摘要
A method of quantifying the penetration of the Kuroshio into the Luzon Strait is improved with simulat- ed salinity. The new method is applied in an area bounded by 0.6 correlation coefficient contour to the point of 20°N, 118°E which is determined by EOF analysis. The results suggest that the method is suitable for indicating Kuroshio＇s intrusion into the South China Sea quantitatively. As an indicator, the Kuroshio penetrating the Luzon index （KLI） reveals obvious annual cycle and weak bi-modality. For annual period- s, indexes on the surface and subsurface which point the same events have totally opposite signs due to the winter burst of surface westward current. On long-term period, the surface and subsurface indexes have consistent signs. A subsurface index on 150 m avoiding high frequency signals from the surface can be used for indicating long-term Kuroshio intrusion variation. An anti-phase pattern in wavelet coherence map between KLI and Japan large meander index shows that the Luzon Strait is a ＂smoother＂ reducing the variability of the Kuroshio transport changes on long-term periods.
A method of quantifying the penetration of the Kuroshio into the Luzon Strait is improved with simulat- ed salinity. The new method is applied in an area bounded by 0.6 correlation coefficient contour to the point of 20°N, 118°E which is determined by EOF analysis. The results suggest that the method is suitable for indicating Kuroshio＇s intrusion into the South China Sea quantitatively. As an indicator, the Kuroshio penetrating the Luzon index （KLI） reveals obvious annual cycle and weak bi-modality. For annual period- s, indexes on the surface and subsurface which point the same events have totally opposite signs due to the winter burst of surface westward current. On long-term period, the surface and subsurface indexes have consistent signs. A subsurface index on 150 m avoiding high frequency signals from the surface can be used for indicating long-term Kuroshio intrusion variation. An anti-phase pattern in wavelet coherence map between KLI and Japan large meander index shows that the Luzon Strait is a ＂smoother＂ reducing the variability of the Kuroshio transport changes on long-term periods.
基金
The National Basic Research Program of China under contract No. 2012CB417401
the National Natural Science Foundation of China under contract No. 40890152
the National Science Foundation for Young Scientist of China under contract No. 41006004
the Open Fund of Key Laboratory of Data Analysis and Applications, the first institute of oceanography, under contract No. LDAA-2011-03
作者简介
Corresponding author, E-mail： fwang@qdio.ac.cn
