Weakening Trend of Luzon Strait Overflow Transport in the Past Two Decades

The Luzon Strait overflow is a deep current of dense water flowing persistently into the South China Sea (SCS) from the Pacific. It is the primary driving force of the deep SCS circulation and potentially influenced by ocean mass changes. Limited by the lengths of in situ observations, long-term changes in the Luzon Strait overflow transport (LSOT) have not been ascertained. Based on 14 years of satellite-based ocean bottom pressure (OBP) time series, here we provide an evidence of a weakening of the LSOT by -0.43 Sv decade(-1) between 2003 and 2016. Moreover, both OBP data and mooring time series reveal a large annual cycle in the LSOT. The weakening trend in the LSOT may profoundly influence the deep SCS circulation, as well as heat and mass fluxes between the SCS and surrounding oceans.

Automated summary

Based on satellite data and in situ measurements, a weakening trend of the Luzon Strait overflow has been identified, along with a large annual cycle. This weakening trend may significantly affect the deep circulation of the South China Sea and the heat and mass fluxes between the South China Sea and surrounding oceans.