It is normally characterized by complex and abnormally warm ocean temperatures in the Pacific Ocean in the area near the equator which results in global weather events and sea-surface temperature changes. 7 . Des ouragans se forment au milieu du Pacifique et frappent la Polynésie. El Niño is a climate cycle in the Pacific Ocean with a global impact on weather patterns. – NOAA's National Ocean Service, Ocean Currents – El Niño – Multimedia Discovery Missions, Currents (pdf, 381 KB) – Learning Ocean Science through Ocean Exploration: A Curriculum for Grades 6-12, Subscribe El Niño - Oxford Reference A weakening of the Equatorial Current, allowing warm water to accumulate off the South American Pacific coast; it is associated with a change in the atmospheric circulation known as a southern oscillation, the two together comprising an El Niño—Southern Oscillation (ENSO) event. On periods ranging from about three to seven years, the surface waters across a large swath of the tropical Pacific Ocean warm or cool by anywhere from 1°C to 3°C, compared to normal. Ainsi les eaux près de l'Australie et de l'Asie sont plus froides, provoquant des sécheresses. Bon plan Amazon : -124 € sur l'aspirateur robot Neato Robotics D750, Incroyable offre Black Friday : -65 % de réduction sur le logiciel VideoProc, Bon plan Cdiscount : -289 € sur le PC portable gamer Lenovo Legion Y540-15IRH, Meilleur lisseur cheveux 2020 ? The reason for this lies in the fact that almost the entire planet, and especially the tropical zone, “feels” its appearance, often through extreme weather conditions in many regions. El Niño is accompanied by high air pressurein the western Pacific and low air pressure in … While El Niño as the warm phase of ENSO, La Niña is sometimes referred to as the cold phase of ENSO. The image on the left represents "normal" conditions in the equatorial Pacific during January 1997. El Niño and La Niña are opposite phases of what is known as the El Niño-Southern Oscillation (ENSO) cycle.The ENSO cycle is a scientific term that describes the fluctuations in temperature between the ocean and atmosphere in the east-central Equatorial Pacific (approximately between the International Date Line and 120 degrees West). Peruvian fishermen have long noted that in some winters, coastal waters heat up and fish stocks dwindle, a phenomenon they named El Niño, a reference to the birth of the Christ child, which also came in winter. Ceci a pour effet de pousser les eaux chaudes de surfaces vers l'ouest, où il se produit conséquemment de fortes précipitations (à cause de la chaleur et l'humidité) et une remontée des eaux froides le long des côtes américaines. National Oceanic and Atmospheric Administration Disclaimer These images show sea surface topography and upper ocean temperature data from satellites and buoys. El Niño means The Little Boy or Christ child in Spanish. El Niño definition is - an irregularly recurring flow of unusually warm surface waters from the Pacific Ocean toward and along the western coast of South America that prevents upwelling of nutrient-rich cold deep water and that disrupts typical regional and global weather patterns. In fact, that timing is the source of the name: “El Niño” means “male child” in Spanish, and also refers to the baby Jesus. In Spanish, El Niño means "the boy," a reference to the Christ child, since historically the phenomenon has been observed near Christmas. An early start to the West Pacific typhoon season in 2015 due to El Nino. El Niño avait provoqué des anomalies de températures en 1997. Computer models, buoys and satellites are an upgrade from Gilbert Walker’s telegraph brigade — but timing, location and competing climate patterns make it tough to say how and when and where and how the effects of this — or any year’s — El Niño will arrive. Contrairement à La Niña, il se traduit pas une hausse de la température à la surface de l'eau (10 mètres environ) de l'est de l'océan Pacifique, autour de l'équateur (voir carte ci-dessous). Download image (jpg, 52 KB). El Niño and La Niña are opposite phases of El Niño-Southern Oscillation (ENSO) cycle. U.S. Department of Commerce, NOAA Pacific Marine Environmental Laboratory, El Niño & La Niña (El Niño-Southern Oscillation), Learning Ocean Science through Ocean Exploration: A Curriculum for Grades 6-12, National Oceanic and Atmospheric Administration. El Niño is a natural phenomenon experienced in the equatorial Pacific which causes temporary alterations in the world climate. Les dernières occurrences du phénomène se sont produites en 2009-2010, 2006-2007, 2002, 2003, 1997-1998, 1994-1995, 1990-1993, 1986-1988, 1982-1983, etc. Merci pour votre inscription.Heureux de vous compter parmi nos lecteurs ! In an El Niño year, the easterly wind weakens and the equatorial upwelling is suppressed. Water temperature is shown in color, ranging from 30°C as red to 8°C, shown in dark blue. Did You Know? Les couleurs chaudes indiquent une anomalie positive (donc une augmentation de température). Severe El Niños cause death and destruction across countries, even continents, and yet the cause and consequences of these events is still not well understood. Recently however, the term has been applied to those years when there is a change in this annual pattern. Interview : comment les cactus résistent-ils si bien à la sécheresse ? The height of the sea is represented by hills and valleys. Intéressé par ce que vous venez de lire ? Historically, El Niño occurred about once or twice per decade, but there is some indication that the frequency of these events is increasing.