Gravity Wave Interactions in the Global Atmosphere (GWING)

重力内波将对流层到热层的不同大气层联系起来，并驱动中层大气的大尺度环流。然而，许多从产生到传播再到消散的过程仍然不完全被理解，而且由于它们的长度很小(通常是次网格)，它们在数值天气预报和气候模式中的表现很差。GWING是MS-GWaves研究单位的项目之一，旨在促进我们对上述涉及大气GW的多尺度动力过程的理解，最终目的是发展从源到耗散的亚格子尺度GW过程(及其影响)的统一参数化。为此，GWING项目的中心目标是开发和应用UA-ICON大气环流模式。通过UA-ICON，GWING项目正在整合整个MS-GWaves部门产生的新知识。在GWING的第二阶段，我们将集中讨论以下主要的科学问题：a)在经典的参数化方案中被忽略的GW特征，即水平传播、非瞬时传播和波瞬变-平均流相互作用的相关性是什么。b)重力波对全球大气环流及其变异性的作用是什么？为了回答这些问题，我们将在GW允许的分辨率和粗分辨率下使用全球UA-ICON，但使用最先进的WKB GW-参数化(MS-GWaM)。此外，我们将继续用当地高分辨率、GW分辨率的巢来模拟和分析事件。模型模拟将与伙伴项目的观测知识相结合。因此，GWING第二阶段的主要UA-ICON开发目标是实施MS-GWaM(在合作伙伴项目3DMSD中开发)，实施基于物理的震源(与合作项目SV和3DMSD一起)，以及在高模式分辨率下改进GW的处理。使用UA-ICON的不同配置将最终允许评估到目前为止被忽视的功能的重要性，即回答我们的第一个首要问题。GWING的一个具体目标是对SSW期间的情况进行评估，SSW为GW提供了快速变化和地带性不均匀的传播条件，因此可能特别容易受到非瞬时传播和波浪瞬变-平均流相互作用的影响。关于第二个最重要的问题，全球环流对全球大气环流的作用，除SSW外，我们还将重点讨论a)全球环流在全球变暖下对高层大气环流变化的作用和b)全球环流对天气预报技能的作用。

Internal gravity waves (GWs) link different layers of the atmosphere from the troposphere to the thermosphere and drive the large-scale circulation of the middle atmosphere. However, many of the processes from their generation via propagation to dissipation are still incompletely understood and due to their small (often sub-grid) length scale they are poorly represented in numerical weather prediction and climate models. GWING is one of the projects of the research unit MS-GWaves that aims at advancing our understanding of the above mentioned multiscale dynamical processes involving atmospheric GWs with the ultimate goal to develop a unified parameterization of sub-grid scale GW processes (and their effects) from the sources to the dissipation. To contribute to this, the central goal of the project GWING is the development and application of the UA-ICON atmospheric general circulation model. With UA-ICON, the GWING project is integrating the new knowledge generated by the whole MS-GWaves unit. In the 2nd phase of GWING we will focus on the following overarching scientific questions:a) What is the relevance of GW features neglected in classical parameterizations, i.e. horizontal propagation, non-instantaneous propagation, and wave transience-mean flow interactions.b) What is the role of gravity waves for the global atmospheric circulation and its variability?To answer these questions, we will use UA-ICON globally at both GW-permitting resolution and coarse resolution but with a state-of-the-art WKB GW-parameterization (MS-GWaM). Furthermore, we will continue to simulate and analyse episodes with locally highly resolved, GW-resolving nests. The model simulations will be combined with the observational knowledge from the partner projects. The major UA-ICON development goals in phase 2 of GWING are therefore the implementation of MS-GWaM (developed in partner project 3DMSD), the implementation of physics-based sources (jointly with partner projects SV and 3DMSD), and the improved treatment of GWs at high model resolutions. Using the different configurations of UA-ICON will finally allow to assess the importance of so far neglected features, i.e. to answer our first overarching question. A specific objective for GWING is this assessment for the situation during SSWs which provide rapidly changing and zonally inhomogeneous propagation conditions for GWs, and therefore may be particularly prone to effects of non-instantaneous propagation and wave transience-mean flow interactions. With respect to the 2nd overarching question, the role of GWs for the global atmospheric circulation, besides SSWs, we will focus on a) the role of GWs and model extension to the upper atmosphere for circulation changes under global warming, and b) the role of GWs for weather forecasting skill.