Algorithm flags rogue ocean waves before they strike

Economist : Rogue waves are giant ocean waves that form when multiple smaller waves merge. The most extreme ones can reach heights of nearly 30 m and sink all but the largest merchant ships. Predicting the occurrence of rogue waves has not been possible, but now Will Cousins and Themistoklis Sapsis of MIT believe they have developed a way to do so. Previous attempts required radar monitoring of large areas of the ocean and hours of number crunching on supercomputers. The new model uses data collected over years to determine how an area of the ocean behaves normally. The historical analysis is combined with real-time radar measurements of wave heights and movements to identify groups of waves that could merge into a rogue wave. Only then does the model predict the future behavior of those groups of waves. The algorithm works on an average laptop that would be available to most ships’ captains. When examining simulated data with 336 examples of rogue waves, the model identified all of them, but it also generated 91 false alarms. Cousins and Sapsis say that the average time between when the algorithm flagged a rogue wave and when each struck was 153 seconds, which should be enough time for crews to prepare for the hit.