NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration, Version 2

This data set provides a monthly Climate Data Record (CDR) of sea ice concentration from passive microwave data for both the north and south polar regions.

The NOAA/NSIDC CDR is based on the recommendations from the National Research Council (NRC) (2004). It is produced from gridded brightness temperatures from the Defense Meteorological Satellite Program (DMSP) F8, F11, and F13 Special Sensor Microwave Imager (SSM/I) passive microwave radiometers and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS) passive microwave radiometer.

The NOAA/NSIDC CDR sea ice concentrations are an estimate of the fraction of ocean area covered by sea ice that is produced by combining concentration estimates created using two algorithms developed at the NASA Goddard Space Flight Center (GSFC): the NASA Team algorithm (Cavalieri et al. 1984) and the Bootstrap algorithm (Comiso 1986). NSIDC applies the individual algorithms to brightness temperature data from Remote Sensing Systems, Inc. (RSS).

The data are gridded on the NSIDC polar stereographic grid with 25 x 25 km grid cells and includes four different sea ice concentration variables: a variable with the primary CDR sea ice concentrations created by NSIDC and three variables with sea ice concentrations created by GSFC.

The three GSFC-produced sea ice concentrations are the GSFC NASA Team algorithm sea ice concentrations, the GSFC Bootstrap sea ice concentrations, and a merged version of the two sea ice concentrations. These GSFC-produced sea ice concentrations are included in the data files for a number of reasons. First, the merged GSFC NASA Team/Bootstrap sea ice concentrations are an ancillary data set that is analogous to the NOAA/NSIDC CDR data but that adds late 1978 through mid 1987 data to the record. A different instrument, the Scanning Multichannel Microwave Radiometer (SMMR), was the source for the brightness temperatures from this period. Sea ice concentrations from the extended period are not part of the primary NSIDC-produced CDR record because complete documentation of the SMMR brightness temperature processing method is not available. Second, the separate GSFC NASA Team and Bootstrap sea ice concentrations are provided for reference.

Variables containing standard deviation, quality flags, and projection information are also included.


Meier, W., F. Fetterer, M. Savoie, S. Mallory, R. Duerr, and J. Stroeve. 2013, updated 2015. NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration, Version 2. Boulder, Colorado USA: National Snow and Ice Data Center.

NSIDC-produced CDR sea ice concentrations (avg, stdev), day of year on which melting sea ice was first detected, quality flags, Merged GSFC NASA Team/Bootstrap monthly sea ice concentrations, GSFC NASA Team monthly sea ice concentrations, GSFC Bootstrap monthly sea ice concentrations, polar stereo projection information,
Zonal Global by 25 km
Meridional Northern polar region: 31.10N to 89.84N by 25 km
Southern polar region: 39.36S to 89.84S by 25 km
Temporal Nov 1978 to Dec 2014 by varies
Static? yes
Volume North polar region: 3.6MB/month; South polar region: 2.8MB/month
Server public:
Acquired Sep 25, 2015
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