La Niña
The cool climate phase of the El Niño-Southern Oscillation (ENSO) characterized by abnormally cold sea surface temperatures in the central and eastern tropical Pacific.
Governing formula
ENSO Index: Southern Oscillation Index (SOI) > 0, Sea Surface Temp Anomaly < -0.5 °C
SI unit
Sea Surface Temperature Anomaly (°C)
In depth
Occurs when trade winds strengthen, pushing warm surface water westward toward Australasia and enhancing deep cold water upwelling off the South American coast, triggering global weather anomalies.
Examples in the real world
La Niña conditions causing increased rainfall in Australia and intensified hurricane activity in the Atlantic.