what is the weather system el nino ? where can i find out more about it ?
2006-07-06 04:03:27 · 8 answers · asked by stitchybaby 1 in Science & Mathematics ➔ Weather
El Niño-Southern Oscillation (ENSO) is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Niño and La Niña (also written in English as El Nino and La Nina) are major temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The names, from the Spanish for "the little boy" and "the little girl", refer to the Christ child, because the phenomenon is usually noticed around Christmas time in the Pacific Ocean off the west coast of South America. Their effect on climate in the southern hemisphere is profound. These effects were first described in 1923 by Sir Gilbert Thomas Walker from whom the Walker circulation, an important aspect of the Pacific ENSO phenomenon, takes its name. The atmospheric signature, the Southern Oscillation (SO) reflects the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin. El Nino affects Australia by drought.
ENSO is a set of interacting parts of a single global system of coupled ocean-atmosphere climate fluctuations that come about as a consequence of oceanic and atmospheric circulation. ENSO is the most prominent known source of inter-annual variability in weather and climate around the world (~3 to 8 years), though not all areas are affected. ENSO has signatures in the Pacific, Atlantic and Indian Oceans.
In the Pacific, during major warm events El Niño warming extends over much of the tropical Pacific and becomes clearly linked to the SO intensity. While ENSO events are basically in phase between the Pacific and Indian Oceans, ENSO events in the Atlantic Ocean lag behind those in the Pacific by 12 to 18 months. Many of the countries most affected by ENSO events are developing countries within main continents (South America, Africa...), with economies that are largely dependent upon their agricultural and fishery sectors as a major source of food supply, employment, and foreign exchange. New capabilities to predict the onset of ENSO events in the three oceans can have global socio-economical impacts. While ENSO is a global and natural part of the Earth's climate, whether its intensity or frequency may change as a result of global warming is an important concern. Low-frequency variability has been evidenced. Inter-decadal modulation of ENSO might exist.
El Niño and La Niña
El Niño and La Niña are officially defined as sustained sea surface temperature anomalies of magnitude greater than 0.5°C across the central tropical Pacific Ocean. El Niño is associated with a positive anomaly, and La Niña with a negative anomaly. When the condition is met for a period of less than five months, it is classified as El Niño or La Niña conditions; if the anomaly persists for five months or longer, it is classified as an El Niño or La Niña episode. Historically, it has occurred at irregular intervals of 2-7 years and has usually lasted one or two years.
The first signs of an El Niño are:
Rise in air pressure over the Indian Ocean, Indonesia, and Australia
Fall in air pressure over Tahiti and the rest of the central and eastern Pacific Ocean
Trade winds in the south Pacific weaken or head east
Warm air rises near Peru, causing rain in the deserts there
Warm water spreads from the west Pacific to the east Pacific. It takes the rain with it, causing rainfall in normally dry areas and extensive drought in eastern areas.
El Niño's warm current of nutrient-poor tropical water, heated by its eastward passage in the Equatorial Current, replaces the cold, nutrient-rich surface water of the Humboldt Current, also known as the Peru Current, which support great populations of food fish. In most years the warming lasts only a few weeks or a month, after which the weather patterns return to normal and fishing improves. However, when El Niño conditions last for many months, more extensive ocean warming occurs and its economic impact to local fishing for an international market can be serious.
2006-07-06 04:16:05 · answer #1 · answered by Sherlock Holmes 6 · 2⤊ 1⤋
A major warming of the equatorial waters in the Pacific Ocean. El Nino events usually occur every 3 to 7 years, and are characterized by shifts in "normal" weather patterns.
2006-07-06 11:09:19 · answer #2 · answered by Chicky_S 3 · 0⤊ 0⤋
It is a natural Phenonomon occuring in the pacific ocean. Rather like the Gulf Stream in the Atlantic ocean. It is a large movement of water ( Current ) caused by the fact that cold water sinks and warmer water rises. This effect results in a current or flow of water either eastwards or westwards. The temp of the water affects land temperatures and this in turn can cause storms or the opposite i.e. Droughts.
2006-07-06 11:14:25 · answer #3 · answered by Anonymous · 0⤊ 0⤋
El Niño is a disruption of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe.
check this site out to find out more. http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html
2006-07-06 11:14:04 · answer #4 · answered by deb_hwan 2 · 1⤊ 0⤋
Here is the main page from the government forecast.
El niño meaning in English is The Boy
It's a type of weather that continues for a long, long time that causes Hurricane, tornadoes, snow storm, etc.
http://www.elnino.noaa.gov/
2006-07-06 11:08:21 · answer #5 · answered by Evy 4 · 0⤊ 0⤋
Isn't it similar to the Gulf Stream, a band of high pressure (therefore warm) that comes around at a certain time of year?
2006-07-06 11:07:05 · answer #6 · answered by sirdaz_uk 3 · 0⤊ 1⤋
I think it was a tornado that stroke one or two years ago!
2006-07-06 11:07:47 · answer #7 · answered by soubassakis 6 · 0⤊ 1⤋
it's like a giant storm.
2006-07-06 11:07:37 · answer #8 · answered by complete_shopper 2 · 0⤊ 2⤋