I. History of El Niño
El Niño is one of the most powerful forces driving global weather. El Niño is a reoccurring phenomenon on earth that alters the climate across half the planet. El Niño was discovered hundreds of years ago off the coast of Peru; "El Niño" means different things to different people. In Spanish, El Niño means small boy or child. In capital letters, 'El Niño' refers to Jesus as an infant was named after the Christ child ("Dictionary.com"), because it usually starts around Christmas ("El Nino"). El Niño is a severe atmospheric and oceanic disturbance in the Pacific Ocean that transpires every three to six years in a phase with a seesaw variation of atmospheric pressure (McIntosh). Because El Niño influences global weather patterns and affects human lives and ecosystems, the prediction of an El Niño is progressively important in predicting them with advance notice. It was not until about 25 years ago that the world started paying attention to El Niño. The giant El Niño of 1997-98 had deranged weather patterns around the world, killing an estimated 2,100 people, and caused at least 33 billion [U.S.] dollars in property damage (Forrester). History dates between 1200 and 1525, the Inca population lived in the part of South America extending from the Equator to the Pacific coast of Chile. Their cities and fortresses were mostly built on highlands and on the steep slopes of the Andes Mountains. The architecture of the Incan cities still amazes and puzzles most scientists ("Inca"). The Incan knows about El Niño, they built their cities on the tops of hills, and populations kept stores of food in the mountains. There are written records of evidence of El Niño along the Peruvian coastal communities. Another El Niño fact, “600,000 people died in just one region of India from the epic droughts of the 1789-1793 El Niño.” ("El Niño, Facts")
II. Methods of observation El Niño
Currently there are several methods of monitoring conditions in the Pacific that trigger El Niño: satellites, moored ATLAS; PROTEUS buoys; drifting buoys, sea level analysis; and XBT’s. The most effective way of monitoring TAO (tropical atmosphere/ocean) are the 70 moored buoys, this is the early warning system for changes in the tropical ocean. They monitor water temperature from the surface down to 1,600 feet [500 meters], as well as winds, air temperature, and relative humidity.

The Moored buoys are weather sentinels of the sea. There are two types: Discus and NOMAD. They are deployed offshore in the western Atlantic to the Pacific Ocean near the Hawaii Islands; and from the Bering Sea to South Pacific (McIntosh). The Moored buoys measure and transmit barometric pressure; wind direction; speed, and gust; sea temperature; and wave height. The Moored buoys come in assorts sizes: 3 meter, 10 meter, 12 meter hulls; and 6-m boat-shaped. The data collected by the buoys are transmitted to satellites and then to NOAA’s Pacific Marine Environmental Laboratory in Seattle, Washington. See photo below. MOORED BUOYS - Percent of Data Disseminated in Real Time
Station ID Hull No./Config and
Location Location
Lat/Long Sea Level Press Wind Speed & Dir Air Temp Sea Sfc Temp Sig Wave Ht. Dew Point
41001* 6N60 /A E HATTERAS 34.70N/ 72.73W 92 95 94 92 70 S
41002* 3DV11 /A S HATTERAS 32.38N/ 75.41W R R R R R N
41004* 3D37 /P EDISTO 32.50N/ 79.10W 100 100 100 100 100 100
41008* 3D36 /P GRAYS REEF 31.40N/ 80.87W 100 100 100 100 100 S
41009 6N23 /A CANAVERAL W 28.52N/ 80.17W 100 100 100 100 100 100 Another method is the scatterometer, which sends microwave pulses to the earth's surface and measure the backscattered power from the surface roughness (Air-Sea Interaction & Climate). Scatterometers are unique among satellite remote sensors in the ability to determine the wind direction over water (Center for Ocean-Atospheric Perdiction Studie). The scatterometers are used for weather forecasting, marine safety, commercial fishing, and El Nino prediction and monitoring. All scatterometers have been active microwave sensors: they send out a signal and measure how much of that signal returns after interacting with the target. Microwaves are Bragg scattered by short water waves; the fraction of energy returned to the satellite (backscatter) is a function of wind speed and wind direction. The NASA Scatterometer (NSCAT) was launched on the polar orbiting ADEOS satellite and measured wind speeds from Sept. 15, 1996 to June 30, 1997. The observational coverage was 600 km wide swaths on both sides of the satellite. The wind speed can be determined from the strength of the backscatter signal (Center for Ocean-Atospheric Perdiction Studie). The roughness may describe characteristics of polar ice or vegetation over land. Over the ocean, which covers over three-quarters of the earth's surface, the backscatter is largely due the small centimeter waves on the surface ("Air-Sea Interaction & Climate").Actual Image from the TOPEX/POSEIDON Satellite

