Sea ice concentration

The data, maps and sea ice analyses of the Arctic and Antarctic available for download are based on the information of the satellite radiometers mentioned below. Measurements of the satellite radiometer AMSR-E range from June 19th, 2002 until September 30th, 2011. On Oct 4, 2011, measurements of AMSR-E stopped.

AMSR-E‘s successor AMSR2 was successfully deployed to orbit on May 18th 2012. Since August 1st, 2012 AMSR2 has been sending microwave data from which daily sea ice concentrations are derived. Sea ice concentration based on SSMIS has been available from October 1st, 2011 up to today. Data of AMSR2 is of higher quality than SSMIS data. On, SSMIS data is therefore only used to fill data gaps of AMSR2. The sensor used to define sea ice concentrations is recorded in the name of the respective daily file.

The sea ice concentration data is written in HDF-format. The coordinates and land mask files needed for further processing can be downloaded here and will be needed only once per hemisphere.

All sea ice concentration data of the Arctic and the Antarctic, including data until June 19th 2002, (HDF-format) from the University of Bremen (Institute of Environmental Physics) can be accessed there. This site includes data sets for Arctic, Antarctic and, in a higher temporal resolution (3.125km), a number of regional maps. They use a polar stereographic projection with equal area at 70° latitude. The geographical coordinates of the pixels are given in separate files for Arctic (geographical coordinates Arctic (HDF)) and for Antarctica (geographical coordinates Antrctic (HDF)).

Furthermore, downloads of daily updated KMZ files usable for Google Earth depictions are available for the Arctic (daily updated KMZ file Arctic) and Antarctic (daily updated KMZ file Antarctic).

Soon, also KMZ- and GeoTIFF-files will be available for download for the entire period via the selection menu.

Besides the daily data sets, monthly data sets can be downloaded as well. Development, validation and improvement of the evaluating algorithms were performed in connection with the EU project DAMOCLES (Developing Arctic Modeling and Observing Capabilities for Long-term Environmental Studies). Sea ice extent was determined by direct satellite measurements and the so-called “ARTIST” sea ice algorithm. It has been used and validated in many scientific studies.

We assume no liability for any of the provided data available for downloaded.

Sea ice concentration is represented in the maps by a uniform color scale: White represents a sea ice concentration of 100%, dark blue marks the regions with the lowest sea ice concentration. According to standard definition , sea ice extent is the continuous area for which a sea ice concentration of at least 15 % is measured.

All graphs need to be cited according to the rules listed in the "Terms of Use".

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For the use of, users are asked to include the following citation:

  1. Grosfeld, K.; Treffeisen, R.; Asseng, J.; Bartsch, A.; Bräuer, B.; Fritzsch, B.; Gerdes, R.; Hendricks, S.; Hiller, W.; Heygster, G.; Krumpen, T.; Lemke, P.; Melsheimer, C.; Nicolaus, M.; Ricker, R. and Weigelt, M. (2016), Online sea-ice knowledge and data platform <>, Polarforschung, Bremerhaven, Alfred Wegener Institute for Polar and Marine Research & German Society of Polar Research, 85 (2), 143-155, doi:10.2312/polfor.2016.011 (PDF).

For the use of the specific data from the data portal of, users are asked to include the associated citations as indicated below.

For all sea ice concentration data, please

  1. include the following phrase into the acknowledgment: Sea ice concentration data from DATE to DATE were obtained from (grant: REKLIM-2013-04).
  2. refer to: Spreen, G.; Kaleschke, L. and Heygster, G. (2008), Sea ice remote sensing using AMSR-E 89 GHz channels J. Geophys. Res.,vol. 113, C02S03, doi:10.1029/2005JC003384.

In case of questions or any difficulties, please contact us at: Meereisportal Team.