Inter-annual and decadal fluctuations of the Kuroshio in East China Sea and connection with surface fluxes of momentum and heat

Despite attempts in the literature to link large-scale wind to long-term variations of the Kuroshio in East China Sea (ECS), the driving mechanism(s) are unknown. Here we use satellite altimetry data, wind, surface heat fluxes and sea-surface temperatures (SST) to explain the low-frequency fluctuations of Kuroshio path (KP) in ECS. The dominant fluctuations occur northeast of Taiwan. The KP correlates best with the PTO index of Chang and Oey (2012), less with the PDO index and a Kuroshio transport index, and poorly with other climate indices. The forcing are wind stress curl and surface heat flux northeast of Taiwan, which produce a thermocline tilt along the Kuroshio. Shelf's SST warms and cools in response to onshore and offshore KP, but prominent change occurs at a localized coastal zone shoreward of the above dominant KP-fluctuations. Over the past 2 decades, the KP has shifted onshore, coincident with a coastal warming trend.