Aquarius V5.0: Monthly Descending Rain-Flagged Sea Surface Salinity

Aquarius Level 3 data provides monthly, gridded sea surface salinity measurements at 1-degree spatial resolution, specifically from satellite descending passes with rain-flagging applied. The dataset originates from the NASA-CONAE AQUARIUS/SAC-D satellite, which used three radiometers and a scatterometer operating at 1.413 GHz and 1.26 GHz, respectively, to measure brightness temperature and ocean backscatter for salinity retrieval. This processed product is designed for analyzing large-scale salinity patterns and their relation to ocean circulation and the freshwater cycle.

Use Cases

• Monitoring large-scale ocean salinity patterns and freshwater input based on gridded 1-degree resolution data.
• Analyzing seasonal and interannual salinity variability using the monthly averaged time series.
• Correcting salinity estimates for surface roughness effects using scatterometer-derived ocean backscatter measurements.
• Studying the impact of rainfall on sea surface salinity through the use of rain-flagged data values.

Strengths

• Provides data from a dedicated satellite mission (AQUARIUS/SAC-D) developed by NASA and CONAE, ensuring a focused instrument design.
• Offers multiple spatial footprints (e.g., 76x94 km to 96x156 km) and a 370 km swath from three radiometers, allowing for cross-track coverage.
• Includes corrections for surface roughness using a dedicated 1.26 GHz scatterometer, which likely improves salinity retrieval accuracy.

Limitations

• Metadata completeness is low; specific column names, row counts, and exact data volumes are not provided in any source.
• Sources conflict on dataset freshness; one platform lists an update date of 2026-03-13 (likely a placeholder), while another lists 2015-06 07, indicating potentially stale metadata.
• The dataset is limited to descending pass retrievals only, omitting data from ascending passes.

Provenance

Source

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

Collection Method

Satellite remote sensing via the Aquarius instrument on the AQUARIUS/SAC-D platform, using L-band radiometers and a scatterometer.

Time Range

Monthly averages (specific start and end dates not provided).

Freshness

2026-03 13 17:26:34.332450 (from datagov, but this date is likely a placeholder or error given the mission timeline; an earlier source lists 2015-06-07)

Geography

Global ocean coverage within the instrument's 370 km cross-track swath.