报告人简介:
陈兆云,博士,中山大学特聘研究员。2007.9—2009.7,4166金沙之选主页通道环境科学硕士;2009.9—2014.2,美国特拉华大学和4166金沙之选主页通道物理海洋双博士。2014.6—2016.1至香港中文大学从事博士后研究工作。主要研究兴趣为上升流动力机制,陆架区冲淡水分布及动力机制,上升流与冲淡水相互作用。
摘要:
In situ observation and satellite images show that Pearl River plume axis extends either alongshore between the upwelling off the Guangdong coast and in the Taiwan Bank or offshore in the northeastern South China Sea (SCS), depending on the upwelling intensities. Numerical model is set up to reproduce the upwelling processes and the areal extent of the Pearl River plume surroundingthe upwellingareas. Model experiments are conducted to examine the effects of wind strength and baroclinicity on the upwelling and the corresponding pathway and freshwater transport of the Pearl River plume. The freshwater primarily transports alongshore, passing through the two separated upwelling regions in the initial stage of upwelling off the Guangdong coast, while it primarily transports offshore when the upwelling is fully-developed. The plume trajectory is modulated by the upwelling processes, related to the forcing agents. The baroclinicity is important to intensify the horizontal velocity at the upwelling front and freshwater transport in the northeastern SCS. The freshwater flux is decomposed into advection, vertical shear and tidal pumping components. The advection is the dominant contribution to the freshwater flux. As the upwelling off the Guangdong coast develops, the relative high pressure gradient zone moves offshore, because of the offshore Ekman transport and the shift of the upwelling front. The freshwater is thus brought offshore till east of the Taiwan Bank. When the plume water is transported to the outer-shelf, it could be further entrained into eddies, allowing its export to the open sea.