摘要
本文认为东海本身所存在的流场、风场和压力场是影响和控制长江冲淡水运移的环境因子,并将这些因子引入流轴运动方程。台湾暖流、沿岸流和风海流给长江冲淡水一个推力,使其流轴运移方向夏天向左偏,冬天向右偏。黑潮控制着长江冲淡水的扩展。风的效应由直接和间接效应组成,其综合效应相当重要,不可忽略。
The spreading direction and movement path of the Changjiang River Diluted Water vary greatly with season.In general,in summer months,the diluted water flows to NE and heads for the Cheju Island,its path turns to the left,but in winter months,it flows down to S or SE along the coast of Jiangsu-Zhejiang,the path turns to the right.In this paper,the cause of the path turning of the Changjiang River Diluted Water is suggested.The current field,wind field and pressure field in the East China Sea are all considered as the main environmental factors affecting the movement of the Changjiang River Diluted Water.On the basis of Lagrange’s analysis method,the path of the Changjiang River Diluted Water is expressed by motion equations of a certain liquid mass which possesses the characteristics of the Changjiang River Diluted Water.The results in this paper show that the complicated paths of the Changjiang River Diluted Water are caused by multiple factors such as current,wind,pressure and so on.Among them the current field may be the most important.The western surface currents of the East China Sea which are composed of Taiwan Warm current,Coastal Current and Wind Current run generally in S-N direction and give the Changjiang River Diluted Water a pushing force in S-N direction.It is the pushing force which causes the path of the Changjiang River Diluted"Water to turn to the left in summer and to the right in winter.In the eastern region where the Kuroshio and its branches occupy,the surface inclines upward from west to east,so the extension of diluted water is blocked.The Kuroshio,in fact,is an impassible eastern liquid boundary of the Changjiang River Diluter Water and its position directly governs the spreading extend of the latter.The effect of wind field in the Bast China Sea is very important too.Its practical effect should be both direct and indirect.The indirect effect should not be neglected.Owing to less value of pressure gradient in S-N direction,the influence of the pressure field produced especially by baroelinic effect is not very important.
作者
顾玉荷
Gu Yuhe(Institute of Oceanology,Academia Sinica,Qingdao)
出处
《海洋与湖沼》
1985年第5期354-363,共10页
Oceanologia Et Limnologia Sinica
