A case study of a Kuroshio main path cut-off event and impacts on the South China Sea in fall-winter 2013-2014

Abstract

This study examines a Kuroshio main path (KMP) cut-off event east of Taiwan Island occurred in fall-winter 2013-2014 and its impacts on the South China Sea (SCS) by analyzing satellite altimetry and mooring observations. Satellite altimeter sea level anomaly (SLA) images reveal a complete process that a huge cyclonic eddy (CE) from the Pacific collided with the Kuroshio and the western boundary from 15 October 2013 to 15 January 2014. Mooring observations evidenced that the Kuroshio upper ocean volume transport was cut off more than 82% from 17x106 m(3)/s in September to 3x10(6) m(3)/s in November 2013. The KMP cut-off event caused the Kuroshio branching and intruding into the SCS and strengthened the eddy kinetic energy in the northern SCS west of the Luzon Strait. Using the total momentum as a dynamic criterion to determine the role of eddy collision with the Kuroshio reasonably explains the KMP cut-off event.