what is the el nino effect, how is it caused?

Answer 1

Causes of El Niño

The mechanisms which might cause an El Niño event are still being investigated. It is difficult to find patterns which may show causes or allow forecasts.

Major theories:

* Bjerknes in 1969 suggested that an anomalously warm spot in the eastern Pacific can weaken the east-west temperature difference, causing weakening in the Walker circulation and trade wind flows, which push warm water to the west. The result is increasingly warm water toward the east.
* Wyrtki in 1975 proposed that 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. However, there was no such buildup preceding the 1982-83 event.
* Recharge oscillator: Several mechanisms have been proposed where warmth builds up in the equatorial area, then is dispersed to higher latitudes by an El Niño event. The cooler area then has to "recharge" warmth for several years before another event can take place.
* Western Pacific oscillator: In the western Pacific, several weather conditions can cause easterly wind anomalies. For example, a cyclone to the north and anticyclone to the south force easterly winds between. Such patterns may counteract the westward flows across the Pacific and create a tendency toward continuing the eastward motion. A weakening in the westward currents at such a time may be the final trigger.
* Equatorial Pacific Ocean may tend to be near El Niño conditions, with several random variations affecting behavior. Weather patterns from outside the area or volcanic events may be some such factors.
* The Madden-Julian Oscillation (MJO) is an important source of variability that can contribute to a more rapid evolution toward El Niño conditions through related fluctuations in low-level winds and precipitation over the western and central equatorial Pacific. Eastward-propagating oceanic Kelvin waves can be produced by MJO activity.
* Adams, Mann and Ammann showed in 2003, using statistical analysis of paleoclimatic records, that a volcanic event in the tropics tends to trigger a 3 year El Niño followed by 3 years of La Niña.

Answer 2

El Nino is a shift in ocean temperatures and atmospheric conditions in the tropical Pacific that disrupts weather around the world. It is a poorly understood recurrent climatic phenomenon that primarily affects the Pacific coast of South America, but has dramatic impacts on weather patterns all over the world.
CAUSE:
Normally, trade winds blow towards the west, across the Pacific, pushing warm surface water away from the South American coast towards Australia and The Philippines. Along the Peruvian coast the water is cold and nutrient-rich, supporting high levels of primary productivity, diverse marine ecosystems, and major fisheries. During El Nino, the trade winds relax in the central and western Pacific. This allows warm water to accumulate in the surface, which causes the nutrients produced by the upwelling of cold water to significantly come down, leading to the killing of plankton and other aquatic life such as fish and the starvation of many seabirds. This is also responsible for destructive disruptions of worldwide weather patterns

Answer 3

The term El Niño (Spanish for "the Christ Child") refers to a warm ocean current that typically appears around Christmas-time and lasts for several months, but may persist into May or June. The warm current influences storm patterns around the globe. As a result, these "El Niño" climatic events commonly cause bring heavy rains and blustery storms, and drought. Basically, the warmth normally seen in the Pacific Ocean near the southwest Pacific spreads toward the center of the ocean during an El Niño. The warm water carrries with it rain stroms that would typically hit Australia and parts of the western Pacific.

The current El Niño will probably surpass the greatest El Niño of century, that of 1982-83. During the past 40 years, nine El Niños have affected the western coasts of North and South America. Most of them raised water temperatures along 5000 miles of coast. The weaker events raised sea temperatures only a few degrees Fahrenheit and caused mild changes in weather. But the strong ones, like the El Niño of 1982-83, left a climatic imprint that was global in extent.

El Niño recurs irregularly, from two years to a decade, and no two events are exactly alike. Before the 1982-83 El Niño event, scientists did not collect detailed information on El Niños, so information is scanty for making high-quality predictions about the effects of the current El Niño of 1997-98.

The impacts of El Niños can be devastating, as illustrated by some of the effects of the unusually strong El Niño of 1982-83:

Drought (sometimes with associated wildfires) in many nations (particularly in the western Pacific Rim, southern and northern Africa, southern Asia, southern Europe, and parts of South and Central America)
severe cyclones that damaged island communities in the Pacific
flooding over wide areas of South America, western Europe, and the Gulf Coastal states
severe storms in the western and northeastern United States.
Effects of the 1982-1983 El Niño

The 1982-1983 El Niño is the largest well-studied El Niño event, and it had dramatic effects on millions of people. In Ecuador and northern Peru, up to 100 inches of rain fell, transforming the coastal desert into a grassland dotted with lakes. Lush vegetation disrupted populations of many animals, from grasshoppers to toads, birds, and fish. The disruptions had both beneficial and destructive consequences for the people of the region. For example, some flooded coastal estuaries set shrimp production records, but also set records for the number of mosquito-borne malaria cases.

In North America, winter storms battered southern California and caused widespread flooding across the southern United States, while northern ski resort owners complained of unusually mild weather and a lack of snow. Inland lakes rose and flooded communities and roads. Landslides destroyed homes and killed people. Rivers flooded and destroyed parts of cities.

Overall, the loss to the world economy in 1982-83 as a result of the climate changes amounted to over $8 billion. The toll in terms of human suffering is much more difficult to estimate.

Answer 4

The Effect:
Drought
Severe cyclones
Flooding
Severe Storms
and the worse effect lose many of life.....

http://geology.wr.usgs.gov/wgmt/elnino/what.html

http://seawifs.gsfc.nasa.gov/OCEAN_PLANET/HTML/oceanography_el_nino.html

http://www.geotimes.org/mar05/feature_ENSO.html

Answer 5

tjw63_2004 is right. u r probably in the ninth grade. if u r, then let me tell u a single thing. i didnt understand a thing in that climate chapter.