Sea surface salinity (SSS) data is produced by NASA's Soil Moisture Active Passive (SMAP) observatory using the JPL Combined Active-Passive retrieval algorithm. The dataset provides global 0.25-degree gridded 8-day running mean averages, with data collection starting on April 1, 2015 and ongoing. It is produced by the POCLOUD organization.
Use Cases
- Analyzing temporal trends in sea surface salinity (SSS) using the 8-day running mean values across global ocean basins.
- Validating ocean circulation models by comparing simulated salinity against the gridded SSS and ancillary HYCOM surface salinity data.
- Investigating the impact of surface wind speed on salinity retrievals by correlating SSS with the associated SMAP wind speed variable.
- Assessing retrieval uncertainty in different regions by analyzing the SSS uncertainty variable provided with each data point.
- Studying polar ocean processes by filtering data using the ancillary ice concentration variable.
Strengths
- Global spatial coverage at a 0.25-degree grid resolution, providing consistent worldwide data.
- Continuous temporal coverage from April 2015 onward, supporting long-term trend analysis.
- Data incorporates enhanced calibration for brightness temperatures, reducing biases between satellite passes.
Limitations
- Spatial resolution is approximately 60km, which may be too coarse for studying fine-scale coastal or eddy processes.
- The primary radar (scatterometer) failed in July 2015, requiring use of collocated wind speed data for corrections, which may introduce methodological dependencies.
- Data has a 7-day latency in processing and availability, limiting real-time applications.
Provenance
- Source
- NASA Soil Moisture Active Passive (SMAP) observatory, processed by the Jet Propulsion Laboratory (JPL).
- Collection Method
- Satellite remote sensing using an L-band radiometer, with data processed via the JPL Combined Active-Passive (CAP) retrieval algorithm.
- Time Range
- April 1, III - present.
- Freshness
- Ongoing data collection with a 7-day processing latency.
- Geography
- Global.