Necessary Conditions for Warm Inflow Toward the Filchner Ice Shelf, Weddell Sea
Necessary Conditions for Warm Inflow Toward the Filchner Ice Shelf, Weddell Sea
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DOI：
10.1029/2020gl089237
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发表时间：
2020-11-28
影响因子：
5.2
通讯作者：
Hellmer, H. H.
中科院分区：
文献类型：
--
作者：
Daae, K.;Hattermann, T.;Hellmer, H. H.
了解南极冰架基底融化的变化是预测未来海平面的主要挑战。目前，南极洲周围温暖的环极深水限制了威德尔海大陆架的进入；因此，费尔奇纳-罗纳冰架的融化速度很低。然而，大尺度模式预估表明，南极坡锋和沿海环流的变化可能会在本世纪增强暖流。我们使用区域高分辨率冰架空洞和海洋环流模型来探索可能触发这种状态转变的强迫变化。我们的研究结果表明，支持持续温暖流入菲奇纳冰架空洞的两个必要条件是：(i)南极坡锋密度梯度的极度松弛和（ii）密集的冰架水的大量清新。研究还发现，威德尔海西部陆架上的陆架运输对菲奇纳海槽溢流特征非常敏感。
Understanding changes in Antarctic ice shelf basal melting is a major challenge for predicting future sea level. Currently, warm Circumpolar Deep Water surrounding Antarctica has limited access to the Weddell Sea continental shelf; consequently, melt rates at Filchner-Ronne Ice Shelf are low. However, large-scale model projections suggest that changes to the Antarctic Slope Front and the coastal circulation may enhance warm inflows within this century. We use a regional high-resolution ice shelf cavity and ocean circulation model to explore forcing changes that may trigger this regime shift. Our results suggest two necessary conditions for supporting a sustained warm inflow into the Filchner Ice Shelf cavity: (i) an extreme relaxation of the Antarctic Slope Front density gradient and (ii) substantial freshening of the dense shelf water. We also find that the on-shelf transport over the western Weddell Sea shelf is sensitive to the Filchner Trough overflow characteristics.