<?xml version="1.0" encoding="UTF-8"?><OAI-PMH xmlns="http://www.openarchives.org/OAI/2.0/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/ http://www.openarchives.org/OAI/2.0/OAI-PMH.xsd"><responseDate>2026-05-23T09:31:45Z</responseDate><request identifier="NSIDC-0024.001" metadataPrefix="dif" verb="GetRecord">http://nsidc.org/api/dataset/metadata/oai</request><GetRecord><record><header><identifier>oai:nsidc.org/NSIDC-0024.001</identifier><datestamp>2026-03-03T21:04:33Z</datestamp><setSpec>v0_daac</setSpec><setSpec>v0_all</setSpec><setSpec>retired</setSpec><setSpec>nasa_nsidc_daac</setSpec></header><metadata>
<DIF xmlns="http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/ http://gcmd.gsfc.nasa.gov/Aboutus/xml/dif/dif_v9.7.1.xsd"><Entry_ID>NSIDC-0024.001</Entry_ID><Entry_Title>Nimbus-7 SMMR Derived Monthly Global Snow Cover and Snow Depth</Entry_Title><Data_Set_Citation><Dataset_Creator>Chang, A. T.</Dataset_Creator><Dataset_Title>Nimbus-7 SMMR Derived Monthly Global Snow Cover and Snow Depth</Dataset_Title><Dataset_Release_Date>2003-06-11</Dataset_Release_Date><Dataset_Release_Place>Boulder, Colorado USA</Dataset_Release_Place><Dataset_Publisher>NASA NSIDC DAAC: NASA National Snow and Ice Data Center Distributed Active Archive Center</Dataset_Publisher><Version>1</Version><Other_Citation_Details><Invert_Citation_Order>false</Invert_Citation_Order></Other_Citation_Details><Dataset_DOI>10.5067/5C8R32YS4VHU</Dataset_DOI><Online_Resource>https://nsidc.org/sites/default/files/nsidc0024_pdf.pdf</Online_Resource><Dataset_Series_Name>NSIDC-0024</Dataset_Series_Name></Data_Set_Citation><Personnel><Role>Investigator</Role><First_Name>Alfred</First_Name><Middle_Name>T.C.</Middle_Name><Last_Name>Chang</Last_Name><Email>achang@rainfall.gsfc.nasa.gov</Email><Phone>1-301-614-5766</Phone><Fax>1-301-614-5808</Fax><Contact_Address><Address>Laboratory for Hydrospheric Processes</Address><Address>Code 974.0</Address><Address>NASA Goddard Space Flight Center</Address><City>Greenbelt</City><Province_or_State>MD</Province_or_State><Postal_Code>20771</Postal_Code><Country/></Contact_Address></Personnel><Personnel><Role>Technical Contact</Role><First_Name>NSIDC</First_Name><Last_Name>User Services</Last_Name><Email>nsidc@nsidc.org</Email><Phone>1-303-492-6199</Phone><Fax>1-303-492-2468</Fax><Contact_Address><Address>CIRES, 449 UCB</Address><Address>University of Colorado</Address><City>Boulder</City><Province_or_State>CO</Province_or_State><Postal_Code>80309-0449</Postal_Code><Country>USA</Country></Contact_Address></Personnel><Parameters><Category>EARTH SCIENCE</Category><Topic>CRYOSPHERE</Topic><Term>SNOW/ICE</Term><Variable_Level_1>SNOW COVER</Variable_Level_1><Variable_Level_2> </Variable_Level_2><Variable_Level_3> </Variable_Level_3><Detailed_Variable> </Detailed_Variable></Parameters><Parameters><Category>EARTH SCIENCE</Category><Topic>TERRESTRIAL HYDROSPHERE</Topic><Term>SNOW/ICE</Term><Variable_Level_1>SNOW COVER</Variable_Level_1><Variable_Level_2> </Variable_Level_2><Variable_Level_3> </Variable_Level_3><Detailed_Variable> </Detailed_Variable></Parameters><Parameters><Category>EARTH SCIENCE</Category><Topic>CRYOSPHERE</Topic><Term>SNOW/ICE</Term><Variable_Level_1>SNOW