British Sign Language Glossaries of Curriculum Terms

BSL Environmental Science Glossary - El Niño definition

Definition: El Niño is the name of an event that happens every 2 - 7 years, and it affects the wind and ocean currents in the equatorial Pacific Ocean. These currents normally flow from South America to Australia and when this happens nutrients and algae are brought up from the depths of the ocean off the coast of South America, which then supports large numbers of fish upon which the fishing industry in Chile relies upon.

These currents also impact local weather conditions on both sides of the Pacific. The cooler air off South America condenses, and winds then blow it eastward, where it rains on the ocean; on the other side of the world, warmer air draws water from the ocean, where it falls as rain on the land in Australia.

During an El Niño event, these processes are reversed, and the major currents flow in the opposite direction which has a negative impact on the environment. The ocean doesn't bring algae to the surface, which means it supports fewer fish which impacts the fishing industry in Chile.

The heavy rainfall that would ordinarily fall on the ocean now falls on the land, which, because dry, leads to floods. Over in Australia where they typically have moderate rainfall, the rain falls on the ocean - the land becomes dry and here's then an increased risk of fire. In summary, El Niño events reverse the usual flow of wind and ocean currents.