The turbulent interaction among scale-separated gravity waves and between gravity waves and synoptic-scale flow

重力波在大气动力学中起着重要的作用。然而，即使是分辨率最高的天气预报模型，也无法分辨出整个范围的重力波。结果参数化问题的复杂性增加了这样一个事实，即在GWs受到破碎影响的情况下，波-湍流相互作用是重要的。该项目旨在通过分层方法解决天气尺度流中GW排放的参数化，它们的传播和破坏。(1)高分辨率直接数值模拟（DNS）数据将用于开发隐式亚网格尺度（SGS）湍流参数化。这些DNS将通过关注导致破波的最有效的初始扰动来描述GW耗散的典型范例。(2)研究小尺度GWs与大尺度GWs相互作用的射线追踪算法，并结合典型案例的大涡模拟（LES）数据进行验证。(3)同样利用LES对旋转环空天气尺度流的gw发射进行了研究。结果应与实验室实验结果进行比较。

Gravity waves (GWs) play an important role in the dynamics of the atmosphere. Even the highest-resolution weather-forecast models, however, cannot resolve the entire range of gravity waves. The complexity of the resulting parameterization problem is increased by the fact that, where GWs are affected by breaking, wave-turbulence interactions are important. The project intends to address the parameterization of GW emission from synoptic-scale flow, their propagation and breaking by a hierarchical approach. (1) Data from high-resolution direct numerical simulations (DNS) of turbulence from breaking GWs will be used in the development of an implicit sub-grid scale (SGS) turbulence parameterization. These DNS will describe typical paradigms of GW dissipation by focusing on the initial perturbations most effective in leading to wave breaking. (2) A ray-tracing algorithm for the interaction of small-scale GWs with large-scale GWs, an important aspect of GW dynamics, shall be developed and validated against data from large-eddy simulations (LES) of typical cases. (3) Also using LES, the emission of GWs from synoptic-scale flow in a rotating annulus shall be studied. The results shall be compared with those from the laboratory experiment.