El Niño and La Niña

ocean · climate · weather · tropical

Ocean temperature swings. El Niño happens when the tropical Pacific Ocean gets warmer than usual, while La Niña is when it cools down. These two opposite phases flip back and forth in an irregular pattern, like a seesaw that doesn't always tick like a clock.

Wind and water together. ENSO starts with changes in tropical Pacific winds and sea surface temperatures that are locked together, kind of like a dance partner team. When one changes, the other follows along.

Global weather impacts. These ocean changes in the tropical Pacific send ripples of weather effects all around the world to the tropics and subtropics. Even places far away from the Pacific Ocean feel the effects through invisible atmospheric connections.

Tricky to predict. Scientists have a hard time knowing when ENSO will happen next because the pattern is irregular and doesn't follow a strict schedule. It's one of the biggest weather puzzles they study.

Atmospheric partner. The Southern Oscillation is the atmosphere's side of ENSO, with air pressure and wind patterns shifting along with the ocean temperatures.