SMAP-SSS: Near-Real-Time Global Sea Surface Salinity

Remote Sensing Systems' SMAP-SSS Level 2C NRT V5.0 dataset provides validated, near-real-time orbital swath data for global sea surface salinity. Derived from NASA's Soil Moisture Active Passive (SMAP) satellite launched on January 31, 2015, the dataset includes salinity, uncertainty, brightness temperature, wind speed, and ancillary data on a 0.25-degree fixed Earth grid. Data from July 28, 2022, to the present is available with approximately 6-hour latency and a spatial resolution of about 70 km.

Use Cases

• Monitoring large-scale salinity anomalies and freshwater plumes based on the derived SMAP SSS data.
• Assimilating near-real-time salinity observations into ocean forecasting models using the 6-hour latency data.
• Studying the relationship between sea surface salinity and wind-driven processes using the included wind speed and direction data.
• Validating and calibrating other satellite or in-situ salinity measurements using the validated product and its uncertainty estimates.
• Investigating polar ocean processes with the caveat of using data only from sea-ice zone 0, as per the dataset's recommendation.

Strengths

• Provides near-real-time data with a latency of about 6 hours, suitable for operational monitoring.
• Offers global coverage on a consistent 0.25-degree grid with an approximate 70 km resolution.
• Is a validated product sponsored by the NASA Ocean Salinity Science Team, indicating scientific review.
• Includes multiple derived and ancillary variables (SSS, uncertainty, TB, wind) supporting integrated analysis.

Limitations

• Key metadata such as row count, column names, and specific license terms are missing from all platform entries.
• The NRT processing uses ancillary inputs from 2 days prior (e.g., SST, sea-ice mask) and performs no sea-ice contamination correction, limiting use in icy regions.
• The dataset's time range is specified only as 'from July 28, 2022 to present', with no explicit end date provided.

Provenance

Source

Remote Sensing Systems (RSS), sponsored by the NASA Ocean Salinity Science Team.

Collection Method

Derived from NASA's SMAP satellite passive microwave instrument using the NRT SMAP Salinity Retrieval Algorithm.

Time Range

July 28, 2022 to present

Freshness

2026-04-09 22:54:28.636151

Geography

Global