With the vertical velocity obtained by POM for simulating the circulation in the East China Seas,the upwelling and downwelling in the Changjiang River Mouth area are discussed. This simulation showed convincingly that upwelling exists in the area of the northern part of the Changjiang River Mouth; and that the downwelling which exists in its southern part which separates the upwelling at the Changjiang River Mouth from the Men and Zhe coastal upwelling. This simulation showed that the upwelling at the Changjiang River Mouth is caused by interaction of the Taiwan Warm Current with the slope bottom topography; and that southwest the monsoon in summer can strengthen the upwelling at the Changjiang River Mouth and the Men and Zhe coastal upwelling.
A three dimensional baroclinic prognostic model on σ-coordinates was established on the basis of POM to simulate the East China Seas circulation in summer considering the topography, inflow and outflow at the open boundary, Changjiang runoff, heat flux and wind stress on the surface. This study showed that ① the Kuroshio flows along the contnental shelf slope of the East China Sea flowing in accordance with the slope topography and some eddies appear on its two sides;②the upper water of the Taiwan Warm Current comes mainly from the Taiwan Strait and that the bottom water comes mostly from Kuroshio sub-surface water flowing on the shelf and passing through the east of Taiwan Island;③ the Tsushima Warm Current in summer comes from multiple sources:the Taiwan Warm Current, one of the branches of the Kuroshio, mixed water of Changjiang Diluted Water with West Korea Coastal Current and Taiwan Warm Current;④ the Changjiang Diluted Water turns northwards rapidly after flowsing out the Changjiang River Mouth, affected by Zhejiang Coast Current, Taiwan Warm Current and southwest monsoon, and flows southeastwards after arriving at around 34°N;⑤ there is a meso-scale anticyclonic eddy in the northeast of the Changjiang River Mouth it was formed by the north branch of the Taiwan Warm Current and there is another cyclonic eddy in southwest of Chejudo Island;⑥ the circulation of the Huanghai Cold Water Mass in summer is divided into north and south parts and their current is strong in the upper layer and weak near the bottom layer;⑦ there is a meso-scale anticyclone eddy near the Qingdao-Shidao coast area.
