The National Centers for Environmental Information (NCEI) satellite oceanography team produces 1.0-degree longitude/latitude Level-3 gridded sea-surface salinity (SSS) 3-day and monthly mean datasets by box averaging satellite observations over the global ocean.

The NCEI Level-3 SSS products are generated directly from the European Space Agency’s (ESA) Soil Moisture – Ocean Salinity (SMOS) mission’s Microwave Imaging Radiometer with Aperture Synthesis (MIRAS) Level-2 swath data (currently V6.22). These products improve the application of satellite SSS products in NOAA by minimizing the data latency to within 24 hours of Level-2 data availability.


Key Description
Platform/Sensor SMOS/Microwave Imaging Radiometer with Aperture Synthesis (MIRAS)
Measurement/Products Earth Science > Oceans > Surface Salinity
DOI n/a
Short Name NCEI-binned-SMOS-L3
Sample Filename 3-day:
Dataset Type Open
Processing Level L3
Spatial Coverage Global
Temporal Coverage 1 May 2010 - current
Resolution 1.0x1.0 longitude/latitude degree
Projection n/a
Latency 24 hours
Swath Width n/a
Sample Frequency n/a
Temporal Repeat 3 days and 1 month
Orbital Period 23-day repeat cycle, 3-day sub-cycle
Orbit altitude 763km, Sun-synchronous, near-polar (6am/pm crossing)
Data Provider Creator: Yongsheng Zhang, NOAA/NCEI/CCOG
Release Place: Silver Spring, MD, USA
Release Date: 2014-Aug-05
Keywords SMOS, ESA, satellite sea-surface salinity
Formats PNG, TIFF, HDF

Data Access

Data are available through the following servers:
Service Resource Locator
with daily or 3-day composite filename ( SM_Dyyyyddd_Map_SATSSS_data_[1day|3days].nc where yyyy = Year and ddd=day of year)
NCEI Archive Resource Locator

[Please acknowledge "NOAA CoastWatch/OceanWatch" when you use data from our site and cite the particular dataset DOI as appropriate.]


  • Barcelona Expert Center (2016). SMOS-BEC Ocean and Land Products Description. BEC-SMOS-0001-PD,Version 1.5. Technical report, BEC.
  • Reagan, J., T. Boyer, J. Antonov, and M. Zweng (2014), Comparison analysis between Aquarius sea surface salinity and World Ocean Database in situ analyzed sea surface salinity, J. Geophys. Res. Oceans, 119, 8122–8140, doi:10.1002/2014JC009961.
  • SMOS-BEC Team 2016: SMOS-BEC Ocean and Land Products Description. BEC-SMOS-0001-PD.pdf , version 1.5
  • SMOS Team, 2014: SMOS L2 OS Input/output data definition. SO-TN-ARG-GS-009. Issue 2, Rev 25, 5 September, 2014. ARGANS.

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