Warmer ocean conditions could impact future ice loss from Antarctica due to their ability to thin and reduce the buttressing of laterally confined ice shelves. Previous studies highlight the potential for a cold to warm ocean regime shift within the sub-shelf cavities of the two largest Antarctic ice shelves—the Filchner–Ronne and Ross. However, how this impacts upstream ice flow and mass loss has not been quantified. Here using an ice sheet model and an ensemble of ocean-circulation model sub-shelf melt rates, we show that transition to a warm state in those ice shelf cavities leads to a destabilization and irreversible grounding line retreat in some locations. Once this ocean shift takes place, ice loss from the Filchner–Ronne and Ross catchments is greatly accelerated, and conditions begin to resemble those of the present-day Amundsen Sea sector—responsible for most current observed Antarctic ice loss—where this thermal shift has already occurred.

海洋条件变暖可能会影响南极洲未来的冰损失，因为它们能够使横向限制的冰架变薄并减少支撑。先前的研究强调了两个最大的南极冰架——菲尔希纳-龙纳冰架和罗斯冰架的亚架空腔内海洋状况从冷向暖转变的可能性。然而，这对上游冰流和质量损失的影响尚未量化。在这里，我们使用冰盖模型和海洋环流模型子架融化速率的集合，表明这些冰架空腔向温暖状态的转变会导致某些位置的不稳定和不可逆转的接地线后退。一旦发生这种海洋转移，菲尔希纳-罗讷和罗斯流域的冰损失就会大大加速，并且条件开始类似于现在的阿蒙森海区（负责目前观察到的大多数南极冰损失），这种热转移已经在那里发生了。已经发生了。