What is El Nino?

Question

What is an El Nino???

I know that it has something 2 do with the pacfic ocean and temperatures in rising. But what is it exacty.

Thx 4 any help!

Answer 1

El Nino is the name given for warmer than average sea surface temperatures over the central and eastern equatorial Pacific Ocean. It's name, meaning "the boy child" was derived from the Christ child, since this event typically makes it's appearance in December. It is significant in that it affects the general atmospheric circulation over the Pacific Ocean, and effects may even translate further eastward into the Atlantic.

Answer 2

Good qestion and so far you have received a lot of smoke and mirrows and unfortunately, little light. So here is the scientific answer you are looking for. When non El Nino conditions exist we find a high pressure ridge over the eastern Pacific Ocean and lower pressures over Indonesia. This gives us the typical easterlies along the equator. This condition is accompanied by upwelling and cooler ocean water in the eastern Pacific with warmer water in the western Pacific. The trades are the lower extent of what is called the Walker circulation - rising air and heavy rain over the western Pacific and sinking dry air over the eastern Pacific. When this condition I have just described in very strong an exceptionaly cool eastern Pacific is referred to as a La Nina event. The name means "the girl child".

When the high pressure ridge over the eastern Pacific weakens and the low pressure over the western Pacific is replaced by high pressure the easterlies are weakended and basically replaced by westerlies. This carries warm water eastward and the Walker circulation is reversed with heavy precipitation over the eastern Pacific and drier sinking air over the west. This describes an El Nino event. Because it is often observed around December and Christmas it was given the name "the boy child".

The upper atmosphere reflects these reversals when a ridge in the upper atmospheric flow is replaced by a trough in the east and the trough in the west is replaced by a ridge. The trough in the east now brings the heavy precipitation into the western US bringing snow to higher elevations and latitudes and rain to northern Mexico. Because there is likely to be another trough over the eastern US, there will be warmer and wetter weather there as well. With this information you can decide which event you believe is worse, El Nino or La Nina.

I've provided you with this answer because these two weather phenomena are closely related and must be understood together.

Answer 3

El Nino is a periodical reversal of Pacific ocean currents.In a normal year, currents flow west,driven by the trade winds.In an El Nino year,the trade winds fail and warm water drifts back eastwards towards Peru.El Nino events begin in December or January,hence its name,'The Christ Child'.
La Nina occurs when equatorial waters in the Pacific ocean become colder than normal.Both affect global weather.

Answer 4

El Niño-Southern Oscillation (ENSO) is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Niño and La Niña are important temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The name El Niño, from the Spanish for "the little boy", refers to the Christ child, because the phenomenon is usually noticed around Christmas time in the Pacific Ocean off the west coast of South America. La Niña, similarly, means "the little girl". 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. The most recent occurrence of El Niño started in September 2006 and lasted until early 2007. From June 2007 on, data indicated a weak La Niña event.

ENSO is a set of specific 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 (about 3 to 8 years), though not all areas are affected. ENSO has signatures in the Pacific, Atlantic and Indian Oceans. El Niño causes weather patterns involving increased rain in specific places but not in others. This is one of many causes for drought.

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-economic 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: the quasi-decadal oscillation (QDO). Inter-decadal (ID) modulation of ENSO (from PDO or IPO) might exist. This could explain the so-called protracted ENSO of the early 1990s.

Answer 5

well...

el nino and la nina are global, coupled ocean atmospheric changes. they are temperature fluctuations in waters on the surface of the tropical east pacific ocean. el nino is named "boy" in spanish after jesus, because it occurs around christmas time. both these surface temperature fluctuations cause annual weather changes, causing rain in some areas and decreased rain in others.