The Kuroshio Extension region has shown a northern shift in its mean latitudinal position in recent years. This shift has let to pronounced warming in upper-oceanic temperature along the eastern coast of Japan, contributing to the occurrence of marine heat waves. To investigate the mechanism underlying this northern shift, we used an idealized two-layer model representing the subtropical gyre of the Northern Pacific. Model results suggest that the latitudinal position of the Kuroshio Extension to be closely linked to the pathway of the Kuroshio south of Japan. When the Kuroshio follows the straight path, the Kuroshio extension forms a zonal jet at similar latitude. In contrast, when the Kuroshio takes the Large Meander path, the Kuroshio extension shifts northward. Theis coupling between the Kuroshio pathways south and east of Japan appears to arise from changes in the momentum balance around the Izu Ridge.
 

Kuroshio Current,Western Boundary Current