期刊名称:Tellus A: Dynamic Meteorology and Oceanography
电子版ISSN:1600-0870
出版年度:2002
卷号:54
期号:1
页码:89-98
DOI:10.3402/tellusa.v54i1.12126
摘要:Conceptual box models of the interhemispheric thermohaline circulation are studied withrespect to bifurcations. Freshwater fluxes are the main control parameters of the system: theydetermine the stable states and transitions between stable states of the large-scale thermohalinecirculation. In this study of interhemispheric box models both numerical and analytical methodsare used to investigate transition mechanisms of the thermohaline circulation. The box modelexamined first is an interhemispheric four-box model. It is shown that the two bifurcationswhere the present THC can become unstable, the saddle-node and the Hopf bifurcation, dependin a different way on hemispheric freshwater fluxes. A reduction of the model variables leadsto the conclusion that two fixed freshwater fluxes between three surface boxes are the modelfeature responsible for the bifurcation behaviour found. The significance of the Hopf bifurcationfor the stability of the thermohaline circulation is discussed.