Researchers from the UAB affirm that predicting hurricane intensity will never be 100% reliable

Cerdanyola del Vallès (CNA).- The Mathematics Research Centre of the Universitat Autònoma de Barcelona (UAB) has issued a study which points to future limitations in hurricane prediction. The study shows a mathematic relation between the number of hurricanes in a concrete zone of the planet and the energy they release. The distribution is valid for types of hurricanes studied independently from the period of the year and the geographic zone. In addition, the study concludes that nowadays there are not a greater number of hurricanes than in the 1950s.
Researchers from the UAB have analysed data corresponding to tropical storms that have taken place in different zones of the planet between 1945 and 2007. They have discovered that the mathematic relation, linking the number of hurricanes and the zone of the planet, obeys an exponent law, a concrete mathematic formula that is obeyed by hurricanes independently from their position on the planet or the period of the year.

From this discovery, researchers have concluded that the dynamics of these phenomena may correspond to a “critical process” which would make it completely impossible to predict its intensity, as these processes are unpredictable by definition.

One of the variables that institutions monitoring hurricane dangers have been trying to study and predict is hurricane intensity. Measuring the intensity is determinant to activating an alert system and planning out civilian protection when facing a hurricane. Until now, despite all the economic resources and scientific efforts allocated to investigation within this field, results are very poor. What has really improved in the last years is the prediction of hurricanes’ trajectories. “The fact that hurricanes follow an exponent law, like other natural phenomena where large quantities of energy intervene, such as earthquakes, raises serious doubts about the capacity to predict their intensity”, affirms Álvaro Corral, one of the researchers involved in the study. He further explains that the law ruling these intense hurricanes is exactly the same one that rules the medium and small-sized ones. “The way that a small storm evolves into a large and devastating hurricane depends on fluctuations that tend to amplify the storm instead of reducing it”, he adds. These fluctuations do not obey to specific reasons and thus it is impossible to know with sufficient time which fluctuations will dominate over the others.

No more hurricanes than in the 1950s

In addition, the study has a second conclusion: nowadays, in the Northern Atlantic, there are more hurricanes than in the 1990s but not more than in the 1950s. Therefore, the increase of the number of hurricanes in the last two decades cannot only be explained by the global warming effect. However, the research gives evidence that there is some kind of relation between global warming and the distribution of tropical storms. “The number of hurricanes is inversely proportional to the energy released, except for the highest values of energy, where this relation is suddenly interrupted”, indicates Corral.