VORTEX2: A Study of Tornado and Tornadic Thunderstorm Dynamics through High-Resolution Simulation, Advanced Data Assimilation and Prediction

验证龙卷风实验2（VORTEX 2）中的旋转起源是对导致龙卷风发生的因素的多尺度调查。 VORTEX 2是VORTEX 1的后续，其现场阶段在1994年和1995年春季进行。 涡1先进的知识龙卷风和非龙卷风风暴的运动学结构，并提供了一些线索，超级单体风暴和龙卷风的演变非常精细的空间尺度异质性的敏感性。 VORTEX 2社区打算扩展并建立在VORTEX 1的结果之上。 进一步了解龙卷风的障碍之一是缺乏足够高分辨率的大气状态的完整观测。涡2号的实地阶段将收集对流风暴和龙卷风及其环境规模的前所未有的观测结果。 风暴分析和预报中心的一个小组将参加涡2号现场实验，并在四个主要领域进行研究：1）生成实时高分辨率（1 - 2公里）风暴尺度集合和确定性预报; 2）进行超高分辨率（1 - 2公里）风暴尺度集合和确定性预报; 3）进行高分辨率（1 - 2公里）风暴尺度集合和确定性预报。为概念模型的动态理解和验证而进行的龙卷风情况的（低至几米）分辨率数值模拟试验; 3）研究微物理过程及其参数化对雷暴下沉气流、冷池和阵风锋动力学的影响及其在龙卷风发生中的作用; 4）将常规和特殊观察同化为非常-高分辨率四维数据集，以通过龙卷风尺度促进对雷暴的动力学和可预测性的理解，并研究特殊领域数据对NWP的影响，初始条件敏感性。智力优点：预计该项目将大大有助于解决有关龙卷风的形成和衰减、龙卷风雷暴动力学及其与风暴环境的相互作用、龙卷风雷暴中微物理过程的作用以及龙卷风和龙卷风雷暴的可预测性等许多科学问题。所获得的知识将有助于更好地评估超级单体雷暴中发生龙卷风的概率，从而在预测龙卷风强度和寿命方面取得进展。更广泛的影响：这项研究将直接解决天气研究最重要的目标之一-提高准确预测强烈危险天气的能力。该项目将让研究生和年轻的博士后科学家接触重大的科学现场实验，并为他们提供使用实验数据集的实践经验。它将在高级数据同化和高分辨率模拟及数值预报等日益重要的领域为他们提供急需的教育和培训。研究结果将通过该小组与业务数据同化系统和预测模型的合作以及通过他们参与NOAA危险天气测试台（HWT）春季预报实验直接进入业务。后者使业务天气预报员以及大学科学家接触到最先进的预报能力和产品。

The Verification of Origins of Rotation in Tornadoes Experiment #2 (VORTEX 2) is a multi-scale investigation of factors that lead to tornadogenesis. 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 community intends to extend and build upon the results of VORTEX 1. One of the obstacles in furthering understanding of tornadoes is the lack of complete observations of the atmospheric state at a sufficiently high resolution. The field phase of VORTEX 2 will collect unprecedented observations at the scales of convective storms and tornadoes and of their environment. A team from the Center for Analysis and Prediction of Storms (CAPS) will participation in the VORTEX 2 field experiment and conduct research in four principal areas: 1) Generate real-time high resolution (1-2 km) storm-scale ensemble and deterministic forecasts; 2) Conduct ultra-high (down to few meters) resolution numerical simulation experiments for tornado cases for dynamic understanding and validation of conceptual models; 3) Study the impact of microphysical processes and their parameterizations on thunderstorm downdraft, cold pool, and gust front dynamics and their roles in tornadogenesis; 4) Assimilate routine and special observations into very-high resolution four dimensional data sets to advance understanding of dynamics as well as predictability at the thunderstorm through tornado scales and for studying the impact of special field data on NWP and initial condition sensitivities. Intellectual merit: The project is expected to contribute significantly to addressing many of the scientific questions concerning tornadogenesis and decay, tornadic thunderstorm dynamics and their interaction with storm environment, the role of microphysical processes within tornadic thunderstorms, and the predictability of tornadoes and tornadic thunderstorms. The knowledge gained will allow better assessment of the probability of tornadoes occurring in supercell thunderstorms and thus will lead to advances in forecasting tornado intensity and longevity. Broader Impacts: The research will directly address one of the most important goals of weather research -- to improve the ability to accurately predict intense hazardous weather. This project will expose graduate students and young post-doctoral scientists to a major scientific field experiment and give them hands-on experiences working with experimental data sets. It will provide much needed education and training for them in the increasingly important areas of advanced data assimilation and high-resolution simulation and NWP. The research findings will have a direct path to operations through the group's work with operational data assimilation systems and prediction models and through their participation in the NOAA Hazardous Weather Testbed (HWT) Spring Forecast Experiments. The latter exposes operational weather forecasters, as well as university scientists, to cutting-edge forecasting capabilities and products.