CAREER: Variability of Severe Convective Storm Mode and Hazards as a Function of Environment and Pre-convective Updraft Forcing

虽然数十年的研究大大提高了对严重雷暴的科学认识和预测，但它们每年仍对美国的生命和财产构成重大威胁。这些风暴有各种类型或"模式"，它们产生的危害的类型和严重程度不同，但在相似的环境中形成。特别是，被称为超级单体的离散旋转风暴会产生最严重的龙卷风和最大的冰雹，但它们形成的环境条件与支持严重飑线的环境条件非常相似，这往往会产生大片的破坏性直线风。一个给定的恶劣天气情景如何发挥作用还取决于对风暴发展早期阶段的细节知之甚少。由于这些原因，仍然很难预测哪种模式将占主导地位，导致特定的恶劣天气事件。使用许多复杂的计算机模拟，并将其与真实世界风暴的行为进行比较，该项目将研究严重风暴模式如何取决于一系列不同环境中早期风暴发展的细节。这项调查的结果将有助于预报员区分最有可能产生给定风暴模式及其相关恶劣天气的早期风暴发展的环境和细节。该项目的另一个方面是将新兴的和负担得起的虚拟现实技术应用于模拟结果，以可视化这些风暴的复杂3D结构。将利用这些平台开发互动式教育空间，以吸引从高中到大学的学生，特别重视代表性不足的少数民族和经济弱势群体的学生。该项目的第一个目标是填补我们对强对流风暴（SCS）如何发展，持续和产生严重危害的理解中的一个主要空白，作为其大尺度环境（LSE）的函数，其启动和相互作用的小尺度细节，以及它们之间的联系。使用一套大的理想化风暴尺度数值模拟，该项目将1）调查SCS模式对一系列LSE的对流启动形态的敏感性，2）确定对流冷池在调制不同LSE的超级单体与QLCS模式中的作用，以及3）调查龙卷风发展，寿命和强度的变化作为风暴模式和LSE的函数。 更广泛地说，这项研究的结果将提高我们对中纬度大陆对流如何在气候系统中运作的理解，并将有助于为过去，现在和未来气候建模提供信息。这项研究的另一个目标是开发基于交互式虚拟现实的模拟风暴的3D可视化，使其复杂的结构和行为对学生和研究人员来说更容易理解和直观。这一努力旨在增加公众参与，并最终扩大STEM社区的多样性。 它将专门针对本科生的课堂和发展外展活动，以高中的代表性不足的少数民族和经济上处于不利地位的学生占很大比例。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

While decades of study have led to greatly improved scientific understanding and forecasts of severe thunderstorms, they continue to present a substantial threat to life and property in the United States each year. These storms come in various types or “modes” that differ in the type and severity of the hazards they produce, but otherwise form in similar environments. In particular, discrete, rotating storms known as supercells produce the most severe tornadoes and largest hail, but the environmental conditions in which they form are very similar to those that support severe squall lines, which tend to produce large swaths of damaging straight-line winds. How a given severe weather scenario plays out also depends on poorly understood details of the early stages of storm development. For these reasons it remains difficult to anticipate which modes will be dominant leading up to a given severe weather event. Using many sophisticated computer simulations and comparing them with the behavior of real-world storms, this project will investigate how severe storm mode depends on the details of early storm development across a range of different environments. The results of this investigation will aid forecasters in their ability to discriminate between environments and details of early storm development that are most likely to produce a given storm mode and its associated severe weather. An additional aspect of this project is the application of emerging and affordable virtual reality technology to the simulation results to visualize the complex 3D structures of these storms. These platforms will be leveraged to develop interactive educational spaces designed to engage students from a high school to college level, with a particular emphasis on those students from underrepresented minorities and economically disadvantaged groups. The first goal of this project is to fill a major gap in our understanding of how severe convective storms (SCS) develop, persist, and produce severe hazards as a function of their large-scale environment (LSE), the small-scale details of their initiation and interaction, and the links between them. Using a large suite of idealized storm-scale numerical simulations, this project will 1) investigate the sensitivity of SCS mode to the morphology of convective initiation across a range of LSE’s, 2) determine the role of convective cold pools in modulating supercell vs. QLCS modes in different LSE’s, and 3) investigate the variability of tornado development, longevity, and intensity as a function of storm mode and LSE. More broadly, results of this study will improve our understanding of how mid-latitude continental convection operates within the climate system and will help inform future avenues in the modeling of past, present, and future climate. The other goal of this study is to develop interactive virtual reality-based 3D visualizations of simulated storms to make their complex structure and behavior more accessible and intuitive to students and researchers alike. This effort aims to increase public engagement with and ultimately broaden the diversity of the STEM community. It will specifically target both the undergraduate classroom and develop outreach events to high schools with a large proportion of underrepresented minorities and economically disadvantaged students.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.