Evaluation of WRF-SFIRE performance with field observations from the FireFlux experiment

A. K. Kochanski,J. Mandel,M. A. Jenkins,J. D. Beezley,C. B. Clements,S. Krueger

doi:10.5194/gmd-6-1109-2013

A. K. Kochanski, J. Mandel + Show 4 more

Open Access

https://doi.org/10.5194/gmd-6-1109-2013

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Abstract

Abstract. This study uses in situ measurements collected during the FireFlux field experiment to evaluate and improve the performance of the coupled atmosphere–fire model WRF-SFIRE. The simulation by WRF-SFIRE of the experimental burn shows that WRF-SFIRE is capable of providing realistic head-fire rate of spread and vertical temperature structure of the fire plume, and fire-induced surface flow and vertical velocities within the plume up to 10 m above ground level. The simulation captured the changes in wind speed and direction before, during, and after fire front passage, along with the arrival times of wind speed, temperature, and updraft maxima, at the two instrumented flux towers used in FireFlux. The model overestimated vertical wind speeds and underestimated horizontal wind speeds measured at tower heights above 10 m. It is hypothesized that the limited model spatial resolution led to overestimates of the fire front depth, heat release rate, and updraft speed. However, on the whole, WRF-SFIRE simulated fire plume behavior that is consistent with FireFlux observations. The study suggests optimal experimental pre-planning, design, and execution strategies for future field campaigns that are intended to evaluate and develop further coupled atmosphere–fire models.

Highlights

Over the last two decades, significant advances have been made on the development of coupled atmosphere–fire numerical models for simulating wildland fire behavior
Fire-spread rates are determined by the time series of 4.5 m a.g.l. at the Main Tower (MT) and 5 m a.g.l. at the Short Tower (ST) simulated and observed air temperatures shown in Fig. 4
The results indicate that even though the Weather Research and Forecasting Model (WRF)-SFIRE did not capture these high-frequency fluctuations, it predicted the FireFlux peak temperatures at 28 m and 43 m a.g.l. very accurately

Summary

Introduction

Over the last two decades, significant advances have been made on the development of coupled atmosphere–fire numerical models for simulating wildland fire behavior. While numerical studies using coupled atmosphere–fire models have shed light on the dynamics of fire–atmosphere interactions (Clark et al, 1996; Morvan and Dupuy, 2001; Linn et al, 2002; Linn and Cuningham, 2005; Coen, 2005; Cunningham et al, 2005; Sun et al, 2006; Mell et al, 2007; Cunningham and Linn, 2007), none of these models have been evaluated or validated using in situ, field-scale observational data. For both research and operational use, each has its strengths and weaknesses

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