NSFGEO-NERC: Transfer of energy from the ocean mesoscale to the internal wave field by stimulated loss of balance

海洋能量收支尚未得到很好的了解，海洋能量库的含量和通量存在不确定性。由风、潮汐和地形相互作用产生的内波遍布整个海洋，约占海洋能量收支的10%，其余90%与中尺度涡旋有关。为了达到稳态，进入系统的能量必须与离开系统的能量相同；然而，去除的方法并不明确。这组研究人员最近获得的结果表明，能量从中尺度流转移到近惯性波。这种能量损失也被称为受激平衡损失（SLOB），它影响中尺度流动。该项目旨在量化海洋内波对中尺度流的影响，并确定内潮是否也作为能量转移的来源。研究人员计划利用理论和数值模拟来研究内波在中尺度能量收支中的作用。从这一建议中获得的知识将加强对内波的理解，这可以用来改进气候模型。对内部潮汐的更好理解也可能导致对卫星高度计数据的更准确解释。通过本项目，两名博士后研究助理将受益于最先进的物理海洋学和应用数学培训。该项目支持斯克里普斯海洋学研究所和爱丁堡大学之间的国际合作。由此产生的模型和模型输出将提供给其他研究人员用于教学和学习目的。这组研究人员最近的研究结果表明，中尺度气流对近惯性波的平流和折射必然伴随着能量从中尺度气流向惯性波的转移。理论和数值分析将用于开发一个将内波动力学与平衡中尺度流耦合的模型，以了解中尺度水库通过SLOB向内波的能量转移。该项目的具体目标是：评估和发展SLOB在中尺度能量收支中起主要作用的假设，并通过内波谱的组成部分，特别是内潮来研究SLOB。所提出的方法还将有助于开发和评估具有广泛适用性的技术，以解决涉及湍流波的散射和转换的多尺度问题。作为这个项目的结果，将获得对SLOB在海洋能量收支中所起作用的定量理解。

The ocean energy budget is not well understood and there is uncertainty in the content of and fluxes between ocean energy reservoirs. Internal waves, which result from wind, tides and topographic interactions, are present throughout the ocean and contain about 10% of the ocean energy budget while the remaining 90% is associated with mesoscale eddies. In order to reach steady-state, the same amount of energy entering the system must leave the system; however, the method of removal is not clear. This group of researchers has recently obtained results that suggest a transfer of energy from the mesoscale flow to near-inertial waves. This loss of energy is also known as the stimulated loss of balance (SLOB), which influences mesoscale flow. This project seeks to quantify the impact of ocean internal waves on mesoscale flow as well as determine if internal tides also act as a source of energy transfer. The researchers plan to utilize theory and numerical simulations to investigate the role of internal waves in the mesoscale energy budget. The knowledge gained from this proposal will enhance understanding of internal waves, which can be used to advance climate models. A better understanding of internal tides will likely lead to more accurate interpretations of satellite altimeter data as well. Two postdoctoral research assistants will benefit from state-of-the-art physical oceanography and applied mathematics training through this project. This project supports an international collaboration between Scripps Institute of Oceanography and the University of Edinburgh. The resulting models and model output will be made available to other researchers for teaching and learning purposes.Recent results produced by this group of researchers show that the advection and refraction of near-inertial waves by mesoscale flow is necessarily accompanied by a transfer of energy from the mesoscale flow to the inertial waves. Theoretical and numerical analyses will be used to develop a model that couples internal wave dynamics with that of balanced mesoscale flow to understand energy transfers from the mesoscale reservoir to internal waves via SLOB. The specific objectives of this project are to: assess and develop the hypothesis that SLOB plays a major role in the mesoscale energy budget, and to investigate SLOB by components of the internal wave spectrum, particularly the internal tide. The proposed methodology will also aid in the development and assessment of techniques with broad applicability to multi-scale problems involving the scattering and transformation of waves by turbulent flows. As a result of this project, a quantitative understanding of the role played by SLOB in the ocean energy budget will be obtained.