304.

  • Bryan, K., 1984: Accelerating the convergence to equilibrium of ocean-climate models. J. Phys. Oceanogr., 14 , 666673.

  • Cessi, P., 1996: Convective adjustment and thermohaline excitability. J. Phys. Oceanogr., 26 , 481491.

  • Dansgaard, W., , S. J. Johnsen, , H. B. Clausen, , D. Dahl-Jensen, , N. Gundestrup, , C. U. Hammer, , and H. Oescger, 1984: North Atlantic climate oscillations revealed by deep Greenland ice cores. Climate Processes and Climate Sensitivity, Geophys. Monogr., Vol. 5, Amer. Geophys. Union, 288–298.

    • Search Google Scholar
    • Export Citation
  • Dijkstra, H. A., 2000: Nonlinear Physical Oceanography. Kluwer Academic, 456 pp.

  • Dijkstra, H. A., , and M. J. Molemaker, 1997: Symmetry breaking and overturning oscillations in thermohaline flows: A bifurcation study. J. Fluid Mech., 331 , 169198.

    • Search Google Scholar
    • Export Citation
  • Edwards, N. R., , A. J. Willmott, , and P. D. Killworth, 1998: On the role of topography and wind stress on the stability of the thermohaline circulation. J. Phys. Oceanogr., 28 , 756778.

    • Search Google Scholar
    • Export Citation
  • Ganopolski, A., , and S. Rahmstorf, 2001: Rapid changes of glacial climate simulated in a coupled climate model. Nature, 409 , 153158.

  • Ganopolski, A., , and S. Rahmstorf, 2002: Abrupt glacial climate changes due to stochastic resonance. Phys. Rev. Lett., 88 .038 501, doi:10.1103/PhysRevLett.88.038501.

    • Search Google Scholar
    • Export Citation
  • Gent, P. R., , and J. C. McWilliams, 1990: Isopycnal mixing in ocean circulation models. J. Phys. Oceanogr., 20 , 150155.

  • Gildor, H., , and E. Tziperman, 2003: Sea-ice switches and abrupt climate change. Philos. Trans. Roy. Soc. London, A361 , 19351942.

  • Gregory, J. M., , O. A. Saenko, , and A. J. Weaver, 2003: The role of the Atlantic freshwater balance in the hysteresis of the meridional overturning circulation. Climate Dyn., 21 , 707717.

    • Search Google Scholar
    • Export Citation
  • Griffies, S. M., , and E. Tziperman, 1995: A linear thermohaline oscillator driven by stochastic atmospheric forcing. J. Climate, 8 , 24402453.

    • Search Google Scholar
    • Export Citation
  • Guan, Y. P., , and R. X. Huang, 2007: Stommel’s box model of thermohaline circulation revisited: The role of mechanical energy supporting mixing and the wind-driven gyration. J. Phys. Oceanogr., in press.

    • Search Google Scholar
    • Export Citation
  • Hall, A., , and R. J. Stouffer, 2001: An abrupt climate event in a coupled ocean-atmosphere simulation without external forcing. Nature, 409 , 171174.

    • Search Google Scholar
    • Export Citation
  • Haney, L. R., 1971: Surface boundary condition for ocean circulation models. J. Phys. Oceanogr., 1 , 241248.

  • Hasumi, H., , and N. Suginohara, 1999: Atlantic deep circulation controlled by heating in the southern ocean. Geophys. Res. Lett., 26 , 18731876.

    • Search Google Scholar
    • Export Citation
  • Heinrich, H., 1988: Origin and consequences of cyclic ice rafting in the northeast Atlantic Ocean during the past 130,000 years. Quat. Res., 29 , 142152.

    • Search Google Scholar
    • Export Citation
  • Houghton, J. T., , Y. Ding, , D. J. Griggs, , M. Noguer, , P. J. van der Linden, , X. Dai, , K. Maskell, , and C. A. Johnson, 2001: Climate Change 2001: The Scientific Basis. Cambridge University Press, 881 pp.

