VORTEX2: Damage Survey and Photogrammetric Analyses of Tornadoes, Mesocyclones, and Hook Echoes Observed during VORTEX II

VORTEX2：VORTEX II 期间观测到的龙卷风、中气旋和钩状回波的损害调查和摄影测量分析

• 批准号: 0757714
• 负责人: Nolan Atkins
• 金额: $ 23.83万
• 依托单位: Lyndon State College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-12-01 至 2012-11-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0757714&HistoricalAwards=false
• 关键词: VORTEX2; Damage; Survey; Photogrammetric; Analyses

This award is one component of a mutli-investigator effort known as the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX 2). VORTEX 2 is a follow on to VORTEX 1 whose field phase was conducted during the Spring of 1994 and 1995. The VORTEX 1 advanced knowledge of the kinematic structures of tornadic and non tornadic storms and provided some hints as to the sensitivity of the evolution of supercell storms and tornadogenesis to very fine spatial scale heterogeneity. The VORTEX 2 research objectives will focus on the genesis and maintenance of tornadoes and on the structure of the near wind field of the tornado. The VORTEX 2 is being conducted in conjunction with the National Oceanic and Atmospheric Administration and it will involve an unprecedented observational network of stationary and mobile facilities that include Doppler radars, surface and upper air observations. . The Principal Investigators will perform detailed ground and aerial damage surveys and collect high-resolution photographic data of tornadic storms during the VORTEX II. This data will be combined with high-resolution, ground-based radar data to address the following three objectives. The first objective is to better understand the relationship between the tornado and its parent circulation. Specifically, the time evolution of tornado, mesocyclone, and damage intensities will be examined. Previous studies suggest both strong and weak correlations between tornado and mesocyclone strength. The causes of nonlinear surface damage patterns such as trochoidal and scalloping marks, left and right turns, and sinusoidal patterns documented in past damage survey data will also be explored. These patterns have been attributed to single or multiple vortices orbiting around the parent circulation. Surprisingly, no previous study has verified the visual characteristics of suction vortex and trochoidal marks in surface damage. Recent high-resolution mobile Doppler radar data sets have revealed intriguing single-Doppler velocity features, multi-parameter signatures, and reflectivity features such as weak echo eyes and debris rings within the hook echo of tornadic supercells. The second objective will be to superimpose damage survey and cloud photography data onto these radar features. Such an analysis will further understanding of the relationship between the visual characteristics of the tornado and attendant debris cloud, damage, and the radar-detected features within the hook echo. Finally, it has been shown that ground based Doppler radars at close range to large tornadoes are able to sample the flow within and around the tornado. The third objective is to examine the relationship between radar-detected wind speeds with wind speed estimates based on the Enhanced Fujita (EF) scale assessments. Such an analysis will verify the wind speeds associated with the various degrees of damage for a given damage indicator and potentially identify new damage indicators. The analysis will also examine the correlation of different wind intensity metrics such as highest wind gusts, duration of intense winds, time integrated wind speeds, and local accelerations with observed damage intensity. Intellectual Merit Realizing the above objectives will further understanding of the relationship between the mesocyclone, tornado, and attendant surface damage intensity and damage patterns. Superposition of photography and damage survey data onto high-resolution radar data will allow proper interpretation of intriguing features observed within the hook echo region. It is also anticipated that a better understanding of how tornadic flow creates observed damage will result from this research along with refinements to the newly adopted EF scale. Broader Impacts The research results will have important operational implications for the tornado detection and warning process. A better understanding of the relationship between the mesocyclone and tornado will be very useful in the tornado warning process. An improved understanding of the single-Doppler data within the hook echo may lead to tornadic precursors or identifiable features when the tornado is producing damage at the surface. Any modifications to the EF scale will improve the accuracy of the United States tornado climatology. The research will also expose undergraduate students to the data collection process during a major field experiment and the subsequent analysis. The work will enhance the research infrastructure at Lyndon State College (LSC) and the knowledge gained will be incorporated into many of the undergraduate classes taught at LSC.

该奖项是一个多研究人员的努力，被称为在龙卷风实验2（涡2）旋转的起源验证的一个组成部分。 VORTEX 2是VORTEX 1的后续，其现场阶段在1994年和1995年春季进行。 涡1先进的知识龙卷风和非龙卷风风暴的运动学结构，并提供了一些线索，超级单体风暴和龙卷风的演变非常精细的空间尺度异质性的敏感性。 VORTEX 2的研究目标将集中在龙卷风的形成和维持以及龙卷风近场风场的结构上。 正在与国家海洋和大气层管理局联合进行涡动2号试验，它将涉及一个前所未有的固定和移动的设施观测网络，其中包括多普勒雷达、地面和高空观测。 .主要调查员将进行详细的地面和空中损害调查，并在涡II期间收集龙卷风的高分辨率摄影数据。 这些数据将与高分辨率地面雷达数据相结合，以实现以下三个目标。第一个目标是更好地了解龙卷风与其母体环流之间的关系。具体而言，龙卷风，中气旋，和损害强度的时间演变将被检查。以往的研究表明，龙卷风和中气旋强度之间的强相关和弱相关。非线性表面损伤模式的原因，如余摆线和扇形标记，左，右转弯，和正弦曲线模式记录在过去的损害调查数据也将进行探讨。这些模式被归因于围绕母环流的单个或多个涡旋。令人惊讶的是，没有以前的研究已经证实了表面损伤的吸力涡和余摆线痕迹的视觉特征。最近的高分辨率移动的多普勒雷达数据集揭示了有趣的单多普勒速度功能，多参数签名，和反射率功能，如弱回波的眼睛和碎片环内的钩状回波的龙卷风超级单体。第二个目标是将损害调查和云层摄影数据记录到这些雷达特征上。这种分析将进一步了解龙卷风的视觉特征和伴随的碎片云、损害以及钩状回波中雷达探测到的特征之间的关系。最后，它已经表明，地面多普勒雷达在近距离大龙卷风能够采样内和周围的龙卷风的流动。第三个目标是研究雷达探测到的风速与基于增强型藤田（EF）尺度评估的风速估计值之间的关系。这种分析将核实与给定损害指标的不同程度损害相关的风速，并可能确定新的损害指标。分析还将检查不同风强度指标的相关性，如最高阵风，强风持续时间，时间积分风速和局部加速度与观测到的破坏强度。实现上述目标将进一步了解中气旋、龙卷风和伴随的地表破坏强度和破坏模式之间的关系。将摄影和损害调查数据叠加到高分辨率雷达数据上，将能够对钩状回波区域内观察到的有趣特征进行适当解释。还预计，通过对新采用的EF尺度进行改进，沿着这项研究将更好地了解龙卷风流如何造成观测到的损害。更广泛的影响研究结果将对龙卷风探测和预警过程产生重要的业务影响。 更好地了解中气旋与龙卷风之间的关系将对龙卷风预警过程有重要意义。 当龙卷风在地表造成破坏时，对钩状回波中的单多普勒数据的更好理解可能会导致龙卷风前兆或可识别的特征。 对EF尺度的任何修改都将提高美国龙卷风气候学的准确性。 该研究还将使本科生在主要的实地实验和随后的分析过程中接触数据收集过程。这项工作将加强林登州立学院（LSC）的研究基础设施，所获得的知识将被纳入LSC教授的许多本科课程。