第九届青年地学论坛

The Kuroshio transports warm water poleward from low to mid-high latitudes and strongly affects ocean-atmosphere-land interactions. Previous studies indicate a strengthening trend in the Kuroshio at its origin during recent decades. However, changes in Kuroshio on a centennial scale is unclear yet due to the lack of observations before the Industrial Revolution. Here, we use precisely dated and monthly resolved Porites coral Sr/Ca records from the southern Taiwan island, where the coral is significantly influenced by the Kuroshio, to generate a continuous reconstruction of Kuroshio transport (KT) during the past two centuries of the last millennium, spanning from 1788 to 2013. Our reconstruction reveals a consistent decline in the KT over the past 226 years, with the most significant reduction observed after the 1990s, and it is noteworthy that the amplitude of this decrease has become more stable before 1950s and then increased. We find that a southward shift of the bifurcation latitude of the North Equatorial Current is important to the decreasing trend of KT which also affected by accelerated global ocean warming. In addition, it seems that the KT was influenced by the negative phase of Pacific Decadal Oscillation (PDO) and La Niña events before 1935, and the El Niño events and PDO’s positive phases after 1935.
 

coral, Kuroshio, SST, Sr/Ca