One of the first major signs of this year's "Super El Niño" has reached the U.S.It's called a Kelvin wave – a deep ocean wave that's currently raising sea levels along the West Coast.Scientists have long known about Kelvin waves, but this year, the phenomena grabbed the public's attention with video explanations receiving thousands of views across TikTok and X."It does surprise me – I mean, here it's been around all this time," says Mark Cane, who created one of the first models to forecast and predict El Niño.
"I'm sure Lord Kelvin is happy in his grave."(Lord Kelvin, the British physicist who also developed the Kelvin temperature scale, first described the wave back in the late 1800s.)Kelvin waves can develop along the equator during El Niño years, when a vast region of water in the Pacific Ocean becomes much warmer than usual.Some of this warm water, in the form of a Kelvin wave that stretches thousands of miles, moves slowly east beneath the ocean's surface until it reaches South America.Then it splits, traveling north along the West Coast and as far south as Chile."It's like an enormous bathtub sloshing around," Cane says, professor emeritus of earth and climate sciences at Columbia University.
"But the slosh is very peculiar, because it only goes west to east along the equator in a Kelvin wave."These are not the massive, highly visible waves that crash into shorelines during major storms and hurricanes."It's not a wall of water, it's not a tsunami, it's not a wave you can surf," says Dillon Amaya, an assistant professor of atmospheric sciences at North Carolina State University."It's a planetary-scale wave."A Kelvin wave's impact is gradual, raising sea levels as it moves up the coast, and bringing with it an elevated risk of floods and warmer water temperatures.Kelvin waves can increase the risk of flooding and coastal erosion.By themselves, Kelvin waves don't cause flooding, Amaya says.
Instead, they load the dice, making flooding more likely by ra...