VORTEX 2: Storm-scale Baroclinity Using Fine-scale Observations and Numerical Models

该奖项是多方研究人员努力的一个组成部分，被称为龙卷风旋转起源实验2 （VORTEX 2）的验证。旋涡2是旋涡1的后续，旋涡1的实地阶段是在1994年和1995年春季进行的。涡旋1号提高了对龙卷风和非龙卷风风暴的运动结构的认识，并为超级单体风暴和龙卷风形成的演变对非常精细的空间尺度非均质性的敏感性提供了一些线索。“漩涡2号”的研究目标将集中在龙卷风的发生和维持以及龙卷风近风场的结构上。涡旋2号正在与美国国家海洋和大气管理局联合进行，它将涉及一个前所未有的固定和移动设施观测网络，包括多普勒雷达、地面和高空观测。众所周知，超级单体雷暴包含潜在的重要热力学和运动学梯度，其中许多被怀疑与低层中气旋形成有关。由于虚位温的强梯度已经在先前的数值研究中得到解决，因此怀疑风暴尺度的斜压性在斜压产生水平涡度中起作用，在某些情况下，水平涡度可以被风暴的主要上升气流倾斜和拉伸。虽然迄今为止在野外收集的相对稀疏的原位观测资料对斜压性问题提供了一些启示，但这些观测资料的空间分辨率通常较差。该奖项下的研究项目在知识方面的价值来自于引进新开发的“StickNet”技术，即一系列快速部署的地面站。这些系统将在“涡旋二号”期间部署，从龙卷风形成和验证/改进风暴尺度数值天气预报模式的角度来解决风暴尺度斜压性的问题。这些测量将提供超级单体中气旋附近热力学和运动学数量变化的前所未有的细节，结合双多普勒分析和数值模型计算的空气包裹轨迹，将允许构建进入低层中气旋的空气包裹的涡度预算。StickNet的测量还将提供对多风暴相互作用的哪些特性有利于龙卷风形成和龙卷风维持的见解。StickNet数据还将用于验证数值风暴尺度模型，并将为验证和改进现有的热力学检索技术方法提供基础。这项研究的广泛影响将在许多方面体现出来。一些研究生和本科生将被用于规划和执行StickNet数据收集。其中一些学生在气象学以外的领域有背景（例如，风力工程），因此将有机会扩大他们的知识基础。鉴于德州理工大学学生群体的典型种族多样性，预计传统上未被充分代表的群体，特别是那些西班牙裔，将有充分的机会参与到VORTEX2的StickNet组成部分。研究的最终目标是通过实时观测和短期数值模拟来改进强雷暴和龙卷风的预报。预报技能的提高对保护生命和财产至关重要。通过在期刊出版物和会议报告中广泛传播研究成果，所有研究目标的实现将对社区产生重大影响。

This award is one component of a mutli-investigator effort known as the Verification of the Origins of Rotation in Tornadoes Experiment 2 (VORTEX 2). VORTEX 2 is a follow on to VORTEX 1 whose field phase was conducted during the Spring of 1994 and 1995. The VORTEX 1 advanced knowledge of the kinematic structures of tornadic and nontornadic storms and provided some hints as to the sensitivity of the evolution of supercell storms and tornadogenesis to very fine spatial scale heterogeneity. The VORTEX 2 research objectives will focus on the genesis and maintenance of tornadoes and on the structure of the near wind field of the tornado. The VORTEX 2 is being conducted in conjunction with the National Oceanic and Atmospheric Administration and it will involve an unprecedented observational network of stationary and mobile facilities that include Doppler radars, surface and upper air observations. . Supercell thunderstorms are known to contain potentially significant thermodynamic and kinematic gradients, many of which are suspected to be relevant to low-level mesocyclogenesis. Owing to the strong gradients in virtual potential temperature that have been resolved in prior numerical studies, storm-scale baroclinity is suspected to play a role in the baroclinic generation of horizontal vorticity, which can be tilted and stretched by the principal updraft of the storm in some circumstances. Though the relatively sparse in-situ observations gathered in the field to this point have shed some light on the issue of baroclinity, these observations are typically poor in spatial resolution.The intellectual merit of the research under this award follows from the introduction of newly-developed "StickNet" technology, an array of rapidly-deployable surface stations. These systems will be deployed during VORTEX 2 to address the issue of storm-scale baroclinity both from the standpoint of tornadogenesis and the verification/improvement of storm-scale numerical weather prediction models. These measurements will provide unprecedented detail of variations in thermodynamic and kinematic quantities in close proximity to supercell mesocyclones which, in combination with air parcel trajectories calculated from dual-Doppler analyses and numerical models, will permit the construction of a vorticity budget for air parcels entering the low-level mesocyclone. StickNet measurements will also provide insight into what properties of multi-storm interactions are favorable to tornadogenesis and tornado maintenance. The StickNet data also will be used to validate numerical storm-scale models and also will provide a basis for verification and improvement of existing methods of thermodynamic retrieval techniques. The broader impacts of the study will be felt in a number of ways. A number of graduate and undergraduate students will be utilized in the planning and execution of StickNet data collection. Some of these students have background in fields other than meteorology (e.g., wind engineering), and therefore will have the opportunity to expand their knowledge base. Given the typical ethnic diversity of the student population at Texas Tech University, it is expected that traditionally underrepresented groups, particular those of Hispanic descent, will have full opportunity to participate in the StickNet component of VORTEX2. The ultimate goal of the research is the improvement of severe thunderstorm and tornado forecasts, both through real-time observation and short-term numerical modeling. This increase in forecast skill is of utmost importance for the protection of life and property. Through the broad dissemination of research results in journal publications and conference presentations, all research objectives that are met will have significant impact in the community.