Spontaneous Imbalance (SI)

重力波在大尺度上有着深远的影响，因此需要对其进行参数化处理。虽然有几个流量依赖的参数化从地形和对流源的全球变暖的辐射确实存在，情况是欠发达的波从大尺度斜压流。这种GWs的来源与自发不平衡（SI）有关，即在假定的准地转流中自发打破平衡，从而辐射GWs。研究自发GW发射和验证参数化方案是具有挑战性的，因为事实上，GW将总是嵌入在复杂的锋面流与大量的相互作用的过程。因此，我们将联合收割机理论和数值模拟与互补的实验室实验相结合。后者保证了所考虑的大规模流动情况的完全可重复性。实验和模式数据之间的直接对应关系以及数据的可重复性使实验室实验成为参数化和气候相关过程的强大测试环境。 在BTU（勃兰登堡工业大学科特布斯-森夫滕贝格）建立和进行的差热旋转环实验为GU-F（歌德大学法兰克福）和IAP（莱布尼茨大气物理研究所，Kühlungsborn）的模型模拟基准提供了必要的参考数据。我们将集中在实验描绘的首选条件发生SI和相关的背景流特性的大气类大坦克。作为补充，GU-F和IAP将使用理想化模拟来开发GW变异性和相关自发发射过程的有效描述。这里的核心问题是识别大尺度流和中尺度GWs源之间的有用关系，以及在自洽的粗分辨率射线跟踪模拟中验证这种方法。我们的目标是建立一个分辨率依赖的SI参数化。将根据BTU的环空实验验证从模型数据确定的源参数化。这将伴随着高分辨率和低分辨率的UA-ICON模拟分析。最后，参数化GW将耦合到UA-ICON中的射线跟踪GW模型MS-GWaM。

Gravity waves (GWs), spatially often too small to be resolved by present day weather and climate models, need to be parameterized since they have a profound effect on the large scales. While several flow-dependent parameterizations for the radiation of GWs from orographic and convective sources do exist, the situation is less developed for waves emitted from large-scale baroclinic flows. This source of GWs is related to spontaneous imbalance (SI), i.e. the spontaneous breakdown of balance in a supposed quasi-geostrophic flow that in consequence radiates GWs. Studying spontaneous GW emission and validating parameterization schemes is challenging due to the fact that GWs will always be embedded in the complex frontal flow with a large number of interacting processes. Therefore, we combine theory and numerical modelling with complementary laboratory experiments. The latter guarantee the full repeatability of the large-scale flow situation under consideration. The direct correspondence between experimental and model data and the data reproducibility makes the lab experiment a powerful testing environment for parameterizations and climate related processes. The differentially heated rotating annulus experiment, built and conducted at BTU (Brandenburg Technische Universität Cottbus-Senftenberg) provides the necessary reference data for benchmarks of model simulations at GU-F (Goethe Universität Frankfurt) and IAP (Leibniz Institute for Atmospheric Physics, Kühlungsborn). We will focus on experimentally delineating preferred conditions for the occurrence of SI and relevant background flow properties for the atmosphere-like big tank. Complementary, an efficient description of GW variability and the related spontaneous emission process will be developed by GU-F and IAP, using idealized simulations. Core issue here is the identification of a useful relationship between the large-scale flow and the source of meso-scale GWs, and the validation of this approach in self-consistent coarse-resolution ray-tracing simulations. The goal is to construct a resolution-dependent SI parameterization. This source parameterization identified from model data will be validated against the annulus experiment at BTU. This will be accompanied by an analysis of UA-ICON simulations with high and low resolution. Finally, the parameterized GWs will be coupled to the ray-tracing GW model MS-GWaM in UA-ICON.