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RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V6.0 Validated Dataset. DOI:

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RSS SMAP Level 3 Sea Surface Salinity Standard Mapped Image 8-Day Running Mean V3.0 40km Validated Dataset

DescriptionThe version 3.0 SMAP-SSS level 3, 8-Day running mean gridded product is based on the third 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). Enhancements with this release include: Use of the version 4 L1B SMAP RFI filtered antenna temperatures; Implementation of the geophysical model function from Aquarius version 5 adapted to SMAP; Use of the near real time CCMP wind speed and direction data as ancillary input, and inclusion of IMERG rain rate for the atmospheric liquid cloud water correction and rain flagging; Improved computation of antenna weighted land fraction gland and enhanced correction for land radiation intrusion from antenna sidelobes; Improved SMAP mesh antenna emissivity settings with empirical adjustments to the JPL thermal model. Users should note that significant degradation in the performance is observed if the gain weighted land fraction gland exceeds 1 percent. Because of that, observations with gland greater than 0.8 percent are not used in the Level 3 processing. 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 and gridded at 0.25degree x 0.25degree with an approximate spatial feature resolution of 40km. Note that for most open ocean applications, the related 70-km V3.0 products are the best to use as they have significantly lower noise than the 40-km products. 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.
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Citation is critically important for dataset documentation and discovery. Please cite the data as follows, and cite the reference papers when it is appropriate.
Citation Remote Sensing Systems (RSS). 2018. SMAP Sea Surface Salinity Products. Ver. 3.0. PO.DAAC, CA, USA. Dataset accessed [YYYY-MM-DD] at

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For more information see Data Citations and Acknowledgments.

Journal Reference Meissner, T. and F. J. Wentz, 2018: Remote Sensing Sytems SMAP Ocean Surface Salinities, Version 3.0 validated release. Remote Sensing Systems, Santa Rosa, CA, USA.