Collaborative Research: Polarimetric Tornado Precursor Signatures

龙卷风在美国是一种重大危险，尽管龙卷风警报时间在过去几十年里有所延长，但仍有改进的空间。龙卷风科学最近的技术进步之一是使用双极化雷达数据。双极化雷达在水平和垂直方向上发射信号。通过这些信号的组合，我们可以推断雨、雪和冰雹的性质，如它们的大小和形状。已经观察到，在一些龙卷风事件之前出现了特定的偏振信号。该研究奖将调查这些信号，以确定它们形成的原因，以及它们是否适合用作龙卷风发展的指标。该项目的社会影响与改善龙卷风警报时间和提高公共安全有关。该研究小组还与一位作者合作，开发了一本关于龙卷风科学家的非虚构类书籍，目标人群为8至11岁的儿童，以提高科学素养。该项目的目标是开发具有潜在预测龙卷风发生价值的超级细胞中反复出现的差异反射率特征的概念模型。研究小组将分析超级单体中现有的快速扫描双极化雷达观测，使用一种新型的快速扫描双极化移动雷达系统收集新的观测数据，并利用这两组观测数据来开发和完善与龙卷风发生有关的这些差异反射率(ZDR)特征的概念模型。研究人员将系统地关注龙卷风发生前的Zdr柱和Zdr弧的行为，全面记录和分析8-10个超级单体的样本。至少五个额外的龙卷风超级单体将在颁奖期间的实地研究期间使用UMassamherst相位倾斜天气雷达(PTWR)进行采样。

Tornadoes are a significant hazard in the United States and while tornado warning times have lengthened over the past few decades, there is still room for improvement. One of the recent technological advancements in tornado science is the use of dual-polarimetric radar data. Dual-polarimetric radars transmit signals horizontally and vertically. Through the combination of those signals, we can infer properties of rain, snow and hail, such as their size and shape. It has been observed that there are specific polarimetric signals that show up prior to some tornado events. This research award will investigate those signals to determine why they form and whether they are good candidates to be used as indicators for developing tornadoes. The societal impact of the project is related to improving tornado warning times and increasing public safety. The research team is also working with an author to develop a non-fiction book about tornado scientists, targeted at 8 to 11-year-olds, to enhance scientific literacy.The goal of this project is to develop conceptual models of recurring differential reflectivity signatures in supercells with potential prognostic value for tornadogenesis. The research team will analyze existing rapid-scanning dual-polarized radar observations in supercells, collect new observations using a novel rapid-scanning dual-polarized mobile radar system, and utilize both sets of observations to develop and refine conceptual models of these differential reflectivity (Zdr) signatures in relation to tornadogenesis. The researchers will systematically focus on the Zdr column and Zdr arc behavior immediately prior to tornadogenesis, comprehensively documenting and analyzing a sample of 8-10 supercells. At least five additional tornadic supercells will be sampled using the UMass-Amherst phase-tilt weather radar (PTWR) during field studies during the award.