NSFGEO-NERC: Scattering of ocean surface gravity waves by submesoscale turbulence

这是一个由国家科学基金会地球科学理事会（NSF/GEO）和联合王国国家环境研究理事会（UKRI/NERC）通过NSF/GEO-NERC牵头机构协议共同资助的项目。该协议允许美国/英国提交一份联合提案，并由研究者拥有最大预算比例的机构进行同行评审。在成功联合确定授标后，每个机构为与本机构调查员和工作组成部分有关的预算和调查员提供资金。海洋表面重力波被亚中尺度海流随机散射、折射和聚焦，导致波场的空间调制或斑块。在这些斑块内，在10至100 km的水平尺度和几小时至一天的时间尺度上，有效波高可能变化多达30%。因此，斑块对表面重力波及其对海洋环流的影响的建模和预测构成了重大挑战。斑块影响波浪破碎率和与气候有关的海气相互作用，如气体交换率、气溶胶产生和与海洋的风应力耦合。补丁可能是重要的贡献者，复杂的海流高度推断的海况偏差误差。该项目将通过纳入未分辨海流的统计影响，从而消除与涌浪延迟到达有关的误差，从而有助于改进实际使用的表面重力波模型的性能。这将提高预测波活动与海军，商业和娱乐的应用。本项目将应用动力学理论和新版本的广义拉格朗日平均理论，以证明次中尺度流对波浪的影响以及波浪对次中尺度流的相互影响。将开发次中尺度湍流对表面重力波散射的新统计模型。这些模型将反过来被用来解释补丁变异的主要特点，包括最近发现的显着波高的功率谱和次中尺度动能谱之间的关系，并制定一个参数化的表面重力波散射的次中尺度湍流，将被纳入WAVEWATCH III。有效波高的空间和时间波动反映在表面重力波场的其他特性中，包括斯托克斯速度，因此也反映在控制表面重力波对海流的作用力的波均涡和斯托克斯-科里奥利力中。假设波和平均流之间的相互作用是强大的补丁时间和空间scales.This奖项将被调查和新的建模工具将被开发和定制这些scales.This反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

This is a project that is jointly funded by the National Science Foundation’s Directorate of Geosciences (NSF/GEO) and the National Environment Research Council (UKRI/NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award, each Agency funds the proportion of the budget and the investigators associated with its own investigators and component of the work. Random scattering, refraction and focusing of ocean surface gravity waves by submesoscale currents results in spatial modulation — or patches — in the wave field. Within these patches the significant wave height may vary by as much as 30% on horizontal scales of 10 to 100 km and time scales of a few hours to a day. As a result, patches pose a major challenge for the modelling and prediction of surface gravity waves and of their impact on the ocean circulation. Patches affect the wave-breaking rate, and climate-relevant air-sea interaction such as gas exchange rates, aerosol production and wind-stress coupling to the ocean. Patches are likely important contributors to sea-state bias errors that complicate altimetric inference of currents. The project will contribute to improving the performance of operational surface gravity wave models by including the statistical effects of unresolved currents, consequently removing errors related to delayed swell arrival. This will improve predictions of wave activity with naval, commercial, and recreational applications. This project will apply kinetic theory, and a new version of generalized Lagrangian mean theory, to demonstrate the effect of submesoscale currents on waves and the reciprocal effect of waves on submesoscale currents. New statistical models of the scattering of surface gravity waves by submesoscale turbulence will be developed. These models will in turn be used to explain the main features of patch variability, including a recently discovered relation between the power spectrum of significant wave height and the submesoscale kinetic energy spectrum, and to develop a parametrization of surface gravity wave scattering by submesoscale turbulence that will be incorporated into WAVEWATCH III. Spatial and temporal fluctuations in significant wave height are reflected in other properties of the surface gravity wave field including the Stokes velocity, and hence the wave-averaged vortex and Stokes-Coriolis forces which control the forcing of currents by surface gravity waves. The hypothesis that the interaction between waves and mean flows is strong on patch time and space scales will be investigated and new modeling tools will be developed and tailored to these scales.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.