Analysis of Mobile Doppler Radar and Lidar Data of Severe Convective Storms

这个研究项目旨在进一步加深我们对强对流风暴和龙卷风的基本物理认识，重点是由超级细胞产生的龙卷风。总体目标将通过分析最先进的移动多普勒雷达和移动多普勒激光雷达（TWOLF：车载风观测激光雷达设施）收集的数据来完成。前者包括：1)快速扫描（机械扫描）、极化、x波段雷达（RaXPol）；2)快速扫描相控阵x波段雷达（MWR-05XP）；3)高分辨率w波段雷达（马萨诸塞大学阿默斯特分校的w波段雷达）。分析的部分雷达数据包括2009年和2010年春季VORTEX2（第二次龙卷风旋转起源验证实验）期间收集的数据集。其余需要分析的雷达数据包括2011年春季在一个小型的局部现场项目中收集的RaXPol和MWR-05XP数据，2012年春季收集的RaXPol数据，2013年春季收集的RaXPol和TWOLF/MWR 05XP数据，以及2014年和2015年春季收集的RaXPol数据。智力优势：利用快速扫描雷达，将在产生龙卷风和不产生龙卷风的超级细胞中探索涡旋特征在时间和空间上的演变。这些信息可以用来帮助评估龙卷风形成的机制。极化雷达将用于推断超级单体内部微物理过程的信息，以及它们与风暴结构和演变以及龙卷风形成的关系。在VORTEX2期间收集的高分辨率w波段雷达数据将进一步分析，以记录龙卷风和龙卷风状漩涡的精细结构。TWOLF将主要用于测量龙卷风和中气旋内部及其附近最低100米的垂直风向变化，由于地面杂波污染，雷达很难做到这一点，而现场探测则极具挑战性。人们对龙卷风或风暴形成时的边界层知之甚少。边界层的特征被认为是决定强涡（如龙卷风）潜在强度的一个非常重要的因素。更广泛的影响：预计龙卷风和其他恶劣天气现象（如大冰雹和直线风）的预报和警报将随着对它们的物理认识的增加而得到改善。该项目的结果可能对国家气象局和私人预报公司有用，并有助于减轻财产损失和拯救生命。研究生将接受培训，成为下一代研究人员的一部分。

This research project seeks to further our basic physical understanding of severe convective storms and tornadoes, with an emphasis on tornadoes produced by supercells. The overall goal will be accomplished through the analysis of data collected by state-of-the-art mobile Doppler radars and a mobile Doppler lidar (TWOLF: Truck-Mounted Wind Observing Lidar Facility). The former include: 1) a rapid-scan (mechanically scanning), polarimetric, X-band radar (RaXPol); 2) a rapid-scan, phasedarray, X-band radar (MWR-05XP); and 3) a high-resolution, W-band radar (University of Massachusetts-Amherst's W-band radar).Some of the radar data to be analyzed includes datasets collected during VORTEX2 (The 2nd Verification of the Origin of Rotation in Tornadoes Experiment) in the springs of 2009 and 2010. The remainder of the radar data to be analyzed include RaXPol and MWR-05XP data collected a during a small, local, field program during the spring of 2011, RaXPol data collected during the spring of 2012, RaXPol and TWOLF/MWR 05XP data collected during the spring of 2013, and RaXPol data collected during the springs of 2014 and 2015.Intellectual Merit: Using the rapid-scan radars, the evolution of vortex signatures in time and space will be explored in both supercells that produce tornadoes and those that do not. This information can be used to help assess the mechanism(s) of tornado formation. The polarimetric radar will be used to infer information about microphysical processes within supercells and how they might relate to storm structure and evolution, and tornado formation. The high-resolution W-band radar data already collected during VORTEX2 will be further analyzed to document the fine-scale structure of tornadoes and tornado-like vortices. TWOLF will be used mainly to measure the vertical variation in winds in and near tornadoes and mesocyclones in the lowest 100 m, an undertaking, owing to ground clutter contamination, that is difficult with radars and is extremely challenging by in-situ probing. Very little is known about the boundary layer in tornadoes or under storms when they form. The character of the boundary layer is thought to be a very important factor in determining the potential intensity of intense vortices such as tornadoes.Broader Impacts: It is anticipated that forecasts and warnings of tornadoes and other severe weather phenomena such as large hail and straight-line winds will be improved with an increase in a physical understanding of them. The results from this project may be useful to the National Weather Service and private forecasting companies, and could help mitigate property damage and save lives. Graduate students will be trained and become part of the pool of the next-generation of researchers.