In extreme cases, embers transported in a bushfire plume have been documented to start new fires over thirty kilometres away. Even in less extreme situations, new ignitions a kilometre away can complicate fire management and risk safety. The ability to forecast spotting due to ember transport in fire plumes would assist fire management and improve fire models.

Here, we use a bulk model of plume behaviour, accompanied by parameterisations of in-plume turbulence and ember transport and deposition, to model ember transport. Although the bulk model is based on the fundamental fluid dynamical equations, it is sufficiently simplified as to be many orders of magnitude quicker to calculate. The results will be compared to those from explicit particle transport calculations from large-eddy model simulations, and to available observations.

This scheme has been designed to be highly computationally efficient and is suitable for inclusion in bushfire prediction models, both stand-alone and coupled fire-atmosphere models.