The GOES-West satellite observed four tropical cyclones roiling the Pacific on September 1, 2015, during an El Niño event. (Image courtesy of the NASA/NOAA GOES Project.) During an El Niño event, the surface waters in the central and eastern Pacific Ocean become significantly warmer than usual.
El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Nino is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO). ... El Niño was recognized by fishers off the coast of Peru as the appearance of unusually warm water.
The Southern Oscillation is a change in air pressure over the tropical Pacific Ocean. When coastal waters become warmer in the eastern tropical Pacific (El Niño), the atmospheric pressure above the ocean decreases. Climatologists define these linked phenomena as El Niño-Southern Oscillation (ENSO).
As El Niño brings rain to South America, it brings drought s to Indonesia and Australia. These droughts threaten the region’s water supplies, as reservoir s dry and rivers carry less water. Agriculture, which depends on water for irrigation, is threatened. Stronger El Niño events also disrupt global atmospheric circulation.
Since 2000, El Niño events have been observed in 2002–03, 2004–05, 2006–07, 2009–10, 2014–16, and 2018–19. Major ENSO events were recorded in the years 1790–93, 1828, 1876–78, 1891, 1925–26, 1972–73, 1982–83, 1997–98, and 2014–16.
The 1982/83 and 1997/98 El Niños have been among the most damaging and well-documented events in the modern record (both are classified as 'extreme' events) and illustrate the magnitude of impacts El Niño can have in California.
An El Niño condition occurs when surface water in the equatorial Pacific becomes warmer than average and east winds blow weaker than normal. The opposite condition is called La Niña. During this phase of ENSO, the water is cooler than normal and the east winds are stronger. El Niños typically occur every 3 to 5 years.
El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Nino is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO).
2015–2016Overall, the most recent El Niño event in 2015–2016 caused $327 million in agricultural production losses. ENSO's most notable effect is on average rainfall, which declines during El Niño and rises during La Niña.
Previous La Ninas occurred during the winter of 2020-2021 and 2017-2018, and an El Nino developed in 2018-2019. When neither climate pattern is present, ENSO is neutral and does not influence global climate patterns. Learn more: Meet a NOAA scientist behind the La Nina forecast.
In April, both the trade winds and upper-level winds were stronger than average. Along with the April 2022 pattern of more rain than average in the western Pacific and less in the central/eastern Pacific, we have ample confirmation that La Niña conditions are still going strong.
La Niña continues as the Northern Hemisphere heads into winter, and forecasters are confident that it will hang around through the rest of the winter. This La Niña, the second in two years, will likely transition to ENSO-neutral sometime in the spring.
The latest forecasts from the WMO Global Producing Centres of Long-Range Forecasts indicate a moderate chance (about 65%) of the current La Niña conditions continuing during March-May 2022, and about a 35% chance of their further weakening to El Niño/Southern Oscillation (ENSO)-neutral conditions.
El Niño occurs when warm water builds up along the equator in the eastern Pacific. The warm ocean surface warms the atmosphere, which allows moisture-rich air to rise and develop into rainstorms. The clearest example of El Niño in this series of images is 1997.
El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. The cycle begins when warm water in the western tropical Pacific Ocean shifts eastward along the equator toward the coast of South America. Normally, this warm water pools near Indonesia and the Philippines.
El Niño (EN) is characterized by a large scale weakening of the trade winds and warming of the surface layers in the eastern and central equatorial Pacific Ocean. El Niño events occur irregularly at intervals of 2-7 years, although the average is about once every 3-4 years.
Historical research has suggested that the Spanish conquest of the Incas and Peru may have been aided by El Niño conditions. When Francisco Pizarro first sailed from Panama along the west coast of South America in 1524, his progress was slowed and ultimately stopped by persistent south and southeasterly winds—which follow the pattern of the north-flowing coastal currents. In 1525-26, however, Pizarro got much farther down the coast, riding on favorable northeasterly winds, according to geographer Cesar Caviedes, author of El Niño in History.
Winds near the equator (5° North to 5° South) blew more forcefully from west to east in the western and central Pacific; meanwhile, the easterly (east to west) trade winds weakened near the Americas. These wind shifts allowed pulses of warm water to slosh from Asia toward the Americas over the course of 2015.
While working as Director of Observatories in India and studying the monsoon, Gilbert Walker noted that "when pressure is high in the Pacific Ocean it tends to be low in the Indian Ocean from Africa to Australia; these conditions are associated with low temperatures in both these areas, and rainfall varies in the opposite direction to pressure." He dubbed the alternating atmospheric weather pattern the " Southern Oscillation ," noting how highs over the tropical Pacific coincided with lows over the Indian Ocean, and vice versa.
Some of this difference is due to tropical trade winds , which predominantly blow from east to west across the Pacific Ocean, piling up water near Asia and Oceania. Some of it is also due to the heat stored in the water, so measuring the height of the sea surface is a good proxy for measuring the heat content of the water.
The ocean is not uniform. Temperatures, salinity, and other characteristics vary in three dimensions, from north to south, east to west, and from the surface to the depths. With its own forms of underwater weather, the seas have fronts and circulation patterns that move heat and nutrients around ocean basins. Changes near the surface often start with changes in the depths.
Today, most scientists use the terms El Niño and ENSO interchangeably. Scientists use the Oceanic Nino Index (ONI) to measure deviations from normal sea surface temperatures. El Niño events are indicated by sea surface temperature increases of more than 0.9° Fahrenheit for at least five successive three-month seasons.
La Nina, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the region’s surface waters. El Niño and La Niña are considered the ocean part of ENSO, while the Southern Oscillation is its atmospheric changes.
Vocabulary. El Niño is a climate pattern that describes the unusual warming of surface waters in the eastern tropical Pacific Ocean. El Nino is the “warm phase” of a larger phenomenon called the El Nino-Southern Oscillation (ENSO). La Nina, the “cool phase” of ENSO, is a pattern that describes the unusual cooling of the region’s surface waters.
Upwelling provides food for a wide variety of marine life, including most major fisheries. Fishing is one of the primary industries of Peru, Ecuador, and Chile. Some of the fisheries include anchovy, sardine, mackerel, shrimp, tuna, and hake. The upwelling process also influences global climate.
The Southern Oscillation is a change in air pressure over the tropical Pacific Ocean. When coastal waters become warmer in the eastern tropical Pacific (El Niño), the atmospheric pressure above the ocean decreases. Climatologists define these linked phenomena as El Niño-Southern Oscillation (ENSO).