2026-05-22T16:11:51Zhttp://nsidc.org/api/dataset/metadata/oaioai:nsidc.org/SPL4SMGP.0072026-05-15T20:16:14Zcumulusecsretirednasa_nsidc_daac
SPL4SMGP.007SMAP 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. & Bechtold, M.SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data2022-11-17Boulder, Colorado USANASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center7false10.5067/EVKPQZ4AFC4Dhttps://nsidc.org/sites/default/files/documents/user-guide/multi_spl4smau-v007-userguide_1_0.pdfSPL4SMGPTechnical ContactNSIDCUser Servicesnsidc@nsidc.org1-303-492-61991-303-492-2468CIRES, 449 UCBUniversity of ColoradoBoulderCO80309-0449USAEARTH SCIENCELAND SURFACESOILSSOIL MOISTURE/WATER CONTENTROOT ZONE SOIL MOISTURE EARTH SCIENCELAND SURFACESOILSSOIL MOISTURE/WATER CONTENTSURFACE SOIL MOISTURE Climatology/Meteorology/AtmosphereGeoscientific InformationEASE-Grid SM-projectL4SMAP-projectSMAP-project-L4NOT APPLICABLESMAP L-BAND RADIOMETERSMAP L-Band RadiometerGEOS-5Goddard EOS Data Assimilation System-5SMAPSoil Moisture Active and Passive Observatory2015-03-312025-07-03deprecated-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.These data have been retired and are no longer accessible, though a more recent version of these data may be available.These data have been retired and are no longer available for use, though a more recent version of these data may be available. Cite any prior or planned use of these data according to the recommended citation at https://nsidc.org/about/data-use-and-copyright. For more information on the NASA EOSDIS Data Use Policy, see https://earthdata.nasa.gov/earth-observation-data/data-use-policy.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 GBHDF5SMAP 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/EVKPQZ4AFC4D)
* SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Analysis Update (SPL4SMAU, DOI: 10.5067/LWJ6TF5SZRG3)
* SMAP L4 Global 9 km EASE-Grid Surface and Root Zone Soil Moisture Land Model Constants (SPL4SMLM, DOI: 10.5067/KN96XNPZM4EG).
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/documents/user-guide/multi_spl4smau-v007-userguide_1_0.pdfSMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data, Version 7 User GuideCEOS IDN DIFVERSION 9.92022-11-172026-05-15NSIDCVersion SummaryChanges to this version include:
- The Catchment model now includes the PEATCLSM hydrology module for peatlands and uses an updated global map of peatland distribution.
- Revised parameters are used in the L-band radiative transfer model that converts the simulated soil moisture and temperature estimates into Tb predictions for the radiance-based L4_SM analysis. Specifically, the L-band parameters for scattering albedo climatology, soil roughness climatology, and (seasonally-varying) vegetation opacity climatology are obtained from the SPL2SMP_E, Version 5, dual-channel retrieval product (April 2015 - March 2022).
- The brightness temperature scaling parameters in the updated Level-4 soil moisture algorithm are based on seven years of SMAP observations and model simulations (April 2015 - March 2022).
- For peatlands, the EnKF state vector now additionally includes the "catchment deficit" model prognostic variable.
