NASA-SSH: Global Mean Sea Level from Satellite Altimetry

Global mean sea level change is measured in centimeters using satellite radar altimeter data from missions including TOPEX/Poseidon, Jason series, and Sentinel-6. The time series is derived from the NASA-SSH Simple Gridded Sea Surface Height dataset, calculated as an area-weighted average and provided with both raw and 60-day smoothed estimates. This indicator is not adjusted for Glacial Isostatic Adjustment, which expert users must account for in sea level budget studies.

Use Cases

• Tracking global sea level rise trends based on satellite altimetry observations.
• Validating climate models using a standardized, long-term global mean sea level record.
• Studying the sea level budget by combining this indicator with other mass and steric change data.
• Providing a core climate indicator for environmental reports and assessments.

Strengths

• Data is sourced from a continuous, standardized series of reference satellite altimeter missions, ensuring consistency.
• The dataset is regularly updated, with the latest file always named 'NASA_SSH_GMSL_INDICATOR.txt'.
• Provides both a raw and a 60-day smoothed version of the global mean sea level estimate.

Limitations

• Critical metadata such as row count, file size, and specific column names are unavailable across all platforms.
• The estimate is not adjusted for Glacial Isostatic Adjustment, a necessary correction for expert budget analyses.
• The 'last updated' date of 2026-04-09 appears to be a future date, indicating a potential metadata error.

Provenance

Source

National Aeronautics and Space Administration (NASA)

Collection Method

Satellite observations of sea surface height anomaly from radar altimeter missions, processed into a gridded product and area-averaged.

Freshness

Last updated date is listed as 2026-04-09, which is a future date and may be erroneous.

Geography

Global