The didactic and practical value of a simple wildfire plume model

Here we present a simple entraining‑plume model designed to represent the essential dynamic and thermodynamic behaviour that develops above an active wildfire. The model combines widely used theory describing how wildfire heat is injected into the atmosphere, with plume parameterisations commonly employed in weather and climate models, into a new representation of convection above a wildfire. We tune the model’s entrainment and detrainment rates to align with direct numerical simulation experiments, and we validate its performance using in‑situ observations collected across a broad range of wildfires (through surface rates of spread and fuel models) and their associated plumes (through in-plume and environmental radiosondes). In this presentation, we describe how a simple model of this kind can support predictions of regime transitions during wildfire events, for example by indicating the potential onset of moist pyroconvection. We also outline how the model can serve as an instructional tool for fire analysts or other practitioners: It allows them to explore fundamental plume processes by testing sensitivities to a small set of surface and atmospheric control parameters, such as fuel moisture content, fire size, fire intensity, free tropospheric stability, inversions, boundary-layer and free-tropospheric humidity, and boundary layer height. Ultimately, despite its deliberate simplicity, we conclude that the model retains enough physical realism to provide meaningful insight into wildfire plumes. As such, we believe that in an age of increasingly complex, data-driven models, simple tools such as this one remain a valuable resource for both wildfire analysis in the field, but especially for educational activities.