What is the Southern Oscillation Index?
El Niño-Southern Oscillation or “ENSO,” is a coupled ocean-atmosphere phenomenon centered in and over the tropical Pacific. It involves large-scale fluctuations in a number of oceanic and atmospheric variables such as sea surface temperature, sea level pressure, etc. El Niño (warm phase) and La Niña (cold phase) episodes are the opposite extremes of the ENSO phenomena. During an El Niño, above normal sea surface temperatures (SST) extend across the central and eastern tropical Pacific Ocean. Learn more at AIRWeather.
