Sea surface height of the China adjacent seas from a variable-grid global ocean circulation model

A fine-grid model (1/6°) covering the South China Sea (SCS), East China Sea and Japan/East Sea, which is embedded into a coarse-grid (2°) global model, was established to study the sea surface height of the China adjacent seas. In the present paper, we report the model-produced monthly and annual mean sea surface heights(SSH) and their anomalies of the China adjacent seas. Comparison to the TOPEX/Poseidon data shows that the model-produced monthly sea surface height anomalies (SSHA) are in good agreement with altimeter measurements. Based on the results, the distribution of the China adjacent seas SSH and its seasonal variation are discussed. In the East China Sea, the seasonal variation of SSH is not as remarkable as that in the South China Sea. There is an area whose SSH is high near the northern continental slope of the SCS all the year round. On the contrary, there is a low-SSH region in the south of SCS in summer and high-SSH in winter. It could be diagnosed from the distribution of SSH that the western Philippine Sea water intrudes into the SCS through the Luzon Strait in the surface layer, especially in autumn, winter and spring. The SE Vietnam Off-Shore Current in summertime and the Yellow Sea Warm Current in the wintertime are reproduced reasonably. The changing characteristics of SSH in the China adjacent seas indicate the significant effect of the external forcing and open seas on the distribution of SSH in the China adjacent seas.