Pacific Ocean

El Niño Southern Oscillation - ENSO

Better knowledge of ocean circulation is enabling us to better understand and predict climate, especially natural catastrophes such as El Niño. This phenomenon, caused by anomalous warm water arrivals on the coast of Peru, brings severe weather patterns, such as drought, flooding, and cyclones. It is now possible to predict El Niño from ocean data.

ENSO 1997

Monthly mean of Sea Level Anomalies (in cm) over the Ocean Pacific as computed for the El Niño indicator (annual and seasonnal cycles removed). Download enlarged images from the Gallery. Credits CNES/EU Copernicus Marine Service.

  • What is El Niño/La Niña ?

    Explanation of the phenomenon : normal pattern, when El Niño awakens and La Niña pattern.

  • Chronology

    Altimetric satellites have continuously tracked related ocean-climate changes in the Pacific Ocean, such as warm El Niño (1992, 1994, 1997, 2002, 2004, 2006 and 2009) and cold La Niña episodes (1995,1996,1998,1999 and 2007).

  • Forecasting El Niño

    Since the 1990s, an in situ observation system has been set up in the Pacific and new satellites have continuously scanned the global ocean. Though we cannot avoid El Niño's whims, we can predict and mitigate its impacts.

  • Impacts around the world

    Warm El Niños and cold La Niñas follow each other against the backdrop of the ocean seasons. These surface temperature and sea level anomalies in the intertropical Pacific affect climate worldwide.

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