SMAP Level 2 and Level 3 soil moisture products will version up in mid-October of 2021. At that time additional products may also be reprocessed. Should you have questions, please contact user services at nsidc@nsidc.org. Thank you for your patience while we update the data.
Data Set ID: 
SPL2SMP

SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 7

This Level-2 (L2) soil moisture product provides estimates of global land surface conditions retrieved by the Soil Moisture Active Passive (SMAP) passive microwave radiometer during 6:00 a.m. descending and 6:00 p.m. ascending half-orbit passes. SMAP L-band brightness temperatures are resampled to an Earth-fixed, global, cylindrical 36 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) [and made available as the SPL1CTB product], and the gridded brightness temperatures are then used to derive gridded soil moisture data.

This is the most recent version of these data.

Version Summary: 

Changes to this version include:
- Improved calibration methodology was applied to the Level-1B radiometer brightness temperatures.
- Improved land surface model outputs from the NASA Global Modeling and Assimilation Office (GMAO) were used to estimate the effective soil temperature used as input to Level-2 soil moisture geophysical inversion. This effective soil temperature is not to be confused with the physical soil temperature at a given depth (Choudhury et al., 1982).
- Improved retrieval performance of DCA (formerly known as MDCA or "the option 3" option algorithm in previous releases). DCA retrieves both soil moisture and vegetation optical depth (VOD or tau).
- Use of a new global 250-meter resolution soils database called SoilGrid250m available at https://openlandmap.org. Work is underway to address limited spatial anomalies of these soil property estimates at high latitudes over areas rich in organic soils.
- Data quality flags were updated and corrected where faulty.
- The baseline algorithm (SCA-V) remains unchanged.

For the full major and minor version history, go to https://nsidc.org/data/smap/data_versions.

COMPREHENSIVE Level of Service

Data: Data integrity and usability verified; data customization services available for select data

Documentation: Key metadata and comprehensive user guide available

User Support: Assistance with data access and usage; guidance on use of data in tools and data customization services

See All Level of Service Details

Parameter(s):
  • MICROWAVE > BRIGHTNESS TEMPERATURE
  • SOILS > SOIL MOISTURE/WATER CONTENT > SURFACE SOIL MOISTURE
Data Format(s):
  • HDF5
Spatial Coverage:
N: 85.044, 
S: -85.044, 
E: 180, 
W: -180
Platform(s):SMAP
Spatial Resolution:
  • 36 km x 36 km
Sensor(s):SMAP L-BAND RADIOMETER
Temporal Coverage:
  • 31 March 2015
Version(s):V7
Temporal Resolution49 minuteMetadata XML:View Metadata Record
Data Contributor(s):O'Neill, P. E., S. Chan, E. G. Njoku, T. Jackson, R. Bindlish, and J. Chaubell.

Geographic Coverage

Other Access Options

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As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

O'Neill, P. E., S. Chan, E. G. Njoku, T. Jackson, R. Bindlish, and J. Chaubell. 2020. SMAP L2 Radiometer Half-Orbit 36 km EASE-Grid Soil Moisture, Version 7. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: https://doi.org/10.5067/F1TZ0CBN1F5N. [Date Accessed].

Literature Citation

As a condition of using these data, we request that you acknowledge the author(s) of this data set by referencing the following peer-reviewed publication.

  • Chan, S., R. Bindlish, P. E. O'Neill, E. G. Njoku, T. Jackson, A. Colliander, F. Chen, M. Burgin, S. Dunbar, J. R. Piepmeier, S. Yueh, D. Entekhabi, M. Cosh, T. Caldwell, J. Walker, A. Berg, T. Rowlandson, A. Pacheco, H. McNairn, M. Thibeault, J. Martinez-Fernandez, A. González-Zamora, D. Bosch, P. Starks, D. Goodrich, J. Prueger, M. Palecki, E. E. Small, M. Zreda, J. Calvet, W. T. Crow, and Y. Kerr. 2016. Assessment of the SMAP passive soil moisture product, IEEE Transactions on Geoscience and Remote Sensing. 54. 4994–5007. https://doi.org/10.1109/TGRS.2016.2561938

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How To

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FAQ

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