El Niño Watch from Space

During the first two weeks of June, QuikSCAT observed the weakening of the trade winds in the equatorial Pacific, which was followed by an unusual warming of the equatorial water, as reflected in the sea level and sea surface temperature anomalies revealed by the Topex/Poseidon altimeter and the microwave imager on the Tropical Rain Measuring Mission

III. The Physical Mechanism of El Niño
El Niño is a severe atmospheric and oceanic disturbance in the Pacific Ocean that occurs every seven to fourteen years. It is called El Niño, meaning “the Child”, because it usually appears near the Christmas season (Dictionary.com). Warm surface waters flow from the central Pacific towards the eastern Pacific, suppressing the cold, nutrient-rich upwelling of the Humboldt Current off the coast of South America (McIntosh). This disturbance leads to a fall in the number of plankton, wreaking havoc upon the entire ocean food chain and devastating the fishing industry (El Nino, Facts). The influence of the currents alters the winds to a complete reversal; bring torrential rain, flooding, and mudslides. A strong El Niño is often associated with wet winters over the southeastern US, as well as drought in Indonesia and Australia. Keep in mind that you aren't guaranteed these effects even though there is an El Niño going on; but the El Niño does make these effects more likely to happen. The giant El Niño of 1997-98 had deranged weather patterns around the world, killed an estimated 2,100 people, and caused at least 33 billion [U.S.] dollars in property damage (El Nino, Facts). In fact, northern-tier states saved an estimated five billion dollars in heating costs during the 1997-98 El Niño (El Nino, Facts).
What causes El Niño? Usually, the wind blows strongly from east to west along the equator in the Pacific. This actually piles up water in the western part of the Pacific. In the eastern part, deeper water (which is colder than the sun-warmed surface water) gets pulled up from below to replace the water pushed west. So, the normal situation is warm water (about 30 C) in the west, cold (about 22 C) in the east (McIntosh). In an El Niño, the winds pushing the water around getting weaker, as a result, some of the warm water piled up in the west; and returns back to the east. Both these tend to make the water in the eastern Pacific warmer, which is one of the hallmarks of an El Niño. But it doesn't stop there. The warmer ocean then affects the winds--it makes the winds weaker! So if the winds get weaker, then the ocean gets warmer, which makes the winds get weaker, which makes the ocean get warmer (Forrester) ... this, is called a positive feedback, and is what makes an El Niño grow (The University of Illinois at Urbana-Champaign).
Normal Winter El Niño Winter http://ww2010.atmos.uiuc.edu/(Gh)/wwhlpr/washington.rxml
IV. Signals of El Niño
Now it’s time to discuss what make an El Niño grow. Now we will discuss what makes it stop growing. Everybody knows that the oceans are full of waves. The Rossby wave is not like a wave you see at the New Jersey shores. This wave is cousin to a tidal wave. The difference is that a tidal wave goes very quickly, with all the water moving pretty much in the same direction. In a Rossby wave, the upper part of the ocean, say the top 100 meters or so, will be leisurely sliding one way, while the lower part, starting at 100 meters and going on down, will be slowly moving the other way. After a while they switch directions (McIntosh). This happens very slowly and under the surface of the water invisible to the eye. This action is so slow that it could take months or years to cross the oceans. The water moves at the speed of 1/100th of walking speed. Another wave you rarely hear about is called a Kelvin wave, and it has some characteristics in common with Rossby waves, but is somewhat faster and can only exist close to the equator (Air-Sea Interaction & Climate).

