EAGER: Observing Extreme Fire Behavior in Canyons

峡谷中的火灾行为通常与造成世界各地许多消防员死亡的爆炸性蔓延率有关。然而，对峡谷中爆炸性火灾生长的主要物理过程仍然知之甚少，也很少观察到。该项目旨在通过开展实地规模的实验，收集一系列关于火灾在陡峭峡谷蔓延的新观察结果，从而提高对峡谷火灾行为和相关火灾天气的理解。这个新的数据集将有助于确定导致陡峭峡谷火灾加速的关键过程，并将作为火灾预测模型开发的国际基准，并提供目前不存在的数据。在更广泛的范围内，该EAGER项目的结果将有助于改进火灾风险评估，提高消防员的安全性，并改善山区的管理决策，特别是在气候变化导致野火变得越来越频繁和具有破坏性的情况下。使用一套以前从未有过的测量，这个EAGER项目将从机载和地面遥感系统观察完整的火灾演变。对峡谷地形敏感的对流和辐射传热机制以及由此产生的火-大气相互作用，包括火诱导的风和湍流结构，将与火动力学一起进行采样。此外，火锋附近的羽流动力学和相关的微气象学将为热对流和火灾环境之间的相互作用提供额外的背景。这些新的观察结果将为探索许多问题奠定基础，包括火灾引发的上升气流如何推动火灾蔓延，以及与峡谷轴对齐的风如何增加燃料的对流加热并加速蔓延速度。测量活动将通过使用耦合火灾-大气预报系统进行的数值模拟来支持，并将作为一个完整的数据集，提供对峡谷地形中控制火灾蔓延的物理特性的前所未有的检查。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Fire behavior in canyons is often associated with explosive rates of spread responsible for many firefighter fatalities around the world. Yet, the dominant physical processes responsible for explosive fire growth in canyons remain poorly understood and rarely observed. This project seeks to improve understanding of canyon fire behavior and associated fire weather by conducting a field-scale experiment to collect a suite of new observations of a fire spreading through a steep canyon. This new dataset will help to identify the critical processes leading to the fire acceleration in steep canyons and will serve as an international benchmark for fire prediction model development and provide data that do not currently exist. In the broader scope, the results from this EAGER project will lead to improved fire risk assessment, increased firefighter safety, and better management decisions in mountain regions particularly as wildfires are becoming increasingly more frequent and destructive due to climate change. Using a suite of measurements never previously available, this EAGER project will observe the complete fire evolution from both airborne and ground based remote sensing systems. Convection and radiative heat transfer mechanisms sensitive to canyon topography and resulting fire-atmosphere interactions including fire-induced winds and turbulence structures will be sampled together with the fire dynamics. Furthermore, plume dynamics and associated micrometeorology near the fire front will provide additional context of the interactions between the pyroconvection and fire environment. These novel observations will serve as a foundation to explore many questions including how fire-induced updrafts drive fire spread and how wind alignment with the canyon axis increases convective heating of the fuels and accelerates the rate of spread. The measurement campaign will be supported by numerical simulations made using a coupled fire-atmosphere forecasting system and together will serve as a complete dataset providing an unprecedented examination of the physics governing fire spread in canyon topography.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.