SMAP-SSS: Monthly Gridded Sea Surface Salinity from NASA Satellite

From April 1, 2015 to present, this dataset provides monthly averaged, globally gridded sea surface salinity (SSS) measurements from NASA's Soil Moisture Active Passive (SMAP) satellite. It is the validated Version 4.0 Level 3 product, processed by Remote Sensing Systems (RSS) with a one-month latency and includes both 40KM and 70KM resolution SSS fields along with estimated uncertainty. The data is intended for monitoring ocean salinity patterns, studying freshwater fluxes, and validating ocean circulation models.

Use Cases

• Monitoring large-scale ocean salinity patterns and freshwater input from rivers or precipitation based on the monthly 0.25-degree gridded data.
• Studying the relationship between sea surface salinity and ocean circulation or climate indices like ENSO using the continuous time series from 2015 onward.
• Validating and calibrating oceanographic or climate models using the validated standard mapped salinity data and its included uncertainty estimates.
• Comparing the performance of different spatial resolutions (40KM vs. 70KM) for specific regional or coastal applications.
• Analyzing surface roughness corrections for salinity retrieval using collocated wind speed data from sources like WindSat, as referenced following the SMAP scatterometer malfunction.

Strengths

• Provides a continuous, ongoing global time series from April 2015 with one-month latency, supporting near-real-time monitoring.
• Includes both 40KM and 70KM resolution salinity fields within a single product, allowing users to select the optimal resolution for their application.
• Version 4.0 incorporates specific enhancements like an improved land correction table, a revised sea-ice mask, and estimated SSS-uncertainty.
• Data is produced operationally by Remote Sensing Systems (RSS) for NASA, indicating a validated and standardized processing pipeline.

Limitations

• Key metadata such as specific column names, row counts, and exact file sizes are not provided across any platform, complicating initial data assessment.
• The dataset's license is listed as 'other-license-specified' on Data.gov but is 'None' on NASA Earthdata, creating a conflict that requires verification.
• The primary instrument's scatterometer malfunctioned in July 2015, necessitating reliance on collocated wind speed data from other satellites for corrections.

Provenance

Source

National Aeronautics and Space Administration (NASA), processed by Remote Sensing Systems (RSS).

Collection Method

Satellite remote sensing via the SMAP observatory's L-band radiometer (1.41GHz) and radar (1.26GHz), with data mapped to a global 0.25-degree grid.

Time Range

2015-04-01 to present (ongoing)

Freshness

2026-04-09 22:54:28.648011

Geography

Global