Wave Breaking Across the Inner Shelf and Nearshore Regions

内大陆架区域是风和波浪驱动的上层海洋与海底接触并受海底改变的区域，这是一个仍然知之甚少的海洋区域。该区域是碎波带和陆架之间物质运输的重要通道，也是表面波开始在沉积物的流动和分布中发挥作用的区域。在这一地区的波浪破碎起着重要的作用，从大气到水柱的动量传递，并可能提供了一个强大的控制的形式和强度的平均电流，这将改变作为破碎事件的性质随深度的变化。该项目将开发各种建模方法，以研究从深水到浅水深度范围内的波浪破碎，建立在该团队最近在实验室环境中破碎事件的高分辨率大涡模拟方面的经验，以及正在进行的开发波浪解析和波浪平均模型的工作。该项目还将有助于培养一名博士。学生和K-12外展活动，通过实验室参观和向公众提供信息的科学讲座，公开讲座的网络广播，以及特拉华州大学开放日的特别活动。该研究将侧重于从深水破裂的拓扑结构（其中产生跨越破裂事件下侧的涡环）到浅水破裂的过渡，其中破碎事件由产生终止于表面和底部的垂直涡核的区域横向界定。这两种拓扑结构之间的过渡将被表示为中间深度和浅水行为之间的主要分界。特别是，过渡区代表了从较深的水，与打破作出重大贡献的水平涡量的产生，浅水，在那里打破主要是垂直涡量在长度尺度对应于打破波峰几何形状。这项工作将分三个主要专题进行：（1）详细检查从深水到浅水的相对水深范围内有限波峰长度的破碎，使用基于组合大涡模拟和流体体积模型的高分辨率计算，该模型先前已在波浪水槽实验中验证用于中间深度破碎，（2）扩展现有的非流体静力学模型，用于表面波破碎的波解析、冲击捕获解算器，以改进中、深水波破碎的表示，用于更大的空间尺度，以及（3）开发用于单个破碎波的冲击力模型，以及破碎事件在空间和时间中的分布的随机公式，其跨越从深水到浅水的深度范围。这最后一个模型将在一个非流体静力学、波浪平均模型中实施，用于描述从海岸线到内陆架的整个水深范围内的波浪驱动过程。

The inner shelf region, in which the wind and wave-driven upper ocean comes in contact with, and is modified by, the bottom, represents a still poorly understood region of the ocean. The region is important as a pathway for the transport of materials between the surf zone and shelf, and represents the area where surface waves begin to play a role in the mobilization and distribution of sediments. Wave breaking in this region plays an important role in momentum transfer from atmosphere to water column and likely provides a strong control on the form and strength of mean currents which would shift as the nature of breaking events changes with depth. The project will develop a variety of modeling approaches to study wave breaking in the range of depths from deep to shallow water, building on this team's recent experience in high resolution Large Eddy Simulation of breaking events in laboratory settings, and on ongoing work in developing wave resolving and wave-averaged models for dispersive wave processes. The project will also contribute to the training of a Ph.D. student and K-12 outreach activities through laboratory visits and informational scientific talks to the public, web broadcasting of public lectures, and special events at open houses at the University of Delaware.The study will focus on a transition from the topology of deep water breaking, where a vortex ring spanning the underside of the breaking event is generated, and shallow water breaking, where the breaking event is laterally bounded by regions in which vertical vortex cores ending at the surface and bottom are generated. The transition between these two topologies will be denoted as a principal demarcation between intermediate depth and shallow water behavior. In particular, the transition region represents a shift from deeper water, with breaking making a significant contribution to horizontal vorticity generation, to shallow water, where breaking primarily contributes to predominantly vertical vorticity at length scales corresponding to breaking wave crest geometries. This effort will be organized in three main topics: (1) detailed examination of breaking of finite crest lengths in a range of relative water depths spanning from deep to shallow water, using high resolution calculations based on a combined Large Eddy Simulation and Volume of Fluid model previously verified for intermediate depth breaking in wave flume experiments, (2) development of extensions to an existing non hydrostatic, wave-resolving, shock-capturing solver for surface wave breaking to improve the representation of intermediate and deep water wave breaking, for application to larger spatial scales, and (3) development of an impulsive force model for individual breaking waves, together with a stochastic formulation for the distribution of breaking events in space and time, which spans the depth range from deep to shallow water. This last model will be implemented in a non hydrostatic, wave-averaged model for use in describing wave-driven processes in the full range of water depths from shoreline to inner shelf.