Sea Ice Concentration data: Overview, Comparison table and graphs

Main content

Sea ice concentration is both an indicator and driver of high-latitude climate change with strong societal and ecological importance. It is a key boundary condition for atmospheric models (including those used in atmospheric reanalyses) and a benchmark for coupled climate models. As such, numerous methods have been developed to estimate sea ice concentration. The most widely used sea ice data sets for climate research are derived from passive microwave instruments, including SMMR, SSMI, SSMIS, AMSR-E and AMSR-2, flying on various satellite platforms. The algorithms applied to the microwave brightness temperatures use different combinations of channels, making different corrections for weather, satellite drift, and other factors. Users of sea ice data should be aware of the different algorithms and their attributes, the different spatial footprints of the satellite instruments and channels, and the methods for combining different source data into long-term data sets. The table and links below provide a starting point for understanding and locating the appropriate data sets. The focus is on long-term data sets rather than near-real-time products.

Expert User Guidance

Expert User Guidance

We are actively seeking contributions from sea ice data users and developers! Please consider contributing your knowledge and questions! Possible topics include discussing the pros and cons of each algorithm, how weather effects can be dealt with, differences among passive microwave satellite sensors, alternative means of estimating sea ice beyond passive microwave, comparisions of data sets among each other and with field observations, best data sets for boundary conditions, best data sets for evaulating coupled models, etc.

Key Figures

Arctic sea ice extent and area, September 1979-2001

September Arctic sea ice extent (solid lines) and area (dashed lines), 1979-2010, for the NASA Team (red) and Bootstrap (black) algorithms. Source: NSIDC Data Set 0192: Stroeve, J., and W. Meier. 1999, updated 2011. Sea Ice Trends and Climatologies from SMMR and SSM/I-SSMIS, 1979-2010. Boulder, Colorado USA: NSIDC. Digital media. (Figure by D. Schneider, NCAR)

Arctic sea ice comparison of data sets

Comparison of September Arctic sea ice concentration climatologies for 2003-2007. For reference, the 15% ice concentration contour of the NT2 AMSR-E data set is plotted as a red line on all of the maps. Bottom right map is for 2007 only. Data are from various sources; see the table on climatedataguide.ucar.edu/seaice. (figure by D. Schneider).

Other Information

Earth system components and main variables
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Please cite data sources, following the data providers' instructions
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Key Publications
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Summary of sea ice concentration datasets

Name Snapshot Source Domain Years of record Timestep Spatial Resolution Formats Input Data
CERA-20C: ECMWF's Coupled Ocean-Atmosphere Reanalysis of the 20th Century Skill scores (contributed by P. Laloyaux) ECMWF Global to Sub-daily, Daily, Monthly ~ 125km; 160 x 320; 91 model levels/ 37 pressure levels / 16 potential temperature levels, and the 2 PVU potential vorticity level netCDF, GRIB

Surface pressures and mean sea level pressures from ISPDv3.2.6 and ICOADSv2.5.1. Surface marine winds from ICOADSv2.5.1. Sea surface temperature from HadISST2. Temperature and salinity profiles from EN4.

Merged Hadley-NOAA/OI Sea Surface Temperature & Sea-Ice Concentration (Hurrell et al, 2008) Sea ice concentration: Merged Had-OI NCAR / James Hurrell, Adam Phillips, Dennis Shea Global, Antarctic, Arctic, NH - Northern Hemisphere, SH - Southern Hemisphere to Monthly 1° x 1° netCDF

HadISST 1870-Nov 1981; NOAA OI Dec 1981-present

NSIDC Sea Ice Index NH extent timeseries (contributed by W Meier) National Snow and Ice Data Center Antarctic, Arctic to Daily, Monthly 25km x 25km ascii, csv, GeoTIFF, Image, shapefile
Sea Ice Concentration data from AMSR-E, AMSR2 & SSMIS, U Bremen and U Hamburg ASI algorithm Arctic sea ice: ASI v5.6i Lars Kaleschke - CLiSAP (Hamburg, Germany) , Stefan Kern - CliSAP (Hamburg, Germany) , Gunnar Spreen - JPL NH - Northern Hemisphere, SH - Southern Hemisphere, Antarctic, Arctic to Daily 6.25 x 6.25 km netCDF, HDF, GeoTIFF

