Climate Patterns

El Niño

El Niño is a warming of the sea surface in the central and eastern Pacific Ocean along and near the equator to above mean temperatures.

La Niña

La Niña is generally the opposite conditon to El Niño. The central and eastern Pacific water surface near the equator surface cools to below mean temperatures.

El Niño Southern Oscillation (ENSO)

The El Niño Southern Oscillation is a cycle of switching back and forth between El Niño and La Niña conditions with a period of near neutral conditions between the two states.

Arctic Oscillation (AO)

Pacific Decadal Oscillation (PDO)

More on El Niño and La Niña

More on the Arctic Oscillation


NOAA National Ocean Service

NOAA NWS Climate Prediction Center

"What is the El Niño–Southern Oscillation (ENSO) in a nutshell?" - Michelle L'Heureux, May 5, 2014, NOAA <--REFERENCES FOR AO AND PDO TO BE ADDED ONCE REVIEWED-->