The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

The Luzon Strait (LS), connecting the South China Sea (SCS) and the northwestern Pacific Ocean, is a crucial channel for water (heat/salt) exchange. While mesoscale eddies in the Pacific are known to propagate westward and play a significant role in heat transport, their potential to cross the LS and contribute to heat and salt transports remains poorly understood. Based on satellite altimetry observations spanning from January 1993 to June 2021, this study identifies 21 anticyclonic eddies and 14 cyclonic eddies passing through the LS from the northwestern Pacific to the SCS. Moreover, this study investigates the factors influencing the mesoscale eddies crossing the Kuroshio, with preliminarily findings indicating that eddy’s polarity and intensity, as well as the path and intensity of the Kuroshio, are key factors. Heat and salt transports induced by each eddy are calculated using reanalysis data from Copernicus Marine Service. The result shows that eddy-induced heat transport accounts for 1% to 10% of the monthly mean heat transport through the LS (at the section of 121°E), while the salt transport accounts for less than 1% of the monthly mean heat transport through the LS. This study provides direct evidence of mesoscale eddies crossing the LS from the Pacific to the SCS, and highlights their contribution to the net heat and salt exchanges between the Pacific and the SCS.

mesoscale eddy, heat and salt transports, Pacific-South China Sea exchange, satellite altimetry