Cheng Chen, Jenkins Adrian, Holland Paul R, Wang Zhaomin, Dong Jihai, Liu Chengyan
Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai, 519080, China.
Department of Geography and Environmental Sciences, Faculty of Engineering and Environment, Northumbria University, Newcastle upon Tyne, NE1 8ST, UK.
Nat Commun. 2024 Apr 3;15(1):2877. doi: 10.1038/s41467-024-47351-z.
Growing evidence has confirmed the critical role played by basal channels beneath Antarctic ice shelves in both ice shelf stability and freshwater input to the surrounding ocean. Here we show, using a 3D ice shelf-ocean boundary current model, that deeper basal channels can lead to a significant amplification in channelized basal melting, meltwater channeling, and warming and salinization of the channel flow. All of these channelized quantities are also modulated by channel width, with the level of modulation determined by channel height. The explicit quantification of channelized basal melting and the meltwater transport in terms of channel cross-sectional shape is potentially beneficial for the evaluation of ice shelf mass balance and meltwater contribution to the nearshore oceanography. Complicated topographically controlled circulations are revealed to be responsible for the unique thermohaline structure inside deep channels. Our study emphasizes the need for improvement in observations of evolving basal channels and the hydrography inside them, as well as adjacent to the ice front where channelized meltwater emerges.
越来越多的证据证实了南极冰架下方的底部通道在冰架稳定性以及向周围海洋输入淡水方面所起的关键作用。在此，我们使用三维冰架 - 海洋边界流模型表明，更深的底部通道会导致通道化底部融化、融水通道化以及通道水流的变暖和盐化显著增强。所有这些通道化的量也受到通道宽度的调节，调节程度由通道高度决定。根据通道横截面形状对通道化底部融化和融水输送进行明确量化，可能有助于评估冰架质量平衡以及融水对近岸海洋学的贡献。研究发现复杂的地形控制环流是深通道内部独特热盐结构的成因。我们的研究强调需要改进对不断演变的底部通道及其内部以及冰架前端附近（通道化融水在此处流出）的水文状况的观测。
