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 (Hanno Müller) and Matthias Maasch, Mirco Czerwonka, Helene Hoffmann of the overwintering team.