Fires that stay concentrated rather than spreading out are more likely to produce higher smoke plumes that can create a thunderstorm and become a firestorm.
Dr Rachel Badlan and Associate Professor Jason Sharples are part of a team at UNSW Canberra and ACT Emergency Services that has found the shape of a fire is an important factor in whether it will turn into a firestorm.
Their predictive model for firestorms is being trialled with the NSW Rural Fire Service.
The model will help identify the most dangerous fires and better determine the best deployment of fire resources.
Thunderstorms generated by the heat from a fire are the most dangerous manifestation of a bushfire,” said Dr Badlan, postdoctoral fellow at UNSW Canberra.
These firestorms create their own weather with lightning, strong winds, and even tornadoes that spread fire in multiple directions. These ingredients make them impossible for firefighters to put out,” says Rachel, who is a .
Currently, there’s no way to predict them. Previous work attributes these firestorms solely to the total energy released by the fire, however, we have found the shape of a fire is a vital factor in the development of firestorms.
The team used advanced computer models to incorporate details of terrain, wind, and atmosphere, and the fire’s shape, size and intensity, to determine how high the plume will be.
This information then tells the researchers about the potential for a fire to develop into a firestorm (known as a pyrocumulonimbus).
With firestorms commonly occurring in Australia—more than 50 since 2001—and set to increase due to hotter and drier conditions, it’s vital that fire managers can determine which fires are likely to transition into a firestorm so that evacuation may occur as early as possible.
We hope that once the model has been trialled it will be suitable to use globally, said Dr Badlan.