A massive underwater wave associated with this year’s El Niño weather phenomenon is making its way along the western coast of the Americas, prompting concerns among researchers about how climate change is amplifying the effects of this naturally occurring event.
Known as the Kelvin wave, this occurrence is not unexpected. However, it is occurring in conjunction with human-induced climate change, which has already led to ocean and atmospheric warming.
An earlier smaller wave reached British Columbia earlier this summer, with another wave anticipated to arrive in one to two weeks, as noted by Bill Merryfield, a research scientist at Environment and Climate Change Canada.
The Kelvin wave, like El Niño, is a natural weather pattern. During normal years, winds blow from east to west along the equator in the Pacific Ocean, pushing water from South America towards Asia. However, during El Niño years, these winds weaken or change direction, allowing water to move eastward.
When these Kelvin waves reach the South American coast, the water piles up and then disperses, traveling up and down the Americas’ coasts and eventually reaching Canada.
Sea-level monitoring data from Tofino on Vancouver Island’s Pacific coast reflects the impact of the previous Kelvin wave in June. Rather than creating a tsunami-like wave, the Kelvin wave temporarily elevates sea levels, creating a broad, shallow bulge across the ocean surface.
The effects of the Kelvin wave are most noticeable during king tides, especially high tides resulting from the combined gravitational pull of the sun and moon. When combined with potential winter storms causing storm surges, the additional sea level rise from El Niño can have significant consequences.
The compounding effects of the Kelvin wave, intensified northward winds, winter storms, and existing climate change impacts could exacerbate flooding and erosion along the coast. Past strong El Niños have caused extensive erosion on California’s beaches.
Local authorities are taking preventive measures, such as adding emergency sand to beaches, in anticipation of the Kelvin wave raising water levels. The impacts of the Kelvin wave and El Niño could extend beyond the current season, with implications for global warming trends.
The release of stored oceanic heat into the atmosphere during El Niños is expected to contribute to 2027 potentially becoming the warmest year on record. Similar warnings have been issued by various climate research organizations and scientists.