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

海洋表面重力波（SGW）的随机散射，折射和聚焦的亚中尺度流导致空间调制-“补丁”-在波场。一个签名的补丁是，有效波高Hs变化高达30%的水平尺度在10至100公里的范围内，时间尺度为几个小时到一天，这些尺度反映了亚中尺度的电流和远小于风应力强迫的SGW，这是传统上认为控制的时空变异的Hs。因此，补丁构成了一个重大的挑战，建模和预测的SGW及其对海洋环流的影响。该项目将通过开发次中尺度湍流对SGW散射的新统计模型来应对这一挑战。我们将使用这些模型来解释斑块变化的主要特征，包括最近发现的Hs功率谱和亚中尺度动能谱之间的关系，并开发一个参数化的SGW散射亚中尺度湍流，我们将纳入WAVEWATCH III。空间和时间波动的Hs反映在其他属性的SGW场，包括斯托克斯速度，以及因此控制SGW对水流的强迫的波平均涡旋力和斯托克斯-科里奥利力。我们将调查的假设，波和平均流量之间的相互作用是强大的补丁的时间和空间尺度，并开发新的建模工具，这些尺度。

Random scattering, refraction and focussing of ocean surface gravity waves (SGWs) by submesoscale currents result in spatial modulation - "patches'' - in the wave field. A signature of patches is that the significant wave height Hs varies by as much as 30% on horizontal scales in the range 10 to 100 km and time scales of a few hours to a day; these scales reflect those of submesoscale currents and are much smaller than those of the wind-stress forcing of SGWs which is traditionally assumed to control the spatio-temporal variability of Hs. As a result, patches pose a major challenge for the modelling and prediction of SGWs and of their impact on the ocean circulation. This project will tackle this challenge by developing new statistical models of the scattering of SGWs by submesoscale turbulence. We will use these models to explain the main features of patch variability, including a recently discovered relation between the power spectrum of Hs and the submesoscale kinetic energy spectrum, and to develop a parametrization of SGW scattering by submesoscale turbulence that we will incorporate into WAVEWATCH III.Spatial and temporal fluctuations in Hs are reflected in other properties of the SGW field including the Stokes velocity, and hence the wave-averaged vortex and Stokes-Coriolis forces which control the forcing of currents by SGWs. We will investigate the hypothesis that the interaction between waves and mean flows is strong on patch time and space scales, and develop new modeling tools tailored to these scales.