Video: Fractal forecasting

Beautiful prediction (Image: Kerry Mitchell)

WE’VE all watched those vast heaps of cotton wool float across the sky. Lofted and shaped by updrafts of warm air, cumulus clouds mesmerise with their constantly changing shape. Some grow ever taller, while others wither and die before our eyes. All bear witness to the ceaseless roiling of the ocean of air we call the atmosphere.

About 80 years ago, the British mathematician Lewis Fry Richardson was pondering the shapes of such clouds when a startling thought occurred to him: the laws that govern the atmosphere might actually be very simple.

Even at the time, with scientific meteorology still in its infancy, the idea seemed absurd: key equations governing the behaviour of the 5 million billion tonnes of air above us had already been identified – and they were anything but simple.

No one was more aware of this than Richardson, who is recognised as one of the founders of modern weather forecasting. Even now, the world’s most powerful computers are pushed to their limits extracting predictions of future weather and climate from the equations he wrestled with using pencil and paper.

Yet Richardson suspected that behind the mathematical complexity of the atmosphere lay a far simpler reality – if only we looked at it the right way.

Now an international team of researchers analysing signals from satellites, aircraft and ground-based stations have found clear evidence that Richardson’s intuition was right and that the complexity of the atmosphere could really be an illusion.

The results point to a new view of the atmosphere as a vast collection of cascade-like processes, with large structures …