Available high-resolution optical imagery of sea ice north of the Canadian Arctic Archipelago and Greenland. The map (a) shows the location of the imagery in (b). Each high-resolution (1 m) image is 2 km on a side. The imagery used here is described by Kwok (2014) and available through the Global Fiducials Library at USGS (URL: http://gfl.usgs.gov/). DOI: https://doi.org/10.1525/elementa.311.f3