El Niño/Southern Oscillation (ENSO)

Posted: 21 August 2000

El Niño is the name originally given by local inhabitants to a weak warm ocean current flowing along the coast of Ecuador and Peru. ENSO is an extensive, intense, atmospheric and oceanic phenomenon affecting the tropical Pacific Ocean. It is associated with major anomalies in atmospheric circulation and rainfall patterns. El Niño occurs irregularly, but approximately every four years on average. ENSO events have impacts on fisheries, bird life and mainland weather.