南黄海春季中层冷水形成机制研究

The middle layer cold water appeared in Spring, when the Yellow Sea Warm Current and the Yellow Sea Cold Water Mass alternated. It's character and formation mechanism is very important to discover the dynamic process of the Yellow Sea in Spring. The project plan to use the historical investigated data, combined with the high time and spatial resolution data aquired this year to discribe the time and spatial style of the middle layer cold water, and discover it's relationship to the surrounding water mass. Through the sensitive test of numerical modle, find the dynamic process to cause the middle layer cold water, and discover the mechanism of formation, maintaining and vanishing.

南黄海中层冷水现象出现于黄海暖流和黄海冷水团的交替演变的春季，它的水文特性和形成机制的研究对于揭示过渡季节南黄海动力过程具有十分重要的参考意义。本项目拟采用现有的各种实测历史资料，结合近年来获取的高时空分辨率的数据描述中层冷水的时空分布特征，揭示其与周围水团的相关关系。通过模式的各种敏感性实验，寻找可能诱发中层冷水的动力过程，揭示其形成、维系、消亡的机制。

春季在成山头东南海域50m等深度线附近出现中层冷水现象，冷水块在10-30m水层里，纬向尺度100km，其中心水温比周边低2°C、比表层低1.5°C、比底层低1.0°C。它是由黄海暖流水、沿岸冷水以及春季升温过程等诸因素在该海域相互作用的结果。首先是南下的成山头外海水带来低温、低盐的海水，这支海流在南下过程中与局地增温的表层海水和底层黄海暖流高盐水相遇，因为密度的原因插入两层海水之间，形成了低温、低盐的中层冷水。