From July to December, when the current is strongest, the North Brazil Current leaves the coast between 4 and 6N and feeds the North Equatorial Counter Current. During the rest of the year it follows along the coast and delivers a sizeable contribution of warm water into the North Atlantic subtropical gyre. Csanady is going to model the physical processes that control the retro- flection of the North Brazil Current. These models will provide the theoretical framework to interpret the observational program of NOBREX (North Brazil Current Experiment).