Filmmaker Chris Tangey recorded the above video of a fire whirl whisking through the Australian Outback near Alice Springs on September 11. Since then, the clip has swerved from news sites to blogs to social media around the world. In its wake came this simple explanation from New York State climatologist Mark Wysocki on how a fire devil forms, via Life's Little Mysteries:
Like the dust devils that spring up on clear, sunny days in the deserts of the Southwest, a fire devil is birthed when a disproportionately hot patch of ground sends up a plume of heated air. But while dust devils find their heat source in the sun, fire devils arise from hot spots in preexisting wildfires.
"These plumes form in a very small region over the land," Wysocki explained. "They start to rise very rapidly, and as things start to rise, they suck the surrounding air in like a vacuum. Then you get this twisting that begins to resemble a vortex."
As the vortex rises and sucks the blaze up with it, its diameter begins to shrink and, like an ice skater pulling in her limbs to gather speed in a spin, its rotation accelerates.