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<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>G02135</Entry_ID>
  <Entry_Title>Sea Ice Index</Entry_Title>
  <Data_Set_Citation>
    <Dataset_Creator>Fetterer, F., K. Knowles, W. Meier, and M. Savoie. </Dataset_Creator>
    <Dataset_Title>Sea Ice Index</Dataset_Title>
    <Dataset_Release_Date>2002-12-05updated 2009</Dataset_Release_Date>
    <Dataset_Release_Place>Boulder, Colorado USA</Dataset_Release_Place>
    <Dataset_Publisher>NSIDC: National Snow and Ice Data Center</Dataset_Publisher>
    <Online_Resource>http://nsidc.org/data/g02135.html</Online_Resource>
    <Dataset_DOI>http://dx.doi.org/10.7265/N5QJ7F7W</Dataset_DOI>
  </Data_Set_Citation>
  <Personnel>
    <Role>Investigator</Role>
    <First_Name>F.</First_Name>
    <Last_Name>Fetterer</Last_Name>
    <Email>fetterer@nsidc.org</Email>
    <Contact_Address>
      <Address>CIRES</Address>
      <Address>National Snow and Ice Data Center</Address>
      <Address>449 UCB</Address>
      <City>Boulder</City>
      <Province_or_State>CO</Province_or_State>
      <Postal_Code>80309</Postal_Code>
      <Country>USA</Country>
    </Contact_Address>
  </Personnel>
  <Personnel>
    <Role>Investigator</Role>
    <First_Name>Kenneth</First_Name>
    <Last_Name>Knowles</Last_Name>
    <Contact_Address>
      <Address>National Snow and Ice Data Center</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>
  <Personnel>
    <Role>Investigator</Role>
    <First_Name>Walt</First_Name>
    <Last_Name>Meier</Last_Name>
    <Email>walt@nsidc.org</Email>
    <Contact_Address>
      <Address>CIRES</Address>
      <Address>National Snow and Ice Data Center</Address>
      <Address>449 UCB</Address>
      <Address>University of Colorado</Address>
      <City>Boulder</City>
      <Province_or_State>CO</Province_or_State>
      <Postal_Code>80309</Postal_Code>
      <Country>USA</Country>
    </Contact_Address>
  </Personnel>
  <Personnel>
    <Role>Investigator</Role>
    <First_Name>Matthew</First_Name>
    <Last_Name>Savoie</Last_Name>
    <Email>savoie@nsidc.org</Email>
    <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>
  <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 x</Phone>
    <Fax>1 303  492-2468 x</Fax>
    <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>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Cryosphere</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Ice Extent</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Cryosphere</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Ice Growth/Melt</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Cryosphere</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Reflectance</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Cryosphere</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Sea Ice Concentration</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Oceans</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Ice Extent</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Oceans</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Ice Growth/Melt</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Oceans</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Reflectance</Variable_Level_1>
  </Parameters>
  <Parameters>
    <Category>EARTH SCIENCE</Category>
    <Topic>Oceans</Topic>
    <Term>Sea Ice</Term>
    <Variable_Level_1>Sea Ice Concentration</Variable_Level_1>
  </Parameters>
  <ISO_Topic_Category>Climatology/Meteorology/Atmosphere</ISO_Topic_Category>
  <ISO_Topic_Category>Oceans</ISO_Topic_Category>
  <Keyword>NOAA</Keyword>
  <Keyword>Sea Ice</Keyword>
  <Keyword>Sea Ice Anomalies</Keyword>
  <Keyword>Sea Ice Conditions</Keyword>
  <Keyword>Sea Ice Trends</Keyword>
  <Sensor_Name>
    <Short_Name>SMMR</Short_Name>
    <Long_Name>Scanning Multichannel Microwave Radiometer</Long_Name>
  </Sensor_Name>
  <Sensor_Name>
    <Short_Name>SSM/I</Short_Name>
    <Long_Name>Special Sensor Microwave/Imager</Long_Name>
  </Sensor_Name>
  <Source_Name>
    <Short_Name>DMSP</Short_Name>
    <Long_Name>Defense Meteorological Satellite Program</Long_Name>
  </Source_Name>
  <Source_Name>
    <Short_Name>NIMBUS-7</Short_Name>
  </Source_Name>
  <Source_Name>
    <Short_Name>SATELLITES</Short_Name>
  </Source_Name>
  <Temporal_Coverage>
    <Start_Date>1979-01-01</Start_Date>
  </Temporal_Coverage>
  <Data_Set_Progress>in work</Data_Set_Progress>
  <Spatial_Coverage>
    <Southernmost_Latitude>-90</Southernmost_Latitude>
    <Northernmost_Latitude>-39.23</Northernmost_Latitude>
    <Westernmost_Longitude>-180</Westernmost_Longitude>
    <Easternmost_Longitude>180</Easternmost_Longitude>
  </Spatial_Coverage>
  <Spatial_Coverage>
    <Southernmost_Latitude>30.98</Southernmost_Latitude>
    <Northernmost_Latitude>90</Northernmost_Latitude>
    <Westernmost_Longitude>-180</Westernmost_Longitude>
    <Easternmost_Longitude>180</Easternmost_Longitude>
  </Spatial_Coverage>
  <Location>
    <Location_Category>CONTINENT</Location_Category>
    <Location_Type>ANTARCTICA</Location_Type>
  </Location>
  <Location>
    <Location_Category>GEOGRAPHIC REGION</Location_Category>
    <Location_Type>ARCTIC</Location_Type>
  </Location>
  <Data_Set_Language>English</Data_Set_Language>
  <Originating_Center>NSIDC_NOAA</Originating_Center>
  <Data_Center>
    <Data_Center_Name>
      <Short_Name>NSIDC</Short_Name>
      <Long_Name>National Snow and Ice Data Center</Long_Name>
    </Data_Center_Name>
    <Data_Center_URL>http://nsidc.org</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>
      <Fax>1 303  492-2468 </Fax>
      <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>
  <Data_Center>
    <Data_Center_Name>
      <Short_Name>NSIDC_NOAA</Short_Name>
      <Long_Name>NSIDC National Oceanic and Atmospheric Administration</Long_Name>
    </Data_Center_Name>
    <Data_Center_URL>http://nsidc.org/noaa/</Data_Center_URL>
    <Personnel>
      <Role>Data Center Contact</Role>
      <First_Name>NSIDC NOAA</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>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>ASCII Text</Distribution_Format>
  </Distribution>
  <Distribution>
    <Distribution_Media>FTP</Distribution_Media>
    <Distribution_Format>ESRI Shapefiles</Distribution_Format>
  </Distribution>
  <Distribution>
    <Distribution_Media>FTP</Distribution_Media>
    <Distribution_Format>PNG</Distribution_Format>
  </Distribution>
  <Reference>Agnew, T. A., and S. Howell. 2002a. The use of operational i ce charts for evaluating passive microwave ice concentration data. Internal Report of the Meteorological Service of Canada. 34 pp.

