The decadal sea surface salinity (SSS) variability in the western tropical Pacific (WTP) is crucial for the stratification of the upper ocean and the regional marine ecosystem. Robust intensification is detected for decadal SSS variability in the WTP since the early 1960s. Using salinity budget, we find freshwater flux and ocean dynamics are the two key factors that shape the amplified decadal variability of SSS in the WTP. Furthermore, Commonwealth Scientific and Industrial Research Organization Large Ensemble (CSIRO-MK3.6) show the impact of this external forcing on the amplification of the decadal SSS. This study provides a better understanding of the intensification of SSS decadal variability in the WTP, which is important for both ocean-climate research and marine ecosystem forecasting.
 

Western Tropical Pacific,Sea Surface Salinity,Decadal variability