This review provides new insight for future studies of the mechanisms underlying seasonal, interannual and interdecadal variations in the Kuroshio path and volume transport. The variations are summarized based on both observations and theories over the entire Kuroshio region from Luzon Island to the eastern coast of Kyushu. Additionally, the common features and differences are clarified, particularly by focusing on the dynamics that govern seasonal variations. In almost all Kuroshio regions, the Kuroshio path tends to meander in the winter, while a straight path state is observed in the summer, and volume transport is generally largest in summer. The important dynamics that govern these seasonal variations include local and remote processes in the western boundary region, such as nonlinear Ekman dynamics over the jet and wave dynamics along the continental slope. Interannual and interdecadal variations are mainly governed by conventional Sverdrup dynamics, but there are cases where such variations are affected by these local processes.
Interannual and interdecadal variations, Remote response