Non-stationary Gravity Wave retrievals for GLORIA

GLORIA 的非平稳重力波反演

• 批准号: 423229691
• 负责人: Dr. Peter Preuße
• 金额: --
• 依托单位: IEK-7: Stratosphäre
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/423229691?language=en
• 关键词: Non; stationary; Gravity; Wave; retrievals

Gravity waves (GWs) are an essential driver of global circulation patterns in the stratosphere and mesosphere. Frequently discussed are GWs excited by jets and fronts or GWs excited by flow over orography. In idealized model studies it is easy to separate the two different sources, but for observed waves this is more difficult.We propose to observe GWs with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) during the SouthTRAC campaign, perform retrievals confined by GW physics with a simple spectral GW model, separate different wave packets by different phase speeds and investigate the origin of these waves via ray-tracing methods.In detail, this will involve the following steps:In order to study GWs in the upper troposphere and lower stratosphere, we perform GW targeted research flights with GLORIA deployed in the belly pod of HALO. We derive 3-D distributions of atmospheric temperatures and trace species from the measured radiances by means of inverse modeling.Due to the time needed to acquire tomographic measurements, at the moment this requires the temperature field to be nearly stationary.To overcome this limitation and investigate non-stationary GWs, we will extend the inversion by including a spectral GW model in the forward model. The aim is a direct gravity wave parameter retrieval.By using the built-in gravity wave model to simulate the vertical propagation of the assumed waves, we achieve a drastic reduction of the state vector and thus a more stable retrieval. This reduction will allow us to include also non-zero ground-based frequencies in the state vector.From the results, 3D temperature fields can be reconstructed for different synoptic time steps.The spectral representation of the GWs inferred in the retrieval can be utilized to separate different phase speeds associated with different sources. The technique can be applied to superpose different waves in the same altitude and time-domain or in the same region. In the upcoming SouthTRAC campaign multi-instrument measurements of complex atmospheric situations will be acquired to observe GWs from different sources over a wide altitude range. This offers the opportunity to examine, how well these waves can be separated and, ideally, if and how these GWs interact.The PhD project consists of three major work packages to achieve this goal.First, the tomographic inversion method needs to be fully developed in cooperation with the mathematics department of the RWTH Aachen. Its capabilities and limitations will be thoroughly investigated using synthetic and model data. The second work package deals with taking active part in the measurement campaign.The third work package will use the newly developed tools to analyze the data acquired during SouthTRAC and gain physical insight into the observed GWs and their source processes.

重力波(GW)是平流层和中间层全球环流格局的重要驱动力。经常讨论的是由急流和锋面激发的GW或由地形上的气流引起的GW。在理想化模型研究中，分离两个不同的波源是很容易的，但对于观测到的波来说，这是很困难的。我们建议在SouthTRAC战役期间使用GLORIA大气辐射成像观测器(GLORIA)观测GW，用一个简单的光谱GW模型进行GW物理约束的反演，用不同的相速分离不同的波包，并通过射线跟踪方法研究这些波的起源。具体来说，这将涉及以下步骤：为了研究对流层上部和平流层下部的GW，我们进行了GW定向研究飞行，Gloria部署在Halo的腹舱中。为了克服这一限制并研究非平稳的GW，我们将在正演模型中加入一个光谱GW模型来扩展反演的范围。该方法的目的是直接反演重力波参数，通过使用内置的重力波模型来模拟假设波的垂直传播，从而实现状态向量的急剧减少，从而实现更稳定的反演。这一简化将允许我们在状态向量中包括非零的地面频率。根据结果，可以针对不同的天气时间步长重建3D温度场。在反演中推断的GW的谱表示可以用于分离与不同源相关联的不同相速度。该技术可应用于同一高度、同一时间域或同一区域的不同波的叠加。在即将开展的南轨行动中，将获得复杂大气状况的多种仪器测量，以便在广泛的海拔范围内观测来自不同来源的GW。这为研究这些波的分离程度提供了机会，理想的情况是，这些GW是否以及如何相互作用。PHD项目由三个主要工作包组成，以实现这一目标。首先，层析反演法需要与亚琛RWTH的数学部门合作充分开发。它的能力和局限性将使用合成数据和模型数据进行彻底调查。第二个工作包涉及积极参与测量活动。第三个工作包将使用新开发的工具来分析在SouthTRAC期间获得的数据，并对观测到的GW及其源过程进行物理洞察。