el nino/el nina

El Niño

A climate pattern where trade winds weaken or reverse, causing warm ocean water to move east toward South America.

Effects of El Niño

Warmer than normal Pacific Ocean waters in the east, more rain and flooding in South America, droughts in Australia and Indonesia, weaker upwelling leading to fewer nutrients and reduced fish populations.

La Niña

A climate pattern where trade winds strengthen, pushing warm water farther west than normal.

Effects of La Niña

Cooler than normal Pacific Ocean waters in the east, heavy rain in Indonesia and Australia, drier conditions in South America, stronger upwelling leading to more nutrients and more fish.

Trade Winds

Steady winds that blow from east to west near the equator, moving from subtropical high pressure zones toward the equator, helping drive ocean currents and playing a key role in El Niño and La Niña.

Prevailing Westerlies

Winds that blow from west to east in the mid-latitudes (30°-60°), moving weather systems across the United States and Europe.

Polar Easterlies

Cold winds that blow from east to west near the poles.

Hadley Cell

A circulation cell that operates from 0° to 30°, where warm air rises at the equator, moves poleward high in the atmosphere, sinks at ~30° latitude creating deserts, and drives trade winds.

Ferrel Cell

A middle-latitude circulation cell (30°-60°) where air flows in the opposite direction of surface winds aloft and influences prevailing westerlies.

Polar Cell

A circulation cell (60°-90°) where cold air sinks at the poles, moves toward 60° latitude, and rises again at subpolar regions.

Coriolis Effect

The apparent deflection of winds and ocean currents due to Earth's rotation, to the right in the Northern Hemisphere and to the left in the Southern Hemisphere.

Upwelling

Process where deep, cold, nutrient-rich water rises to the surface, strong during La Niña, supporting high fish populations.