The main idea behind El Nino is that the wind changes direction across the Pacific Ocean. In a non El Nino year (normal), the trade winds blow from east to west across the ocean, from North and South America towards the tropical regions of the Pacific Ocean. In an El Nino year, the trade winds change direction and blow from Asia and the tropical Pacific towards North and South America (NOAA B, 2004). The changes in these winds, commonly called Southern Oscillation winds because the majority of activity happens in the southern parts of the Pacific, produce many other changes. In the final analysis, the winds are the root of this scheme. John Daly (2004) discussed how the winds produce major changes in the temperature of the ocean water. This is the second main concept of El Nino. In normal years, when the wind blows from east to west, the temperature at "Sea Surface" is about 8 degrees cooler in the west than in the east. During El Nino, the winds blow a certain amount of water towards the west, thus piling it up and making its depth approximately one half meter deeper. Because of the loss of water at either coast, the deeper ocean water rises to replace what is gone. The deeper/cooler water is the source of many incomes in North and South America; however, in an El Nino year, the warmer
Cited: AIMS Research (Australian Institute of Marine Science). June 16, 2003. Townsville, Australia. http://www.aims.gov.au/pages/research/coral-bleaching/coral-bleaching.html. Daly, John, "El Nino Southern Oscillation." January 27, 2004. http://www.vision.net.au/~daly/elnino.htm. Hernandez, Greg. NOAA Magazine. "The Economic Implications of El Nino." March 6, 2002. Kwok, Ron Mayell, Hillary. Environmental News Network. "History of El Nino; tracking a global mystery." September 22, 1997. http://www.enn.com/specialreports/elnino/history.asp. National Oceanic and Atmospheric Administration (NOAA). Washington D.C. Last updated April 22, 2004. http://www.pmel.noaa.gov/tao/elnino/el-nino-story.html. (A) National Oceanic and Atmospheric Administration(NOAA) National Oceanic and Atmospheric Administration (NOAA). Washington D.C. Last updated April 22, 2004. http://www.pmel.noaa.gov/tao/elnino/impacts.html. (C) Redmond, Kelly United States Geological Survey (USGS). "1998 California Flood." From News Release. Feb. 3, 1998, http://ca.water.usgs.gov/archive/floods/flood98/. University of Illinois, Champaign Illinois. Last updated April, 2000. http://ww2010.atmos.uiuc.edu/(Gh)/guides/mtr/eln/rcnt.rxml. Williams, Jack. USA Today. "Scientists Gather Information on El Nino Impact in Antarctica." January 8, 2003.