Agnew, T. A., and S. Howell. 2002b. Comparison of digitized Canadian ice charts and passive microwave sea-ice concentrations. Procedures of the International Geoscience and Remote Sensing Symposium, July 24-28. Toronto: Canada.

Cavalieri, D.J., P. Gloersen and W. J. Campbell. 1984. Determination of sea ice parameters with the NIMBUS-7 SMMR. Journal of Geophysical Research 89 (D4): 5355-5369.

Cavalieri, D.J., K.M. St. Germain and C.T. Swift. 1995. Reduction of weather effects in the calculation of sea ice concentration with the DMSP SSM/I. Journal of Glaciology 41: 455-464. Cavalieri, D., P. Gloerson, and J. Zwally. 1990. DMSP SSM/I daily polar gridded sea ice concentrations. Edited by J. Maslanik and J. Stroeve. Boulder, CO: National Snow and Ice Data Center. Digital media.

Cavalieri, D., C. Parkinson, P. Gloerson, and H.J. Zwally. 1997, updated 2005. Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data, June to September 2001. Boulder, CO: National Snow and Ice Data Center. Digital media and CD-ROM. Cavalieri, D., P. Gloerson, and J. Zwally. 2002, updated daily. Near Real-Time DMSP SSM/I Daily Polar Gridded Sea Ice Concentrations. Edited by J. Maslanik and J. Stroeve. Boulder, CO: National Snow and Ice Data Center. Digital media. Comiso, J. C., and R. Kwok. 1996. Surface and radiative characteristics of the summer arctic sea ice cover from multi-sensor satellite observations. Journal of Geophysical Research 101 (C12): 28, 397-28, 416.

Comiso, J. C., and K. Steffen. 2001. Studies of Antarctic sea ice concentrations from satellite data and their applications. Journal of Geophysical Research 106 (C12): 31, 361-31, 386. Emery, W. J., C. Fowler, and J. Maslanik. 1994. Arctic sea ice concentration from Special Sensor Microwave Imager and Advanced Very High Resolution Radiometer satellite data. Journal of Geophysical Research 99: 18,329-18,342. Eppler, D.T., L.D. Farmer, A.W. Lohanick, M.A. Anderson, D. Cavalieri, J. Comiso, P. Gloersen, C. Garrity, T.C. Grenfell, M. Hallikainen, J.A. Maslanik, C. Mätzler, R.A. Melloh, I. Rubinstein, and C.T. Swift. 1992. Passive microwave signatures of sea ice. In Microwave remote sensing of sea ice. Edited by F.D. Carsey. Washington, D.C.: American Geophysical Union. 47-71.

