PLEA Network

11 November 2016, The Conversation, Firestorms: the bushfire/thunderstorm hybrids we urgently need to understand. Fire has been a driving force across Australia for millennia. Indeed, the health of many of our ecosystems is intrinsically dependent on fire. But bushfires are also one of our most frequent natural hazards, with a total cost estimated at A$340 million per year. In the past decade or so, extreme bushfires in southeastern Australia have burned more than a million hectares, claiming more than 200 lives and over 4,000 homes. Similar losses in other major urban areas have prompted questions about whether we are seeing a shift towards a significantly more hazardous fire regime, characterised by increasing fire frequency and intensity, and the development of catastrophic “firestorms”. While these extreme bushfires account for only a very small percentage of fire events, they are responsible for the lion’s share of bushfire-related losses. In contrast to typical bushfires, which spread across the landscape as well-defined burning fronts with smoke plumes perhaps a few kilometres high, extreme bushfires exhibit deep and widespread flaming and produce smoke plumes that can extend 10-15km into the atmosphere. At these altitudes, bushfire plumes can actually develop into thunderstorms (hence the term “firestorm”). As such, extreme bushfires become much more difficult for emergency services to handle, making them all but impossible to suppress and their spread difficult to predict. Read More here