| 摘要: |
| 采用σ坐标下三维斜压非线性的浅海陆架数值模式，研究风、边界力流(台湾暖流、黑潮、长江冲淡水)及地形等因子对上升流形成的影响。结果表明，风、台湾暖流是影响冬季闽浙沿岸上升流形成的最重要因子，其中风对浙江沿岸上升流的形成影响较大；台湾暖流对福建沿岸及其远海域上升流的形成影响较大；长江冲淡水对长江口附近上升流有一定的影响，对闽浙沿岸上升流影响不大；地形对闽浙沿岸上升流的形成作用显著；潮对闽浙沿岸上升流形成的影响也很显著。M2，分潮对近海岸区域及台湾东北附近海域上升流的形成影响较大。 |
| 关键词: 闽浙沿岸，上升流，断面结构，数值研究 |
| DOI： |
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| 基金项目:国家703“台湾海峡甚高分辨率浪流耦合及其同化”子专题资助项目，03-03-03-05号 |
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| NUMERICAL STUDY ON WINTER COASTAL UPWELLING OFF FUJIAN AND ZHEJIANG COAST |
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PAN Yu-Ping, SHA Wen-Yu
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College of Meterology, Institute of Science and Engineering of the Chinese People's Liberation Army
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| Abstract: |
| Many studies were done about the coastal upwelling of Fujian and Zhejiang．But most of them were obtained by analysis of observational data，or by diagnostic analysis．Few were done by numerical study．The factors considered were not complete．Although wind stress，topography and current had been thought as important factors，the effects of them however，were not fully described．This paper takes the coastal of Fujian and Zhejiang as an example，dynamical factors that influenced the coastal upwelling of Fujian and Zhejiang were studied in detm1．
A three-dimensional nonlinear baroclinic shallow water and continental shelf model with primitive equations in σ. coordinate system is used in this paper．The model equations were come from the prime equations in spherical coordinate of the lamellar ocean flow，went through the reduction such as shallow layer approximation，sea water incompressibility approximation，Boussinesq approximation，static equilibrium at vertical direction and horizontal isotropic turbulence approximation，then changes into the σ coordinate．Wind stress on sea surface，sea bottom friction stress，vertical eddy viscosity and vertical eddy diffusivity are parameterized in the model also．
The horizontal grid used an“Arakawa C”differencing scheme in this numerical mode1．The difference scheme of nonlinear advetion term in horizontal momentum equation is semi momentum scheme．The baroclinic part of horizontal pressure gradient term is calculated in z coordinate after pressure is interpolated to z coordinate．The difference scheme of advection terms in temperature equation and salinity equation are upstream scheme，all other terms used centered finite difference scheme．The calculated area bracketed 117。-125。E，24。-32。N．Horizontal resolution is 7.5’×7.5’and vertical resolution is 11 layers．
The boundary condition of the model is as followed：Sea surface boundary is free sea surface with the action of really wind stress，in spite of the salinity change induced by physical process such as precipitation and evaporation on sea surface．Sea bottom boundary is viscous an d moving，no salinity an d heat exchange between seawater and sea bottom ．The shore lateral boundary is viscous，no salinity and heat flux．On lateral water boundary，water level data is got from the observational data；boundary flow is got from investigation data or radiation boundary condition when the calculation consider the action of boundary flows；salinity and heat transport is in stationary and no gradient out at boundary ．The initial condition of the model is：When calculating sea flow，initial velocity，water level an d salinity are constant；the initial flux through the five open boundaries used Zhao baoren’s(1991)investigation data．
In order to better understand how wind stress，Kuroshio current，Taiwan warm current，Changjiang River diluted water，topography and tide impact on the coastal upwelling，winter upwelling in the coastal areas of Fujian and Zhejiang(South East China)was computed．Results show that the influence of wind stress and Taiwan warm current and the sea bottom topography are also important factors．The upwelling of Taiwan and the areas east of Taiwan is influenced by Kuroshio current．The Changjiang River diluted water has only a minor influence on winter coastal upwelling． |
| Key words: Coastal Fujian and Zhejiang,Upwelling,Latitudinal section,Numerical study |
