The CNRS has developed a method to predict the intensity of cyclones… with soap bubbles! They reproduced the Earth’s atmosphere to define a calculation.
Predict the intensity of cyclones by deciphering soap bubbles… The idea seems poetic, even impractical. However, physicists from the CNRS published on December 13 a method to predict the power of these meteorological phenomena in the journal Nature Scientific Reports.
A rotation that intensifies and then weakens
Physicists from the Aquitaine Waves and Matter Laboratory have modeled the Earth’s atmosphere with soap bubbles, in particular atmospheric flows. Water and 1% detergent provided the ideal composition. They produced a half bubble with the same curvature as the earth and then heated it from the base. Isolated eddies formed. Their intensity and properties were measured.
The researchers found that the rotation promotes the formation of vortices near the pole, and prevents them from lasting for long. The evolution of this phenomenon has also been identified: the rotation is weak at the start, then reaches a maximum speed before starting a decay phase, following a Gaussian curve. Thanks to these data, the researchers tried to define a law which precisely governs the evolution of their intensity. It makes it possible to estimate the maximum intensity of the tourbillon and the evolution it will take, in particular the time it will take to reach its maximum power. For this, approximately fifty hours are necessary after formation, ie a quarter of the life of a vortex.
An application in a real situation
This formula has a very substantial practical interest. Predicting the intensity of hurricanes, cyclones and typhoons is the main goal of meteorologists. The prediction is difficult to establish with certainty: the evolution factors are multiple, the interaction of the phenomenon with its environment almost unpredictable. For example, a tropical cyclone does not evolve in the same way depending on whether it is on sea or on land.
The vortices modeled in the laboratory were also two-dimensional. Those generated by hurricanes have three. It was therefore necessary to verify that this calculation method was applicable in a real situation. For this, the researchers joined forces with a unit from Reunion Island of the CNRS. They applied the calculations to nearly 150 cyclones in the Pacific and Atlantic Oceans. They have proven to be effective on these phenomena, but also on meteorological depressions. A glimmer of hope for the regions regularly affected by these natural disasters. The lives of hundreds of thousands of people could perhaps be spared, such as in the Philippines where Typhoon Haiyan killed more than 6,000.
Look at the result of the CNRS experiments:
.
