Quentin Rauschenbach, Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Bremerhaven, Germany, Wilken-Jon von Appen, Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Physical Oceanography of the Polar Seas, Bremerhaven, Germany, Claudia Wekerle, Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research, Physical Oceanography of the Polar Seas, Bremerhaven, Germany and Torsten Kanzow, Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; University of Bremen, Bremen, Germany