Aquarius CAP V5.0: Monthly Global Sea Surface Salinity from Satellite

Aquarius CAP V5.0 Level 3 data provides monthly, 1-degree gridded maps of global sea surface salinity, derived from a unique combined active-passive algorithm using both radiometer and scatterometer instruments. This fourth algorithm release incorporates improved geophysical models with 4th order harmonics and uses Canadian Meteorological Center sea surface temperature data. The dataset originates from the NASA-CONAE AQUARIUS/SAC-D satellite, which featured three radiometers at 1.413 GHz and a scatterometer at 1.26 GHz across a 370 km swath.

Use Cases

• Monitoring global ocean freshwater fluxes and salinity trends based on monthly 1-degree gridded data.
• Validating and improving ocean circulation models using satellite-derived sea surface salinity maps.
• Studying air-sea interface stability effects on salinity retrievals using the updated Geophysical Model Functions.
• Analyzing the correlation between sea surface temperature (from CMC data) and salinity from the combined CAP algorithm.

Strengths

• Algorithm utilizes a combined active-passive (CAP) method, simultaneously retrieving salinity and wind from radiometer and scatterometer data to minimize model-observation differences.
• Provides data at a consistent 1-degree spatial resolution averaged over monthly timescales, suitable for large-scale climate studies.
• Represents the fourth release (V5.0) with documented improvements, including updated geophysical models and a new ancillary SST data source.

Limitations

• Key metadata conflicts exist: last update dates differ significantly between platforms (2015 vs. 2026), and no column names or row counts are provided.
• The spatial resolution (1 degree) is coarse, limiting analysis of mesoscale or coastal salinity features.
• Documentation on data formats (JPEG, PDF, ISO, BIN) is inconsistent and lacks clear guidance for scientific use.

Provenance

Source

Jet Propulsion Laboratory (JPL), developed for the NASA and CONAE AQUARIUS/SAC-D satellite mission.

Collection Method

Satellite remote sensing via the Aquarius instrument's three-beam push-broom radiometer and scatterometer.

Time Range

Monthly averages (specific date range not provided in input).

Freshness

2026-03-13 17:34:59.405411

Geography

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