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，从极低的高度到平流层及以上的自由大气的垂直结构通常具有薄的、强稳定的、非湍流的“片层”的特征，这些“片层”被较厚的、分层较弱且通常为湍流的“层”隔开。自由大气中“片状层”(S&L) 结构的出现和形态被认为受到更大规模的风切变、不同频率的重力波 (GW)、局部 S&L 不稳定动力学、湍流和混合及其相互作用的控制。几十年来，人们知道 S&L 结构在光学和无线电波传播以及热量传输和混合中发挥着重要作用。 势头和成分。还有证据表明，这些小尺度流动特征可能对更大规模的动力学产生重要影响，包括伴随巨星传播到更高海拔的不稳定性和动量传输。 然而，在理解潜在的动力学或解决不稳定和湍流的作用、它们之间的相互作用或这些流动对传输和混合的影响方面进展甚微。特别是，稳定层结中间歇性湍流事件的来源、形态和统计数据，以及它们对环境条件的依赖性仍有待通过观测来定义（例如，S&L厚度的不稳定性特征和统计数据、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，很大程度上可归因于观测和计算方面的挑战。 以足够的空间和时间分辨率捕获相关的大气结构和动态。伴随大气分层的理想、不稳定性、动力学和能量研究项目将进行地面和现场测量以及相关建模，以量化这些过程，并提供对整个分层大气中的 S&L 动力学和影响的关键见解。 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，这些地方的受限空域已经得到保证。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来观察自由对流层中普遍存在的 S&L 结构的动态。 雷达剖面仪和无线电探空仪，距离约 50 m 至 4 km。对观测结果的指导和解释将得到高分辨率 DNS 的帮助，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：对稳定分层大气中的 S&L 动力学进行更定量的理解将有助于参数化其对输送和混合的影响，并提高与许多研究团体相关的预测能力。其中包括污染和无组织排放影响、微气候预报和航空安全等多种应用。该项目将培训两名研究生进行大气科学、航空航天工程和计算流体动力学的最先进研究。这项工作中开发的测量技术和技术将有利于未来的现场研究活动和监管合规要求。

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.