Patrick Scholz, Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Climate Sciences, Bremerhaven, Germany, Sergey Danilov, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany, Tridib Banerjee, Goethe University Frankfurt, Geosciences and Geography, Frankfurt am Main, Germany and Knut Klingbeil, Leibniz Institute for Baltic Sea Research Warnemuende (IOW), Rostock, Germany