簡單來說南極海面已經變鹹難以結冰，學界對此束手無策。
論文出處：
https://www.science.org/doi/10.1126/sciadv.aeb0166
Antarctic sea ice extent began declining in 2015, reaching its minimum in the
post-1970s observational era in 2023. To diagnose the drivers of this
decline, we analyze an observationally constrained sea ice–ocean model
spanning 2013–2023 and identify three distinct phases of sea ice retreat.
First, intensifying westerlies preconditioned the Southern Ocean via
increased upwelling of warm, saline circumpolar deep water (CDW).
Second, strong winds in 2015–2016 enhanced the mixing of CDW into the upper
ocean, thereby initiating sea ice loss, particularly in East Antarctica.
Third, sustained mixing of CDW into the surface layer, combined with reduced
equatorward sea ice–derived freshwater export, maintained an unprecedentedly
low sea ice state. East Antarctic sea ice loss was primarily subsurface
driven via enhanced upward CDW flux, whereas West Antarctic sea ice loss was
also forced by longwave radiative flux anomalies. Our findings suggest that
persistent upwelling-favorable conditions under anthropogenic forcing may
push the Southern Ocean into a prolonged low sea ice state.
南極海冰範圍自2015年開始減少，並在2023年達到1970年代後觀測時代的最低點。為了探
討導致海冰減少的驅動因素，我們分析了一個基於觀測資料的、涵蓋2013年至2023年的海
冰-海洋模型，並識別出海冰退縮的三個不同階段。
首先不斷增強的環極深層水（Circumpolar Deep Water）開始將來自深海的溫暖高鹽海水
帶到更接近海面的位置。
其次，2015年至2016年的強風增強了CDW向表層海洋的混合，從而引發了海冰的損失，尤
其是在南極東部。
第三，CDW持續向表層混合，加上赤道方向海冰來源的淡水輸出減少，維持了前所未有的
低海冰狀態。由於冰量減少，融化的冰層減少，導致海面保持高鹽度和溫暖狀態，從而
抑制了新冰的形成。