Three-dimensional calculations of the currents in the Huanghai Sea and East China Sea during June of 1999

Based on the wind and hydrographic data obtained by R/V Xiangyanghong 14 duringJune of 1999, the currents in the Huanghai Sea and East China Sea are computed by the three dimensional non-linear diagnostic, semidiagnostic models and prognostic in the a coordinate. The computed results show that the density and velocity fields and so on have been adjusted when time is about 3 days, namely the solution of semidiagnostic calculation is obtained. In the northwest part of the computed region, the Huanghai coastal current flows southeastward, and then it flows out the computed region south of Cheju Island. In the west side of the southern part of the computed region, there is other current, which is mainly inshore branch of Taiwan Warm Current, and it flows cyclonically and turns to the northeast. In the region north of the above two currents, there is a cyclonic eddy southwest of Cheju Island, and it has characteristics of high density and low temperature. There is an offshore branch of Taiwan Warm Current in the west side of the Kuroshio, and it makes a cyclonic meander, then flows north-eastward. The Kuroshio in the East China Sea is stronger, and flows northeastward. Its maximum hori-zontal velocity is 108.5 cm/s at the sea surface, which is located at the northern boundary, and it is 106.1 cm/s at 30 m level, 102.2 cm/s at 75 m level and 85.1 cm/s at 200 m level, respectively, whichare all located at the southern boundary. Comparing the results of diagnostic calculation with those ofsemidiagnostic and prognostic calculations indicates that the horizontal velocity field agrees qualitatively,and there is a little difference between them in quantity. The comparison between the computed veloci-ties and the obeered velocities at the mooring station show that they agree each other.