Fetterer, F., and N. Untersteiner. 1998. Observations of melt ponds on arctic sea ice. Journal of Geophysical Research 103 (C11): 24,821-24,835.

Hollinger, J.P., J.L. Peirce, and G.A. Poe. 1990. SSM/I Instrument Evaluation. IEEE Transactions on Geoscience and Remote Sensing 28 (5): 781-790.

Kwok, R. 2002. Sea ice concentration estimates from satellite passive microwave radiometry and openings from SAR ice motion. Geophysical Research Letters 29 (9): 10.1029/202GL014787.

Markus, T., and S. T. Dokken. 2002. Evaluation of late summer passive microwave arctic sea ice retrievals. IEEE Transactions on Geoscience and Remote Sensing 40 (2): 348-356.  Meier, W. N., M .L. V. Woert, and C. Bertoia. 2001. Evaluation of operational SSM/I algorithms. Annals of Glaciology 33: 102-108.

Meier, W. N. 2005. Comparison of passive microwave retrievals with AVHRR imagery in arctic peripheral seas. IEEE Transactions on Geoscience and Remote Sensing 43 (6): 1324-1337.

Parkinson, C.L., D.J. Cavalieri, P. Gloersen, H.J. Zwally, and J.C. Comiso. 1999. Arctic sea ice extents, areas, and trends, 1978-1996. Journal of Geophysical Research 104 (C9): 20,837-20,856.

Partington, K., T. Flynn, D. Lamb, C. Bertoia, and K. Dedrick. 2003. Late twentieth century Northern Hemisphere sea-ice record from U.S. National Ice Center ice charts. J. Geophys. Res. 108(C11): 3343. doi:10.1029/2002JC001623.

Steffen, K., and A. Schweiger. 1991. NASA team algorithm for sea ice concentration retrieval from Defense Meteorological Satellite Program Special Sensor Microwave Imager: comparison with Landsat satellite imagery. Journal of Geophysical Research 96 (C12): 21,971-21,987.

Steffen, K., J. Key, D. Cavalieri, J. Comiso, P. Gloersen, K.S. Germain, and I. Rubinstein. 1992. The estimation of geophysical parameters using passive microwave algorithms in microwave remote sensing of sea ice. Edited by F.D. Carsey. Washington, D.C.: American Geophysical Union. 201-231.</Reference>
  <Summary>The Sea Ice Index provides a quick look at sea ice changes in spatial and historical context, and gives a consistent, up-to-date source of sea ice extent and sea ice concentration values and images. The NSIDC Near-Real-Time DMSP SSM/I Daily Polar Gridded Sea Ice Concentrations and the Sea Ice Concentrations from Nimbus-7 SSMR and DMSP SSM/I Passive Microwave Data data sets are used to generate the monthly records of sea ice extent and sea ice concentration for the Arctic and Antarctica from satellite passive microwave data.

Data files tabulate monthly mean extent and area, in millions of square kilometers, by year for a given month. Plots of monthly sea ice extent anomalies with trend lines and significance intervals are available. Monthly images show sea ice extent (with an outline of the median extent for that month for comparison), sea ice concentration, trends in sea ice concentration, and anomalies in sea ice concentration. Anomalies and median extent are calculated using a reference period of 1979 through 2000.

Daily images of sea ice extent and concentration, along with a time series plot of extent for the most recent four months, can be viewed and downloaded on the data product site but are not archived. Some products are available as GIS compatible shapefiles and KML files. The Browse Image Spreadsheet Tool (BIST) can be used for animated images and for displaying archived images of extent and trends side by side, to make it easy to compare images from different years and months.

Data are stored in ASCII text, Portable Network Graphics (PNG), Keyhole Markup Language (KML), and Geospatial Vector Data format and are available from November 1978 to present via FTP or the Sea Ice Index Web site.</Summary>
  <Related_URL>
    <URL_Content_Type>
      <Type>VIEW PROJECT HOME PAGE</Type>
    </URL_Content_Type>
    <URL>http://nsidc.org/data/seaice/index.html</URL>
    <Description>Sea Ice Data at NSIDC</Description>
  </Related_URL>
  <Related_URL>
    <URL_Content_Type>
      <Type>VIEW PROJECT HOME PAGE</Type>
    </URL_Content_Type>
    <URL>http://nsidc.org/data/seaice/</URL>
    <Description>Sea Ice Products at NSIDC</Description>
  </Related_URL>
  <Metadata_Name>CEOS IDN DIF</Metadata_Name>
  <Metadata_Version>9.7</Metadata_Version>
  <DIF_Creation_Date>2002-12-05</DIF_Creation_Date>
  <Last_DIF_Revision_Date>2013-03-07</Last_DIF_Revision_Date>
  <DIF_Revision_History> Added DOI</DIF_Revision_History>
</DIF>
