El Niño

El Niño 
El Niño–Southern Oscillation (pron.: /ɛlˈniːnjoʊ/, Spanish pronunciation: [el ˈniɲo], ENSO), or El Niño/La Niña–Southern Oscillation, is a band of anomalously warm ocean water temperatures that occasionally develops off the western coast of South America and can cause climatic changes across the Pacific Ocean. The 'Southern Oscillation' refers to variations in the temperature of the surface of the tropical eastern Pacific Ocean (warming and cooling known asEl Niño and La Niña, respectively) and in air surface pressure in the tropical western Pacific. The two variations are coupled: the warm oceanic phase, El Niño, accompanies high air surface pressure in the western Pacific, while the cold phase, La Niña, accompanies low air surface pressure in the western Pacific.Mechanisms that cause the oscillation remain under study.

The extremes of this climate pattern's oscillations cause extreme weather (such as floods and droughts) in many regions of the world. Developing countries dependent upon agriculture and fishing, particularly those bordering the Pacific Ocean, are the most affected. In popular usage, the El Niño–Southern Oscillation is often called just "El Niño". El niño is Spanish for "the boy", and refers to the Christ child, Jesus, because periodic warming in the Pacific near South America is usually noticed around Christmas.