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

For FTP access, connect to ftp://seaice.uni-bremen.de. The products are available in the directory "MultiYearIce". Please set your ftp client to "active mode". Otherwise no connection is possible. The user name is "anonymous" and no password is needed.

• amsre-qscat/final/ contains data from 2002 to 2009
• amrse-ascat/final/ contains data from 2009 to 2011
• amsr2-ascat/final/  contains data fom 2012 to date

For HTTP access, visit https://seaice.uni-bremen.de/data/MultiYearIce, the structure is the same as for FTP.

Multiyear ice maps since 2009 are available as PNG image, and all the underlying data are available as NetCDF files (icluding the 2002-2009 data).

There is one file per day.

Data based on AMSR-E/AMSR2 and ASCAT, 2009-now:

Each NetCDF file contains a two-dimensional array 'MYI' of the MYI concentration in a polar stereographic grid, and another array 'CR_FLAG' that shows which correction scheme was applied to which pixel. Information about the projection (EPSG and Proj.4) is contained in the global attributes. In addition, the longitude and latitude coordinates of each pixel in the NetCDF files can be found in an extra file  (see also the README file https://seaice.uni-bremen.de/data/grid_coordinates/README).

Date based on AMSR-E and QSCAT, 2002-2009:

Each NetCDF file contains a one-dimensional array 'NMYI' of the corrected MYI concentration, and one-dimensional arrays 'YI', 'FYI', 'MYI'  of the uncorrected ice types. The data have been projected to a polar stereographic grid with nominal grid cell size of 4.45 km.

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