Collaborative Research: Polarimetric Tornado Precursor Signatures

龙卷风在美国是一个重大的危险，虽然龙卷风警报时间在过去几十年里延长了，但仍有改进的空间。 龙卷风科学的最新技术进步之一是使用双极化雷达数据。 双极化雷达水平和垂直地发射信号。 通过这些信号的组合，我们可以推断雨，雪和冰雹的性质，例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，以及它们是否是用作发展龙卷风指标的良好候选者。 该项目的社会影响与改善龙卷风预警时间和提高公共安全有关。 该研究小组还与一位作者合作，编写一本关于龙卷风科学家的非小说类书籍，目标是8至11岁的孩子，以提高科学素养。该项目的目标是开发超级单体中重复出现的差异反射率特征的概念模型，对龙卷风的形成具有潜在的预测价值。 研究小组将分析现有的快速扫描双极化雷达观测超级单体，收集新的观测使用一种新型的快速扫描双极化移动的雷达系统，并利用这两组观测发展和完善这些差异反射率（ZDR）签名的概念模型与龙卷风发生。 研究人员将系统地关注Zdr柱和Zdr弧在龙卷风发生前的行为，全面记录和分析8-10个超级单体的样本。 在授予期间的实地研究期间，将使用马萨诸塞大学阿默斯特相位倾斜天气雷达（PTWR）对至少另外五个龙卷风超级单体进行采样。

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.