Earlier this month, the California coast was hit by a Kelvin wave, a deep ocean wave that can raise sea levels, but to most people, it wasn’t immediately visible. Named after Lord Kelvin, the mathematician who discovered them in the late 19th century, these waves don’t roll and crash along the shore like a tsunami or hurricane. They are slow-moving, mostly flat, waves of warm water that can stretch thousands of miles across the Pacific Ocean.
“It’s like an enormous bathtub sloshing around,” Mark Cane, professor emeritus of earth and climate sciences at Columbia University, told NPR on Monday. Kelvin waves are totally natural, forming throughout the year from warming ocean water and usually not impacting coastlines by a noticeable amount. But this year’s record-shattering El Niño climate pattern threatens to make Kelvin waves a little more intense throughout the winter, potentially inundating hundreds of thousands of Californians with up to two feet of elevated sea level, Daniel Swain, a climate scientist at the University of California, told USA Today. He called it “pretty significant.”
