Disassociation of the Kuroshio Current with the Pacific Decadal Oscillation since 1999

Abstract

Variability of the Kuroshio Current along the margin of the East China Sea was examined using principal component analysis of 21-year (1993-2013) multi-satellite geostrophic velocity data. Its seasonal zonal migration agrees with previous observations and model simulations. Beyond seasonal time scales, the influence of the Pacific Decadal Oscillation (PDO) on the Kuroshio decreased considerably since 1999. Wind patterns over the North Pacific varied primarily in the meridional direction before 1999, but exhibited strong zonal variation thereafter. Post-1998 climate variability was particularly evident over the central and eastern Pacific. The strong association between PDO and Kuroshio variability also deteriorated after that time.