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    • RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V5.0 Validated Dataset

    Metadata Updated: September 18, 2025

    The version 5.0 SMAP-SSS level 3, 8-Day running mean gridded product is based on the fifth release of the validated standard mapped sea surface salinity (SSS) data from the NASA Soil Moisture Active Passive (SMAP) observatory, produced operationally by Remote Sensing Systems (RSS). The major changes in Version 5.0 from Version 4 are: (1) the addition of formal uncertainty estimates to all salinity retrieval products. (2) Sea-ice flagging and sea-ice side-lobe correction based on direct ingestion of AMSR-2 brightness temperature (TB) measurements. This is in contrast to Version 4 and earlier versions in which the sea-ice correction was based on an external sea-ice concentration product. The use of AMSR-2 TB measurements in the SMAP Version 5 products allows for salinity retrievals closer to the sea-ice edge and aids in the detection of large icebergs near the Antarctic. Daily data files for this product are based on SSS averages spanning an 8-day moving time window. SMAP data begins on April 1,2015 and is ongoing. L3 products are global in extent with a default spatial resolution of approximately 70KM. The datasets are gridded at 0.25degree x 0.25degree. Note that while a SSS 40KM variable is also included in the product, for most open ocean applications, the default SSS variable (70KM) is best used as they are significantly less noisy than the 40KM data. The SMAP satellite is in a near-polar orbit at an inclination of 98 degrees and an altitude of 685 km. It has an ascending node time of 6 pm and is sun-synchronous. With its 1000km swath, SMAP achieves global coverage in approximately 3 days, but has an exact orbit repeat cycle of 8 days. On board instruments include a highly sensitive L-band radiometer operating at 1.41GHz and an L-band 1.26GHz radar sensor providing complementary active and passive sensing capabilities. Malfunction of the SMAP scatterometer on 7 July, 2015, has necessitated the use of collocated wind speed, primarily from WindSat, for the surface roughness correction required for the surface salinity retrieval.

    Access & Use Information

    Public: This dataset is intended for public access and use. License: No license information was provided. If this work was prepared by an officer or employee of the United States government as part of that person's official duties it is considered a U.S. Government Work.

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    Dates

    Metadata Created Date April 11, 2025
    Metadata Updated Date September 18, 2025

    Metadata Source

    Harvested from NASA Data.json

    Other Data Resources

    Additional Metadata

    Resource Type Dataset
    Metadata Created Date April 11, 2025
    Metadata Updated Date September 18, 2025
    Publisher RSS;NASA/JPL/PODAAC
    Maintainer
    Identifier 10.5067/SMP50-3SPCS
    Data Last Modified 2025-09-11
    Category Earth Science
    Public Access Level public
    Bureau Code 026:00
    Metadata Context https://project-open-data.cio.gov/v1.1/schema/catalog.jsonld
    Schema Version https://project-open-data.cio.gov/v1.1/schema
    Catalog Describedby https://project-open-data.cio.gov/v1.1/schema/catalog.json
    Harvest Object Id f58c4c32-d349-4e45-b2be-09146a92840e
    Harvest Source Id 58f92550-7a01-4f00-b1b2-8dc953bd598f
    Harvest Source Title NASA Data.json
    Homepage URL https://podaac.jpl.nasa.gov/CitingPODAAC
    Old Spatial "CARTESIAN",{"WestBoundingCoordinate":-180.0,"SouthBoundingCoordinate":-90,"EastBoundingCoordinate":180.0,"NorthBoundingCoordinate":90}
    Program Code 026:000
    Source Datajson Identifier True
    Source Hash 2600b8a2579012ad80f4a0b72036e41e90333bddfcd3bbb8efd73a5f2ab950df
    Source Schema Version 1.1
    Spatial
    Temporal 2015-03-27/2015-03-27

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