Collaborative Research: Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering (IDEAL)

合作研究：伴随大气分层的不稳定性、动力学和能量（IDEAL）

• 批准号: 1632772
• 负责人: David Fritts
• 金额: $ 47.75万
• 依托单位: GLOBAL ATMOSPHERIC TECHNOLOGIES AND SCIENCES, INC.
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-09-01 至 2020-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1632772&HistoricalAwards=false
• 关键词: Collaborative; Research; Instabilities; Dynamics; Energetics

The vertical structure of the free atmosphere under stable conditions from very low altitudes into the stratosphere and above is often characterized by thin, strongly stable, non-turbulent "sheets" separated by thicker, more weakly stratified, and often turbulent "layers". The occurrence and morphology of "sheet-and-layer" (S&L) structures in the free atmosphere are believed to be governed by larger-scale wind shears, gravity waves (GWs) at various frequencies, local S&L instability dynamics, turbulence and mixing, and their interactions.S&L structures have been known for several decades to play important roles in optical and radiowave propagation and in transport and mixing of heat, momentum, and constituents. There is also evidence that these small-scale flow features can have important implications for larger-scale dynamics, including instabilities and momentum transport accompanying GWs propagating to higher altitudes. However, little progress has been made in understanding the underlying dynamics or addressing the roles of instabilities and turbulence, the interactions among them, or the consequences of these flows for transport and mixing. In particular, the sources, morphologies, and statistics of intermittent turbulence events in stable stratification, and their dependence on environmental conditions remain to be defined observationally (e.g., instability character and statistics of S&L thicknesses, turbulence structure parameters and scales, and mechanical and thermal energy dissipation rates).Our lack of understanding of these dynamics to date can largely be attributed to observational and computational challenges in capturing the relevant atmospheric structures and dynamics with sufficient spatial and temporal resolution. The research program IDEAL, Instabilities, Dynamics, and Energetics accompanying Atmospheric Layering will conduct ground-based and in-situ measurements and associated modeling combined to quantify these processes and provide key insights into S&L dynamics and effects throughout the stratified atmosphere. The IDEAL will perform measurements either at Dugway Proving Ground (DPG) in Utah or at Camp Guernsey Joint Training Center (CG) in Wyoming, where restricted airspace is already assured.Intellectual Merit:For the first time, the dynamics underlying ubiquitous S&L structures in the free troposphere will be observed with multiple, coordinated, high-resolution, in-situ sensors together with the integrated sounding radar profiler and radiosondes from ~50 m to 4 km. Guidance and interpretation of the observations will be aided by high-resolution DNS, enabling identification of key dynamics and evaluation of theories and models of stratified turbulence, mixing, and transport.Broader Impacts:A more quantitative understanding of S&L dynamics in the stably stratified atmosphere will contribute to parameterization of their implications for transport and mixing and improve predictive capabilities of relevance to many research communities. These include applications as diverse as pollution and fugitive emission impacts, micro-climate forecasting, and aviation safety. The project will train two graduate students in state-of-the-art studies in atmospheric science, aerospace engineering, and computational fluid dynamics. Measurement technologies and techniques developed in this work will benefit future field research campaigns and regulatory compliance mandates.

在稳定条件下，从极低高度进入平流层及以上的自由大气的垂直结构通常以薄的、非常稳定的、无湍流的“薄片”为特征，中间隔着较厚的、分层较弱的、通常是湍流的“层”。自由大气中“片层”结构的出现和形态被认为是由更大规模的风切变、不同频率的重力波（GWs）、局部的“片层”不稳定动力学、湍流和混合以及它们之间的相互作用所控制的。几十年来，人们已经知道“片层”结构在光学和无线电波传播以及热、动量和成分的传输和混合中起着重要作用。也有证据表明，这些小规模的流动特征对更大规模的动力学具有重要意义，包括伴随GWs向更高高度传播的不稳定性和动量输运。然而，在理解潜在的动力学或解决不稳定性和湍流的作用，它们之间的相互作用，或这些流动对输送和混合的影响方面，几乎没有取得进展。特别是，稳定分层中间歇性湍流事件的来源、形态和统计，以及它们对环境条件的依赖，仍然需要通过观测来确定（例如，S&amp；L厚度的不稳定性特征和统计，湍流结构参数和尺度，以及机械和热能耗散率）。迄今为止，我们对这些动力学缺乏了解，很大程度上归因于观测和计算方面的挑战，即以足够的空间和时间分辨率捕捉相关的大气结构和动力学。研究项目IDEAL、不稳定性、动力学和伴随大气分层的能量学将进行地面和原位测量，并结合相关建模来量化这些过程，并为整个分层大气的S&amp；L动力学和影响提供关键见解。IDEAL将在犹他州的杜格威试验场（DPG）或怀俄明州的根西营联合训练中心（CG）进行测量，那里已经有了限制空域。智力优势：将首次利用多个协调的高分辨率原位传感器，以及集成探测雷达剖面仪和无线电探空仪，在50米至4公里的范围内观测到自由对流层中无处不在的S&amp；L结构的动力学。高分辨率DNS将有助于指导和解释观测结果，从而能够识别关键动力学并评估分层湍流、混合和输送的理论和模型。更广泛的影响：对稳定分层大气中S&amp；L动力学的更定量的了解将有助于参数化它们对运输和混合的影响，并提高与许多研究团体相关的预测能力。其中包括各种各样的应用，如污染和逸散排放影响、微气候预报和航空安全。该项目将培养两名研究大气科学、航空航天工程和计算流体动力学的研究生。在这项工作中开发的测量技术和技术将有利于未来的实地研究活动和法规遵从性授权。

项目成果

Numerical Simulations of High‐Frequency Gravity Wave Propagation Through Fine Structures in the Mesosphere

• DOI: 10.1029/2018jd029746
• 发表时间: 2019-08
• 期刊: Journal of Geophysical Research: Atmospheres
• 作者: Tyler S. Mixa;D. Fritts;T. Lund;B. Laughman;Ling Wang;L. Kantha

On the Performance of the Range Imaging Technique Estimated Using Unmanned Aerial Vehicles During the ShUREX 2015 Campaign

关于 ShuUREX 2015 活动期间使用无人机估计的距离成像技术的性能

• DOI: 10.1109/tgrs.2017.2772351
• 发表时间: 2018
• 期刊: IEEE Transactions on Geoscience and Remote Sensing
• 影响因子: 8.2
• 作者: Luce, Hubert;Hashiguchi, Hiroyuki;Kantha, Lakshmi;Lawrence, Dale A.;Tsuda, Toshitaka;Mixa, Tyler;Yabuki, Masanori
• 通讯作者: Yabuki, Masanori

Comparisons between high-resolution profiles of squared refractive index gradient M2 measured by the Middle and Upper Atmosphere Radar and unmanned aerial vehicles (UAVs) during the Shigaraki UAV-Radar Experiment 2015 campaign

2015 年信乐无人机雷达实验活动期间中高层大气雷达和无人机测量的平方折射率梯度 M2 高分辨率剖面之间的比较

• DOI: 10.5194/angeo-35-423-2017
• 发表时间: 2017
• 期刊: Annales geophysicae
• 影响因子: 1.9
• 作者: Luce, H.