摘要
On the basis of the latest version of a U.S. Navy generalized digital environment model （GDEM-V3.0） and World Ocean Atlas （WOA13）, the hydraulic theory is revisited and applied to the Luzon Strait, providing a fresh look at the deepwater overflow there. The result reveals that： （1） the persistent density difference between two sides of the Luzon Strait sustains an all year round deepwater overflow from the western Pacific to the South China Sea （SCS）; （2） the seasonal variability of the deepwater overflow is influenced not only by changes in the density difference between two sides of the Luzon Strait, but also by changes in its upstream layer thickness; （3） the deepwater overflow in the Luzon Strait shows a weak semiannual variability; （4） the seasonal mean circulation pattern in the SCS deep basin does not synchronously respond to the seasonality of the deepwater overflow in the Luzon Strait. Moreover, the deepwater overflow reaches its seasonal maximum in December （based on GDEM-V3.0） or in fall （October-December, based on the WOA13）, accompanied by the lowest temperature of the year on the Pacific side of the Luzon Strait. The seasonal variability of the deepwater overflow is consistent with the existing longest （3.5 a） continuous observation along the major deepwater passage of the Luzon Strait.
On the basis of the latest version of a U.S. Navy generalized digital environment model （GDEM-V3.0） and World Ocean Atlas （WOA13）, the hydraulic theory is revisited and applied to the Luzon Strait, providing a fresh look at the deepwater overflow there. The result reveals that： （1） the persistent density difference between two sides of the Luzon Strait sustains an all year round deepwater overflow from the western Pacific to the South China Sea （SCS）; （2） the seasonal variability of the deepwater overflow is influenced not only by changes in the density difference between two sides of the Luzon Strait, but also by changes in its upstream layer thickness; （3） the deepwater overflow in the Luzon Strait shows a weak semiannual variability; （4） the seasonal mean circulation pattern in the SCS deep basin does not synchronously respond to the seasonality of the deepwater overflow in the Luzon Strait. Moreover, the deepwater overflow reaches its seasonal maximum in December （based on GDEM-V3.0） or in fall （October-December, based on the WOA13）, accompanied by the lowest temperature of the year on the Pacific side of the Luzon Strait. The seasonal variability of the deepwater overflow is consistent with the existing longest （3.5 a） continuous observation along the major deepwater passage of the Luzon Strait.
基金
The National Natural Science Foundation of China(NSFC)-Shandong Joint Fund for Marine Science Research Centers of China under contract No.U1606405
the National Basic Research Program(973 Program) of China under contract No.2011CB403502
the National High Technology Research and Development Program(863 Program) of China under contract No.2013AA09A506
the National Program on Global Change and Air-Sea Interaction under contract Nos GASI-IPOVAI-01-02 and GASI-03-01-01-04
the National Natural Science Foundation of China under contract No.41606040
