Collaborative Research: SGER--Measurements of Particle Size and Fall Velocity Distributions within Supercell Thunderstorms

合作研究：SGER——超级单体雷暴中颗粒尺寸和下落速度分布的测量

• 批准号: 0910424
• 负责人: Katja Friedrich
• 金额: $ 4.06万
• 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: 2009
• 资助国家: 美国
• 起止时间: 2009-02-01 至 2010-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0910424&HistoricalAwards=false
• 关键词: Collaborative; Research; SGER; Measurements; Particle

The investigators will develop a unique network of mobile and rapidly deployable low-cost laser disdrometer instruments for the collection of in situ microphysical data within severe storms during the first year of the Verification of the Origins of Tornadoes Experiment 2 (VORTEX2) campaign in spring of 2009. Measurements will be coordinated with other VORTEX2 components enabling fusion of data sources for a more complete retrieval of the near surface buoyancy, microphysical composition and kinematics of the storm. The microphysical composition of severe storms is known to have significant impacts on storm evolution and behavior, particularly by controlling the cold pool characteristics beneath the storm. While polarimetric radar observations can provide information related to the microphysical character of a storm, the microphysics of the near surface environment, believed to be most important for tornadogenesis, is usually below the radar horizon of even mobile polarimetric radar platforms. Microphysics can play a key role in near surface buoyancy tendency which several recent studies have shown may modulate the likelihood of tornado development. As such, in situ measurements of near surface microphysics within rainy downdrafts are needed in order to determine cold pool buoyancy characteristics and to infer relations with polarimetric radar observations collected above the surface. The research will lead to a greater understanding of the relationship between storm microphysics, cold pool characteristics beneath severe storms and storm behavior. The intellectual merit of the research stems from the novel in situ microphysical data collection method within severe storms coordinated with mobile polarimetric radars. Two methods for optical disdrometer deployment will be simultaneously explored in a collaborative approach to maximize data collection. There are considerable challenges and hazards associated with data acquisition within severe storms. This effort marks a first known attempt to collect in situ near surface measurements of particle size distributions by a network of disdrometers. The collected observations will enable new understanding of the relationship between microphysical characteristics of severe storms and their behavior in line with several key foci of the VORTEX2. The Broader impacts of the work include improved predictability of severe storm behavior. This is expected to emerge from a better understanding of storm evolution dependence on microphysical characteristics, which to date remains relatively unknown. Better understanding of severe storm behavior can ultimately lead to more timely and accurate warnings that can save lives and allow additional time to protect property. Further, the developed instrumentation suite for this project will also be quite suitable for application to particle size distribution measurements in other types of precipitating systems. The verification of microphysical parameterizations used in storm-scale numerical weather prediction models also would benefit from verification data provided in part by the measurements. Particle size distribution measurements will also aid in mobile radar calibration and attenuation metrics. This project will enable graduate students opportunities to participate in data collection efforts as part of a major field campaign.

研究人员将开发一个独特的移动且可快速部署的低成本激光测速仪网络，用于在春季验证龙卷风起源实验 2 (VORTEX2) 活动的第一年收集强风暴中的现场微物理数据。 2009 年。测量将与其他 VORTEX2 组件协调，实现数据源融合，以便更完整地检索近表面浮力、微物理成分和运动学风暴。 众所周知，强风暴的微物理成分对风暴的演变和行为具有重大影响，特别是通过控制风暴下方的冷池特征。 虽然极化雷达观测可以提供与风暴的微物理特征相关的信息，但被认为对龙卷风形成最重要的近地表环境的微物理通常位于移动极化雷达平台的雷达地平线以下。 微物理学在近地表浮力趋势中发挥着关键作用，最近的几项研究表明，近地表浮力趋势可能会调节龙卷风发展的可能性。 因此，需要对多雨下沉气流中的近地表微物理进行原位测量，以确定冷池浮力特性并推断与地表上方收集的极化雷达观测数据的关系。该研究将有助于更好地了解风暴微物理、强风暴下的冷池特征和风暴行为之间的关系。这项研究的智力价值源于与移动极化雷达相协调的强风暴内新颖的原位微物理数据收集方法。 将通过协作方式同时探索两种光学测距仪部署方法，以最大限度地收集数据。强风暴中的数据采集存在相当大的挑战和危险。这项工作标志着首次已知尝试通过测速仪网络在近地表处原位收集颗粒尺寸分布测量值。 收集到的观测结果将使我们能够对强风暴的微物理特征及其行为与 VORTEX2 的几个关键焦点一致的行为之间的关系有新的认识。这项工作的更广泛影响包括提高严重风暴行为的可预测性。 预计这将通过更好地了解风暴演化对微物理特征的依赖而出现，而迄今为止，微物理特征仍然相对未知。 更好地了解严重的风暴行为最终可以带来更及时、更准确的预警，从而挽救生命并留出更多时间来保护财产。 此外，为该项目开发的仪器套件也非常适合应用于其他类型的沉淀系统中的粒度分布测量。 风暴规模数值天气预报模型中使用的微物理参数化的验证也将受益于部分由测量提供的验证数据。粒度分布测量还将有助于移动雷达校准和衰减指标。 该项目将使研究生有机会参与数据收集工作，作为主要实地活动的一部分。