CAREER:Developing a Consensual Validation and Benchmarking Procedure for Pyroclastic Density Current (PDC) Hazard Models

这项建议的重点是促进对与火山碎屑密度流(PDC)相关的危害的广度和深度的了解。拟议的研究将集中于五个总体目标：1)开发适用于所有类型的PDC的一般物理/沉积学模型；2)通过基于社区的验证和基准练习，评估数值模型在描述PDC相关现象方面的准确性；3)推动PDC危险评估的未来研究(例如，“验证”实验、现场测量、不确定性分析)；4)为火山流动危险评估研究提供一个社区范围的解释框架；5)发展地球科学教育中的量化技能，提高社区对数字工具的潜力和局限性(“模型素养”)以及实验(实验室和实地)和数值研究的互补性的认识。这一框架将提供关于依赖于这些模型的危险评估中的不确定性的关键信息。之所以要了解这一知识，是因为目前的危险评估研究在捕捉这种火山流动的真正潜在危险方面取得的成功有限。拟议工作的更广泛目标是：(1)将多学科团队聚集在一起，讨论实地研究、计算建模和危险评估之间的关系；(2)使地学学生和更广泛的社区更加熟悉和限制计算建模工具；(3)根据用户社区的需求定制危险评估。一般方法基于集成数据、理论和模型的迭代过程。在这一过程中，数据收集(通过实地调查、实验室实验、遥感、监测和数值模拟)使调查人员能够重新审视和修订科学理论和原则(例如，一般的物理/沉积学PDC模型)，然后将其作为计算和实验模型的基础(通过校准、验证、基准和预测)，然后将这些模型应用于收集的数据，以增进对PDC的动力学及其危险评估研究的了解。这项综合研究将遵循为验证用于模拟复杂工业和技术系统的计算流体动力学代码而提出的方法，该方法基于将数值模型与实验和观测进行比较的分层过程。此外，整个课程(SSAC)教育模式(https://serc.carleton.edu/sp/ssac/index.html)的电子表格将被纳入VHUB网络基础设施(www.vhub.org)，以：(1)通过促进利用结构化环境解决问题来提高地球科学的计算素养，(2)开发、分享和传播与模型验证和基准工作相关的所有活动和交付成果，这些活动和交付成果将作为推动未来火山流动危险评估研究的基础。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。

This proposal focuses on advancing the breadth and depth of understanding of the hazards associated with pyroclastic density currents (PDCs). The proposed study will focus on five overarching goals: 1) developing a general physical/sedimentological model applicable to all types of PDCs; 2) evaluate the accuracy of numerical models in representing PDC-related phenomena through community-based validation and benchmarking exercises; 3) drive future research on PDC hazard assessment (e.g., "validation" experiments, field measurements, uncertainty analysis); 4) provide a community-wide interpretation framework for volcanic flow hazard assessment studies; 5) developing quantitative skills in geoscience education and increasing awareness of the community about the potential and limits of numerical tools ("model literacy") and the complementarity of experimental (both laboratory and field based) and numerical studies. This framework will provide critical information about the uncertainties in hazard assessments that depend on these models. The drive for this knowledge stems from the limited success of current hazard assessment studies to capture the real hazard potential of such volcanic flows. The broader goals for the proposed work are: (1) bringing multi-disciplinary teams together to discuss the relationship between field studies, computational modeling and hazard assessment; (2) increasing familiarity with and limitations of computational modeling tools to both geoscience students and the broader community; and (3) tailoring the hazard assessment to the needs of the user communities.The general approach is based on an iterative process of integrating data, theories and models. In this process, the data collection (through field investigations, laboratory experiments, remote sensing, monitoring and numerical modeling) allow investigators to revisit and revise scientific theories and principles (for example, a general physical/sedimentological PDC model), which then serve as a basis for computational and experimental models (through calibration, validation, benchmarking and prediction) that can then be applied to the collected data to improve the understanding of the dynamics of PDCs, as well as their hazard assessment studies. This integrative study will follow the methodology proposed for the validation of computational fluid dynamics codes designed to simulate complex industrial and technological systems, based on a hierarchical process of comparing numerical models with experiments and observations. In addition, the Spreadsheets across the Curriculum (SSAC) educational model (https://serc.carleton.edu/sp/ssac/index.html) will be integrated into the VHub cyberinfrastructure (www.vhub.org) to: (1) enhance computational literacy in the geosciences by promoting problem-solving using a structured environment, (2) develop, share and disseminate all activities and deliverables related to model validation and benchmarking efforts that will serve as a basis to drive future research on volcanic flow hazard assessment studies.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.