Atmospherical Sciences

The chaotic mathematics of whirlwinds

NASA / SVS Turbulent flows capable of generating whirlwinds show recurring patternsNASA / SVS

In an article published 55 years ago, Edward Lorenz, a professor of meteorology at the Massachusetts Institute of Technology (MIT), argued that delicate forces can influence the weather and result in catastrophic events. Understanding the response of the atmosphere and the seas to these small forces helps researchers explain how huge tornadoes develop from a turbulent combination of small whirlwinds. But it is still impossible to predict where and when such turbulent dynamics will result in storms. Now, a team led by Michael Schatz at the Georgia Institute of Technology has created a computational model that forecasts the stages of this kind of turbulence through mathematical equations describing fluid flows (Physical Review Letters, March 15). Schatz identified recurring patterns by analyzing thousands of images of a two-dimensional turbulent flow produced in a laboratory. These models indicate the conditions under which whirlwinds grow or shrink, and help to predict their evolution. The mathematics behind these patterns is similar to the chaotic motion of an inverted pendulum.