Thermal Turbulence 2 : An atmospheric disturbance, sometimes rather violent above and downwind of a major wildland fire, that occurs when a rising column of heated gases is displaced by cooler air
Ralph W. Burklin & Robert G. Purington, Fire Terms: A Guide to Their Meaning and Use, National Protection Association, Boston, MA 1980 USA. (Guide: Meaning and Use, Nat Prot Association Fr Srvc - Amer) {457}