El Niño

What Is an El Niño? El Niño is a disruption of the normal ocean-atmosphere system in the tropical Pacific. This disruption occurs when warm waters from the western Pacific flow eastwards as far as the coast of Ecuador and Peru. The warmer, lighter water flows over top of the normally cold ocean current that normally flows northward along the Pacific Coast of South America. This causes instability in the coastal atmosphere, bringing heavy rains to the normally arid coast of Peru.

What Is an El Niño? This causes instability in the coastal atmosphere, bringing heavy rains to the normally arid coast of Peru. The diagrams on the next two slides show Pacific oceanic temperatures under normal conditions and how this pattern changes during El Niño events.

Normal Conditions North America South America SE Asia Warm Water Cold Water

The previous slide shows Pacific Ocean Temperatures - Normal Conditions Warm ocean waters are concentrated in the West Pacific Ocean while cool waters occur against the coast of South America

El Niño Event North South America America SE Asia Warm Water Cold Water

The previous slide shows Pacific Ocean Temperatures - El Niño Event Notice the shift of warm ocean water against the west coast of South America, signalling El Niño conditions

World Impacts Now that we know what exactly an El Niño is, we are going to look at and compare the impacts on the world. Your task is to complete the world impacts activity that will be given to you.

El Niño: World Impacts Use the handout map and information to complete the following questions. 1. Describe how the arrival of El Niño changes the Pacific Ocean from its normal condition. 2. a) What two countries of the Americas are most directly affected by the arrival of El Niño? b) Describe the effects of its arrival on these two countries. c) What other countries and/or regions of the Americas are affected indirectly by its arrival? d) Describe how each is affected. 3. Suggest reasons why research into forecasting the timing and size of future El Niño events has become an international priority.