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Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS, Version 2

This sea ice concentration data set was derived using measurements from the Scanning Multichannel Microwave Radiometer (SMMR) on the Nimbus-7 satellite and from the Special Sensor Microwave/Imager (SSM/I) sensors on the Defense Meteorological Satellite Program's (DMSP) -F8, -F11, and -F13 satellites. Measurements from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard DMSP-F17 are also included. The data set has been generated using the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Bootstrap Algorithm with daily varying tie-points. Daily (every other day prior to July 1987) and monthly data are available for both the north and south polar regions. Data are gridded on the SSM/I polar stereographic grid (25 x 25 km) and provided in two-byte integer format. Data are available via FTP.

Version Summary:

Changes to this version include:

  • Adjusted tie-points to be consistent with the AMSR-E Bootstrap algorithm
  • Reprocessed entire SMMR-SSM/I time series

Important: Because Version 2 is inter-calibrated with AMSR-E, it is not compatible with Version 1 of this data set. Users should acquire the entire Version 2 data set in order to update their time series. This product is also not consistent with the NSIDC-produced Bootstrap Product, the DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures.
For further information on Version 2 data processing, see Enhanced Sea Ice Concentrations from Passive Microwave Data.

Geographic Coverage

Data Set Tabs

Spatial Coverage:
  • N: -39, S: -90, E: 180, W: -180

  • N: 90, S: 30, E: 180, W: -180

Spatial Resolution:
  • 25 km x 25 km
  • 25 km x 25 km
Temporal Coverage
  • 1978-10-26 to 2014-12-31
(updated 2015)
Temporal Resolution:
1 day, 1 month
  • Sea Ice > Sea Ice Concentration
DMSP 5D-2/F11, DMSP 5D-2/F13, DMSP 5D-2/F8, DMSP 5D-3/F17, NIMBUS-7
Sensor(s): SMMR, SSM/I, SSMIS
Data Format(s):
  • Binary
Data Contributor(s): Josephino 'Joey' Comiso

Data Citation

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

Comiso, J. C. 2000, updated 2015. Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS, Version 2. [indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. [Date Accessed].

Questions? Please contact:

NSIDC User Services
Phone: 1 303 492-6199
Fax: 1 303 492-2468
Contact Address:
National Snow and Ice Data Center
University of Colorado
City: Boulder
Province or State: CO
Postal Code: 80309-0449
Country: USA