Pacific Decadal Variability: The Tropical Pacific Mode and the North Pacific Mode*

Abstract

Pacific decadal variability is studied in a series of coupled global ocean-atmosphere simulations aided by two ''modeling surgery'' strategies: partial coupling (PC) and partial blocking (PB). The PC experiments retain full ocean-atmosphere coupling in selected regions, but constrain ocean-atmosphere coupling elsewhere by prescribing the model climatological SST to force the atmospheric component of the coupled system. In PB experiments, sponge walls are inserted into the ocean component of the coupled model at specified latitudinal bands to block the extratropical-tropical oceanic teleconnection.