El Niño–Southern Oscillation is a climate phenomenon that exhibits irregular quasi-periodic variation in winds and sea surface temperatures over the tropical Pacific Ocean. It affects the climate of much of the tropics and subtropics, and has links to higher latitude regions of the world. The warming phase of the sea surface temperature is known as El Niño and the cooling phase as La Niña. The Southern Oscillation is the accompanying atmospheric component, which is coupled with the sea temperature change. El Niño is associated with higher than normal air sea level pressure over Indonesia, Australia and across the Indian Ocean to the Atlantic. La Niña has roughly the reverse pattern: high pressure over the central and eastern Pacific and lower pressure through much of the rest of the tropics and subtropics. The two phenomena last a year or so each and typically occur every two to seven years with varying intensity, with neutral periods of lower intensity interspersed. El Niño events can be more intense but La Niña events may repeat and last longer.