Impacts of the Kuroshio Extension Stability on the Storm-track over the North Pacific

Abstract

The Kuroshio Extension (KE) modulates and influences the weather and climate over the North Pacific and even the entire earth through intense sea-air interactions. In this study, the seasonal responses of the North Pacific storm-track to the KE inter-annual variability are investigated by employing the lag regression approach. The results show that, there are significant seasonal variations in the storm-track responses to the KE stability variability. When the KE is stable in spring, the atmospheric low-level baroclinicity is intensified over the mid-latitudes of the North Pacific, resulting in the enhancement and upstream displacement of the storm-track. Similarly, the summer storm-track is also strengthened as a result of the stronger baroclinicity over the mid-latitudes of the North Pacific. In autumn and winter, the intensified baroclinicity in the upstream region of the storm-track, which is conducive for the development of synoptic eddies to the upstream of its climatological region, causes an upstream displacement of storm-track.