El Niño–La Niña: ENSO Weather Cycle

Category: Geography / Climatology

  • El Niño and La Niña are opposite phases of the El Niño–Southern Oscillation (ENSO).
  • El Niño: Abnormal warming of surface waters in the central and eastern tropical Pacific Ocean.
  • La Niña: Abnormal cooling of these waters.
  • ENSO influences global rainfall, temperature, droughts and extreme weather.
  • ENSO can significantly affect the Indian monsoon, although the relationship is not perfectly deterministic.
  • Southern Oscillation refers to changes in atmospheric pressure between the tropical western and eastern Pacific.

Key Pointer: ENSO → Pacific Ocean → El Niño = warming → La Niña = cooling