2026-05-14T10:20:54Zhttp://nsidc.org/api/dataset/metadata/oaioai:nsidc.org/SPL4SMGP.0042026-05-05T20:15:56Zcumulusecsretirednasa_nsidc_daac
SPL4SMGP.004SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical DataReichle, R., De Lannoy, G., Koster, R. D., Crow, W. T., Kimball, J. S. & Liu, Q.SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data2018-06-14Boulder, Colorado USANASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center4false10.5067/KPJNN2GI1DQRhttps://nsidc.org/sites/default/files/multi_spl4smau-v004-userguide_2.pdfSPL4SMGPTechnical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468CIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAEARTH SCIENCELAND SURFACESOILSSOIL MOISTURE/WATER CONTENTSURFACE SOIL MOISTURE Climatology/Meteorology/AtmosphereGeoscientific InformationEASE-Grid SM-projectSMAP-projectSMAP-project-L4SMAP L-BAND RADIOMETERSMAP L-Band RadiometerSMAPSoil Moisture Active and Passive Observatory2015-03-312020-08-27deprecated-85.04485.044-180180GEOGRAPHIC REGIONGLOBAL LAND9 km9 km3 hourSMAP products provide multiple means to assess quality. Uncertainty measures and file-level metadata that provide quality information are provided within each product. For details, refer to the Data Fields and Metadata Fields documents.
Each HDF5 file contains file-level metadata. A separate metadata file with an .xml file extension is also delivered to NSIDC DAAC with the HDF5 file; it contains essentially the same information as the file-level metadata. In addition, a Quality Assessment (QA) file with a .qa file extension is provided for every HDF5 file. QA files contain spatial statistics across the SMAP Level-4 soil moisture products, such as the global minimum, mean, and maximum of each data field.
Level-4 surface and root zone soil moisture estimates are validated to a Root Mean Square Error (RMSE) requirement of 0.04 m3 m-3 after removal of the long-term mean bias. This accuracy requirement is identical to Level-2 soil moisture product validation and excludes regions with snow and ice cover, frozen ground, mountainous topography, open water, urban areas, and vegetation with water content greater than 5 kg m-2. Research outputs (not validated) include the surface meteorological forcing fields, land surface fluxes, soil temperature and snow states, runoff, and error estimates that are derived from the ensemble.As a condition of using these data, you must cite the use of this data set using the recommended citation. For more information, see the Use and Copyright page at https://nsidc.org/about/use_copyright.html.These data are offered free of charge. You may use these data freely, provided that you cite NSIDC DAAC as the source, and provide an acknowledgment in any published papers.EnglishNASA/GSFC/SED/ESD/GMAONASA NSIDC DAACNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daacData Center ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-6199National Snow and Ice Data CenterCIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAHTTPS1.1 GBHDF5Brodzik, M. J., B. Billingsley, T. Haran, B. Raup, and M. H. Savoie. 2012. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets. ISPRS Int. J. Geo-Inf. 1(1):32-45. http://dx.doi.org/10.3390/ijgi1010032.
Brodzik, M. J., B. Billingsley, T. Haran, B. Raup, and M. H. Savoie. 2014. Correction: Brodzik, M. J. et al. EASE-Grid 2.0: Incremental but Significant Improvements for Earth-Gridded Data Sets. ISPRS Int. J. Geo-Inf 2012. 1(1):32-45 ISPRS Int. J. Geo-Inf. 3(3):1154-1156. http://dx.doi.org/10.3390/ijgi3031154.
Crow, W. T., F. Chen, R. H. Reichle, and Q. Liu. 2017. L Band Microwave Remote Sensing and Land Data Assimilation Improve the Representation of Prestorm Soil Moisture Conditions for Hydrologic Forecasting. Geophysical Research Letters. In press. http://dx.doi.org/10.1002/2017GL073642.
De Lannoy, G. J. M., and R. H. Reichle. 2016. Assimilation of SMOS Brightness Temperatures or Soil Moisture Retrievals into a Land Surface Model. Hydrology and Earth System Sciences. 20:4895-4911. Hydrol. Earth Syst. Sci., 20:4895-4911. http://dx.doi.org/10.5194/hess-20-4895-2016.
De Lannoy, G. J. M., and R. H. Reichle. 2016. Global Assimilation of Multiangle and Multipolarization SMOS Brightness Temperature Observations into the GEOS-5 Catchment Land Surface Model for Soil Moisture Estimation. Journal of Hydrometeorology, 17:669-691. http://dx.doi.org/10.1175/JHM-D-15-0037.1.
