El Niño

General Information

El Nino is a coupled ocean-atmosphere phenomenon with La Nina. El Nino is a shift in the normal relationship between the atmosphere and ocean in the tropical Pacific Ocean. Or in another way to say it, it’s an important temperature fluctuation in surface water. El Nino is from the Spanish word which means “Christ Child” because this phenomenon is usually occurred around Christmas time off the west coast of west Southern America.

By using the graph it’s easier to understand what El Nino really is.

El Niño can be seen in measurements of the sea surface temperature

In normal, non-El Nino condition, trade winds blow to the west in the Pacific, moving warmer surface water away from North and South America (as shown in red-orange-yellow in the illustration on the right). Therefore, cold water from the ocean depths rises to the surface off the west coast of South America (as shown in light to dark green- light to dark blue in the illustration). This upwelling brings nutrients to the surface, supporting fisheries and ecosystems in the area.

In an El Niño event, these trade winds die down, and relax in the central and western Pacific Ocean causing warmer surface water to accumulate off western North and South America causes the winds in Western Pacific to become weak. The warm water has spread from the western Pacific Ocean towards the east (in direction of south America, the “cold tongue”(which is the upwelling cold water that brings nutrients to the surface) and the winds from way western Pacific are blowing strongly towards the east, pushing the warm water eastward. (as in the read area start to spread east ward which is the warm water that was blown by the wind hitting South part of America as illustrated in the middle and the bottom pictures

What are the signs of El Nino?

1. Rise in air pressure over the Indian Ocean, Indonesia, and Australia
2. Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean
3. Trade winds in the south Pacific weaken or head east
4. Warm air rises near Peru, causing rain in the deserts there

Causes

- increased trade winds could build up the western bulge of warm water, and any sudden weakening in the winds would allow that warm water to surge eastward.

- several weather conditions can cause westerly wind anomalies. ex. cyclones north and south of the equator force west-to-east winds between.

Effect

Because El Niño's warm pool feeds thunderstorms above, it creates increased rainfall across the east-central and eastern Pacific Ocean.

Warm water spreads from the west Pacific and the Indian Ocean to the east Pacific. It takes the rain with it, causing rainfall in normally dry areas and extensive drought in eastern areas.

- increased rainfall
- storm activity
- flooding in the Americas (especially the southwestern United States and Peru)
- drought conditions in Australia and other areas in the western Pacific and the Indian Ocean.
- seriouly affected fisheries on the west coasts of North and South America
- warm and very wet summers along the coasts of northern (Peru)
- causing major flooding whenever the event is strong or extreme (Ecudor)
- Central Chile receives a mild winter with large rainfall
- sometimes faced unusual winter snowfall events. (Peruvian-Bolivain)
- Drier and hotter weather (Amazon River Basin, Columbia and Central America)
- drier conditions (Southeast Asia and Northern Australia)
- increasing bush fires and worsening haze
- decreasing air quality dramatically.
- more sea ice (West of the Antartic Peninsular)

Previous issues

- Major ENSO events have occurred in the years 1790-93, 1828, 1876-78, 1891, 1925-26, 1982-83, and 1997-98.

- The El Niño of 1997 - 1998

It was particularly strong and brought the phenomenon to worldwide attention. The temperature increased by 3°F, compared to the usual increase of 0.5°F in El Niño events.

The period from 1990-1994 was unusual due to El Niños have rarely occurred rapid succession but not so strong.

How people or other factors might affect it

Due to El Nino’s effect upon the fishing-productivity, human could worsen the situation by use more consumption of oil to sail more for fishing activity

El Nino as known for an issue of warm surface water temperature moving west to east and east to west around the Pacific Ocean causes the shifting of warm air which effects the global warming.

El Nino causes bush fire in dry area which more or less create hotter atmosphere, global warming.

Due to typoon, clyclone, and other tropical storms they affect the wind speed such of trade wind and winds circulation, that can contribute to evolution of El Nino.