One of the consequences of the global warming is the modification of the hydrological cycle and then of the freshwater flux get by the ocean which one of its forcing. The ocean circulation, and more accurately the thermohaline circulation, is able to produce some low frequency variability. We are going to study the impact of the freshwater flux on the thermohaline circulation and mainly on the decadal to millennial variability. In the ocean, as in all dynamical systems, two paradigms coexist for the explanation of the observed variability : it can be endogenous or exogenous. Some outstanding results appear. During the study of endogenous variability in a 2D latitude-depth model, the growth mechanism and the oscillation one of a centennial mode are analyzed... |