Entekhabi, D. et al. 2014. SMAP Handbook–Soil Moisture Active Passive: Mapping Soil Moisture and Freeze/Thaw from Space. Pasadena, CA USA: SMAP Project, JPL CL#14-2285, Jet Propulsion Laboratory.
Entekhabi, D., R. H. Reichle, R. D. Koster, and W. T. Crow. 2010. Performance Metrics for Soil Moisture Retrievals and Application Requirements. Journal of Hydrometeorology. 11:832–840. http://dx.doi.org/10.1175/2010JHM1223.1.
Reichle, R. H., and Q. Liu. 2014a. Observation-Corrected Precipitation Estimates in GEOS-5. SMAP Project, Global Modeling and Assimilation Office, Goddard Space Flight Center, Greenbelt, MD, USA. NASA/TM–2014-104606, Vol. 35. (https://gmao.gsfc.nasa.gov/pubs/docs/Reichle734.pdf, 495 KB).
Reichle, R. et al. 2014b. SMAP Algorithm Theoretical Basis Document: L4 Surface and Root-Zone Soil Moisture Product. SMAP Project, JPL D-66483, Jet Propulsion Laboratory, Pasadena, CA, USA. (272_L4_SM_RevA_web.pdf, 1.4 MB)
Reichle, R. et al. 2015a. Soil Moisture Active Passive (SMAP) Mission Level 4 Surface and Root Zone Soil Moisture (L4_SM) Product Specification Document. SMAP Project, Global Modeling and Assimilation Office, Goddard Space Flight Center, Greenbelt, MD, USA. GMAO Office Note No. 10 (Version 1.4), 90 pp. (Reichle789.pdf, 724 KB)
Reichle, R., G. De Lannoy, Q. Liu, A. Colliander, A. Conaty, T. Jackson, J. Kimball, and R. Koster. 2015b. Soil Moisture Active Passive (SMAP) Project Assessment Report for the Beta- Release L4_SM Data Product. Global Modeling and Assimilation Office, Goddard Space Flight Center, Greenbelt, MD, USA. NASA/TM-2015-104606, Vol. 40. 72 pp. (Reichle788.pdf, 5.6 MB).
Reichle, R., G. J. M. De Lannoy, Q. Liu, J. V. Ardizzone, F. Chen, A. Colliander, A. Conaty, W. Crow, T. Jackson, J. Kimball, R. D. Koster, and E. Brent Smith. 2016. Soil Moisture Active Passive Mission L4_SM Data Product Assessment (Version 2 Validated Release). GMAO Office Note No. 12 (Version 1.0), 55 pp, NASA Goddard Space Flight Center, Greenbelt, MD, USA. (Reichle851.pdf, 3.2 MB).
Reichle, R. H., et al. 2017. Assessment of the SMAP Level-4 Surface and Root-Zone Soil Moisture Product Using In Situ Measurements. Journal of Hydrometeorology. Submitted.SMAP Level-4 (L4) surface and root zone soil moisture data are provided in three products:
* SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data (SPL4SMGP, DOI: 10.5067/KPJNN2GI1DQR)
* SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update (SPL4SMAU, DOI: 10.5067/60HB8VIP2T8W)
* SMAP L4 Global 9 km EASE-Grid Surface and Root Zone Soil Moisture Land Model Constants (SPL4SMLM, DOI: 10.5067/KGLC3UH4TMAQ).
For each product, SMAP L-band brightness temperature data from descending and ascending half-orbit satellite passes (approximately 6:00 a.m. and 6:00 p.m. local solar time, respectively) are assimilated into a land surface model that is gridded using an Earth-fixed, global cylindrical 9 km Equal-Area Scalable Earth Grid, Version 2.0 (EASE-Grid 2.0) projection.VIEW RELATED INFORMATIONhttps://nsidc.org/sites/default/files/multi_spl4smau-v004-userguide_2.pdfSMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data, Version 4 User GuideGET DATAhttps://nsidc.org/data/data-access-tool/SPL4SMGP/versions/4/Data Access ToolCEOS IDN DIFVERSION 9.92018-06-142026-05-05NSIDCVersion SummaryChanges to this version include revisions to the land surface modeling system, revisions to the parameters and parameterizations of the surface energy balance and the snow depletion curve, added x and y coordinate variables as well as an EASE-Grid 2.0 projection grid mapping variable, and bug fixes.
