| 摘要: |
| 吐噶喇海峡是西北太平洋重要的内潮产生区域，该区域内产生的内潮对于东海陆架和西北太平洋的混合和物质输运有十分重要的作用。水平分辨率为3km的JCOPE-T（Japan Coastal Ocean Predictability Experiment—Tides）水动力学模式的结果表明，吐噶喇海峡的内潮主要产生在地形变化剧烈的海山和海岛附近，其引起的等密面起伏振幅可达30m。吐噶喇海峡的内潮在垂直于等深线方向分为两支向外传播：一支向西北方向传播，进入东海陆架后迅速减小；另一支向东南方向传播，进入西北太平洋。吐噶喇海峡潮能丰富，其在约半个月内的平均输入的净正压潮能通量为13.92GW，其中约有3.73GW转化为内潮能量。生成的内潮能量有77.2%在当地耗散，传出的内潮能通量为0.84GW，主要通过西北和东南两个边界传出。该区域潮能通量有显著的大小潮变化，大潮期间输入的正压潮净能通量和产生的内潮能通量均约为小潮期间的2倍，但其主要产生区域基本不变，且内潮能量耗散比率均在产生的内潮通量的76%—79%。另外，内潮能通量的传播方向也没有发生变化，仍主要通过西北和东南两个边界传出。因此，大小潮的变化仅影响吐噶喇海峡处产生的内潮能量的大小，不影响其产生区域、传播方向和耗散比率。 |
| 关键词: 吐噶喇海峡 内潮 大小潮 JCOPE-T (Japan Coastal Ocean Predictability Experiment-Tides) |
| DOI：10.11693/hyhz20181000251 |
| 分类号:P722.6 |
| 基金项目:国家自然基金项目，41576010号；中央高校基本业务费，2015120004号；日本爱媛大学全国共同利用研究基地LaMer（Leading Academia in Marine and Environment Pollution Research）。 |
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| ENERGY BUDGET AND SPRING-NEAP VARIATION OF INTERNAL TIDES IN TOKARA STRAIT, JAPAN |
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GAO Jie1, MAO Xin-Yan1, GUO Xin-Yu2,3,4
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1.College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao 266100, China;2.College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China;3.Center for Marine Environmental Studies, Ehime University, Ehime 790-8577, Japan;4.Japan Agency for Marine-Earth Science and Technology, Kanagawa 236-0001, Japan
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| Abstract: |
| Based on a hydrodynamic model (JCOPE-T model:Japan Coastal Ocean Predictability Experiment-Tides) in 3-km horizontal resolution, we studied the internal tides in the Tokara Strait, Japan. The strait features complex topography and stable stratification, in which significant isopycnal movement (up to 30 m) is generated. Internal tides in the strait could form up near the seamounts and islands where topography changes drastically. After an internal tide is generated, it would propagate outwards perpendicular to the isobaths in two directions:one goes northwestward and finally enters the shelf of the East China Sea; another moves southeastward and finally enters the Pacific Ocean. Therefore, the strait is abundant in tidal energy. The model data averaged over-14 diurnal tidal periods show that the barotropic energy propagated into the region is 13.92 GW of which 3.73 GW is converted into internal tidal energy. About 77.2% of the internal tidal energy is dissipated locally, while the remaining part transmits mainly through the northwestern and southeastern boundaries. Both the input of the barotropic tidal energy and the conversion rate (from barotropic tides to baroclinic tides) during spring tide roughly doubled those during neap tide. Even though, the main generation area and the propagation direction remain largely unchanged, namely, internal tides transmit mainly through the northwestern and southeastern boundaries. The dissipation rate of internal tidal energy is between 76%-79% in both neap and spring tides. Therefore, the spring-neap tidal cycle affects only the amount of internal tidal energy generated in the Tokara Strait but does not affect the generation area, the propagation direction, and the dissipation rate. |
| Key words: Tokara Strait internal tide spring-neap tide JCOPE-T (Japan Coastal Ocean Predictability Experiment-Tides) |
