Spatio-Temporal Gravity-Wave-Source Variability (SV)

时空重力波源变异性 (SV)

• 批准号: 258659751
• 负责人: Professor Dr. Ulrich Achatz
• 金额: --
• 依托单位: IEK-7: Stratosphäre
• 依托单位国家: 德国
• 项目类别: Research Units
• 财政年份: 2014
• 资助国家: 德国
• 起止时间: 2013-12-31 至 2020-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/258659751?language=en
• 关键词: Spatio; Temporal; Gravity; Wave; Source

The goal of the project "Source Variability (SV)" in the MS-GWaves researchers group is to understand the role of gravity wave (GW) sources in shaping the global distribution of GWs. For this we combine observations and modeling. Observations represent reality. However, in order to gain understanding we need a theory and, for quantitative understanding, a process model which formulates our concepts and which is to be tested against the observations. Therefore in SV three different sets of global distributions are compared: 1.) a combination of GW source models and GW propagation, 2.) GWs resolved by the UA-ICON GCM and 3.) remote sensing observations from various satellites. By confronting distributions from GW source models with observations we can on the one hand determine free parameters of the models and, on the other hand, assess at which altitudes, regions and seasons which sources are dominant for GW momentum flux (GWMF) and the drag exerted on the main circulation. With increasing resolution, UA-ICON (cf. GWING) resolves a larger part of the GW spectrum. Whether these distributions are realistic, is tested by comparison versus satellite observations. Sources in ICON can be identified by tracing GWs backwards to potential source processes as well as by comparison to the dedicated source models. This allows us to diagnose the reason for deviations and to develop strategies for improvement. In particular, a focus will be on the interaction of orography and spontaneous imbalance (SI): during the GW-LCycle campaign unique 3D temperature measurments were performed with the limb imager GLORIA. In several research flights we have indication of the interplay of both potential source mechanisms. All comparisons of measurements and models performed in SV will take into account the full observational filter of the observation technique. The observational filter quantifies the effect that every observation technique covers only a part of the wave spectrum and that in particular nowadays global observations underestimate the GWMF even in the resolved part of the spectrum. When performing comparisons we consider mean values of GWMF and its variation by season, region and altitude as well as the intermittency of the GWs, that is the distribution of the frequency of large and small wave events. At all resolutions of ICON we aim at a realistic representation of GWs either by resolved waves or by a parametrization which couples sources to the propagation model MS-GWaM. MS-GWaM was developed and integrated into ICON in the project 3DMSD. A particular strength of MS-GWAM is the ability to model direct transient interaction.

MS-GWaves研究小组的“源可变性（SV）”项目的目标是了解重力波（GW）源在塑造全球GW分布中的作用。为此，我们结合联合收割机的观察和建模。观察代表现实。然而，为了获得理解，我们需要一个理论，为了定量的理解，我们需要一个过程模型，这个模型将我们的概念公式化，并将对照观察结果进行检验。因此，在SV中，比较了三组不同的全局分布：1）GW源模型和GW传播的组合，2.）由UA-ICON GCM解析的GW和3.）各种卫星的遥感观测。通过将GW源模型的分布与观测结果相比较，我们一方面可以确定模型的自由参数，另一方面可以评估在哪些高度、区域和季节，哪些源对GW动量通量（GWMF）和施加在主环流上的阻力起主导作用。随着分辨率的提高，UA-ICON（参见GWING）解决了GW频谱的较大部分。这些分布是否是现实的，通过与卫星观测的比较进行测试。ICON中的源可以通过追溯GW到潜在源过程以及通过与专用源模型进行比较来识别。这使我们能够诊断偏差的原因并制定改进策略。特别是，重点将放在地形和自发不平衡（SI）的相互作用：在GW-LCycle活动期间，使用肢体成像仪格洛丽亚进行了独特的3D温度测量。在几次研究飞行中，我们有迹象表明这两种潜在来源机制的相互作用。在SV中进行的所有测量和模型比较将考虑观测技术的完整观测过滤器。观测滤波器量化了每种观测技术仅覆盖波谱的一部分的效果，特别是现在的全球观测即使在波谱的解析部分也低估了GWMF。在进行比较时，我们考虑GWMF的平均值及其随季节、区域和高度的变化，以及GWs的不稳定性，即大小波事件频率的分布。在所有分辨率的ICON，我们的目标是在一个现实的表示GWs无论是通过解决波或通过耦合源的传播模型MS-GWaM的参数化。开发了MS-GWaM并将其集成到3DMSD项目的ICON中。MS-GWAM的一个特殊优势是能够模拟直接瞬态相互作用。