Poleward shift of Circumpolar Deep Water threatens the East Antarctic Ice Sheet
Poleward shift of Circumpolar Deep Water threatens the East Antarctic Ice Sheet
复制标题
DOI：
10.1038/s41558-022-01424-3
复制
发表时间：
2022-08-02
影响因子：
30.7
通讯作者：
Garabato, Alberto C. Naveira
中科院分区：
文献类型：
--
作者：
Herraiz-Borreguero, Laura;Garabato, Alberto C. Naveira
海洋变化可能会影响东南极冰盖及其对海平面上升的贡献。南极东部海域的海洋观测显示，与极地风向变化有关的中深度绕极深水大幅变暖，对冰川融化和冰盖稳定产生了影响。未来海平面上升的预测带有很大的不确定性，主要原因是南极冰盖对气候变化的未知反应。在过去的40年里，东南极冰盖对海平面上升的贡献有所增加。然而，与西南极不同，东南极冰块消失的原因在很大程度上还没有被探索出来。在这里，利用南极东部(东经80-160度)的海洋观测，我们发现在1930-1990年和2010-2018年期间，沿大陆斜坡的中深度绕极深水变暖了0.8-2.0摄氏度。我们的结果表明，这种变暖可能与南极东部冰块的减少和近岸水团的重组有关。此外，它还与南大洋上空西风带以夏季为中心的年代际极移有关。由于这种变化预计将持续到21世纪，南极洲东部的海洋热供应可能会继续加强，威胁到冰盖未来的稳定。
Ocean changes could affect the East Antarctic Ice Sheet and its contribution to sea level rise. Oceanographic observations off East Antarctica show substantial warming of mid-depth Circumpolar Deep Water, linked to poleward wind shifts, with implications for glacial melt and ice sheet stability.Future sea-level rise projections carry large uncertainties, mainly driven by the unknown response of the Antarctic Ice Sheet to climate change. During the past four decades, the contribution of the East Antarctic Ice Sheet to sea-level rise has increased. However, unlike for West Antarctica, the causes of East Antarctic ice-mass loss are largely unexplored. Here, using oceanographic observations off East Antarctica (80-160 degrees E) we show that mid-depth Circumpolar Deep Water has warmed by 0.8-2.0 degrees C along the continental slope between 1930-1990 and 2010-2018. Our results indicate that this warming may be implicated in East Antarctic ice-mass loss and coastal water-mass reorganization. Further, it is associated with an interdecadal, summer-focused poleward shift of the westerlies over the Southern Ocean. Since this shift is predicted to persist into the twenty-first century, the oceanic heat supply to East Antarctica may continue to intensify, threatening the ice sheet's future stability.