Hattermann Tore, Nicholls Keith W, Hellmer Hartmut H, Davis Peter E D, Janout Markus A, Østerhus Svein, Schlosser Elisabeth, Rohardt Gerd, Kanzow Torsten
Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany.
Akvaplan-niva AS, Tromsø, Norway.
Nat Commun. 2021 May 20;12(1):2961. doi: 10.1038/s41467-021-23131-x.
Floating ice shelves are the Achilles' heel of the Antarctic Ice Sheet. They limit Antarctica's contribution to global sea level rise, yet they can be rapidly melted from beneath by a warming ocean. At Filchner-Ronne Ice Shelf, a decline in sea ice formation may increase basal melt rates and accelerate marine ice sheet mass loss within this century. However, the understanding of this tipping-point behavior largely relies on numerical models. Our new multi-annual observations from five hot-water drilled boreholes through Filchner-Ronne Ice Shelf show that since 2015 there has been an intensification of the density-driven ice shelf cavity-wide circulation in response to reinforced wind-driven sea ice formation in the Ronne polynya. Enhanced southerly winds over Ronne Ice Shelf coincide with westward displacements of the Amundsen Sea Low position, connecting the cavity circulation with changes in large-scale atmospheric circulation patterns as a new aspect of the atmosphere-ocean-ice shelf system.
漂浮冰架是南极冰盖的薄弱环节。它们限制了南极洲对全球海平面上升的影响，但却可能因海洋变暖而从底部迅速融化。在菲尔希纳-龙尼冰架，海冰形成的减少可能会提高底部融化速度，并在本世纪内加速海洋冰盖的质量损失。然而，对这种临界点行为的理解很大程度上依赖于数值模型。我们通过在菲尔希纳-龙尼冰架上五个热水钻孔进行的新的多年观测表明，自2015年以来，由于龙尼冰间湖中风驱动海冰形成的增强，密度驱动的冰架腔内环流加剧。龙尼冰架上空增强的南风与阿蒙森海低压位置的西移相吻合，将腔内环流与大规模大气环流模式的变化联系起来，这是大气-海洋-冰架系统的一个新方面。
