Abstract
The assertion that the thermohaline circulation (THC) is driven and sustained by mechanical energy has been increasingly accepted. The simplest conceptual model describing the THC is the Stommel two-box model. Given the vertical stratification in the real ocean, layered models were designed and used. In this research, using a two-layer conceptual model based on energy constraint, we studied basic features of thermal-mode and saline-mode circulations. We focused on the effects of freshwater flux and mixing energy on the intensity and multiple equilibrium states of the THC. The results show that more important than affecting the THC intensity, both the decrease of freshwater flux and increase of mixing energy can lead to an “abrupt transition” in the THC from a stable saline to a stable thermal mode, which further develops the THC energy theory.
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References
Bryan F. 1987. Parameter sensitivity of primitive equation ocean general circulation models. J Phys Oceanogr, 17: 970–985
Cimatoribus A A, Drijfhout S S, Dijkstra H A. 2014. Meridional overturning circulation: Stability and ocean feedbacks in a box model. Clim Dyn, 42: 311–328
Clark P U, Pisias N G, Stocker T F, et al. 2002. The role of the thermohaline circulation in abrupt climate change. Nature, 415: 863–869
De Boer A M, Gnanadesikan A, Edwards N R, et al. 2010. Meridional density gradients do not control the atlantic overturning circulation. J Phys Oceanogr, 40: 368–380
Guan Y P, Huang R X. 2008. Stommel’s box model of thermohaline circulation revisited-The role of mechanical energy supporting mixing and the wind-driven gyration. J Phys Oceanogr, 38: 909–917
Haney R L. 1971. Surface thermal boundary condition for ocean circulation models. J Phys Oceanogr, 1: 241–248
Huang R X. 1999. Mixing and energetics of the oceanic thermohaline circulation. J Phys Oceanogr, 29: 727–746
Huang J F, Guan Y P, Liu Y. 2008. Centennial debating: Is Ocean a heat engine?—100th anniversary review for Sandström’s theorem (in Chinese). Prog Nat Sci, 18: 747–755
Marotzke J, Scott J R. 1999. Convective mixing and the thermohaline circulation. J Phys Oceanogr, 29: 2962–2970
Mu M, Sun L, Dijkstra H A. 2004. The sensitivity and stability of the Ocean’s thermohaline circulation to finite amplitude perturbations. J Phys Oceanogr, 34: 2305–2315
Nilsson J, Broström G, Walin G. 2003. The thermohaline circulation and vertical mixing: Does weaker density stratification give stronger overturning? J Phys Oceanogr, 33: 2781–2795
Nilsson J, Walin G. 2001. Freshwater forcing as a booster of thermohaline circulation. Tellus Ser A-Dyn Meteorol Oceanol, 53: 629–641
Nilsson J, Walin G. 2010. Salinity-dominated thermohaline circulation in sill basins: Can two stable equilibria exist? Tellus Ser A-Dyn Meteorol Oceanol, 62: 123–133
Oliver K I, Watson A J, Stevens D P. 2005. Can limited ocean mixing buffer rapid climate change? Tellus Ser A-Dyn Meteorol Oceanol, 57: 676–690
Shen Y, Guan Y P, Liang C J, et al. 2011. A three-box model of thermohaline circulation under the energy constraint. Chin Phys Lett, 28: 059201
Stommel H. 1961. Thermohaline convection with two stable regimes of flow. Tellus, 13: 224–230
Tziperman E, Toggweiler J R, Bryan K, et al. 1994. Instability of the thermohaline circulation with respect to mixed boundary conditions: Is it really a problem for realistic models? J Phys Oceanogr, 24: 217–232
Wang W, Huang R X. 2005. An experimental study on thermal circulation driven by horizontal differential heating. J Fluid Mech, 540: 49–73
Welander P. 1982. A simple heat-salt oscillator. Dynam Atoms Oceans, 6: 233–242
Yang H J. 2013. Assessing the meridional atmosphere and ocean energy transport in a varying climate. Chin Sci Bull, 58: 1737–1740
Ye Z Z, Yang W L. 1985. Ordinary Differential Equations and Stability Theory of Motion (in Chinese). Tianjin: Tianjin University Press. 78–92
Zhou T J, Yu R C, Liu X Y. 2005. Weak response of the Atlantic thermohaline circulation to an increase of atmospheric carbon dioxide in IAP/LASG climate system model. Chin Sci Bull, 50: 592–598
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Shen, Y., Guan, Y. Feature of thermohaline circulation in two-layer conceptual model based on energy constraint. Sci. China Earth Sci. 58, 1397–1403 (2015). https://doi.org/10.1007/s11430-015-5092-8
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DOI: https://doi.org/10.1007/s11430-015-5092-8