EAR-PF: Integrating Field Deposit, Remote Sensing, and Numerical Modeling Perspectives on the Injection and Fallout of Hazardous Volcanic Ash

Alexa Van Eaton博士被授予美国国家科学基金会地球科学博士后奖学金，在美国地质调查局和亚利桑那州立大学开展一项研究和教育计划。该项目旨在提高我们预测和应对火山爆发危害的能力。在这些事件中注入大气的细小火山颗粒的扩散对基础设施和环境构成了广泛的威胁。鉴于国内和国际对火山云运动的数值预测的强烈依赖，该项目侧重于在现有的火山灰扩散建模方法中引入新的、基于实地的火山喷发动力学观测。两个关键问题激发了这种方法：(1)相对于火山云的可测量特性，粒子聚集的性质是如何演变的？(2)喷发柱不稳定性和地表水相互作用对大气质量垂直分布的控制作用是什么？该项目的初始阶段的目标是同化来自火山碎屑沉积物的现场数据和来自阿拉斯加Redoubt（2009年）和华盛顿州圣海伦斯山（1980年5月18日）有充分记录的火山喷发的遥感档案。这些观测结果将用于表征伴随火山灰扩散的大气反馈的时空影响，并使用称为ATHAM的尖端微物理模型为喷发柱发展的三维模拟提供输入。研究结果将指导新一代灰分散模型的设计和部署，该模型可以在快速运行的操作环境中解释灰聚集和柱不稳定的影响。此外，Van Eaton博士将与卡斯卡德火山观测站（温哥华美国地质勘探局）和地球与空间探索学院（亚利桑那州立大学）合作，开发桌面练习，教育本科生、K-12地球科学教师和电视播音员如何应对火山爆发时的火山灰危害。

Dr. Alexa Van Eaton has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the U.S. Geological Survey and Arizona State University. This project aims to improve our ability to predict and respond to the hazards of explosive volcanic eruptions. Dispersal of fine volcanic particles injected into the atmosphere during these events pose wide-reaching threats to infrastructure and the environment. Given the strong national and international reliance on numerical predictions of volcanic cloud movement, this project focuses on introducing new, field-based observations of eruption dynamics into existing methods of ash dispersal modeling. Two key questions motivate this approach: (1) how does the nature of particle aggregation evolve with respect to measurable properties of volcanic clouds?; and (2) what is the role of eruption column instability and surface water interaction in controlling the vertical distribution of mass in the atmosphere? The initial stage of the project targets assimilation of field data from volcaniclastic deposits and remote sensing archives from the well-documented eruptions of Redoubt, Alaska (2009) and Mount St. Helens, Washington (18 May 1980). These observations will be used to characterize the spatiotemporal impact of atmospheric feedbacks accompanying volcanic ash dispersal, and provide inputs for 3d simulations of eruption column development using a cutting-edge microphysical model known as ATHAM. Results will guide the design and deployment of a new generation ash dispersal model that can account for the impacts of ash aggregation and column instability in a fast-running, operational setting. In addition, Dr. Van Eaton will partner with the Cascades Volcano Observatory (USGS, Vancouver) and School of Earth and Space Exploration (Arizona State University) to develop tabletop exercises educating undergraduate students, K-12 geoscience teachers and TV broadcasters about responding to volcanic ash hazards in the event of an eruption.