El Nino basically refers to the warming of the surface ocean water abnormally, in the eastern tropical pacific and is part of what is called Southern Oscillation. For more details see the link below:
El Nino is Spanish for little boy, but is commonly used to describe the baby Jesus. In more recent times it has also become synonymous with specific weather anomalies in the Pacific Ocean. El Nino-Southern Oscillation (ENSO) is a major temperature fluctuation in the surface waters of the Eastern Pacific Ocean. The name is derived from the fact that the effects of the phenomenon are usually witnessed off of the west coast of South America around Christmas time. El Nino affects Australia by drought, it's warm current of nutrient poor tropical water, replaces the cold, nutrient rich surface water of the Humboldt Current, which supports great populations of food fish. Mostly these effects only last a few weeks, however, in times when they have lasted a few months, more extensive ocean warming occurs causing a great impact to the international fishing markets. In South America, El Nino is associated with warm and very wet summers (December - February), causing major flooding when the event is extreme.