For the full major and minor version history, go to <a href="https://nsidc.org/data/smap/data_versions">https://nsidc.org/data/smap/data_versions</a>.NSIDCMinor VersionVv4010Changed with Version 4 update. 2015-06-052018-10-121Vv4011Reprocessed data from 2015-03-31 through 2018-06-04 using OASIS Level-1C data as input. OASIS data are processed by the Science Data System (SDS) on the Offline Algorithm Staging and Input System (OASIS).2015-03-312018-06-042Vv4030Reprocessed data from 2015-03-31 using published Version 4 Radiometer
Brightness Temperatures (SPL1CTB) as input.2015-03-312020-08-263NSIDCSpatial Reference SystemsEPSG:6933WGS 84 / NSIDC EASE-Grid 2.0 GlobalNSIDCLevel of ServiceNo Data AccessNSIDCFull Dataset CitationReichle, R., De Lannoy, G., Koster, R. D., Crow, W. T., Kimball, J. S. & Liu, Q. (2018). <i>SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data</i>. (SPL4SMGP, Version 4). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. <a href="https://doi.org/10.5067/KPJNN2GI1DQR">https://doi.org/10.5067/KPJNN2GI1DQR</a>. [<i><describe subset used if applicable></i>].NSIDCRetiredtrueNSIDCRelated Toolsapplication/vnd.nasa.cmr.umm+jsonfalsembeigmmt_tool_50907TL3010466318-NSIDC_CPRDNSIDC_CPRD4tool2024-05-28T17:29:12.271Zhttps://zenodo.org/badge/latestdoi/399867529DOWNLOAD SOFTWAREhttps://earthaccess.readthedocs.io/en/latest/DistributionURLNSIDC_CPRD_EARTHACCESSDownloadable Tool0.9.0earthaccessearthaccess is a python library to search and access NASA Earth science data with just a few lines of code.https://github.com/nsidc/earthaccessVIEW RELATED INFORMATIONGitHub RepositoryPublicationURLDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESPUBLISHERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgPUBLISHERNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daac/NASA NSIDC DAACPUBLISHERNational Snow and Ice Data Centerhttp://nsidc.orgNSIDCDEVELOPERAlaska Satellite Facilityhttps://www.asf.alaska.edu/ASFDEVELOPERInstitute for the Study of Earth, Oceans, and Space, University of New Hampshirehttp://www.eos.unh.edu/UNH/EOSDEVELOPERAtmospheric Science Data Center, Science Directorate, Langley Research Center, NASAhttps://asdc.larc.nasa.gov/NASA/LARC/SD/ASDCMIT License
Copyright (c) 2021 Luis Lopez
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SOFTWARE.2024-02-29T00:00:00.000ZAs a condition of use, we request that you properly cite the earthaccess library to acknowledge the creators. Formal citations also make it easier for us to track the use and impact of our data and tools, and helps us report data distribution activity and tool usage metrics to funding agencies.
If you have used earthaccess in your research, please cite as:
Barrett, A., Battisto, C., Bourbeau, J., Fisher, M., Kaufman, D., Kennedy, J., Lopez, L., Lowndes, J., Scheick, J., & Steiker, A. (2024). earthaccess (Version 0.9.0) [Computer software]. https://doi.org/10.5281/zenodo.8365009
See https://github.com/nsidc/earthaccess/releases for more information on the latest version.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0Python3.8 or higherhttps://earthaccess.readthedocs.io/en/latest/application/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_12821TL4019517520-NSIDC_CPRDNSIDC_CPRD1tool2026-02-11T17:45:02.724ZGOTO WEB TOOLhttps://search.earthdata.nasa.gov/searchDistributionURLNSIDC_CPRD_NASA_Earthdata_SearchWeb User Interface1NASA Earthdata SearchSearch and order data from all NASA DAACs using spatial and temporal filters in a map interface. Reformatting, reprojecting, and subsetting options are available for some data sets.https://nsidc.org/support/how/search-order-and-customize-nsidc-daac-data-nasa-earthdata-searchVIEW RELATED INFORMATIONHow to search, order, and customize data with NASA Earthdata SearchPublicationURLDATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgSERVICE PROVIDEREarthdata Service DeskEmailsupport@earthdata.nasa.govAUTHORDEVELOPERORIGINATORPUBLISHERMaintenance and Development, Earth Observing System Data and Information System, Earth Observing System,Goddard Space Flight Center, NASAhttp://newsroom.gsfc.nasa.gov/NASA/GSFC/EOS/EOSDIS/EMDChromeFirefoxSafariThis is the most current release of this tool.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0https://search.earthdata.nasa.gov/search