Collaborative Research: Large Hail Accumulations in Thunderstorms

雷暴造成深度冰雹堆积，对生命和财产构成重大风险，导致机动车事故、道路关闭、机场延误、城市和河流洪水以及水上救援。在监测雷暴冰雹特征方面的数据不均匀和不足，导致在预测未来冰雹发生和评估未来气候预报方面的可信度较低。这项研究的首要目标是分析大量云内冰雹产生导致地面深层冰雹堆积所必需的微物理和动力学条件，方法是：制定和验证一套强大的显著冰雹堆积特有的特征风暴特性；确定加强冰雹产生的机制的作用；以及在观测和模拟中确定冰雹堆积的时间和空间变化。知识价值：知识价值在于它有助于全面了解有大量冰雹积累的严重雷暴的双极化和闪电特征；它们如何以及为什么与环境条件、风暴形态、地形和外流边界有关；以及最先进的区域气候和天气预报模式是否能够再现从观测得出的冰雹积累特征。这项研究将增进我们对雷暴中造成大范围冰雹/冰雹产生的过程的理解，改进对造成自然灾害的极端事件的预测，并扩大现有的直接造福社会的能力。更广泛的影响：更广泛的影响是，这些研究将有助于更好地预报和即时预报有大量冰雹积累的事件，并为评估预报和区域气候模拟提供基础。冰雹对财产和农业造成了巨大的经济影响，造成牲畜死亡和人员受伤。这项研究将提供更好的洞察力，如果冰雹累积也能提供有用的信息，向公众发出可靠的警告，并帮助管理恶劣天气。本科生和研究生将通过自主学习、实习和博士论文等方式参与科学研究。该项目将促进大学大气研究公司的大气研究和科学重大机遇计划与科罗拉多大学的夏季多元文化获取研究培训计划之间的合作，该计划旨在为科学、数学和工程专业的未被充分代表的本科生提供培训。

Thunderstorms that produce deep hail accumulations pose a substantial risk to life and property resulting in motor vehicle accidents, road closures, airport delays, urban and river flooding, and water rescues. Data inhomogeneities and inadequacies in monitoring hail characteristics in thunderstorms leads to low confident in projecting future hail occurrence and evaluation of future climate predictions. The overarching goal of the research is to analyze the microphysical and dynamical conditions necessary for large amounts of in-cloud hail production that lead to deep surface hail accumulations by developing and validating a robust set of characteristic storm properties unique to significant hail accumulation; determining the role of mechanisms enhancing hail production; and determining temporal and spatial variation of hail accumulations in observations and simulations. Intellectual Merit:The intellectual merit lies in its contribution to a comprehensive understanding of the dual-polarization and lighting characteristics in severe thunderstorms with significant hail accumulations; how and why they are linked to environmental conditions, storm morphology, terrain, and outflow boundaries; and if state-of-the-art regional climate and weather forecasting models are capable of reproducing hail accumulation characteristics derived from observations. The research will advance our understanding of processes contributing to large hail/graupel production in thunderstorms, improve the forecasting of extreme events that cause natural disasters, and extend current capabilities to directly benefit society. Broader Impacts:The broader impacts are that the studies will aid in better forecasting and nowcasting events with significant hail accumulation and provide basis for evaluating forecasting and regional climate simulations. Hailstorms have had large economical impacts through damage to property and agriculture with livestock fatalities and human injuries. This study will provide better insight if hail accumulation also provides useful information to issue reliable warnings to the public and assistance in severe weather management. Undergraduates and graduate students will participate in the scientific research through independent studies, internships, and a Ph.D. thesis. The project will promote the collaborations between the University Corporation for Atmospheric Research's Significant Opportunities in Atmospheric Research and Science program and the University of Colorado's Summer Multicultural Access to Research Training program, which are intended for underrepresented undergraduate students in science, math, and engineering.