El Niño Southern Oscillation (ENSO) Ocean Indicator

Sea Surface Height

The ENSO (El Niño Southern Oscillation) index is based on the altimeter sea level anomalies over the Nino3.4 region in the Pacific ocean. The annual, seasonal cycles and 60-day signal have been filtered out and the sea level trend has been removed. Monthly time series are computed and normalized.

Data and resources

El Niño Southern Oscillation Index

THREDDS

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User guide

Product User Manual (handbook)

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Https server

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Latest map of Sea Level Anomaly

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Latest map of Sea Surface Temperature

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Previous maps of Sea level Anomaly and Sea surface Temperature

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Latest Index of El Niño Southern Oscillation from Sea Level Anomaly

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Latest Index of El Niño Southern Oscillation from Sea Surface Temperature

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Digital Object Identifier (DOI)

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Additional information

Temporal extent	1993-01-01 – ongoing
Date (creation)	2015-11-22
Date (lastUpdate)	2020-01-07
Date (lastUpdate)	2022-04-10
Date (publication)	2025-10-13
Date (lastUpdate)	2025-11-27
Status	onGoing
Update frequency	asNeeded
Metadata language	en
License	None
Source metadata	ISO 19115 XML
Last updated	2026-11-04
Created	2026-11-04
API	package_show