East China Sea Kuroshio Temporal And Spatial Variation Of The East China Sea Shelf Water Interaction

The interaction between Kuroshio water and shelf water in the East China Sea, brings material exchange and energy transformation, is the main reason for variations of Chinese coastal circulation, also an important factor affecting the climate in China. So, studying on the interaction between Kuroshio water and shelf water in the East China Sea can help to further understand and predict the climate change in China.In this paper, the temperature and salinity data from the World Ocean Atlas 2009 (WOA09) released by National Oceanographic Data Center (NODC) and bathymetry & topography data released by National Geophysical Data Center (NGDC) were used, temperature-salinity (T-S) scatter diagram statistical analytic method was improved to analyze the interface between Kuroshio water and shelf water, and the temporal and spatial variations of the interaction between Kuroshio water and shelf water were manifested by using the MATLAB computer program. The following main results have been obtained.1. The spatial variations of the interaction between Kuroshio water and shelf water are large in different seasons. In different seasons, the interface shows varying degree of convexity to the shelf area or concavity to the Kuroshio in different locations from the entrance to the exit and the surface to 200 m depth.2. From the entrance to the exit, it is mainly in the northeast of Taiwan and the southwest of Kyushu that the interface bulges to the shelf area greatly above 100 m depth, compared with the middle of the Kuroshio from 100 m to 200 m depth, and so is the main character of Kuroshio water intrusion into shelf area.3. If the convexity to the shelf area is defined as peak and the concavity to the Kuroshio is defined as valley, the interface appears peak and valley alternately from the surface to 200 m depth. Alternate peak and valley changes greatly in different seasons above 100 m depth, but changes little from 100 m to 200 m depth, indicating that the interaction between Kuroshio water and shelf water changes greatly in different seasons above 100m depth, but changes little from 100 m to 200 m depth.4. Overall, the spatial variations of the interfaces in spring and autumn are more dramatic than that in winter and summer, there are eight depth layers with peak or valley in spring and autumn from the surface to 200 m depth, in contrast to seven in winter and summer, indicating that the interaction between Kuroshio water and shelf water in spring and autumn are more dramatic than that in winter and summer.5. From winter to autumn, in terms of the surface, the interaction between Kuroshio water and shelf water changes greatly in the northeast of Taiwan (122.5°E), latitudes reached by the interface are respectively 26.4°N, 25.8°N, 25.3°N and 26.3°N in four seasons, changes little in the middle of the Kuroshio (125.5°E), latitudes reached by the interface are around 28.0°N; changes little except summer in the southwest of Kyushu (128.5°E), latitudes reached by the interface are respectively 31.2°N, 31.5°N, 30.5°N and 31.4°N in four seasons.