Boris Shapkin¹, Vasco Mueller², Claudia Wekerle³ and Sergey Danilov², (1)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Climate Dynamics, Bremerhaven, Germany, (2)Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, (3)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research, Physical Oceanography of the Polar Seas, Bremerhaven, Germany