DEPTH</Variable_Level_1><Variable_Level_2> </Variable_Level_2><Variable_Level_3> </Variable_Level_3><Detailed_Variable> </Detailed_Variable></Parameters><Parameters><Category>EARTH SCIENCE</Category><Topic>TERRESTRIAL HYDROSPHERE</Topic><Term>SNOW/ICE</Term><Variable_Level_1>SNOW DEPTH</Variable_Level_1><Variable_Level_2> </Variable_Level_2><Variable_Level_3> </Variable_Level_3><Detailed_Variable> </Detailed_Variable></Parameters><Keyword>Cryosphere</Keyword><Keyword>EOSDIS</Keyword><Keyword>Snow</Keyword><Keyword>Snow Cover</Keyword><Keyword>Snow Depth</Keyword><Sensor_Name><Short_Name>SMMR</Short_Name><Long_Name>Scanning Multichannel Microwave Radiometer</Long_Name></Sensor_Name><Source_Name><Short_Name>Nimbus-7</Short_Name><Long_Name>Nimbus-7</Long_Name></Source_Name><Temporal_Coverage><Start_Date>1978-11-01</Start_Date><Stop_Date>1987-08-31</Stop_Date></Temporal_Coverage><Data_Set_Progress>deprecated</Data_Set_Progress><Spatial_Coverage><Southernmost_Latitude>-85</Southernmost_Latitude><Northernmost_Latitude>0</Northernmost_Latitude><Westernmost_Longitude>-180</Westernmost_Longitude><Easternmost_Longitude>180</Easternmost_Longitude></Spatial_Coverage><Spatial_Coverage><Southernmost_Latitude>0</Southernmost_Latitude><Northernmost_Latitude>85</Northernmost_Latitude><Westernmost_Longitude>-180</Westernmost_Longitude><Easternmost_Longitude>180</Easternmost_Longitude></Spatial_Coverage><Location><Location_Category>CONTINENT</Location_Category><Location_Type>SOUTH AMERICA</Location_Type></Location><Location><Location_Category>GEOGRAPHIC REGION</Location_Category><Location_Type>POLAR</Location_Type></Location><Location><Location_Category>CONTINENT</Location_Category><Location_Type>NORTH AMERICA</Location_Type></Location><Location><Location_Category>GEOGRAPHIC REGION</Location_Category><Location_Type>GLOBAL</Location_Type></Location><Location><Location_Category>CONTINENT</Location_Category><Location_Type>EUROPE</Location_Type></Location><Location><Location_Category>CONTINENT</Location_Category><Location_Type>ASIA</Location_Type></Location><Location><Location_Category>CONTINENT</Location_Category><Location_Type>ANTARCTICA</Location_Type></Location><Data_Set_Language>English</Data_Set_Language><Data_Center><Data_Center_Name><Short_Name>NASA NSIDC DAAC</Short_Name><Long_Name>NASA National Snow and Ice Data Center Distributed Active Archive Center</Long_Name></Data_Center_Name><Data_Center_URL>https://nsidc.org/daac</Data_Center_URL><Personnel><Role>Data Center Contact</Role><First_Name>NSIDC</First_Name><Last_Name>User Services</Last_Name><Email>nsidc@nsidc.org</Email><Phone>1-303-492-6199</Phone><Contact_Address><Address>National Snow and Ice Data Center</Address><Address>CIRES, 449 UCB</Address><Address>University of Colorado</Address><City>Boulder</City><Province_or_State>CO</Province_or_State><Postal_Code>80309-0449</Postal_Code><Country>USA</Country></Contact_Address></Personnel></Data_Center><Distribution><Distribution_Media>FTP</Distribution_Media><Distribution_Format>IMG</Distribution_Format></Distribution><Distribution><Distribution_Media>FTP</Distribution_Media><Distribution_Format>Binary</Distribution_Format></Distribution><Reference>Chang, A.T.C., J. L. Foster, and D.K. Hall. 1987. Nimbus-7 SMMR
derived global snow cover parameters. Annals of Glaciology. 9:39-44.

