Sea Ice Concentration CDR Updated through 31 December 2017

NOAA@NSIDC is pleased to announce that the NOAA@NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration data product has been processed through 31 December 2017. The input data to the Goddard Bootstrap (BT) variables have been versioned up from v3.0 to v3.1 for 2017 data onward. This change does not affect the sea ice concentration CDR data variables. The specific changes are as follows: Beginning with January 2017 data, the Sea Ice Concentration CDR uses version 3.1 of the Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS data set (NSIDC-0079) as input to the following NetCDF variables: goddard_bt_seaice_conc, goddard_bt_seaice_conc_monthly, goddard_merged_seaice_conc, and goddard_merged_seaice_conc_monthly. All data prior to January 2017 use version 3.0 of the NSIDC-0079 data set. Version 3.1 of the NSIDC-0079 ice concentrations computes sea ice concentration with an open water identifier that is calculated daily for the months of May and October. In version 3.0, this value was calculated using a single monthly value for May and a single monthly value for October. For complete details on the NSIDC-0079 version changes, please see the Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS, Version 3 documentation. Due to this change, users should note that there may be a small discontinuity in the variables mentioned above for data before and after January 2017 occurring in the months of May and October. Other months, as well as the sea ice CDR variables themselves, seaice_conc_cdr and seaice_conc_monthly_cdr, are not affected by this change. To access these data, visit the data set landing page for the NOAA@NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration, Version 3. Data Set DOI: https://doi.org/10.7265/N59P2ZTG This work is supported by the NOAA Climate Data Record program and by NOAA NCEI support to NOAA@NSIDC.