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 researchers about how climate change is amplifying the effects of this natural 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 caused a rise in ocean and atmospheric temperatures.
Earlier this summer, a smaller wave reached British Columbia, and another one 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. Merryfield remarked that the upcoming wave appears to be more potent than the previous one, with sea levels already surging by over 30 centimeters in certain areas in June.
The Kelvin wave is a normal weather phenomenon, much like El Niño itself. In typical years, winds blow from east to west along the equatorial Pacific Ocean, pushing water from South America towards Asia. However, during El Niño years, these east-to-west winds weaken or even change direction, allowing water to move eastward instead.
When the Kelvin waves reach South America’s coast, the water piles up due to geographical constraints, leading to it splitting and flowing up and down the Americas’ coasts, eventually reaching Canada. This results in a temporary increase in sea levels rather than a tsunami-like wave, with the ocean’s surface rising by approximately a foot over a broad area.
The impacts of the Kelvin wave are most noticeable during king tides, especially high tides that occur when the gravitational forces of the sun and moon align to create elevated tides. When combined with a sea level rise of 30 centimeters due to El Niño, along with potential winter storm surges, the situation can become critical.
The compounding effects of the Kelvin wave, intensified northward winds, winter storms, climate change-induced sea level rise, and extreme weather patterns could exacerbate flooding and erosion along the coast. Previous strong El Niños have caused significant erosion on California’s beaches, prompting local authorities to take emergency measures to mitigate potential damages.
The repercussions of the Kelvin wave and El Niño could extend beyond the current season, affecting global temperatures. The oceans typically absorb excess heat due to greenhouse gas emissions, but during El Niños, some of this stored heat is released into the atmosphere. This could lead to 2027 being the warmest year on record by a substantial margin, as indicated by Merryfield and other climate research entities and scientists.
