Collaborative Research: Propagation, Evolution and Rotation in Linear Storms (PERiLS)

合作研究：线性风暴中的传播、演化和旋转（PERiLS）

• 批准号: 2020588
• 负责人: Matthew Parker
• 金额: $ 54.52万
• 依托单位: North Carolina State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2024-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2020588&HistoricalAwards=false
• 关键词: Collaborative; Research; Propagation; Evolution; Rotation

The PERiLS (Propagation, Evolution and Rotation in Linear Storms) project will bring together NSF and NOAA scientists to study severe weather in the Southeastern U.S. In the Southeastern U.S., severe weather is frequently produced by squall lines, also known as quasi-linear convective systems (“QLCSs”). QLCSs are responsible for approximately a quarter of all tornadoes in the U.S. and the majority of QLCS tornadoes occur in the Southeastern U.S. QLCS-spawned tornadoes pose a significant threat to lives and property, but forecasting QLCS tornado events continues to pose significant challenges, even more so than forecasting supercell tornadoes. The small-scale processes and precise environments leading to these hazards are not well observed by the current operational weather observing network and there is a lack of understanding of QLCS tornadogenesis processes. Complicating this further, coarse data and forecast analyses suggest large areas along QLCSs may be favorable for tornadogenesis (tornado formation), but tornadoes tend to occur only within a small fraction of that area. While many field campaigns have focused on a better understanding of supercell tornadogenesis (especially in the Great Plains), no campaigns have focused specifically on collecting data to understand QLCS tornadogenesis. Starting in 2021, PERiLS will be the first such project, and will deploy an extensive network of cuttingedge observing systems to the Southeastern U.S. to gather data to help researchers better understand how tornadoes form in QLCSs, what are the precursors for tornadoes, and what storm processes and characteristics can be used to differentiate storms that will produce severe winds from those that will produce tornadoes.There are critical gaps in our knowledge concerning how QLCS tornadoes form, which must be addressed before forecast skill can be improved. QLCS tornadoes often form within mesovortices, but most mesovortices do not produce tornadoes. Environments with “high-shear” and “low-CAPE” are prevalent in the SE U.S.; storms that form in these environments account for a substantial fraction of severe wind and tornado reports in the region. How this environment specifically supports QLCS tornadogenesis is unknown. Moreover, the characteristics of the temporal and spatial variability, of both the storm and the environment, has yet to be well quantified. While there have been idealized numerical modeling studies and climatologies based on operational data of QLCS tornadoes, there is a dearth of the fine-scale observations that are necessary to characterize storm and sub-storm scale processes and the interaction of storm features with the rapidly-evolving near-storm environment. The PERiLS field campaign will obtain observations needed to address the following interrelated objectives: (1) Identify the mechanisms for low-level mesovortex formation; 2) Identify the characteristics and mechanisms that distinguish tornadic from non-tornadic QLCS mesovortices; 3) Identify the environmental variability and storm-environment interactions that are associated with QLCS mesovortex and tornado formation; and 4) Characterize the roles of cold frontal processes vs. system-generated cold pools in the evolution of strongly-forced QLCSs. This unprecedented data set will facilitate an understanding of the interplay between environmental and within-storm processes that contribute to QLCS tornadogenesis.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.

危险（线性风暴中的传播，进化和旋转）项目将使NSF和NOAA科学家研究美国东南部美国东南部的恶劣天气，恶劣的天气经常是由Squal Lines（也称为Quasi-lineareareareareareareareareareareal-liens）产生的（也称为Quasi-lineareareareareareareareareareareareareareal-Contricection Systems（“ QLCSS”）。 QLCSS在美国大约有四分之一的龙卷风中，大多数QLCS龙卷风发生在美国东南部的美国QLCS产生的龙卷风造成的巨大威胁对现场和财产构成重大威胁，但是预测QLCS龙卷风龙卷风龙卷风仍在为重大挑战带来巨大的挑战，甚至比这比这更重要的超级杂货店更加挑战。当前的操作天气观察网络无法很好地观察到导致这些危害的小规模过程和精确的环境，并且缺乏对QLCS龙核病生成过程的了解。更复杂的是，粗略的数据和预测分析表明，沿QLCS的大面积可能有利于龙卷风发生（龙卷风形成），但是龙卷风往往仅在该地区的一小部分内发生。尽管许多现场运动都集中在更好地理解超级细胞龙卷风发生（尤其是在大平原上），但没有专门针对收集数据来了解QLCS龙卷风的生成。从2021年开始，危险将成为第一个这样的项目，并将在美国东南部部署广泛的尖端观察系统网络，以收集数据，以帮助研究人员更好地了解QLC中的龙卷风如何形成，什么是龙卷风的前体，什么是龙卷风的前体，可以使用什么样的风暴过程和差异化的风暴来使我们的知识与我们的知识相处。 QLCS TORNADOS表格，必须在改进预测技能之前解决。 QLCS龙卷风经常在中间术中形成，但大多数中肥不会产生龙卷风。在美国东南部，具有“高剪切”和“低率”的环境很普遍；在这些环境中形成的风暴占该地区的大风和龙卷风报告的很大一部分。该环境如何专门支持QLCS龙卷风发生是未知的。此外，风暴和环境的临时和空间变异性的特征尚未得到充分量化。尽管基于QLCS龙卷风的操作数据进行了理想化的数值建模研究和气候，但精细尺度观察的死亡是表征风暴和亚验证量表过程以及风暴特征与快速变化的近态环境的相互作用所必需的。危险现场活动将获得解决以下相互关联对象所需的观察值：（1）确定低级中层形成的机制； 2）确定将龙核与非龙骨QLC中交流区分开的特征和机制； 3）确定与QLCS中交流和龙卷风形成相关的环境变异性和风暴环境相互作用； 4）表征冷额过程的作用与系统生成的冷池在强大的QLCS的演变中。这个前所未有的数据集将有助于理解有助于QLCS TORNADESICASION的环境和内部过程之间的相互作用。该奖项反映了NSF的法定任务，并被认为是通过基金会的智力优点和更广泛的影响审查标准通过评估来评估的。