*Richard G Williams¹、Andrew J.S. Meijers²、Vassil Roussenov¹、Anna Katavouta³、Paulo Ceppi⁴、Jonathan Rosser²、Pietro Salvi⁵ (1.Department of Earth, Ocean & Ecological Sciences, University of Liverpool, Liverpool, UK、2.British Antarctic Survey, Polar Oceans, Cambridge, UK、3.National Oceanography Centre, Liverpool, UK、4.Department of Physics, Imperial College London, London, UK、5.Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland.)