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.

研究人员将在2009年春季验证龙卷风实验2（Vortex2）运动的第一年，在严重暴风雨中收集现场微物理数据的独特网络，以收集严重暴风雨中的原位微物理数据（Vortex2）在2009年春季的活动中，该网络将在2009年春季进行。风暴的微物理组成和运动学。 已知严重风暴的微物理组成对风暴的演变和行为产生重大影响，尤其是通过控制风暴下的冷池特征。 虽然极化雷达观测可以提供与风暴的微物理特征有关的信息，但近表面环境的微物理学（认为对龙卷力生成最为重要，通常都低于甚至移动的极化雷达平台的雷达范围。 微物理学在近表面浮力趋势中可以发挥关键作用，最近一些研究表明，这可能会调节龙卷风发展的可能性。 因此，需要原位测量雨天下降气流中的近表面微物理学，以确定冷池浮力特征并推断与表面上方收集的偏振雷达观测值的关系。该研究将使人们对风暴微物理学，严重风暴和风暴行为的冷池特征之间的关系有更深入的了解。研究的智力优点源于与移动极化雷达协调的严重风暴中的新型原位微物理数据收集方法。 将使用协作方法同时探索光学序列部部署的两种方法，以最大程度地提高数据收集。在严重风暴中，与数据获取相关的挑战和危害存在巨大的挑战和危害。这项工作标志着通过拆卸器网络对粒度分布的地表测量的第一次已知尝试。 收集的观察结果将使对严重风暴的微物理特征与其行为之间的关系与涡旋2的几个关键焦点保持一致。这项工作的更广泛影响包括改善严重风暴行为的可预测性。 预计这将从对风暴演化对微物理特征的依赖的更好理解中得出，迄今为止，这些特征仍然相对未知。 更好地了解严重的暴风雨行为，最终会导致更及时，更准确的警告，这些警告可以挽救生命，并留出更多时间来保护财产。 此外，该项目的开发仪器套件也将非常适合于其他类型的沉淀系统中的粒度分布测量。 风暴规模数值预测模型中使用的微物理参数化的验证也将受益于测量所提供的部分验证数据。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，这是大型现场活动的一部分。