Relationship between Kuroshio variation east of Taiwan and the Kuroshio intrusion west of the Luzon Strait during 1998-2013

Although the issue of the global warming hiatus during 1998-2013 is still under debate, the surface velocity of the Kuroshio has been shown to decrease east of Taiwan but increase east of Luzon during the global warm hiatus period. In this study, we revealed a significant increase in cut-off events on the Kuroshio main path east of Taiwan during the hiatus period. This is probably related to the interaction between the weakening Kuroshio off the east of Taiwan and the westward propagation of the mesoscale cyclone eddy from the western Pacific Ocean. The cut-off event of the main path of the Kuroshio is determined using the momentum ratio of the Kuroshio to the eddy. If the ratio is less than one, the eddy dominates and the Kuroshio is cut off. Sea surface velocities derived from satellite altimeter data for these events in the Kuroshio region east of Taiwan and the Kuroshio intrusion region west of the Luzon Strait were then analyzed by empirical orthogonal functions. The results showed that the Kuroshio intrusion to the west of the Luzon Strait increased after an average of about one month after the main Kuroshio off east of Taiwan was cut off. This appears to be reverse feedback from the Kuroshio downstream to upstream.