Data Set ID:

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.

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Geographic Coverage

Data Set Tabs

Temporal Coverage:
  • 1978-10-26 to 2014-12-31
(updated 2015)
Temporal Resolution:
1 month, 1 day
DMSP 5D-2/F11, DMSP 5D-2/F13, DMSP 5D-2/F8, DMSP 5D-3/F17, NIMBUS-7
Sensor(s): SMMR, SSM/I, SSMIS
Spatial Coverage:
  • N: 90, S: 30, E: 180, W: -180

  • N: -39, S: -90, E: 180, W: -180

Spatial Resolution:
  • 25 km x 25 km
  • 25 km x 25 km
  • Sea Ice > Sea Ice Concentration
Data Format(s):
  • Binary
Data Contributor(s): Josephino 'Joey' Comiso
(updated 2015)

We kindly request that you cite the use of this data set in a publication using the following citation. For more information, see Use and Copyright.

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.

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