A massive underwater wave associated with this year’s El Niño weather phenomenon is making its way up the western coast of the Americas, sparking concerns among scientists over how climate change is amplifying the effects of this natural event.
Named the Kelvin wave, this occurrence is not entirely surprising. However, it is occurring in the context of human-induced climate change, which has already heated up both the oceans and the atmosphere.
Earlier this summer, a smaller wave reached British Columbia, and another wave is projected to arrive within the next one to two weeks, as stated by Bill Merryfield, a research scientist at Environment and Climate Change Canada.
The Kelvin wave is a naturally occurring weather event, similar to El Niño itself. In typical years, winds blow from east to west along the equator in the Pacific Ocean, pushing water from South America towards Asia. During El Niño years, these east-to-west winds weaken or even reverse, allowing water to move eastward instead.
When these Kelvin waves reach the South American coast, the piled-up water splits and travels along the coasts of the Americas, eventually reaching Canada. Sea-level data collected at Tofino on Vancouver Island’s Pacific coast illustrates the impact of the previous Kelvin wave in June.
Rather than causing a massive tsunami-like surge, the Kelvin wave temporarily elevates sea levels, creating a broad, shallow bulge across hundreds of miles of ocean surface.
The repercussions of this phenomenon are most noticeable during king tides, particularly high tides resulting from the combined gravitational pull of the sun and moon. When this extra sea level rise from El Niño coincides with king tides and potential winter storms, the effects can be significant.
These effects, compounded by the Kelvin wave, enhanced northward winds, and winter storms, on top of existing climate change impacts, could exacerbate flooding and erosion along the coastlines. Previous strong El Niño events have led to widespread erosion on California’s beaches.
Local authorities in California are taking preventive measures such as placing emergency sand on beaches, anticipating a rise in water levels due to the Kelvin wave. The consequences of the Kelvin wave and El Niño could extend beyond the current season, possibly making 2027 the warmest year on record, according to Merryfield and corroborated by other climate research organizations and scientists.
