| 摘要: |
| 简述北黄海冷水团环流结构研究现状，指出已有研究成果中的主要问题。然后用一个诊断模型给出了冷水团环流结构，得到冷水团环向流动主要存在于海洋上层接近冷水团边界处；径向运动也主要存在于断面两端，上层为离岸流，下层为向岸流；冷水团中心的上升流极为微弱，且仅存在于海洋上层；温跃层下的冷水团中心区域的流动极为微弱，几乎为“死水”一般，上述环流结构对冷水团中心部分的温、盐度长期保持不变及跃层底部溶解氧最大值的形成和保持极为有利。最后用卫星及实测海流资料佐证了所述环流结构。 |
| 关键词: 径向环流 上升流 北黄海冷水团 诊断模型 |
| DOI： |
| 分类号: |
| 基金项目:国家重点基金资助项目，49130015 |
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| A STUDY OF THE CIRCULATIONS OF THE NORTHERN YELLOW SEA COLD WATER MASS (NYSCWM) — EFFECTS OF TIDAL MIXING ON THEM |
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Zhao Baoren
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Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071
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| Abstract: |
| Chinese scientists have conducted many studies on the radial circulations of the Northern Yellow Sea Cold Water Mass (NYSCWM). Early researchers (Guan, 1962; Yuan, 1979: Miao, 1989) thought that notable upwelling appears in the central part of the NYSCWM and downwelling near its boundary areas. But these cannot explain why the dissolved oxygen maximum near the bottom of the thermocline, and T S characteristics in the central part of the cold water mass remain unvarying for long time. Yuan and Li (1993)’s solution of Yuan (1979)'s mathematical model was bassed on the assumption of a very level isotherm and omitted the ?T / ?r term. In fact, because of the existence of a tidal front, ?T / ?r becomes very large (maximum) in the boundary areas of the NYSCWMJ So the ?T / ?r term should not be disregarded as negligible.
We started to study tidal mixing and tidal fronts in the Yellow Sea in 1985 and pointed out that upwelling in the NYSCWM’ s boundary areas is more noticeable than that at its centre. To clarify the NYSCWM’ s circulations characteristics a diagnostic model of tidal front was used to find a numerical solution, which showed mainly circular currents in the upper layer near the NYSCWM boundary, Radial movement of off-shore currents in the upper layer, shoreward currents in the lower layer, the strong upwelling in boundary areas, very weak upwelling in the NYSCWM's upper layer only, and a pound of stagnant water under the thermocline. The above circulation structure of the NYSCWM keeps the dissolved oxygen maximum near the bottom of the thermocline and stabilizes the T S property of the NYSCWM. Measured currtny data and satellite pictures were used to verify the above circulation pattern and show that the Ekman pumping by inner friction of stratified fluid at the thennocline is the main driving force for above the radial circulations. |
| Key words: Radial circulations, Upwelling, Northen Yellow Sea, Cold Water Mass, Diagnostic model |
