Unit 4.9: El Niño and La Niña

Gyers

large ocean circulation patterns due to global wind

Upwelling Zones

areas of ocean where winds blow warm surface water away from a land mass, drawing up colder, deeper water to replace it

Thermohaline Circulation

connects all of the world’s oceans, mixing salt, nutrients, and temperature throughout

El Niño Southern Oscillation (ENSO)

pattern of shifting atmospheric pressure and ocean currents in the pacific ocean between South America and Australia/Southeast Asia

Oscillates

regularly shifts from El Niño to La Niña conditions off the coast of South America

Normal Winds

Trade winds blow the equator’s water from east to west

El Niño Winds

Trade winds weaken and change direction to blow from west to east

La Niña Winds

Stronger than normal trade winds and blows from east to west

Main Effects of El Niño

suppressed upwelling and less productive fisheries in South America

Main Effects of La Niña

stronger upwelling and better fisheries in South America than usual