    • Search Google Scholar
    • Export Citation
  • Huang, B. Y., , P. H. Stone, , A. P. Sokolov, , and I. V. Kamenkovich, 2003: Ocean heat uptake in transient climate change: Mechanisms and uncertainty due to subgrid-scale eddy mixing. J. Climate, 16 , 33443356.

    • Search Google Scholar
    • Export Citation
  • Kaspi, Y., 2002: A mechanism for the abrupt warming and simultaneous ice sheet discharge involved in Heinrich events. Master’s thesis, Weizmann Institute, Rehovot, Israel, 53 pp.

  • Kaspi, Y., , R. Sayag, , and E. Tziperman, 2004: A “triple sea-ice state” mechanism for the abrupt warming and synchronous ice sheet collapses during Heinrich events. Paleoceanography, 19 .PA3004, doi:10.1029/2004PA001009.

    • Search Google Scholar
    • Export Citation
  • Keeling, R. F., 2002: On the freshwater forcing of the thermohaline circulation in the limit of low diapycnal mixing. J. Geophys. Res., 107 .3077, doi:10.1029/2000JC000685.

    • Search Google Scholar
    • Export Citation
  • Kohl, A., 2005: Anomalies of meridional overturning: Mechanisms in the North Atlantic. J. Phys. Oceanogr., 35 , 14551472.

  • Lenderink, G., , and R. J. Haarsma, 1994: Variability and multiple equilibria of the thermohaline circulation associated with deep-water formation. J. Phys. Oceanogr., 24 , 14801493.

    • Search Google Scholar
    • Export Citation
  • Longworth, H., , J. Marotzke, , and T. F. Stocker, 2005: Ocean gyres and abrupt change in the thermohaline circulation: A conceptual analysis. J. Climate, 18 , 24032416.

    • Search Google Scholar
    • Export Citation
  • MacMynowski, D. G., , and E. Tziperman, 2006: Two-way feedback interaction between the thermohaline and wind-driven circulations. J. Phys. Oceanogr., 36 , 914929.

    • Search Google Scholar
    • Export Citation
  • Marotzke, J., , and J. Willebrand, 1991: Multiple equilibria of the global thermohaline circulation. J. Phys. Oceanogr., 21 , 13721385.

  • Marotzke, J., , P. Welander, , and J. Willebrand, 1988: Instability and multiple steady states in a meridional-plane model of the thermohaline circulation. Tellus, 40A , 162172.

    • Search Google Scholar
    • Export Citation
  • Marshall, J., , A. Adcroft, , C. Hill, , L. Perelman, , and C. Heisey, 1997a: A finite-volume, incompressible, Navier–Stokes model for studies of the ocean on parallel computers. J. Geophys. Res., 102 , C3. 57535766.

    • Search Google Scholar
    • Export Citation
  • Marshall, J., , C. Hill, , L. Perelman, , and A. Adcroft, 1997b: Hydrostatic, quasi-hydrostatic, and nonhydrostatic ocean modeling. J. Geophys. Res., 102 , 57335752.

    • Search Google Scholar
    • Export Citation
  • Nilsson, J., , and G. Walin, 2001: Freshwater forcing as a booster of thermohaline circulation. Tellus, 53A , 629641.

  • Oka, A., , H. Hasumi, , and N. Suginohara, 2001: Stabilization of thermohaline circulation by wind-driven and vertical diffusive salt transport. Climate Dyn., 18 , 7183.

    • Search Google Scholar
    • Export Citation
  • Oliver, K. I. C., , A. J. Watson, , and D. P. Stevens, 2005: Can limited ocean mixing buffer rapid climate change? Tellus, 57A , 676690.

  • Paillard, D., , and L. Labeyrie, 1994: Role of the thermohaline circulation in the abrupt warming after Heinrich events. Nature, 372 , 162164.

    • Search Google Scholar
    • Export Citation
  • Pasquero, C., , and E. Tziperman, 2004: Effects of a wind driven gyre on thermohaline circulation variability. J. Phys. Oceanogr., 34 , 805816.

