Data Archive

All data can be found in the data archive, which is accessible via FTP and HTTP.


For FTP access, connect to "" (use a ftp client, browser will not work). The products are available in the given directories, e.g., "amsr2" for the AMSR2 data. Please set your ftp client to "active mode". Otherwise no connection is possible. The user name is "anonymous" and no password is needed.


For HTTP access, visit, the structure is the same as for FTP.

Downloads of multiple files can be performed using the "wget" command under bash. For example for a single month:

wget -A .tif -r -nc -np -nH -e robots=off ""

or several years:

for y in {2002..2012}; do for m in jan feb mar apr may jun jul aug sep oct nov dec; do wget -A .tif -r -nc -nd -np -nH -nv -e robots=off$y/$m/Arctic3125/; done; done

The region (here "Arctic3125"), hemisphere and resolution (here "n3125"), the dataset (here: "asi_daygrid_swath"), and satellite sensor (here "amsre") have to be adapted according to your application.

Data browser

To quickly browse the data, please have a look at the Databrowser.

Data Format

Sea ice concentration maps with two different color scales are available as PNG image. The NIC color scale uses the same colors as the National Ice Center, the "visual" color scale uses white and shades of grey.

There is one file per day per region per color scale.

Sea ice concentration data are available as HDF4, GEOTIFF and netCDF files: There is one file per day per region. Each file contains one two-dimensional array of the sea ice concentration in a polar stereographic grid. The netCDF files are sorted per year.

The longitude and latitude coordinates of each pixel in a the HDF4 file are saved in extra files, one file per region for each available resolution.

They are found here:,  sorted by hemisphere and grid resolution (see also the README file

GEOTIFF and netCDF files contain georeferencing information internally (or you can use the same grid coordinates as for HDF4). GEOTIFF files use the NIC color scale and were tested to work with QGIS. Ice concentrations are scaled between 0 and 100, land and missing values are set to 120 (older files: SIC: 0-200, land/NaN: 255).   


For citing the individual datasets please have a look at the citation section, which can be found at the bottom of all dataset pages.