A massive underwater wave associated with this year’s El Niño weather pattern 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 naturally occurring event.
Known as the Kelvin wave, this phenomenon is not a surprise. However, it is occurring against the backdrop of human-induced climate change, which has already heated up the oceans and the atmosphere.
Earlier this summer, a smaller wave reached British Columbia, and another wave is anticipated to arrive in the next one to two weeks, as per Bill Merryfield, a research scientist at Environment and Climate Change Canada.
Merryfield stated, “We already observed over 30 centimetres in some areas in June. The forthcoming wave appears to be more potent.”
The Kelvin wave, like El Niño, is a naturally recurring weather event. 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 east-to-west winds weaken or change direction, allowing water to move eastward instead. When these Kelvin waves hit the South American coast, the accumulated water splits and moves up and down the coasts of the Americas, eventually reaching Canada.
Data from sea-level monitoring at Tofino, on Vancouver Island’s Pacific coast, demonstrates the impact of the earlier Kelvin wave in June. Rather than a massive tsunami-like wave, the Kelvin wave causes a temporary rise in sea levels.
Describing it as a broad and shallow bulge in the ocean surface, University of California climate scientist Daniel Swain explained that the Kelvin wave elevates the ocean’s height by approximately a foot or more.
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.
Merryfield highlighted that these sea level rises, coupled with king tides and potential winter storms, could lead to significant challenges, emphasizing that the additional sea level rise due to El Niño can have a substantial impact.
These challenges could be exacerbated by El Niño’s influence on sea levels along the B.C. coast, where it can enhance northward winds, pushing more water towards the shore.
The compounding impacts of the Kelvin wave, intensified northward winds, and winter storms, combined with climate change-induced sea level rise and extreme weather patterns, may exacerbate flooding and erosion along the coast.
Authorities in California are already taking preventive measures by placing emergency sand on beaches in anticipation of a six to twelve-inch rise in water levels due to the Kelvin wave.
Merryfield cautioned that the effects of the Kelvin wave and El Niño could extend beyond the current season. He pointed out that during El Niños, some of the heat stored in the oceans due to greenhouse gases is released into the atmosphere, potentially making 2027 the warmest year on record by a significant margin.
These warnings align with similar alerts from various climate research organizations and scientists regarding the far-reaching impacts of El Niño and associated phenomena in the coming years.
