Data Announcement
  • Sea ice

New Beta Version Release: NOAA/NSIDC Climate Data Record of Passive Microwave 12.5 km Sea Ice Concentration, Version 5

NOAA@NSIDC is pleased to announce that the beta release of the NOAA/NSIDC Climate Data Record of Passive Microwave 12.5 km Sea Ice Concentration, Version 5 data set is now available at the National Snow and Ice Data Center (NSIDC). The sea ice concentration (SIC) climate data record (CDR) V5 data set provides a daily and monthly time series of sea ice concentrations beginning 25 October 1978 and continuing to the present for both the north and south polar regions. The data is provided on a 12.5 km x 12.5 km polar stereographic grid.

The major updates in Version 5 include the following:

  • Added AMSR-E and AMSR2 sensors
  • Changed grid from 25 km to 12.5 km
  • Regridded the legacy SMMR, SSM/I, and SSMIS sensors from 25 km to 12.5 km
  • Used the NASA Team 2 land spillover correction instead of the original NASA Team and Bootstrap corrections
  • Adjusted Bootstrap weather filter coefficients for AMSR2
  • Improved the Arctic pole hole filling

Note that this is a beta release of the SIC CDR Version 5 12.5 km product. The data set has not been thoroughly validated so there may be some inaccuracies, especially in the older portion of the record that uses the SMMR, SSM/I, and SSMIS sensors. Data from these sensors were regridded from their original 25 km grid size to the new 12.5 km grid to match the resolution of the AMSR series. Some discontinuities exist at the sensor transitions that still require adjustments and bias corrections. We encourage users to explore the product and provide feedback for any errors they may find to

NSIDC recommends continuing to use Version 4 ( for analyses. If you decide to use Version 5, do so with caution until NSIDC has finished validating the product. Once validation is complete, the beta release designation will be removed. Any issues found will be fixed, and the data set will be formally released. If you would like to be notified when validation of Version 5 is complete and you are not already a registered user of the Version 4 product, you can subscribe to announcements by clicking the SUBSCRIBE button from the web site:

Data set DOI: