Long-term variability of the Kuroshio transport east of Taiwan and the climate it conveys

The Kuroshio Transport (KT) from 1993 to 2010 was established using satellite altimetry data through three different methods: geostrophic relationship (GR), empirical relationship (ER) and transfer function (TF). The relationships were constructed on the observed KT from the World Ocean Circulation Experiment (WOCE) moored current meter array east of Taiwan (i.e., PCM-1) and its surrounding Sea Surface Height (SSH) difference. These methods and the associated characteristics were verified by the ten years climatology model simulations of the KT for long term applications. The GR cannot well represent the high frequency variability of KT (< two months). The KT established by ER has a similar temporal variation to the GR but smaller variance. The TF can establish observed signals covering all available frequencies. However, the PCM-1 data period is not long enough to build an appropriate TF with small variance for long term applications. We then analyzed the long term variability of the KT on PCM-1 Section based on GR and TF approaches. It was found that the annual-averaged KT was mainly controlled by the northern branch of the North Equatorial Current (NEC) and mesoscale eddies generated from the Subtropical Counter Current (STCC) while the NEC is strongly influenced by the ENSO events, and the mesoscale eddies are related with the West Pacific (WP) teleconnection pattern.