Foster, J.L., D.K. Hall, and A.T.C. Chang. 1987. Remote sensing of
snow.  Eos, Transactions of the AGU. 68(32):681-684.

Hall, D.K. 1988. Assessment of polar climate change using satellite
technology.  Reviews of Geophysics, 26(1):26-39.
</Reference><Summary><Abstract>The data set consists of monthly global snow cover and snow depth derived from Nimbus-7 SMMR data for 1978 through 1987. The SMMR data are interpolated for spatial and temporal gaps, and averaged for display in polar stereographic projection. Maps are based on six-day average brightness temperature data from the middle week of each month. Data are placed into 1/2 degree latitude by 1/2 degree longitude grid cells uniformly subdividing a polar stereographic map according to the geographic coordinates of the center of the radiometers' fields of view.  Overlapping data from separate orbits in the same six-day period are averaged to give a single brightness temperature assumed to be at the cell's center. Oceans and bays are masked so that only microwave data for land areas are displayed.

Comparisons of SMMR snow cover maps with previous maps produced by NOAA/NESDIS and US Air Force Global Weather Center indicate that the total snow covered area derived from SMMR is usually about ten percent less than that measured by the earlier products, because passive microwave sensors often can't detect shallow dry snow less than about 5 cm deep. Snow depths are comparable, showing SMMR results to be especially good for uniform snow covered areas such as the Canadian high plains and Russian steppes. Heavily forested and mountainous areas tend to mask the microwave snow signatures, and SMMR snow depth
derivations are less reliable in those areas.

These data were retired from public use on 27 August 2019. Data files are no longer accessible, although the data set documentation will remain available for future reference. This data set was retired because other SMMR-derived snow data with longer temporal records are available at NSIDC DAAC, including the Global Monthly EASE-Grid Snow Water Equivalent Climatology, Version 1 data set (https://doi.org/10.5067/KJVERY3MIBPS).&#xA0;Another alternative data set to consider is the Canadian Meteorological Centre (CMC) Daily Snow Depth Analysis Data, Version 1 (https://doi.org/10.5067/W9FOYWH0EQZ3).</Abstract></Summary><Related_URL><URL_Content_Type><Type>VIEW RELATED INFORMATION</Type></URL_Content_Type><URL>https://nsidc.org/sites/default/files/nsidc0024_pdf.pdf</URL><Description>Nimbus-7 SMMR Derived Monthly Global Snow Cover and Snow Depth, Version 1 User Guide</Description></Related_URL><IDN_Node><Short_Name>USA/NASA</Short_Name></IDN_Node><Metadata_Name>CEOS IDN DIF</Metadata_Name><Metadata_Version>VERSION 9.9</Metadata_Version><DIF_Creation_Date>2003-06-11</DIF_Creation_Date><Last_DIF_Revision_Date>2026-03-03</Last_DIF_Revision_Date><Extended_Metadata><Metadata><Group>NSIDC</Group><Name>Version Summary</Name><Value>Initial Release</Value></Metadata><Metadata><Group>NSIDC</Group><Name>Minor Version</Name><Value/></Metadata><Metadata><Group>NSIDC</Group><Name>Current Version</Name><Value>1</Value></Metadata><Metadata><Group>NSIDC</Group><Name>Level of Service</Name><Value><Level>No Data Access</Level></Value></Metadata><Metadata><Group>NSIDC</Group><Name>Full Dataset Citation</Name><Value>Chang, A. T. (2003). &lt;i&gt;Nimbus-7 SMMR Derived Monthly Global Snow Cover and Snow Depth&lt;/i&gt;. (NSIDC-0024, Version 1). [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. &lt;a href="https://doi.org/10.5067/5C8R32YS4VHU"&gt;https://doi.org/10.5067/5C8R32YS4VHU&lt;/a&gt;. [&lt;i&gt;&lt;describe subset used if applicable&gt;&lt;/i&gt;].</Value></Metadata><Metadata><Group>NSIDC</Group><Name>Retired</Name><Value>true</Value></Metadata></Extended_Metadata></DIF>
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