To model mathematically the spread of fire in wildland fuels, one must predict the rate at which heat is transferred from the fuel that is burning to the fuel that has yet to be ignited, for this is the process that governs the rate of fire spread [1, 2]. Wind-aided fire spread and spread upslope in uneven terrain give rise to the situation in which the hot flame gases from the burning zone can impinge directly upon the unignited fuel. In these cases heat transfer to the unignited fuel must involve convective and radiative mechanisms. Models for such phenomenology have been proposed, ranging from conceptual skeletons [3] to encyclopedically encompassing fluid mechanical simulations [4]. But, as many have realized, the dominant mechanism of heat transfer is often radiation [5-11] for the simple reason that the movement of air is toward the burning zone rather than away from it, at least in the near vicinity of the fire edge where rapid heating of unignited fuel is taking place. This situation obtains even for wind-aided fire spread whenever the flame structure stands erect from the fuel surface rather than being blown through it.

[This publication is referenced in the "Synthesis of knowledge of extreme fire behavior: volume I for fire managers" (Werth et al 2011).]