    • Search Google Scholar
    • Export Citation
  • Rahmstorf, S., , and J. Willebrand, 1995: The role of the temperature feedback in stabilizing the thermohaline circulation. J. Phys. Oceanogr., 25 , 787805.

    • Search Google Scholar
    • Export Citation
  • Rahmstorf, S., , and A. Ganopolski, 1999: Simple theoretical model may explain apparent climate instability. J. Climate, 12 , 13491352.

  • Redi, M. H., 1982: Oceanic isopycnal mixing by coordinate rotation. J. Phys. Oceanogr., 12 , 11541158.

  • Saltzman, B., 2002: Dynamical Paleoclimatology: Generalized Theory of Global Climate Change. Academic Press, 354 pp.

  • Shaffer, G., , and S. M. Olsen, 2001: Sensitivity of the thermohaline circulation and climate to ocean exchanges in a simple coupled model. Climate Dyn., 17 , 433444.

    • Search Google Scholar
    • Export Citation
  • Stommel, H., 1961: Thermohaline convection with two stable regimes of flow. Tellus, 13 , 224230.

  • Stommel, H., , and C. Rooth, 1968: On the interaction of gravitational and dynamic forcing in simple circulation models. Deep-Sea Res., 15 , 165170.

    • Search Google Scholar
    • Export Citation
  • Stouffer, R. J., and Coauthors, 2006: Investigating the causes of the response of the thermohaline circulation to past and future climate changes. J. Climate, 19 , 13651387.

    • Search Google Scholar
    • Export Citation
  • Timmermann, A., , and H. Goosse, 2004: Is the wind stress forcing essential for the meridional overturning circulation? Geophys. Res. Lett., 31 .L04303, doi:10.1029/2003GL018777.

    • Search Google Scholar
    • Export Citation
  • Timmermann, A., , H. Gildor, , M. Schulz, , and E. Tziperman, 2003: Coherent resonant millennial-scale climate oscillations triggered by massive meltwater pulses. J. Climate, 16 , 25692585.

    • Search Google Scholar
    • Export Citation
  • Toggweiler, J. R., , and B. Samuels, 1995: Effect of Drake Passage on the global thermohaline circulation. Deep-Sea Res., 42 , 477500.

  • Tsujino, H., , and N. Suginohara, 1999: Thermohaline circulation enhanced by wind forcing. J. Phys. Oceanogr., 29 , 15061516.

  • Tziperman, E., 1997: Inherently unstable climate behaviour due to weak thermohaline ocean circulation. Nature, 386 , 592595.

  • Tziperman, E., , J. R. Toggweiler, , Y. Feliks, , and K. Bryan, 1994: Instability of the thermohaline circulation with respect to mixed boundary conditions: Is it really a problem for realistic models? J. Phys. Oceanogr., 24 , 217232.

    • Search Google Scholar
    • Export Citation
  • UNESCO, 1983: Algorithms for computations of fundamental properties of seawater. UNESCO Technical Papers in Marine Science 44, 58 pp.

  • Vallis, G. K., 2000: Large-scale circulation and production of stratification: Effects of wind, geometry, and diffusion. J. Phys. Oceanogr., 30 , 933954.

    • Search Google Scholar
    • Export Citation
  • Wang, X., , P. Stone, , and J. Marotzke, 1999: Global thermohaline circulation. Part I: Sensitivity to atmospheric moisture transport. J. Climate, 12 , 7182.

    • Search Google Scholar
    • Export Citation
  • Wang, Z., , and L. Mysak, 2006: Glacial abrupt climate changes and Dansgaard-Oeschger oscillations in a coupled climate model. Paleoceanography, 21 .PA2001, doi:10.1029/2005PA001238.

    • Search Google Scholar
    • Export Citation
  • Welander, P., 1982: A simple heat–salt oscillator. Dyn. Atmos. Oceans, 6 , 233242.

  • Winton, M., 1993: Deep decoupling oscillations of the oceanic thermohaline circulation. Ice in the Climate System, W. R. Peltier, Ed., NATO ASI Series I: Global Environmental Change, Vol. 12, Springer Verlag, 417–432.

