Arctic Sea Ice Concentration and Extent from Danish Meteorological Institute Sea Ice Charts, 1901-1956, Version 1

This data set provides estimates of Arctic sea ice extent and concentration from 1901 to 1956 created from a collection of historic, hand-drawn sea ice charts from the Danish Meteorological Institute (DMI). These were used to create estimates for each summer month from 1901 to 1956 by manual, subjective interpretation of scanned versions of the charts. These estimates, shown in colored-coded fields, are available as GIS shapefiles, gridded NetCDF files, and browse image files.