The Trend of SST, SSS, Ocean Current, and Comparison of Kuroshio Strength to Weather Events in Taiwan

Abstract

Kuroshio is the significant western boundary current and plays an important role in transporting heat, salinity, and nutrients. Though the greenhouse gas concentration increases in the atmosphere, global warming is leveling off, especially from 1993 to 2013. Therefore, this study focuses on studying the trends in sea surface temperature (SST), salinity (SSS), ocean current, and strength of Kuroshio current (KC) during the leveling off period and afterward. Initially, the extent of KC was delineated from its surrounding water masses using a combination of spatial domain filters. The time series decomposition from each autonomous data set pointed to a positive trend in SST and SSS, with a system-wide weakening in the velocity of KC from Taiwan to Tokara Strait. Additionally, for delicate investigation, the KC was sub-divided into three sections to analyze whether the trend in velocity is uniform throughout the entire path of KC from Taiwan to Japan. Interestingly different trends were observed in these three sections. Finally, the KC strength was compared with rainfall and typhoon in Taiwan.