Coastal California braces for Kelvin wave chaos

Many people are familiar with the El Niño phenomenon of warming surface temperatures across the Pacific Ocean. Less known is a separate but related oceanographic feature that is quickly positioning itself as one of — if not the — major disruptive weather events of the season. Dubbed a “Kelvin wave,” researchers warn this large surge of warm ocean water could lead to intense meteorological destruction during a winter storm season already heightened by a particularly active El Niño.

‘Not like crashing waves at the beach’

Unlike a “typical wave” visible across the “surface of the water,” Kelvin waves occur when “bursts of westerly winds push warm water eastward,” said LiveNow from Fox. The eastern push then generates Kelvin waves that “travel beneath the water’s surface along the equator.”

Kelvin waves manifest when ocean trade winds that “usually” move from South America toward Asia “die down or reverse” in El Niño years, said The Guardian, setting off a “massive, slow-moving slosh of water.” But Kelvin waves are “not like crashing waves at the beach.”

Rather, they are “planetary in scale, spanning thousands of miles,” and carry with them an “untold amount of warm water that slowly moves from the western Pacific, along the equator, towards South, Central and North America,” said The Guardian. Unlike normal shoreline waves, Kelvin waves are a “propagating disturbance” that moves energy through the ocean, “shifting heat, pressure, and sea level” along the way, said the Desert Sun.

Lasting impact

This year’s wave has “added nearly a foot to tides in Southern California,” said The Atlantic. It’s also created conditions that “tend to drum up storm activity in the Pacific.”

Potential Kelvin wave damage “depends on the force of the swells and how high tides are,” said The Orange County Register. If the wave is “indeed arriving now” at California’s shoreline, it will dovetail with “6-foot tides” and hurricane conditions “already churning up the ocean’s force.” Though the exact timing of the wave’s impact on coastal California remains uncertain, said The Guardian, researchers predict the wave’s effects will “linger through the winter and into early next year.”