Analytical and Numerical Studies of Deep Overflows and Related Circulations

智力优势：该项目旨在通过对连接到广阔盆地的两层底流的旋转水力学的综合研究，扩展我们目前对深溢流的理解。双层动力学被认为是重要的溢流的一些重要通道，包括丹麦海峡，法罗银行渠道，和Vema渠道，无论是在占的影响，在表面的反向流动或不同的水团的演变喂养的渠道，并包含在溢流。这项研究带来了分析和数值技术承担的一些基本问题，包括动态一致的连接两层水力理论的相邻流域流动的交换和单向流动的情况下，吸入的深层，一般方法识别液压控制和隔离的特殊功能，如水力跳跃在渠道与任意横截面，以及时间依赖性在海峡和海盆-海峡耦合系统中的作用。这些问题的阐明将有助于解释更复杂的数值模型，观测结果，并在规划的战略，长期监测上游流域内的溢流运输。此外，研究人员将继续寻找呈现结果的方法，以利于直觉，并使非专业人员能够接触到。 更广泛的影响：深通道提供了理想的点，以监测翻转环流。然而，这只能做好后，改进现实主义的水力理论的发展，一旦海峡和流域流量之间的动态连接被理解。这项工作将开始回答其中的一些问题，应该是广泛的兴趣超出了这里探讨的具体动态。这两位研究人员都活跃在麻省理工学院/WHOI联合项目中，这项研究的结果将很快进入课堂。 补助金的一小部分将用于支持完成关于海洋海峡和岩床流以及水力学在物理学中的其他应用的研究生课程。 该补助金还将为研究生完成论文提供持续的支持。

Intellectual Merit:This project seeks to extend our current understanding of deep overflows through a comprehensive study of rotating hydraulics of two-layer sill flows connected to broad basins. Two-layer dynamics are thought to be important in the overflows of a number of important passages, including the Denmark Strait, the Faroe-Bank Channel, and the Vema Channel, either in accounting for the influence of reverse flows at the surface or the evolution of distinct water masses feeding the channel and contained within the overflows. This study brings analytical and numerical techniques to bear on a number of fundamental issues including the dynamically consistent connection of two-layer hydraulic theory to the neighboring basin flows for both exchange and unidirectional flow cases, aspiration of deep layers, general methods for the identification of hydraulic control and the isolation of special features such as hydraulic jumps in channels with arbitrary cross section, and the role of time-dependence in straits and coupled basin-strait systems. The elucidation of these issues will aid in the interpretation of results from more complicated numerical models, observations, and in the planning of strategies for long-term monitoring of overflow transport from within upstream basins. Also, the investigators will continue to find ways of presenting the results so as to favor the intuition and to be accessible to the non-specialist. Broader Impacts:Deep passages offer ideal points to monitor the overturning circulation. However, this can only be done properly after development of hydraulic theories with improved realism and once the dynamical connections between strait and basin flows are understood. This work will begin to answer some of these questions and should be of wide interest beyond the specific dynamics explored here. The two investigators are both active in the MIT/WHOI Joint Program and the results of this research will quickly reach the classroom. A small percentage of the grant will support the completion of a graduate text on ocean strait and sill flow and other applications of hydraulics in geophysics. The grant will also provide continuing support for a graduate student to complete his thesis.