Manual measurements of sea ice thickness, sub-ice platelet layer thickness, freeboard, and snow thickness are distributed evenly and repeated along a 25km-long transect across Atka Bay every 2 to 4 weeks. At each measurement location, 5 holes were drilled through the ice in order to determine the aforementioned parameters, one in the center and one in a distance of five meters in each direction, to cover their small-scale spatial variabilities. The measurements have been mainly conducted by the meteorologist (Michael Koch) and Edith Korger, Andreas Müller, Katharina Naundorf, Nils Peters, Thomas Schad, Josefine Stakemann, and Birgit Steckelberg of the overwintering team.