Experimental, free-burning wood fires larger than 5 ha were similar in convection column volume after the initial buoyant, ring-vortex rose from the ground. The fire generated strong vorticity patterns which propagated upward into the convection column. The rotation suppressed lateral entrainment and mixing after the buoyant vortex ring had passed. The maximum height of the convection column was determined by vertical wind shear. Maximum smoke, complex hydrocarbon concentrations, combustion gas concentrations, oxygen depletion and visibility reduction and radiation extinction occurred during the first 210s of the fires.

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