For the full major and minor version history, go to <a href="https://nsidc.org/data/smap/version-history">https://nsidc.org/data/smap/version-history</a>NSIDCMinor Version7031Changes to this version include:
- Discontinues use of IMERG-Late precipitation because of data quality issues following the GPM orbit boost on 7-8 November 2023.2023-11-012025-06-280NSIDCSpatial 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. & Bechtold, M. (2022). <i>SMAP L4 Global 3-hourly 9 km EASE-Grid Surface and Root Zone Soil Moisture Geophysical Data</i>. (SPL4SMGP, Version 7). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. <a href="https://doi.org/10.5067/EVKPQZ4AFC4D">https://doi.org/10.5067/EVKPQZ4AFC4D</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
Permission is hereby granted, free of charge, to any person obtaining a copy
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
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_14311TL3914225088-NSIDC_CPRDNSIDC_CPRD1tool2025-12-15T19:28:44.840ZDOWNLOAD SOFTWAREhttps://www.hdfgroup.org/downloads/hdfview/DistributionURLNSIDC_CPRD_HDFViewDownloadable Tool1HDFViewExplore contents of HDF4 and HDF5 files, including file structure, metadata, and parameter values.https://portal.hdfgroup.org/display/HDFVIEW/HDFView+3.x+User%27s+GuideVIEW RELATED INFORMATIONHDFView 3.X User's GuidePublicationURLDATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgDEVELOPERPUBLISHERHierarchical Data Format, The National Center for Supercomputing Applications, University of Illinois at Urbana-Champaignhttps://www.hdfgroup.org/UI-UC/NCSA/HDFThis is the most current release of this tool. Last updated date is unknown.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0HDF-EOS2HDF-EOS5HDF4HDF5NETCDF-3NETCDF-4ASCIIHDF4HDF5WindowsmacOSLinuxhttps://www.hdfgroup.org/downloads/hdfview/application/vnd.nasa.cmr.umm+jsonfalsecrumlydease_toolsTL3915895804-NSIDC_CPRDNSIDC_CPRD1tool2025-12-16T18:38:49.912ZDOWNLOAD SOFTWAREhttps://github.com/nsidc/easegrids-easeconvDistributionURLNSIDC_CPRD_EASE_ToolsDownloadable Tool0.3 EASE-Grid Data Geolocation ToolsGeolocate and display EASE-Grid and EASE-Grid 2.0 data sets with IDL software.https://nsidc.org/support/faq/does-nsidc-have-tools-geolocating-and-displaying-ease-grid-data-setsVIEW RELATED INFORMATIONDoes NSIDC have tools for geolocating and displaying EASE-Grid data sets?PublicationURLDATA ANALYSISDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgDEVELOPERNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daac/NASA NSIDC DAAC2013-12-18T00:00:00.000ZThis is the most current release of this tool.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0IDLhttps://github.com/nsidc/easegrids-easeconvapplication/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_13636TL3915896594-NSIDC_CPRDNSIDC_CPRD1tool2025-12-16T18:39:31.244ZDOWNLOAD SOFTWAREhttp://hdfeos.org/zoo/index.phpDistributionURLNSIDC_CPRD_HDF-EOS_Tools_Info_CenterDownloadable Tool1HDF-EOS Code ExamplesUse example Python, MATLAB, IDL, or NCL code to import, read, and/or visualize select NSIDC DAAC data products.DATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgAUTHORDEVELOPERPUBLISHERSERVICE PROVIDERHDF-EOS Tools and Information CenterEmaileoshelp@hdfgroup.orgAUTHORDEVELOPERPUBLISHERSERVICE PROVIDERHierarchical Data Format, The National Center for Supercomputing Applications, University of Illinois at Urbana-Champaignhttps://www.hdfgroup.org/UI-UC/NCSA/HDFThis is the most current release of this tool. Last updated date is unknown.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0MATLABPythonIDLhttp://hdfeos.org/zoo/index.phpapplication/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_14328TL3914219125-NSIDC_CPRDNSIDC_CPRD6tool2025-12-15T23:27:51.929ZDOWNLOAD SOFTWAREhttps://www.giss.nasa.gov/tools/panoply/DistributionURLNSIDC_CPRD_PanoplyDownloadable Tool1Panoply Data ViewerVisualize georeferenced arrays in NetCDF, HDF and GRIB formats. Plot data on global or regional maps, choosing from multiple map projections. Overlay continent outlines or masks.
DATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESSTATISTICAL APPLICATIONSDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA ANALYSISDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgAUTHORDEVELOPERPUBLISHERGoddard Institute for Space Studies, Earth Sciences Division, Science and Exploration Directorate, Goddard Space Flight Center, NASAhttps://www.giss.nasa.gov/NASA/GSFC/SED/ESD/GISSAUTHORDEVELOPERSchmunkDr. RobertEmailrobert.b.schmunk@nasa.govPlease send bug reports, feature requests, etc., to Dr. Robert Schmunk. Please note that requests for assistance opening a dataset or interpreting the gridding of the data within will probably require that you provide a copy of the dataset or instructions on where it might be downloaded.This is the most current release of this tool. Last updated date is unknown.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0HDF-EOS2HDF-EOS5HDF4HDF5NETCDF-3NETCDF-4ASCIICSVGIFHDF-EOS2HDF-EOS5HDF4HDF5JPEGKMLNETCDF-3NETCDF-4PNGTIFFWindowsmacOSLinuxhttps://www.giss.nasa.gov/tools/panoply/application/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_13889TL4016626483-NSIDC_CPRDNSIDC_CPRD1tool2026-02-10T21:43:13.884ZGOTO WEB TOOLhttps://cloudsgate2.larc.nasa.gov/cgi-bin/predict/predict.cgiDistributionURLNSIDC_CPRD_NASA_LaRCWeb User Interface1NASA LaRC Satellite Overpass PredictorCalculate past and future satellite overpasses, based on latitude/longitude or map location.DATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC DAAC User ServicesEmailnsidc@nsidc.orgAUTHORDEVELOPERORIGINATORPUBLISHERSERVICE PROVIDERLangley Research Center Distributed Active Archive Center, Science Directorate, Langley Research Center, NASAOtherhttps://asdc.larc.nasa.gov/AUTHORDEVELOPERORIGINATORPUBLISHERSERVICE PROVIDERLangley Research Center Distributed Active Archive Center, Science Directorate, Langley Research Center, NASAhttps://asdc.larc.nasa.gov/NASA/LARC/SD/LARC_DAACSERVICE PROVIDERMinnisPatrick Emailp.minnis@larc.nasa.govSERVICE PROVIDERNguyenLouisEmaill.nguyen@nasa.govSee https://cloudsgate2.larc.nasa.gov/cgi-bin/predict/predict.cgi for more information on the latest version.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0https://cloudsgate2.larc.nasa.gov/cgi-bin/predict/predict.cgiapplication/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_12918TL4019507017-NSIDC_CPRDNSIDC_CPRD1tool2026-02-11T17:41:04.319ZGOTO WEB TOOLhttps://appeears.earthdatacloud.nasa.gov/DistributionURLNSIDC_CPRD_APPEEARSWeb User Interface1AppEEARSExtract point and area samples from geospatial data via spatial, temporal, and/or parameter subsetting. Preview and interact with samples before downloading. The Application for Extracting and Exploring Analysis Ready Samples tool is only available for select NSIDC data products.https://nsidc.org/support/how/extract-point-and-area-data-samples-using-appeearsVIEW RELATED INFORMATIONHow to extract point and area dataPublicationURLDATA VISUALIZATIONDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA ANALYSISDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESGEOGRAPHIC INFORMATION SYSTEMSDATA ANALYSIS AND VISUALIZATIONEARTH SCIENCE SERVICESDATA INTEROPERABILITYDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA REFORMATTINGDATA CUSTOMIZATIONDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESREPROJECTIONSUBSETTING/SUPERSETTINGDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSPATIAL SUBSETTINGSUBSETTING/SUPERSETTINGDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESTEMPORAL SUBSETTINGSUBSETTING/SUPERSETTINGDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESVARIABLE SUBSETTINGSERVICE PROVIDERLP DAAC User ServicesEmailLPDAAC@usgs.govDEVELOPERPUBLISHERSERVICE PROVIDERLand Processes Distributed Active Archive Centerhttps://lpdaac.usgs.gov/LP DAACThis is the most current release of this tool. Last updated date is unknown.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0HDF-EOS2HDF5CSVGEOTIFFHDF-EOS2HDF5JSONhttps://appeears.earthdatacloud.nasa.gov/application/vnd.nasa.cmr.umm+jsonfalsecrumlydmmt_tool_12314TL4019511337-NSIDC_CPRDNSIDC_CPRD1tool2026-02-11T17:42:34.275ZGOTO WEB TOOLhttps://nsidc.org/data/data-access-tool/DistributionURLNSIDC_CPRD_Data_Access_ToolWeb User Interface3.1.0Data Access ToolFilter files before downloading based on date, spatial area, or file name. Choose from various download options, such as Python script. Export bounding boxes as a GeoJSON.https://nsidc.org/support/how/search-filter-and-order-nsidc-dataVIEW RELATED INFORMATIONHow to filter and order from a data set web pagePublicationURLhttps://nsidc.org/data/user-resources/help-center/how-to-use-earthdata-downloadVIEW RELATED INFORMATIONHow to use Earthdata DownloadPublicationURLDATA SEARCHDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESDATA ACCESS/RETRIEVALDATA MANAGEMENT/DATA HANDLINGEARTH SCIENCE SERVICESSERVICE PROVIDERNSIDC User ServicesEmailnsidc@nsidc.orgDEVELOPERPUBLISHERSERVICE PROVIDERNASA National Snow and Ice Data Center Distributed Active Archive Centerhttps://nsidc.org/daac/NASA NSIDC DAAC2025-04-16T00:00:00.000ZChromeFirefoxSafariSee https://github.com/nsidc/data-access-tool-ui/blob/main/CHANGELOG.md for more information on the latest version.https://cdn.earthdata.nasa.gov/umm/tool/v1.0UMM-T1.0https://nsidc.org/data/data-access-tool/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