Visual observations of sea-ice conditions were performed hourly from the bridge of Polarstern. The observations followed the ASSIST protocol (version 2.0).Observer team: Sebastian Albrecht, Stefanie Arndt, Denise Bachmann, John Bailey, Christian Borowski, Diederik D'Hert, Alexander Diehl, Stephen Elliott, Christopher German, Bernd Heesemann, Mike Jakuba, Mechthild Doll, Christopher Judge, Christian Katlein, Norbert Kaul, Henning Kirk, Janna Köhler, Mikko Lensu, Yann Marcon, Christopher McFarland, Massimiliano Molari, Johannes Pliet, Norbert Rieper, Vera Schlindwein, Florian Schmid, Stefano Suman, Andreas Türke, Martin Vogt, Louise Wagner, Michel Watelet, Gunter Wegener, Louis Whitcomb