排序方式: 共有56条查询结果,搜索用时 31 毫秒
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一个典型南海北部第二模态内孤立波的观测分析 总被引:1,自引:0,他引:1
第二模态内孤立波在海洋中极少被观测到。本文基于潜标高时空分辨率观测数据,对南海北部陆架区的一个典型第二模态内孤立波进行了分析。结果表明,该第二模态内孤立波的流核出现在135 m深度处,其最大水平流速为0.66 m/s,传播方向为西偏北58°。沿传播方向的内孤立波流速分布在80~170 m的深度范围内,而与传播方向相反的逆流出现在海表和海底附近。垂向模态分析表明,该第二模态内孤立波水平流速的垂向结构与理论结果吻合良好。能量计算结果显示其动能密度的垂向积分可达14 kJ/m2,而波峰线方向单位长度上的动能估算值为5.98 MJ/m。尽管该第二模态内孤立波的动能比陆架区第一模态内孤立波小1个量级,但其高达0.045 s-1的流速垂向剪切约为典型第一模态内孤立波的2倍,表明其导致的混合可能更强。 相似文献
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Starting from the Simplified Navier-Stokes(SNS)equations presented at first by Godovachev-Kuzmin-Tsopov,and Gao Zhi,Davis,the authors analyze the character of the SNS equations for the laminarflow near the leading edge of a flat plate and far away from the plate by using the Weiner—Hopf meth-od and Fourier transform.It is proved that the solution of the SNS equations agree with the solution of the Navier-Stokes equations for flow near the leading edge of the plate and far away from the plate.How to match the solution of the SNS equations to the Blasius solution of the boundary layer equationsis also discussed. 相似文献
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基于fKdV方程系数的正则特性,以二维两层流的先锋孤立子生成问题为算例,用数值方法对本文部分(Ⅰ)中的理论平均波阻,能量劈分及能量劈分比进行检验。从理论与数值结果的比较知,理论与数值结果符合得很好。这表明本文部分(Ⅰ)中的理论平均波阻,能量劈分及能量劈分比可用于先锋孤立子生成参数的预报,也表明本文部分(Ⅰ)中的理论可推广应用于二维非线性强迫系统。 相似文献
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总结破碎波近年来的研究状况,从理论上对计算破碎波发生率进行分析。并利用先进的实验设备和良好的现场条件,从实验研究出发,在研究波浪破碎过程及其与环境参量的关系中,对破碎波发生率进行实际测量。利用不同的破碎波判据对破碎波发生率进行了计算、比较和分析,结果指出;利用不同的破碎波判据计算的破碎波发生率相差很大,甚至相差3~4倍。 相似文献
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In this paper,we present measurements of velocity,temperature,salinity,and turbulence collected in Prydz Bay,Antarctica,during February,2005.The dissipation rates of turbulent kinetic energy(ε) and diapycnal diffusivities(K z) were estimated along a section in front of the Amery Ice Shelf.The dissipation rates and diapycnal diffusivities were spatially non-uniform,with higher values found in the western half of the section where ε reached 10-7 W/kg and K z reached 10-2 m 2 /s,about two and three orders of magnitude higher than those in the open ocean,respectively.In the western half of the section both the dissipation rates and diffusivities showed a high-low-high vertical structure.This vertical structure may have been determined by internal waves in the upper layer,where the ice shelf draft acts as a possible energy source,and by bottom-generated internal waves in the lower layer,where both tides and geostrophic currents are possible energy sources.The intense diapycnal mixing revealed in our observations could contribute to the production of Antarctic Bottom Water in Prydz Bay. 相似文献
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Longwave breaking is the agent for many important upper ocean layer processes including the trans-fer of horizontal momentum. In a previous study on the process of longwave breaking, only linear bot-tom friction was considered.In this paper, we discuss the longwave breaking phenomena in the moregeneral case of nth power bottom friction. Using the theory of blowup of solution,the criterion for thetime and location of the longwave breaking can be obtained. 相似文献
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lareODUcrI0NThephenomenonofbreakingwavesintheoasnoocurswheneveramomentahiyhighcrestmecheSanunstablecondition.It0ccursintendtimhy,andtheoccurrencefre-qUencydePendsonthescastate.ManystudAshaddricaniedoutontheoccurmcefre-qUencyofbrmkingwavesindeepweter.0chiandTsai(l983),LongueHiggins(l975)andVanD0mandPamn(l975)nadstheptalictonofbrmkingwavesoccurrenceindeePwater,usingabaskingcriterionforindividualwavesbasedonthewavesmpness.ThecriterioncanbeexpmeedintennSofthewaVehdghtHandperiodTasH>PgT'(… 相似文献
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南海北部陆架区内孤立波向岸传播过程研究 总被引:1,自引:0,他引:1
南海北部是全球海洋中内孤立波最强和最为活跃的海域。然而,内孤立波在传入陆架区后,其形态发生显著变化,其传播演变过程表现出高度的复杂性。本研究综合卫星图像和数值模式手段研究了内孤立波在向岸传播过程中的空间变化特征。可见光卫星图像研究结果显示,南海北部陆架区存在三种形态的内孤立波,分别为第一模态下凹型内孤立波、第一模态上凸型内孤立波和第二模态内孤立波。受水深和层结变化的控制,它们的分布区域显著不同。基于MITgcm的数值模拟研究表明,上凸型内孤立波由第一模态下凹内孤立波经过极性转换过程发展而来,而第二模态内孤立波由第一模态下凹内孤立波与急剧变浅地形相互作用而产生。 相似文献