Changes in the Kuroshio Path, Surface Velocity and Transport During the Last 35,000 Years

We consider the sea level, air-sea heat flux, and wind stresses and use an ocean model to investigate the evolution of the Kuroshio path and intensity during the last 35,000 years. Relative to the present, the Kuroshio during the last glacial period traveled the same path albeit with higher surface velocity in the East China Sea, while it migrated northward south of Japan and southward at the Kuroshio Extension (KE). The southward migrations of the KE axis were closely related to the positions of zero wind-stress curl. To a certain extent, stronger glacial trade winds enhanced the North Equatorial Current. Consequently, Kuroshio transport increased in the southern and middle Okinawa Trough. Regarding Kuroshio strength, we suggest that the horizontal gradient of the subsurface temperature would be a better indicator than the upper-ocean vertical thermal gradient, which is a commonly used index in paleoceanography.

Automated summary

This study investigates the evolution of the Kuroshio path and intensity during the last 35,000 years and finds that during the last glacial period, the Kuroshio traveled the same path but with higher surface velocity in the East China Sea. The Kuroshio also underwent northward migration south of Japan and southward migration at the Kuroshio Extension (KE). The strength of the Kuroshio is closely related to the horizontal gradient of the subsurface temperature.