Bifurcation of traveling waves resulting from resonant mode crossings in oceanic currents

We consider parallel currents in a rotating system. The current has a finit e width and is bounded by density fronts on both sides. It has been shown t hat such flows have instabilities associated with a 1:1 resonance, i.e. the merging of two real wave speeds which then become complex. In this paper, we analyze bifurcations resulting from these instabilities. Two types of bi furcations arise; one is a reversible Hopf bifurcation, and the other is a reversible Hopf bifurcation with O(2)-symmetry. (C) Elsevier, Paris.