Summary
Low-intensity prescribed fires used for fuels management often occur in highly heterogeneous forest stands. This heterogeneity, typically characterized by gaps in forest canopy coverage, can affect ambient and fire-induced atmospheric circulations within and near the fire environment, which in turn can affect fire spread and the dispersal of smoke. To improve our understanding of potential atmospheric responses to low-intensity fires in forested environments typical of prescribed burn programs, Forest Service researchers worked with colleagues at Michigan State University to numerically simulate local fire-induced circulations and atmospheric temperature variations that can occur during low-intensity fires within and near forest gaps. Using the canopy version of the Advanced Regional Prediction System (ARPS-CANOPY), a numerical model developed for simulating the atmospheric environment within forest canopies, the researchers were able to show that gaps in forest canopies can have a substantial impact on the vertical and horizontal transport of heat and smoke away from low-intensity surface fires occurring within and near the gaps. The research results highlight the importance of accounting for forest canopy effects on fire-atmosphere interactions in operational fire behavior and smoke dispersion predictive tools.