Fire emissions modulate wildfire spread through aerosol-meteorology feedbacks: Insights from a novel WRF-Chem/Fire coupled model

Abstract

Wildfires represent a devastating global natural hazard, with profound ecological, economic, and societal impacts. Accurate prediction of fire behavior is paramount, yet state-of-the-art models like WRF-Fire often neglect the critical meteorological feedbacks induced by fire-emitted aerosols. To address this gap, this study develops a novel modeling framework that integrates WRF-Chem with WRF-Fire to systematically quantify how smoke-radiation interactions influence near-surface meteorology and subsequent fire behavior. Through a series of sensitivity experiments, we demonstrate that fire emissions trigger a complex, time-dependent feedback loop. Initially, aerosols suppress near-surface winds and moderate temperatures in our simulations, leading to a slower Rate of Spread (ROS) and a constrained burned area. However, as the fire persists, the accumulated emissions fundamentally alter the local atmosphere, intensifying the wind field through fire-induced circulations. This results in a dramatic reversal, with the ”With Fire” scenario subsequently exhibiting the most rapid fire front propagation. Our analysis reveals that the integrated radiative effect of all aerosols, rather than the contribution of any single species like black carbon (BC) or organic carbon (OC), is the dominant driver of these meteorological perturbations. This work concludes that incorporating these dynamic, time-evolving aerosol-meteorology-fire feedbacks is not a mere refinement but a crucial necessity for advancing the predictive accuracy of wildfire models, especially for extreme events, thereby informing more effective mitigation and response strategies.