Abrupt Climate Change and Multistability of the Thermohaline Circulation

Ice core records suggest that the Earth’s climate has undergone rapid, catastrophic shifts on multiple occasions in geologically recent times. The multiplicity of steady states found in fluid convection models has led many to speculate that the changes may have been caused by transitions between different stable modes of ocean current patterns. This paper reviews analytical and numerical modeling of multistability in the thermohaline circulation with particular reference to bifurcation analysis. The relevance of these models to paleoclimate data and contemporary observations is discussed.