El Niño’s often start with a Kelvin wave propagating from the western Pacific over towards South America. It showed a whitish blob moving along the equator from Australia to South America. When an El Niño gets going in the middle or eastern part of the Pacific, it creates Rossby waves that drift slowly towards Southeast Asia. In 1983, climate patterns over the world were altered by largest El Nino, a warming of eastern Pacific waters that occurs irregularly every three or so years and it continue for 18 to 24 months. The last El Nino doused Ecuador with torrential rains, brought record droughts to Australia and killed much ocean life (Forrester). Some of the signs of El Niño are marked by rising ocean temperatures in the tropical Pacific Ocean linked to warm air temperatures, increased rainfall, flooding, drought and wildfires (McIntosh). Early signs of a developing El Niño pattern can appear as early as late fall a year before a mature El Niño pattern sets in. But just because these signals appear, it does not always mean an El Niño will follow. From March to April is the time period that can make or break the forecasting of an El Niño. Scientist still does not fully understand the physical process that takes place during the seasonal transition, known as “spring barrier” (McIntosh). But during this time signs of El Niño can appear or disappear, if the signs continue through the spring barrier, there would be a greater chance of a full scale El Niño. The ocean temperature during El Niño is accompanied by fluctuations in air pressure between the western and eastern tropical pacific know as the Southern Oscillation. For the duration of El Niño higher air pressure covers Indonesia and western Pacific; and record low air pressure travel over the eastern Pacific (McIntosh).

V. How can we predict El Niño?
The first successful prediction of El Niño was made by “Mark Cane and Steve Zebiak at Columbia University's Lamont-Doherty Geological Observatory in the US. They developed an intermediate ocean-atmosphere coupled model. The model successfully predicted the onset of the 1986-7 El Niño one year in advance” (McIntosh). When predicting an El Niño, scientist measure atmospheric, oceanic waves and weather patterns. “The impact of El Niño can have two or more different "flavors." For instance, California can experience very wet conditions (such as in 1940-41, 1982-83, and 1991-92) or drought (1986-87 and 1987-88), depending on how Far East the ENSO-related rainfall extends in the tropical Pacific. Predicting which flavor will dominate for a given event is difficult, because very small changes in SSTs can become magnified to produce large differences in rainfall patterns outside the tropics” (El Nino, Facts).
VI. Economical effect of El Niño
The 1982-1983 El Niño also caused so much destruction that the weather-related damage estimated at more than $6.5 billion (El Nino, Facts). The economical effect of El Niño is an affected by strong storms enough to damages property. The world economic is affected greatly by weather. In the agriculture industry which is sensitive to temperature and precipitation a reliable weather forecast is estimated to save the world $240 to 260 million. In construction activities an El Niño would have impact on project, some are less likely carry out when the weather is bad, and with proper weather forecasting save money by planning a project. With biggest threat flooding, in 1982/83 El Niño, in California caused $300 million in property damages, and over 10,000 people were forced to evacuate their homes (El Nino, Facts).

VII. Conclusion
El Niño is the strongest weather system that can destroy lives and production, both agriculturally and economically, with little warning, occurring every 3-6 years, lasting between 9-12 months. The major impacts of an El Niño are temperature variance, changes in precipitation and floods and droughts throughout the world. To predict an El Niño is hard, but several climate models have predicted the last few successfully. The need for predicting El Niño event saves the world billions of dollars in property damages, agriculture and save lives. Predicting an El Niño event plays major part in the cost to heat homes and businesses.

Works Cited
"Air-Sea Interaction & Climate." 2 APR 2010. Air-Sea Interaction & Climate. .
"Center for Ocean-Atospheric Perdiction Studie." 16 APR 2010. Scatterometry & Ocean Vector Winds Satelite Studies. .
Dictionary.com. 8 APR 2010. .
"El Nino, Facts." 8 APR 2010. El Nino Facts. .
Forrester, Amy. "The Effects of El Nino on Marin Life." 1 APR 2010. University of Miami, Rosenstiel School of Marine and Atmospheric Science. .
"Inca." 1 APR 2010. Minnesota State University at Mankato. .
McIntosh, Robert and Joseph Tainter. The Way the Wind Blows: Claimate, History, and Human Action. New York: Columbia University, 2000.
The University of Illinois at Urbana-Champaign. 7 APR 2010. .