El Nino-Southern Oscillation (ENSO; commonly referred to as simply El Niño) is a global coupled ocean-atmosphere phenomenon. The Pacific ocean signatures, El Nino and La Nina are important temperature fluctuations in surface waters of the tropical Eastern Pacific Ocean. The name El Niño, from the Spanish for "the little boy", refers to the Christ child, because the phenomenon is usually noticed around Christmas time in the Pacific Ocean off the west coast of South America.

        La Nina, similarly, means "the little girl". These effects were first described in 1923 by Sir Gilbert Thomas Walker from whom the Walker circulation, an important aspect of the Pacific ENSO phenomenon, takes its name.El Niño and La Niña are officially defined as sustained sea surface temperature anomalies of magnitude greater than 0.5°C across the central tropical Pacific Ocean. When the condition is met for a period of less than five months, it is classified as El Niño or La Niña conditions; if the anomaly persists for five months or longer, it is classified as an El Niño or La Niña episode. Historically, it has occurred at irregular intervals of 2-7 years and has usually lasted one or two years.

El Nino - (El Nee-nyo) is the warming of water in the Pacific Ocean.

La Nina - (Lah Nee-Nyah) is the cooling of water in the Pacific Ocean.



Effects of elnino

1.Rain and flooding along the Pacific coast

2.Warm water disrupts food chain of fish, birds, and sea mammals

3.Tornadoes and thunderstorms in southern US

4.Fewer than normal hurricanes in the Atlantic

Effects of lanino

1. Snow and rain on the west coast

2. Unusually cold weather in Alaska

3. Unusually warm weather in the rest of the USA

4. Drought in the southwest

5. Higher than normal number of hurricanes in the Atlantic

Interesting facts

1.El Nino was first discovered hundreds of years ago by fishermen    off the coast of Peru.

2.El Nino means "Little Boy" and was named after the Christ child,    because it usually starts around Christmas.

3.El Nino is officially called ENSO - El Nino Southern Oscillation.

4.La Nina means "Little Girl." It is also called El Viejo, which means    "old man," or an ENSO cold event.

5.La Nina occurs roughly half as often as El Nino

6.El Nino and La Nina are the most powerful phenomenon on the    earth and alter the climate across more than half the planet.

7.El Nino may be caused by underwater volcanoes in the Pacific.