Séminaire EPOC : Stefano PIERINI (Universite de Naples "Parthenope")

Abstract:
In this seminar the problem of the internal changes of the climate system paced by external forcings is discussed in general, and analyzed in detail for a relevant oceanic example: the synchronization between the Kuroshio Extension (KE) decadal bimodal variability and the North Pacific Oscillation (NPO). Concepts playing an important role in the phenomenon, such as relaxation oscillators, deterministic and stochastic tipping points and coherence resonance are first outlined in the framework of dynamical systems theory. Modeling results concerning the KE bimodality based on both primitive equations and a low-order system are then presented, supporting the hypothesis of an intrinsic origin of such variability. Recent modeling results explaining the observed synchronization between the NPO and the KE bimodality are finally presented.