Is El Niño high or low pressure?
During El Niño, unusually high atmospheric sea level pressures develop in the western tropical Pacific and Indian Ocean regions, and unusually low sea level pressures develop in the southeastern tropical Pacific.
Does El Niño have high-pressure?
El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. In this phase of the Oscillation, the pool of warm water in the Pacific near South America is often at its warmest about Christmas.
What happens to air pressure during El Niño?
The Southern Oscillation is a change in air pressure over the tropical Pacific Ocean. When coastal waters become warmer in the eastern tropical Pacific (El Niño), the atmospheric pressure above the ocean decreases.
Where is the low pressure system during El Niño?
As a rule, there is a stable low-pressure system above the western Pacific near South East Asia and a high-pressure system in the central Pacific.
Why is there high pressure in Eastern Pacific?
In the eastern tropical Pacific, the warm surface water is replaced by colder water that wells up from below, a process known as upwelling. Relatively cold surface water favors high air pressure and meager precipitation.
How El Niño happens?
An El Niño condition occurs when surface water in the equatorial Pacific becomes warmer than average and east winds blow weaker than normal. The opposite condition is called La Niña. During this phase of ENSO, the water is cooler than normal and the east winds are stronger. El Niños typically occur every 3 to 5 years.
What is El Niño in relation to ocean oscillations?
El Niño–Southern Oscillation (ENSO) is an irregular periodic variation in winds and sea surface temperatures over the tropical eastern Pacific Ocean, affecting the climate of much of the tropics and subtropics. The warming phase of the sea temperature is known as El Niño and the cooling phase as La Niña.
Why is ENSO important?
ENSO is one of the most important climate phenomena on Earth due to its ability to change the global atmospheric circulation, which in turn, influences temperature and precipitation across the globe.
How does El Niño affect the Pacific Ocean?
During El Niño, the surface winds across the entire tropical Pacific are weaker than usual. Ocean temperatures in the central and eastern tropical Pacific Ocean are warmer than average, and rainfall is below average over Indonesia and above average over the central or eastern Pacific.
What are the conditions for El Nino?
For El Niño, the eastern tropical Pacific Ocean has to be 0.5°C or more warmer than average, and winds, surface pressure, and rainfall must have begun to show changes consistent with El Niño. (See What happens during El Niño and La Niña?)
What is El Nino and Southern Oscillation?
The Southern Oscillation is a change in air pressure over the tropical Pacific Ocean. When coastal waters become warmer in the eastern tropical Pacific (El Niño), the atmospheric pressure above the ocean decreases. Climatologists define these linked phenomena as El Niño-Southern Oscillation (ENSO).
What is the difference between El Niño and ENSO?
When coastal waters become warmer in the eastern tropical Pacific (El Niño), the atmospheric pressure above the ocean decreases. Climatologists define these linked phenomena as El Niño-Southern Oscillation (ENSO). Today, most scientists use the terms El Niño and ENSO interchangeably.