HR: 14:30h
AN: OS52L-03    [PDF]
TI: Thermohaline circulation in a 2-box model driven by mechanical stirring
AU: * Huang, R X
EM: rhuang@whoi.edu
AF: Woods Hole, Oceanographic Institution, Woods Hole, MA 02543 United States
AB: A two-box model under the energy control (Model E) is discussed, and the results are compared with a classical two-box model under the buoyancy control (Model B). The bifurcation structure of these models are different because of an essential difference in the basic control regulating the circulation. Both models have three steady solutions: Model B has two thermal modes (a stable spiral and an unstable saddle) and one haline mode (stable note), Model E has one thermal mode (stable spiral) and two haline modes (an unstable saddle and a stable node). Models' sensitivity to parameters can be derived from the perturbations of the steady states. Due to the difference in the basic constraint regulating circulation, sensitivity of Model E is quite different from Model B. Firstly, as the external sources of mechanical energy increase, both the circulation rate and poleward heat flux in Model E increase in response. Secondly, if freshwater flux is increased, poleward mass and heat fluxes in Model B are reduced, in consistent with results from most existing models. However, these fluxes in Model E are greatly enhanced. The difference in sensitivity to freshwater flux might provide important clues to our understanding of the dynamics of the potential upcoming global warming and periods of warm climate over the geological past, such as the Eocene and Early Cenozoic. Model sensitivity to other parameters is also discussed.
DE: 4203 Analytical modeling
DE: 4215 Climate and interannual variability (3309)
DE: 4532 General circulation
SC: Ocean Sciences [OS]
MN: 2004 Ocean Sciences Meeting