Do Peregrine solitons cause rogue waves?

Noaa Wave

Mathematician Howell Peregrine in 1983 identified how pulselike waves can pop out of sine waves under certain conditions, and today some researchers believe that these Peregrine solitons may explain rogue waves in the open ocean, according to an article published in Science News.

Rogue waves, though long reported by mariners, were not proven scientifically until 1995. The first rogue wave accurately measured was the so-called Draupner wave, near the Draupner oil rig platform off of Norway in 1995. During a storm with average wave heights of around 39 feet, a laser device was used to measure accurately a freak wave of around 84 feet.

Earlier this month the U.S. Coast Guard performed a helicopter rescue of the crew of a sailboat that was severely damaged by a rogue wave about 120 miles southeast of Nantucket, according to a report on Sail-World.com. The captain of the 45-foot sailboat, Eva, on a trip from Florida to Greecesaid they were sailing safely in rough conditions with 20- to 30-foot seas when a rogue wave dismasted them, damaging the deck and ports. The boat was taking on water, but the crew was able to ascertain their position with a backup GPS unit and called for help with a satellite telephone. Within two hours a helicopter from Cape Cod plucked the survivors off the boat.

“For a long time, nobody really thought this mathematics would be applicable to the ocean,” says Al Osborne, a physicist at the University of Turin in Italy. “Not only is it applicable, but we’re now undergoing a paradigm shift in understanding ocean waves.”

Amin Chabchoub, a mathematician at the Hamburg University of Technology in Germany, set up an experiment in a water tank where a paddle created uniform small waves, and then occasionally the paddle was jerked to create an anomaly in the wave trains. This process could create waves in the tank of up to three times the normal wave height. The article said that the behavior of these waves satisfied the mathematics described by Peregrine.

“You add an almost imperceptible amount of noise, and all sorts of wacky and unexpected things can happen,” said Daniel Solli, a physicist at UCLA who created the first Peregrine soliton in light waves.

By Ocean Navigator