Collaborative Research: Observing and Understanding Planetary Boundary Layer (PBL) Heterogeneities and Their Impacts on Tornadic Storms during VORTEX-SE 2018 Field Experiment

合作研究：在 VORTEX-SE 2018 现场实验期间观察和理解行星边界层 (PBL) 异质性及其对龙卷风暴的影响

• 批准号: 1917693
• 负责人: Zhien Wang
• 金额: $ 32.58万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1917693&HistoricalAwards=false
• 关键词: Collaborative; Research; Observing; Understanding; Planetary

High-impact weather phenomena such as high winds, hail, and heavy rainfall have huge socio-economic impacts. However, forecast for severe high-impact weather events, especially tornadoes, remains challenging. Historically, tornado research has been concentrated in the Great Plains while the Southeastern U.S. commonly experiences devastating tornadoes as well. Significant differences in environmental conditions over the two regions and frequent occurrence of tornadoes at night in the Southeast (SE) pose challenges to observing and understanding the formation and development of tornadoes in the SE. The Verification of the Origins of Rotation in Tornadoes Experiment - Southeast (VORTEX-SE) is a research program designed to understand how environments in the SE affect the formation, intensity, structure, and path of tornadoes in this region. During the VORTEX-SE field campaign in 2018, unprecedented advanced measurements from an airplane flying around tornadoes have been collected. Such observations cannot be done easily on the ground with hilly forest terrain. The study will utilize the unique observations and advanced computer models to understand airflow structures of tornadic storms and special environments for their formation. New knowledge gained from the research will contribute to improvement of tornado forecasting across the U.S. This project will provide support and training to graduate students in atmospheric measurement technologies, data analysis, and computer modeling and prepare them to become future scientists in severe weather research and prediction.The research team will conduct observational data analysis and advanced data assimilation that integrate observations and atmospheric prediction models. The unprecedented observation includes an advanced downward-pointing Compact Raman Lidar (CRL), a horizontally scanning lower fuselage (LF) radar, and dual Tail Doppler Radars (TDRs) onboard of a NOAA P-3 aircraft. The CRL is capable of measuring high-spatial and temporal resolution of water vapor, temperature, and aerosol profiles in the atmospheric boundary layer upstream of moving storms. Together with the P-3's in-situ measurements and the LF and TDR radar observations, unprecedented characterization of tornadic environments is expected. In addition, tornado-resolving numerical simulations will be performed, and variational, and ensemble-based data analysis and assimilation techniques will be applied. The primary goals of the project include: (1) characterization of spatial heterogeneities and temporal evolution of the PBL around convective storms in the VORTEX-SE domain with CRL measurements; (2) analysis and understanding of the impact of PBL heterogeneities on tornadic storms by synthesizing P-3 and other available observations; (3) identification and understanding of key physical processes involved in the tornadic storms through model simulations with advanced data assimilation methods. The synergy of airborne radar and lidar data with high-resolution model simulations will help pave the way for potentially transformative future process-oriented field experiments.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.

大风、冰雹、暴雨等高影响天气现象产生巨大的社会经济影响。然而，预报严重的高影响天气事件，特别是龙卷风，仍然具有挑战性。从历史上看，龙卷风研究一直集中在大平原地区，而美国东南部也经常经历毁灭性的龙卷风。这两个地区环境条件的显著差异以及东南部夜间龙卷风的频繁发生，给观测和了解东南部龙卷风的形成和发展带来了挑战。东南龙卷风实验旋转起源验证(VORTEX-SE)是一项旨在了解东南部环境如何影响该地区龙卷风的形成、强度、结构和路径的研究计划。在2018年的涡旋-东南场活动中，从一架绕过龙卷风的飞机上收集到了前所未有的先进测量数据。在丘陵森林地形的地面上，这样的观测不容易完成。这项研究将利用独特的观测和先进的计算机模型来了解龙卷风风暴的气流结构及其形成的特殊环境。从这项研究中获得的新知识将有助于改善全美的龙卷风预报。该项目将为研究生提供大气测量技术、数据分析和计算机模拟方面的支持和培训，并为他们成为未来恶劣天气研究和预报的科学家做准备。研究小组将进行观测数据分析和高级数据同化，将观测和大气预测模型结合在一起。这次史无前例的观测包括先进的向下指向紧凑型拉曼激光雷达(CRL)，水平扫描下部机身(LF)雷达，以及NOAA P-3飞机上的双尾多普勒雷达(TDR)。CRL能够测量移动风暴上游大气边界层中水汽、温度和气溶胶轮廓的高空间和时间分辨率。再加上P-3‘S的现场测量以及LF和TDR雷达的观测，预计将出现前所未有的龙卷风环境特征。此外，还将进行龙卷风解析数值模拟，并将应用变分和基于集合的数据分析和同化技术。该项目的主要目标包括：(1)利用CRL测量，在涡旋-东南区描述对流风暴周围边界层的空间异质性和时间演变；(2)通过合成P-3和其他现有观测资料，分析和了解边界层异质性对龙卷风风暴的影响；(3)通过使用先进数据同化方法的模式模拟，查明和了解龙卷风风暴涉及的关键物理过程。机载雷达和激光雷达数据与高分辨率模型模拟的协同将有助于为未来潜在的变革性面向过程的现场实验铺平道路。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Convection initiation and bore formation following the collision of mesoscale boundaries over a developing stable boundary layer: a case study from PECAN

发展中的稳定边界层上的中尺度边界碰撞后的对流引发和孔形成：PECAN 的案例研究

• DOI: 10.1175/mwr-d-20-0282.1
• 发表时间: 2021
• 期刊: Monthly Weather Review
• 影响因子: 3.2
• 作者: Lin, Guo;Grasmick, Coltin;Geerts, Bart;Wang, Zhien;Deng, Min
• 通讯作者: Deng, Min