El Nino
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According to NOAA (National Oceanic and Atmospheric Administration), El Nino is described as the "disruption of the ocean-atmosphere system in the tropical Pacific having important consequences for weather around the globe". This involves the unusual warm conditions that appear in the coastal areas near Peru and Ecuador, South America. Actually El Nino is a term used to describe the warm southward current of the Pacific Ocean, that appears every December of the year. However, it's now become more intense and severe over the past years, especially in the 1982 and 1983 season, and once occurring, it affects the climate for one year around the globe. It's now happening every 3 to 7 years, including 1972, 1976, 1982/1983, 1987, 1991, 1994, 1997.
El Nino's disturbance to the weather system is identified by the reversal of the normal weather conditions in the eastern and western Pacific caused by the sufficiently warm and persistent ocean currents. During this event, the trade winds that usually blow from east to west is collapsed and even reversed to blow from west to east, thus changing the climatic pattern of the western Pacific and the eastern Pacific. The western Pacific that usually moist, warm and high in rainfall is changing to an arid and low rainfall condition thus bringing droughts to south-eastern Asia, India, and southern Africa. While the eastern Pacific that usually arid, cold and low in rainfall is reversed to a moist, warm and high in rainfall, leading to heavy rainfall in the areas.
Below is a table explaining some important pointers for El Nino:
Impacts
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- Increase of rainfall in the eastern Pacific
- Arid conditions causing droughts and in western Pacific: increased risk of forest burns.
- Economical effect particularly in coastal areas of Peru and Ecuador. In normal condition the cold water supports large populations of fish, however, during El Nino the coastal areas are warmer, depleting nutrient in the area thus causing lack of food for the fishes.
- Health problems, especially in drought areas.
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About the name |
The name El Nino was derived from Spanish word that means "a little boy." This term was picked because the event usually occurs in December, near Christmas. |
La Nina :
La Nina is a contrary to El Nino, described as unusual cold condition in the eastern Pacific. During this event, the coastal areas of Peru and Ecuador are dominated by arid and cool weather, making it drier and cooler than ever. While in the western Pacific, the condition is warmer and more moisture, leading to high rate of rainfall. La Nina always come after El Nino, but not every El Nino episode will be followed by La Nina.
The name La Nina means "a little girl." A slight opposite to El Nino. |
