Aquarius CAP: 7-Day Global Sea Surface Salinity Gridded Data

Aquarius CAP Level 3 V5.0 data provides global sea surface salinity (SSS) measurements at a 1-degree spatial resolution, averaged over 7-day running means. The dataset is derived from the AQUARIUS/SAC-D satellite's combined radiometer and scatterometer instruments using the CAP algorithm, which simultaneously retrieves salinity, wind speed, and direction. This fourth release includes improved geophysical models incorporating sea surface temperature and air-sea stability effects.

Use Cases

• Monitoring large-scale salinity patterns and freshwater fluxes in the global ocean based on 7-day gridded data.
• Validating and improving ocean circulation and climate models using satellite-derived sea surface salinity.
• Studying the relationship between sea surface salinity, temperature, and wind speed using the CAP algorithm's simultaneous retrievals.
• Analyzing temporal trends in ocean salinity at a 1-degree spatial resolution for climate change research.

Strengths

• Data is produced by NASA's Jet Propulsion Laboratory (JPL), a leading institution in remote sensing.
• Algorithm utilizes combined active (scatterometer) and passive (radiometer) measurements for simultaneous retrieval of multiple geophysical variables.
• Version 5.0 includes specific improvements to Geophysical Model Functions and uses the CMC sea surface temperature product.

Limitations

• Critical metadata such as row count, file size, and specific column names are unavailable across all platforms.
• Conflicting 'last updated' dates exist between sources (2015 vs. 2026), casting doubt on data freshness and maintenance.
• The license is vaguely specified as 'other-license-specified', requiring further investigation for reuse.

Provenance

Source

NASA Jet Propulsion Laboratory (JPL), from the AQUARIUS/SAC-D satellite (NASA/CONAE collaboration).

Collection Method

Satellite remote sensing using the Combined Active Passive (CAP) algorithm on radiometer (1.413 GHz) and scatterometer (1.26 GHz) data.

Time Range

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Freshness

2026-03-13 (from datagov), but conflicts with a 2015 date from nasa_earthdata.

Geography

Global ocean coverage with a 370 km cross-track swath from the satellite instrument.