【摘要】 本文应用 ECOM模式 ,设计 1个控制试验 ,研究理想河口环流和盐水入侵的动力过程。数值计算结果表明 ,盐水入侵产生盐度锋面 ,在锋面处底层存在着向陆的密度流 ,为保持断面上质量连续 ,上层的流速趋于增大 ;近口门附近底层流有偏南分量 ,表明有横向环流存在。在口门外因斜压和底形的作用 ,产生明显的上升流。盐水入侵在空间上具有不对称性 ,高盐水位于北岸的下层。在拦门沙上游出现上下 2个相反方向的横向环流 ,而在口门处只出现 1个顺时针方向的横向环流。从动力机制上分析了盐水入侵的空间不对称性和横向环流的产生。更多还原

【Abstract】 By using the ECOM model, designing a control experiment, the dynamic processes of estuarine circulation and saltwater intrusion in an idealized estuary are studied. The results of numerical calculation show that the saltwater intrusion produces a salinity front, there exists a land-ward density induced current under the salinity front, and the current speed at the upper layer increases remarkably due to mass continuity through the transverse section. There is a southward component of current at the lower layer near the estuary mouth, and this means there exists a transverse circulation. The interaction of the baroclinicity and the bottom off the mouth produces an obvious upwelling. The saltwater intrusion is of asymmetry, the water of higher salinity, locates at the lower layer and near the north coast. There exist two upstream transverse circulations above the sand bar in which the lower one is clockwise and the upper one is anticlock wise, while there is only one clockwise transverse circulation near the mouth. The asymmetry of the saltwater intrusion and the genaration of the transverse circulation are analyzed in view of dynamic mechanism. =更多还原