| 摘要: |
| 建立一个σ坐标系下三维非线性斜压陆架模式，研究长江冲淡水扩展的动力机制。数值试验再现了夏季长江冲淡水转向东北的现象。夏季风场对长江冲淡水扩展的影响，取决于风速的大小和方向。风速为3m/s的南风，对冲淡水向北扩展的影响比较明显，而当南北风速达到6m/s时，则起着十分显著的作用。西南风加强了冲淡水向东扩展，但对南北向的扩展影响甚微。东南风抑制了冲淡水向东扩展，并使之偏向西北。明确阐明了夏季风场对冲淡水扩展所起的作用。 |
| 关键词: 长江冲淡水 扩展 夏季风场 数值试验 |
| DOI： |
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| 基金项目:国家自然科学基金资助项目，49406070号;上海市青年科技启明星资助 |
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| NUMERICAL SIMULATION OF THE WIND FIELD’S IMPACT ON THE EXPANSION OF THE CHANGJIANG RIVER DILUTED WATER IN SUMMER |
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Zhu Jianrong1, Li Yongping2, Shen Huanting1
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1.State Key Laboratory of Estuarine and Coastal Research,East China Normal University Shanghai 200062;2.Shanghai Typhoon Institute,Shanghai 200030
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| Abstract: |
| A three-dimension nonlinear baroclinic and continental shelf model with primitive equations in σ coordinate system was developed to study the dynamic mechanism of the expansion of the Changjiang River diluted water. The calculation domain is the whole East China Sea. The horizontal resolution of the model is 7.5′× 7.5′, and the vertical resolution is 11 layers. The ocean control equations were discrete in a completely staggered grid system, and the Alternating Direction Implicit (ADI) scheme was adopted for the numerical resolution. The semi-momentum scheme which is quadratic conservation was adopted for the nonlinear terms in the momentum equations. The upstream and implicit scheme were used for the advection terms and the vertical eddy diffusion and convection terms in the temperature and salt equation, respectively. Considering the factors of the Taiwan Warm Current, Kuroshio, coastal current, wind stress and topography, the numerical experiment showed the northeast expanding freshwater tongue and the circulation structure in the East China Sea in summer. The effect of the south wind field on the expansion of the Changjiang River diluted water in summer is determined by the monthly averaged wind speed and direction. At 3 m/s, the south wind obvious expands the diluted water northward; at 6 m/s, the south wind very obviously makes the diluted water expand northward along the Subei coast. The southwest wind enhances the eastward expansion of the diluted water, but has a very little effect on its southward expansion. The southeast wind turns the diluted water’s eastward expansion northwestward. |
| Key words: Changjiang River diluted water, Expansion, Wind field in summer, Numerical experiments |
