Collaborative Research: Airborne Radar Investigation of Mountain Waves and Rotors

合作研究：山地波浪和转子的机载雷达调查

• 批准号: 0742147
• 负责人: Kenneth Kunkel
• 金额: --
• 依托单位: Nevada System of Higher Education, Desert Research Institute
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-02-01 至 2011-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0742147&HistoricalAwards=false
• 关键词: Collaborative; Research; Airborne; Radar; Investigation

Mountain waves have received considerable research attention over the past several decades, primarily for the important role they play in association with damaging winds and severe turbulence both near the ground and aloft. Yet, little is known about the most turbulent of the phenomena associated with mountain waves, that of atmospheric rotors: intense horizontal vortices occurring under wave crests in the lee of mountain ridges. Rotors pose a serious threat to aviation and are important for the lofting and transport of aerosols and contaminants. The internal structure and dynamics of rotors are extremely difficult to sample with standard atmospheric instrumentation. The temporal and spatial scales as well as the variability of rotors are a considerable hurdle to conventional, ground-based, observational tools. Direct penetrations by aircraft carrying in situ instrumentation, as was done during the recently completed Terrain-induced Rotor Experiment (T-REX), can be challenging. T-REX is part of an initiative focused on atmospheric rotors and turbulence over complex terrain and it represents a response to the need for further, more in depth, investigations on the structure of rotors. This research focuses on the analysis of remote sensing data collected with the Wyoming Cloud Radar (WCR) installed on board the University of Wyoming King Air (UWKA) research aircraft during two field campaigns. In addition to the T-REX campaign, which took place over the Sierra Nevada range and the lee-side Owens Valley in California, in March and April 2006, the Principal Investigators will use data from the NASA06 field campaign, which was conducted in the winter of 2006, as a series of research flights over the Medicine Bow range in southeastern Wyoming. The researchers will use these observational data in conjunction with a state-of-the-art mesoscale numerical model to investigate the dynamical evolution and internal structure of atmospheric rotors. The main objective is to describe the radar echo, kinematic structure, and evolution of wave flow and rotor events during T-REX. The Principal Investigators will analyze and merge radar data with in situ and ground-based observations as well as model output from high-resolution numerical simulations in order to provide a multi-dimensional picture of the rotor dynamics and depictions of the boundary-layer structure over complex terrain. A second objective, closely connected to the primary one, specifically deals with the analysis of data from the NASA06 campaign. Although lower and less steep than the Sierra Nevada, the profile of the Medicine Bow and of the adjacent valleys, where the NASA06 campaign took place, induces distinct wave flows aloft. The strong and ubiquitous radar echoes provide a unique opportunity to fill in gaps within the T-REX radar dataset, but also allow for comparisons between different flow regimes as well as extension of T-REX analyses to different environmental conditions. Intellectual Merit: The scientific merit of the research resides in investigation of mountain waves and rotor events and internal rotor structure through cross-sectional data collected by airborne multi-Doppler radar at high resolution (~30m). The two-dimensional representation of the flow kinematics derived via dual- Doppler retrievals across cap and rotor clouds will add important observational dimension to the understanding of dynamical evolution and structure of atmospheric rotors. For the first time, the Principal Investigators will merge airborne remote sensing data with in situ data at flight level to document the physical properties and structures of waves and internal rotor structure over mountainous terrain. The intellectual merit also lies in the synergistic use of advanced remote sensing techniques and high-resolution atmospheric numerical modeling to achieve further improvements in understanding of airflow dynamics in complex terrain.Broader Impact: Results of this research have the potential to improve aviation safety in complex terrain. About 60% of general aviation accidents and incidents in the western United States are associated with mountain-wave and clear-air turbulence. FAA and flight schools will benefit from tangible interpretations and realistic portrayals of rotors and large scale turbulence in the lee of the mountains. The results of this research will be shared with a wider research community in the form of lectures, seminars, and conference presentations. They will also be incorporated into upper-level undergraduate and graduate courses in mesoscale meteorology at the University of Nevada Reno, the University of Wyoming, and the University of Zagreb, Croatia.

在过去的几十年里，山波受到了相当大的研究关注，主要是因为它们在与地面和高空附近的破坏性风和严重湍流相关的重要作用。然而，人们对与山波有关的最动荡的现象，即大气转子，知之甚少：在山脊背风处的波峰下发生的强烈水平涡旋。旋翼对航空业构成严重威胁，对气溶胶和污染物的放样和运输至关重要。转子的内部结构和动力学非常难以用标准大气仪器进行采样。时间和空间尺度以及转子的可变性是常规地面观测工具的一个相当大的障碍。最近完成的地形诱导旋翼实验（T-REX）中，携带现场仪器的飞机直接穿透可能具有挑战性。T-REX是一项专注于大气转子和复杂地形湍流的计划的一部分，它代表了对转子结构进行进一步深入调查的需求的响应。本研究的重点是分析遥感数据收集与怀俄明州云雷达（WCR）安装在船上的怀俄明州空中国王大学（UWKA）研究飞机在两个领域的运动。除了2006年3月和4月在内华达州山脉和加州背风侧欧文斯山谷上空进行的T-REX活动外，主要研究人员还将使用2006年冬季进行的NASA 06野外活动的数据，作为在怀俄明州东南部梅迪辛博山脉上空进行的一系列研究飞行。研究人员将利用这些观测数据与最先进的中尺度数值模型相结合，研究大气转子的动态演变和内部结构。主要目的是描述雷达回波，运动学结构，以及在T-REX的波流和转子事件的演变。主要研究人员将分析和合并雷达数据与现场和地面观测以及高分辨率数值模拟的模型输出，以提供复杂地形上转子动力学和边界层结构的多维图像。第二个目标与第一个目标密切相关，具体涉及对NASA 06活动数据的分析。虽然比内华达州山脉低，也没有那么陡峭，但梅迪辛博和邻近山谷的剖面（美国宇航局06年的活动就是在这里进行的）在高空引起了明显的波浪流。强大而无处不在的雷达回波为填补T-REX雷达数据集的空白提供了独特的机会，同时也允许对不同的流态进行比较，并将T-REX分析扩展到不同的环境条件。智力优势：研究的科学价值在于通过机载多多普勒雷达以高分辨率（~ 30米）收集的横截面数据调查山波和转子事件以及内部转子结构。通过双多普勒反演得到的气流运动学的二维表示将为理解大气转子的动力学演化和结构增加重要的观测维度。主要研究人员将首次将空中遥感数据与飞行水平的现场数据合并，以记录山区地形上波浪和内部转子结构的物理特性和结构。其智力价值还在于协同使用先进的遥感技术和高分辨率大气数值模拟，以进一步提高对复杂地形中气流动力学的理解。更广泛的影响：这项研究的结果有可能提高复杂地形中的航空安全。在美国西部，大约60%的通用航空事故和事件与山波和晴空湍流有关。联邦航空局和飞行学校将受益于有形的解释和逼真的描绘转子和大规模动荡的背风山脉。这项研究的结果将以讲座，研讨会和会议演示的形式与更广泛的研究社区分享。它们还将被纳入内华达州里诺大学、怀俄明州大学和克罗地亚萨格勒布大学的中尺度气象学高级本科和研究生课程。