Collaborative Research: Kinematic, Microphysical and Electrical Processes Leading to Extreme Lightning Flash Rates over Argentina Using RELAMPAGO Observations

地球上一些最大、最活跃的风暴发生在阿根廷中西部的安第斯山脉背风处。这些风暴开始于安第斯山脉和科尔多瓦山脉(SDC)的山脚下，并产生极大的闪电、大冰雹、龙卷风和暴雨。该项目的目标是促进对这一研究不足的地区的闪电特征和原因的了解，这些地区有独特的强烈风暴，以及这些风暴与不同环境中导致如此高影响天气的其他对流风暴之间的带电差异。为了实现这些目标，科罗拉多大学(CU)和阿拉巴马大学亨茨维尔分校(UAH)的研究人员将研究大气条件和物理过程，这些条件和物理过程控制着风暴的带电，并与其他高影响天气一起导致极端闪电频率。这些严重风暴的测量将在计划的Relampago(利用自适应地面观测对电化、闪电和中/微尺度过程的遥感)实地活动期间进行，以实现这些目标。这类风暴具有巨大的经济影响，因为它们对人、财产、农业和基础设施构成危险。对所研究风暴的条件和过程的更好理解将导致对恶劣天气的更好的近距离预报和预报。此外，该项目还将支持研究生和博士后研究人员的教育培训。他们将通过独立研究和参与Relampago野外活动参与科学研究，并有机会与美国和来自多个学科的国际研究人员合作。气象学和电气化之间的一些基本关系尚不完全清楚，包括缺乏关于微物理和运动学过程如何控制深对流风暴内带电区域发展的知识。美国最近的研究表明，微物理、动力学和电学行为之间存在地区差异。因此，需要在阿根廷等世界不同地区进行更多研究，以了解风暴过程、带电和闪电特征之间的物理联系。来自CU和UAH的研究小组将调查环境条件和物理过程，这些环境条件和物理过程控制着暴风雨的电气化，并导致阿根廷中西部地区严重风暴的极端闪电率。这项研究的目的是促进对产生极端闪光率的风暴以及导致高影响天气的对流风暴类型和环境之间的带电差异的了解。这包括确定各种风暴环境、运动学和微物理过程在管理这些极端严重风暴中的电荷、电荷区发展和所产生的闪光率和其他特性(例如，类型、大小、极性、电流、电荷中和)中所起的作用。为了实现这一目标，将在能源部(DOE)为期9个月的仙人掌(云、气溶胶和复杂地形相互作用)实地活动和计划中的NSF/NASA/NOAA Relampago(带电、闪电和中/微尺度过程的遥感与自适应地面观测)实地活动期间进行环境、运动学和微物理测量。作为Relampago的一部分，CU和UAH将部署仪器来测量密集观测期间(11/1-12/15/2018)严重风暴的闪电特征、电场和推断的电荷结构。CU/UAH团队将使用在Relampago部署的雷达和大气探测的测量结果来获得热力学、运动学和微物理测量。这些数据将与加州大学伯克利分校和美国国家航空航天局的闪电测量数据一起用于分析有利于极端闪电产生的环境条件。它们还将被用来研究导致电荷区产生和极端闪电率的物理云过程。

Some of the largest and most electrically active storms on earth occur in west-central Argentina in the lee of the Andes Mountains. These storms initiate at the foothills of the Andes Mountains as well as the Sierras de Córdoba (SDC) and produce extreme lightning amounts, large hail, tornadoes and heavy rainfall. The goal of this project is to advance the understanding of characteristics and causes of lightning in this understudied region of uniquely intense storms and differences in electrification between these storms and other convective storms in different environments that lead to such high impact weather. Towards these goals, researchers at the University of Colorado (CU) and the University of Alabama in Huntsville (UAH) will study atmospheric conditions and physical processes that control storm electrification and lead to extreme lightning flash rates in conjunction with other high impact weather. Measurements of these severe storms will be taken during the planned RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations) field campaign to be able to address these goals. Such storms have a large economic impact as they pose a hazard to people, property, agriculture and infrastructure. An improved understanding of conditions and processes from the studied storms will lead to better nowcasting and forecasting of severe weather. Furthermore, this project will support educational training of graduate students and a postdoctoral researcher. They will participate in the scientific research through independent studies and participation in the RELAMPAGO field campaign and have the opportunity to collaborate with the US and international researchers from a multitude of disciplines.Some fundamental relationships between meteorology and electrification are not completely understood, including a lack of knowledge of how microphysical and kinematic processes control the development of charge regions inside deep convective storms. Recent studies in the US suggest that regional differences between microphysical, dynamical and electrical behavior exist. Thus, more research in different regions of the world such as in Argentina is needed to understand the physical connections between storm processes, electrification and lightning characteristics. The team of researchers from CU and UAH will investigate the environmental conditions and physical processes that control storm electrification and lead to extreme lightning flash rates of severe storms in west-central Argentina. The goal of the research is to advance understanding of storms producing extreme flash rates and of differences in electrification among convective storm types and environments that lead to high impact weather. This includes determining what role various storm environmental, kinematic and microphysical processes play in governing charge, charge region development and resultant flash rates and other properties (e.g., type, size, polarity, current, charge neutralized) in these extremely severe storms. Towards this goal, environmental, kinematic and microphysical measurements will be taken during the 9-month Department of Energy (DOE) CACTI (Clouds, Aerosols, and Complex Terrain Interactions) field campaign and the planned NSF/NASA/NOAA RELAMPAGO (Remote sensing of Electrification, Lightning, And Mesoscale/microscale Processes with Adaptive Ground Observations) field campaign. As part of RELAMPAGO, CU and UAH will deploy instrumentation to measure lightning characteristics, electric fields, and inferred charge structures of severe storms during the Intensive Observing Period (11/1-12/15/2018). The CU/UAH team will use measurements from radars and atmospheric soundings deployed during RELAMPAGO to obtain thermodynamic, kinematic, and microphysical measurements. These will be used together with lightning measurements from CU/UAH as well as NASA to analyze the environmental conditions favoring extreme lightning production. They will also be used to study the physical cloud processes leading to charge region creation and extreme lightning flash rates.