Ember transport sensitivity to wind field and source size distribution

Spotting from wildfires is a source of major uncertainty for fire managers because it can both endanger fire fighters near the main fire front and allow fire to leap over barriers several miles away. While past studies have provided much valuable insight to help fire managers understand potential spot fire impacts, these studies have no examined the role of a changing wind field and the ember size distribution of the embers involved in the process. We created an idealized, time-varying, two-dimensional wind field to represent a fire's updraft. We then combined this with a source distribution function, a mathematical model for ember combustion, and a size-dependent fall speed relationship. The simplicity of the model allowed us to vary the updraft duration and intensity, ember size distribution, and the rate of ember production to determine how these properties influence the spatial and temporal distribution of landing embers.