A significant swell of warm water, hundreds of miles wide, has been detected in the Pacific Ocean, signaling that a Super El Niño event is likely imminent, according to NASA.
Utilizing data from the Sentinel–6 Michael Freilich satellite, which precisely maps ocean surface heights, NASA has observed waves of warmer water moving eastward off the coast of South America. These "warm Kelvin waves" are a recognized precursor to El Niño development. The satellite, launched in 2020, monitors sea level changes across the global ocean.
Kelvin waves typically form when equatorial Pacific winds shift. This change causes warmer water to accumulate in the western Pacific, leading to a rise in sea levels. This warmer water then travels eastward, eventually impacting temperatures and weather patterns along the South American coast.
An El Niño occurs when multiple Kelvin waves appear over several months, causing substantial warming of ocean waters off the coasts of Colombia, Ecuador, and Peru. Current observations suggest that while this year's event began later than major El Niños in 2015 and 1997, it is accelerating.
The World Meteorological Organization (WMO) predicts that this potential Super El Niño could lead to extreme heat globally. Above-normal temperatures are anticipated across nearly all regions, with the most pronounced warming expected in southern and western North America, Central America, the Caribbean, Europe, North Africa, and much of Asia. In the Southern Hemisphere, Northern South America and Southern Africa are likely to experience significant warming. Australia may see warmer conditions along its western, southern, and eastern coasts, while tropical regions, including Equatorial Africa and parts of Southeast Asia, are also forecast to be hotter than usual.
El Niño is the warm phase of the El Niño-Southern Oscillation (ENSO) cycle, a natural climate phenomenon that also includes a cool phase (La Niña) and a neutral phase. The ENSO cycle typically shifts every two to seven years, influencing global temperature, wind, and precipitation patterns. Scientists are monitoring the accumulating warm water to assess the full potential impact of the developing El Niño.