Aquarius L3: Sea Surface Density Gridded Data

Aquarius Level 3 data provides sea surface density estimates on a 1-degree spatial grid, averaged over daily, 7-day, monthly, and seasonal timescales. This version 5.0 product is a mission cumulative series derived from Ascending satellite passes, using retrieved salinity and collocated sea surface temperature. The data originates from the NASA-CONAE AQUARIUS/SAC-D satellite, which uses three radiometers and a scatterometer operating at 1.413 GHz and 1.26 GHz, respectively, to measure ocean brightness temperature and backscatter.

Use Cases

• Analyzing seasonal and interannual variability in ocean density based on gridded daily to seasonal averages.
• Studying ocean circulation and water mass formation using TEOS-10 derived surface density estimates.
• Validating and improving ocean models with satellite-observed sea surface density data.
• Investigating the relationship between sea surface salinity, temperature, and density from combined Aquarius and Reynolds OI SST data.

Strengths

• Provides data at four distinct temporal resolutions (daily, 7-day, monthly, seasonal), enabling analysis at multiple timescales.
• Derived from a specific satellite instrument configuration with detailed technical specifications (e.g., three radiometers at 29°, 38°, 46° incidence, 1.413 GHz frequency).
• Based on a defined scientific standard (TEOS-10) and uses a specific ancillary SST product (Reynolds OI 0.25 degree).

Limitations

• Metadata completeness is low: column names, row counts, and exact file sizes are unknown across all platforms.
• Conflicting freshness indicators: one platform lists an update date in 2026, while another lists 2015, suggesting potential metadata errors.
• The dataset is limited to Ascending satellite passes only, excluding data from Descending passes.

Provenance

Source

National Aeronautics and Space Administration (NASA) and Comision Nacional de Actividades Espaciales (CONAE)

Collection Method

Satellite remote sensing from the AQUARIUS/SAC-D spacecraft, using radiometers and a scatterometer.

Time Range

Mission cumulative series (specific date range not provided).

Freshness

Last updated dates conflict: 2026-03-13 (datagov) and 2015-06-07 (nasa_earthdata).

Geography

Global ocean coverage with a 370 km cross-track swath and 1-degree gridded spatial resolution.