Collaborative Research: Convective Upscale Growth Processes during RELAMPAGO

绵延数百公里、持续数小时至数天的风暴在我们的全球水循环中扮演着重要角色。在安第斯山脉以东的亚热带南美洲，在温暖的月份里，95%的降雨量归因于这些大系统，这些系统还可能产生山洪暴发、毁灭性的冰雹和频繁的闪电。2018年底至2019年初，一个国际科学家小组利用自适应地面观测(Relampago)在阿根廷中部Sierras de Cordoba山脉附近开展了带电、闪电和中/微尺度过程的遥感现场活动，以更高的时间和空间分辨率观测研究这些频繁的、有影响的风暴。这场运动的初步结果为支持这些风暴的启动和快速增长提供了宝贵的洞察，但关于风暴的具体演变及其产生的危险天气，仍有许多问题。因此，该项目以瑞安帕戈的初步调查结果为基础，以进一步了解风暴迅速变大时发生的过程，以及支持这些过程的条件与世界上其他经历类似危险条件的山区的条件进行比较。这项研究还允许通过培训研究生、国际合作和通过不同的团队进行代表来提供继续教育和推广的机会。中尺度对流系统(MCSs)的预报在一定程度上受到对流生命周期的理解和表述的限制。阿根廷中部靠近Sierras de Córdoba山脉的一个地区是全球深度和强烈强对流的热点地区，这种对流也迅速发展到MCS，造成洪水、冰雹和频繁的闪电。该地区是Relampago实地活动的焦点，数据集的初步结果支持以前基于卫星的对流生命周期推断，并就中层垂直风切变、南美低空急流和地形相互作用在高层增长过程中的作用提出了新的发现。这项研究建立在这些结果的基础上，以解决以下主要的科学问题：1)对流系统内的微物理和运动学是如何随着它们的高尺度增长而演变的？2)哪些天气和中尺度因素支持对流的快速高水平增长，以及地形如何改变这些因素？Relampago数据分析、高分辨率模式模拟和再分析数据的组合提供了解决这些问题的方法，并更好地了解了MCS的对流高层增长、对这些高端增长过程的环境控制以及在高端增长期间高闪电率和冰雹的产生。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Storms spanning hundreds of kilometers and lasting for hours into days have an important role in our global water cycle. In subtropical South America east of the Andes, 95% of rainfall during the warmer months are attributed to these large systems, which also can produce flash floods, devastating hail, and frequent lightning. In late 2018 into early 2019, an international team of scientists conducted the Remote sensing of Electrification, Lightning, and Mesoscale/microscale Processes with Adaptive Ground Observations (RELAMPAGO) field campaign near the Sierras de Cordoba mountains in central Argentina to study these frequent, impactful storms with observations at higher temporal and spatial resolution. Initial results from this campaign have provided valuable insight into conditions supporting the initiation and rapid growth of these storms, yet many questions remain regarding the specific evolution of the storms and the hazardous weather they produce. Therefore, this project builds off the initial RELAMPAGO findings to further understand the processes occurring within storms as they rapidly grow large and how the conditions that support these processes compare with those in other mountainous regions of the world that experience similarly hazardous conditions. This research also permits continued education and outreach opportunities through training of graduate students, international collaborations, and representation through a diverse team. Prediction of mesoscale convective systems (MCSs) is challenged in part by limitations in understanding and representation of the convective lifecycle. A region in central Argentina near the Sierras de Córdoba mountain range is a global hotspot for deep and intense severe convection that also grows rapidly upscale to MCSs producing flooding, hail, and frequent lightning. This area was a focal point for RELAMPAGO field campaign, for which initial results from the datasets supported previous satellite-based inferences of convective lifecycle and contributed new findings related to the role of mid-level vertical wind shear, the South American Low-Level Jet, and terrain interactions in the upscale growth process. This research builds off those results to address the following overarching science questions: 1) How do microphysics and kinematics within convective systems evolve as they grow upscale? 2) Which synoptic and mesoscale factors support rapid upscale growth of convection and how does terrain modify those factors? A combination of RELAMPAGO data analysis, high-resolution model simulations, and reanalysis data provides the means to address these questions and gain a better understanding of convective upscale growth to MCSs, the environmental controls on these upscale growth processes, and the production of high lightning flash rates and hail during upscale growth.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.