Measuring Coupled Fire–Atmosphere Dynamics: The California Fire Dynamics Experiment (CalFiDE)

Abstract

The social, economic, and ecological impacts of wildfires are increasing over much of the U.S. and globally, partially due to changing climate and build-up of fuels from past forest management practices. This creates a need to improve coupled fire-atmosphere forecast models. However, model performance is difficult to evaluate due to scarcity of observations for many key fire-atmosphere interactions, including updrafts and plume injection height, plume entrainment processes, fire intensity and rate-of-spread, and plume chemistry. Intensive observations of such fire-atmosphere interactions during active wildfires are rare due to the logistical challenges and scales involved. The California Fire Dynamics Experiment (CalFiDE) was designed to address these observational needs, using Doppler lidars, high-resolution multispectral imaging, and in-situ air quality instruments on a NOAA Twin Otter research aircraft, and Doppler lidars, radar, and other instrumentation on multiple ground-based mobile platforms. Five wildfires were studied across northern California and southern Oregon over 16 flight days from 28 August to 25 September 2022, including a breadth of fire stages from large blow-up days to smoldering air quality observations. Missions were designed to optimize the observation of the spatial structure and temporal evolution of each fire from early afternoon until sunset during multiple consecutive days. The coordination of the mobile platforms enabled four-dimensional sampling strategies during CalFiDE that will improve understanding of fire-atmosphere dynamics, aiding in model development and prediction capability. Satellite observations contributed aerosol measurements and regional context. This article summarizes the scientific objectives, platforms and instruments deployed, coordinated sampling strategies, and presents first results.

A Case Study Featuring the Time Evolution of a Fire‐Induced Plume Jet Over the Rum Creek Fire: Mechanisms, Processes, and Dynamical Interplay

“…The last of the efforts mentioned eventually led to the California Fire Dynamics Experiment (CalFiDE) of 2022, which was a multi-institutional partnership between federal agencies and academia that featured closely coordinated measurements from satellite, aircraft, and ground-based assets to address wildfire dynamics across scales spanning the fireline to the development of the plume (Carroll et al, 2024). Ground-based mobile systems equipped with DL and radar were deployed as well as an instrumented TO that included a scanning DL, a multispectral infrared camera (MSIC), and in situ chemistry and meteorology packages.…”

Satellite Multi‐Angle Observations of Wildfire Smoke Plumes During the CalFiDE Field Campaign: Aerosol Plume Heights, Particle Property Evolution, and Aging Timescales

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The California Fire Dynamics Experiment (CalFiDE) featured the NOAA Chemistry Twin Otter Aircraft, along with NOAA ground-based mobile assets, sampling wildfires in northern California and southern Oregon from late August to late September 2022 (Carroll et al, 2024). The campaign aimed at investigating key science questions related to fire-plume dynamics and the impact wildfire plumes have on air quality.

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“…temperature and wind sensors were deployed on their Pick-Up based Mobile Atmospheric Sounder (PUMAS) truck. A detailed description of the campaign instrumentation and deployment program is given by Carroll et al (2024).…”