    • Search Google Scholar
    • Export Citation
  • Winton, M., , and E. S. Sarachik, 1993: Thermohaline oscillation induced by strong steady salinity forcing of ocean general circulation models. J. Phys. Oceanogr., 23 , 13891410.

    • Search Google Scholar
    • Export Citation
  • Wunsch, C., 2002: What is the thermohaline circulation? Science, 298 , 11791181.

  • Wunsch, C., , and R. Ferrari, 2004: Vertical mixing, energy and the general circulation of the oceans. Annu. Rev. Fluid Mech., 36 , 281314.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 60 60 2
PDF Downloads 46 46 3

A Wind-Induced Thermohaline Circulation Hysteresis and Millennial Variability Regimes

View More View Less
  • 1 Solar Energy and Environmental Physics, BIDR, Ben-Gurion University, Midreshet Ben-Gurion, Israel
  • | 2 Department of Earth and Planetary Sciences, and Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts
© Get Permissions Rent on DeepDyve
Restricted access

Abstract

The multiple equilibria of the thermohaline circulation (THC: used here in the sense of the meridional overturning circulation) as function of the surface freshwater flux has been studied intensively following a Stommel paper from 1961. It is shown here that multistability and hysteresis of the THC also exist when the wind stress amplitude is varied as a control parameter. Both the Massachusetts Institute of Technology ocean general circulation model (MITgcm) and a simple three-box model are used to study and explain different dynamical regimes of the THC and THC variability as a function of the wind stress amplitude. Starting with active winds and a thermally dominant thermohaline circulation state, the wind stress amplitude is slowly reduced to zero over a time period of ∼40 000 yr (40 kyr) and then increased again to its initial value over another ∼40 kyr. It is found that during the decreasing wind stress phase, the THC remains thermally dominant until very low wind stress amplitude at which pronounced Dansgaard–Oeschger-like THC relaxation oscillations are initiated. However, while the wind stress amplitude is increased, these relaxation oscillations are present up to significantly larger wind stress amplitude. The results of this study thus suggest that under the same wind stress amplitude, the THC can be either in a stable thermally dominant state or in a pronounced relaxation oscillations state. The simple box model analysis suggests that the observed hysteresis is due to the combination of the Stommel hysteresis and the Winton and Sarachik “deep decoupling” oscillations.

Corresponding author address: Yosef Ashkenazy, Dept. of Solar Energy and Environmental Physics, The J. Blaustein Institute for Desert Research, Ben-Gurion University, Sede Boker Campus, 84990, Israel. Email: ashkena@bgu.ac.il

Abstract

The multiple equilibria of the thermohaline circulation (THC: used here in the sense of the meridional overturning circulation) as function of the surface freshwater flux has been studied intensively following a Stommel paper from 1961. It is shown here that multistability and hysteresis of the THC also exist when the wind stress amplitude is varied as a control parameter. Both the Massachusetts Institute of Technology ocean general circulation model (MITgcm) and a simple three-box model are used to study and explain different dynamical regimes of the THC and THC variability as a function of the wind stress amplitude. Starting with active winds and a thermally dominant thermohaline circulation state, the wind stress amplitude is slowly reduced to zero over a time period of ∼40 000 yr (40 kyr) and then increased again to its initial value over another ∼40 kyr. It is found that during the decreasing wind stress phase, the THC remains thermally dominant until very low wind stress amplitude at which pronounced Dansgaard–Oeschger-like THC relaxation oscillations are initiated. However, while the wind stress amplitude is increased, these relaxation oscillations are present up to significantly larger wind stress amplitude. The results of this study thus suggest that under the same wind stress amplitude, the THC can be either in a stable thermally dominant state or in a pronounced relaxation oscillations state. The simple box model analysis suggests that the observed hysteresis is due to the combination of the Stommel hysteresis and the Winton and Sarachik “deep decoupling” oscillations.

Corresponding author address: Yosef Ashkenazy, Dept. of Solar Energy and Environmental Physics, The J. Blaustein Institute for Desert Research, Ben-Gurion University, Sede Boker Campus, 84990, Israel. Email: ashkena@bgu.ac.il

Save