Strong Ocean Melting Feedback During the Recent Retreat of Thwaites Glacier
Strong Ocean Melting Feedback During the Recent Retreat of Thwaites Glacier
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DOI：
10.1029/2023gl103088
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发表时间：
2023-04
影响因子：
5.2
通讯作者：
P. Holland;S. Bevan;A. Luckman
中科院分区：
文献类型：
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作者：
P. Holland;S. Bevan;A. Luckman
思韦茨冰川的加速消融对全球海平面上升的贡献约为5%，并可能在未来几个世纪使海平面上升数十厘米。我们使用海洋模型计算了2011年至2022年Thwaites冰川主干的一系列数字高程模型的冰下融化。在这一时期，冰的演化对融化产生了强烈的几何反馈。冰的减薄和退缩使融化面积更大，冰下水柱更厚，连接更好，冰底更陡。这导致了更强的冰下洋流，在没有任何来自更广阔海洋条件的强迫变化的情况下，增加了30%以上的融化。这种仅12年的几何反馈与海洋条件和冰下融水流入的世纪尺度变化引起的融化变化相当。这些发现表明，由海洋驱动的Thwaites冰川的冰损失可能只受到人为排放减缓的微弱影响。
Accelerating ice loss from Thwaites Glacier is contributing approximately 5% of global sea‐level rise, and could add tens of centimeters to sea level over the coming centuries. We use an ocean model to calculate sub‐ice melting for a succession of Digital Elevation Models of the main trunk of Thwaites Glacier from 2011 to 2022. The ice evolution during this period induces a strong geometrical feedback onto melting. Ice thinning and retreat provides a larger melting area, thicker and better‐connected sub‐ice water column, and steeper ice base. This leads to stronger sub‐ice ocean currents, increasing melting by over 30% without any change in forcing from wider ocean conditions. This geometrical feedback over just 12 years is comparable to melting changes arising from plausible century‐scale changes in ocean conditions and subglacial meltwater inflow. These findings imply that ocean‐driven ice loss from Thwaites Glacier may only be weakly influenced by anthropogenic emissions mitigation.