AMSR-E 89 GHz channel; separate data from SSMIS; planned AMSR-2

Sea Ice Concentration data from HadISST Climate Data Guide Image: HADISST ice concentrations UK Met Office Hadley Center / N. Rayner and others Antarctic, Arctic, NH - Northern Hemisphere, SH - Southern Hemisphere to Monthly 1° x 1° netCDF, ascii

numerous sea ice charts, Walsh and Chapman sea ice (NH), adjusted passive microwave sea ice

Sea Ice Concentration data from NASA Goddard and NSIDC based on Bootstrap algorithm Climate Data Guide Image: Sea Ice Concentration data; Goddard Bootstrap NASA Goddard / Joesefino Comiso , NSIDC Antarctic, Arctic, NH - Northern Hemisphere, SH - Southern Hemisphere to Daily, Monthly 25 x 25 km netCDF, binary

SMMR, SSMI, SSMI/S, AMSR-E

Sea Ice Concentration data from NASA Goddard and NSIDC based on NASA Team algorithm Arctic sea ice: NASA Team NASA Goddard / Donald Caveleri, Claire Parkinson and others , NSIDC Antarctic, Arctic, NH - Northern Hemisphere, SH - Southern Hemisphere to Daily, Monthly 25 x 25 km netCDF, binary

SMMR, SSMI, SSMI/S

Sea Ice Concentration data from NASA Goddard and NSIDC using AMSR-E and NASA TEAM2 (NT2) algorithm Arctic sea ice: AMSR-E / NT2 NASA Goddard / Donald Caveleri, Thorsten Markus and Josefino Comiso , NSIDC Antarctic, Arctic to Daily 12.5x12.5 Km or 25x25km HDF-EOS

AMSR-E brightness temperatures

Sea ice concentration data from NASA Goddard based on SSMI and NASA Team (NT2) algorithm Arctic sea ice: SSMI / NT2 NASA Goddard | T. Markus; D. Cavalieri Antarctic, Arctic to Daily 25 x 25 km binary

SSMI: multiple channels

Sea Ice Concentration data from NOAA OI Arctic sea ice: NOAA OI NOAA / Richard Reynolds and others Antarctic, Arctic, NH - Northern Hemisphere, SH - Southern Hemisphere to Monthly, Weekly 1° x 1° netCDF

adjusted passive microwave -derived sea ice from NASA Goddard and NCEP operations

Sea Ice Concentration data reprocessed from SSMR & SSMI, by Eumetsat Artic sea ice: Eumetsat reprocessed. Norwegian Meteorological Institute , Danish Meteorological Institute NH - Northern Hemisphere, SH - Southern Hemisphere, Antarctic, Arctic to Daily 12.5 x 12.5 km netCDF

SMMR and SSM/I

Sea Ice Concentration: NOAA/NSIDC Climate Data Record Arctic sea ice: Climate Data Record NSIDC: Ruth Duerr (Co-I), Florence Fetterer (Co-I), Julienne Stroeve (Co-I) , NASA: Walt Meier (PI) Antarctic, Arctic, NH - Northern Hemisphere, SH - Southern Hemisphere to Daily, Monthly 25 x 25 km netCDF

SSMI using NASA Team or Bootstrap

SST data: NOAA High-resolution (0.25x0.25) Blended Analysis of Daily SST and Ice, OISSTv2 NOAA NCDC/Richard Reynolds Global to Daily 0.25°x0.25° netCDF, binary

ships, bouys, large-scale adjustment of satellite biases, AVHRR, AMSRE

Walsh and Chapman Northern Hemisphere Sea Ice John Walsh (U Illinois) , Bill Chapman (U. Illinois) NH - Northern Hemisphere, Arctic to Monthly 1° x 1° ascii

historical charts, switching to SMMR & SSM/I in 1978