Linking topographic internal wave radiation to near-field processes, dissipation and mixing

智力优势：该项目涉及孤立的地形特征的潮汐流的动力学，特别侧重于参数空间中的制度，其中非线性导致显着的局部混合和耗散相比，在整体能量平衡中的波辐射率。 这种流态既发生在深海，也发生在夏威夷海脊等高大孤立特征附近。一方面，近场耗散和混合的相对重要性，另一方面，远场辐射的相对重要性，在不同地点之间有所不同，并且取决于目前尚未很好理解的因素。 主要目的是了解非线性局部流动现象与远场波辐射的强度和特性之间的动力学联系，并将各种频率下的混合、耗散和辐射速率与流动和地形的特征参数联系起来。该项目将采用一种实验方法，在并行超级计算机上运行高分辨率三维数值模拟。模拟将解决诸如边界层分离和剪切不稳定性以及大约十年的惯性子范围等现象。数值模型是专门为面向过程的研究，如这些，并结合了高精度的数值方法与高效的分布式内存计算设施的实施。更广泛的影响：地形上的分层流是海洋运动的一个基本方面，其特征是广泛的现象学。产生辐射到远场的内波的过程可以共存，并动态地耦合到近场现象，如高阻力状态，内部水跃，耗散和混合。了解物理连接这些本地和全球的反应是一个重要的先驱成功的参数化的能量转换，因此内部波驱动的混合。 该项目将直接支持一名博士的教育和培训。物理海洋学专业的学生 这项工作的各个方面将被纳入研究生班讲授的研究人员在环境流体动力学和湍流环境流的学生在物理海洋学，气候科学和机械和航空航天工程。 研究人员还将维护一个项目网页，传播数值工具，目的是使所有的数值结果：可由其他小组复制;作为相关或扩展研究的起点有用;并适合作为计算流体力学的教育实例。 研究结果还将纳入圣地亚哥飞行标准区办公室关于波浪飞行和下坡流危害的公开讲座。

Intellectual Merit: The project addresses the dynamics of tidal flows over isolated topographic features, focusing in particular on the regime in parameter space where nonlinearity leads to significant local mixing and dissipation in comparison to the rate of wave radiation in the overall energy balance. This flow regime occurs both in the deep ocean and also near tall isolated features such as the Hawaiian Ridge. The relative importance of near-field dissipation and mixing on the one hand, and radiation to the far-field on the other, varies between sites and depends on factors that are not presently well understood. The primary objective is to understand the dynamics linking nonlinear local flow phenomena to the intensity and character of wave radiation to the far field and to relate the rates of mixing, dissipation and radiation at various frequencies to parameters characterizing the flow and the topography. The project will utilize an experimental approach using high-resolution, three-dimensional numerical simulations run on parallel supercomputers. The simulations will resolve phenomena such as boundary layer separation and shear instabilities and about a decade of the inertial sub-range. The numerical model was designed specifically for process-oriented studies such as these and combines high-accuracy numerical methods with efficient implementation on distributed memory computing facilities. Broader Impacts: Stratified flow over topography is a fundamental aspect of oceanic motion characterized by a wide range of phenomenology. The processes that produce internal waves that radiate to the far field can coexist and be dynamically coupled to near-field phenomena such as high-drag states, internal hydraulic jumps, dissipation and mixing. Understanding the physics linking these local and global responses is an important precursor to the successful parameterization of energy conversion and therefore internal wave driven mixing. The project will directly support the education and training of one Ph.D. student in Physical Oceanography. Aspects of this work will be incorporated into graduate classes taught by the investigators in Environmental Fluid Dynamics and Turbulence in Environmental Flows to students in Physical Oceanography, Climate Sciences and Mechanical and Aerospace Engineering. The investigators will also maintain a project web page disseminating numerical tools with the objective of making all of the numerical results: reproducible by other groups; useful as a starting point for related or extended studies; and suitable as educational examples of computational fluid mechanics. Results will also be integrated into public lectures given through the San Diego Flight Standards District Office on wave flights and the hazards of down slope flows.