Interannual Variability in the Mid- and Low-Latitude Western North Pacific

Abstract

Abstract Twenty-two years (1967–88) of hydrographic data collected by the Japan Meteorological Agency along the 137°E meridian and surface wind data compiled by Florida State University (FSU) were analyzed to study the interannual variability in the western North Pacific. In the midlatitude region north of 22°N, the dominant signal in the dynamic height field was the interannual path variations of the Kuroshio. Whereas the eastward transport of the Kuroshio itself had no significant changes between the straight-path and meander-path years, the net transport of the Kuroshio system including recirculations showed a 30% increase during the meander-path years. In the straight-path years when the net transport was small, the Kuroshio tended to take a straight path with a strong recirculation developed to the south. The interannual path variations of the Kuroshio strongly influenced the water-mass movement in the midlatitudes. During the Kuroshio meander years, we found that a significant portion of the North P...