Understanding Polarimetric Radar Tornadic Debris Signatures Using Modeling, Simulations, and Field Measurements

使用建模、仿真和现场测量了解偏振雷达龙卷碎片特征

• 批准号: 1303685
• 负责人: Robert Palmer
• 金额: $ 86.02万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1303685&HistoricalAwards=false
• 关键词: Understanding; Polarimetric; Radar; Tornadic; Debris

The recently completed dual-polarimetric upgrade of the national WSR-88D Doppler radar network has provided a wide variety of new capabilities for weather observations. One notable area of improvement that has as-yet not been the subject of focused research is the ability to detect tornadoes through analysis of polarimetric variables within zones of lofted debris, collectively known as the Tornadic Debris Signature (TDS). While these observations are already being accessed, user confidence in (and hence impact of) these new data is limited in part because the scattering characteristics of tornadic debris are not well understood in a quantitative sense. This multi-pronged project will make use of observations, simulations and modeling to further knowledge on how tornadic debris is observed by weather radars. The project embodies four primary thrusts and associated tasks, which will in-turn enable the study of several scientific questions. The researchers plan to begin their investigation by cataloging radar cross-section (RCS) for common tornadic debris types using theory, simulations and laboratory-type anechoic chamber measurements. Sample objects will include distributions of straight and small twigs, free-standing leaves absent significant roughness and bending effects, small pieces of wood, hydrometeors, and dust. Numerical simulations of polarimetric radar data using the RCS database and 3D wind fields (as generated via prior tornado-scale numerical modeling efforts) will then be conducted. The PIs also plan to collect additional new high-resolution observational data from the Rapid scanning X-band polarimetric (RaXpol) mobile radar and nearby fixed-based network radars, and to evaluate these data in tandem with detailed post-tornado damage surveys. These tasks will subsequently drive development of a suite of signal processing algorithms to improve detection and meaningful characterization tornadic debris signatures with the goal of distinguishing debris type, size, and concentration. The main scientific objectives are to: 1) Investigate the two main hypotheses for negative ZDR in tornadoes, Mie scattering and common scatter alignment, and 2) Examine the physical processes associated with tornadic debris, such as lofting, centrifuging and loading, and their relationship to tornado and supercell dynamics.Broader impacts of this project map strongly on mission agency efforts to increase public safety, as this work will potentially assist the operational meteorological community through improved tornado detection and ability to better estimate severity of ensuing damage in real-time. Development of an anechoic chamber will facilitate future research focusing on antenna design and performance, both by investigators at the grantee university and co-located organizations who are part of the National Weather Center. Graduate and undergraduate students will be directly included in the research activities and the interdisciplinary engineering and meteorology curriculum.

最近完成的国家WSR-88 D多普勒雷达网络的双极化升级为天气观测提供了各种新的能力。 一个值得注意的改进领域尚未成为重点研究的主题，这是通过分析漂浮碎片区域内的偏振变量来检测龙卷风的能力，统称为龙卷风碎片特征（TDS）。 虽然这些观测数据已经被获取，但用户对这些新数据的信心（以及由此产生的影响）有限，部分原因是对龙卷风碎片的散射特性在数量上没有很好的了解。 这个多管齐下的项目将利用观测、模拟和建模来进一步了解气象雷达如何观测龙卷风碎片。 该项目包含四个主要目标和相关任务，这将反过来使几个科学问题的研究成为可能。 研究人员计划开始他们的调查，利用理论、模拟和实验室型消声室测量，对常见龙卷风碎片类型的雷达截面进行编目。 样本对象将包括分布的直和小树枝，独立的叶子没有显着的粗糙度和弯曲的影响，小块木材，水凝物和灰尘。 然后将使用RCS数据库和三维风场（通过先前的龙卷风尺度数值模拟工作生成）对偏振雷达数据进行数值模拟。 PI还计划从快速扫描X波段偏振（RaXpol）移动的雷达和附近的固定网络雷达收集额外的新的高分辨率观测数据，并与详细的龙卷风后破坏调查一起评估这些数据。 这些任务随后将推动开发一套信号处理算法，以改进对龙卷风碎片特征的探测和有意义的定性，目的是区分碎片的类型、大小和浓度。 主要科学目标是：1）调查龙卷风中负ZDR的两个主要假设，Mie散射和共同散射排列，以及2）检查与龙卷风碎片相关的物理过程，如放样，堆积和装载，以及它们与龙卷风和超级单体动力学的关系。该项目对使命机构努力提高公共安全的更广泛影响，因为这项工作将通过改进龙卷风探测和更好地实时估计随之而来的损害严重程度的能力，有可能帮助气象界的业务。 电波暗室的开发将促进未来的研究，重点是天线的设计和性能，无论是在受助大学和共同定位的组织谁是国家气象中心的一部分，研究人员。 研究生和本科生将直接参与研究活动和跨学科的工程和气象课程。

项目成果

Analysis of the 16 May 2015 Tipton, Oklahoma, EF-3 Tornado at High Spatiotemporal Resolution Using the Atmospheric Imaging Radar

使用大气成像雷达以高时空分辨率分析 2015 年 5 月 16 日俄克拉荷马州蒂普顿的 EF-3 龙卷风

• DOI: 10.1175/mwr-d-17-0256.1
• 发表时间: 2018
• 期刊: Monthly Weather Review
• 影响因子: 3.2
• 作者: Mahre, Andrew;Kurdzo, James M.;Bodine, David J.;Griffin, Casey B.;Palmer, Robert D.;Yu, Tian-You
• 通讯作者: Yu, Tian-You

SimRadar: A Polarimetric Radar Time-Series Simulator for Tornadic Debris Studies

SimRadar：用于龙卷碎片研究的偏振雷达时间序列模拟器

• DOI: 10.1109/tgrs.2017.2655363
• 发表时间: 2017
• 期刊: IEEE Transactions on Geoscience and Remote Sensing
• 影响因子: 8.2
• 作者: Cheong, Boon Leng;Bodine, David J.;Fulton, Caleb J.;Torres, Sebastian M.;Maruyama, Takashi;Palmer, Robert D.
• 通讯作者: Palmer, Robert D.