What is El Niño?

Question

What will be an ideal response?

Answer 1

Answer: El Niño is a circulation change in the eastern tropical Pacific Ocean, from westward flow to eastward flow, that occurs every few years. The Spanish term which literally means "the (male) child," is a reference to the Christ child, because the phenomenon occurs around Christmastime. During an El Niño event, the usual cool flow from South America westward is slowed and sometimes reversed, replaced by a warm-water flow from the central Pacific eastward.

The counterpart of El Niño, in which especially cool waters are found in this region, is known as La Niña, or "the female child." Typically, the ocean current off South America's western coast is cold and nutrient-rich, owing to upwelling (the bringing of cold waters from the ocean depths). During La Niña events, this pattern is reinforced so that additional cold waters are added to the ocean surface. The result may be especially dry conditions in Chile and Peru's coastal deserts.

El Niño events are far reaching because a modification of circulation in one part of the globe may cause circulation patterns to change elsewhere in North and South America and the Pacific region. For example, El Niño events are linked to flooding in the U.S. Southwest, droughts in Australia, and reduced rainfall in India. La Niña events often bring wet weather in south and Southeast Asia, and dry conditions in the southern United States.