据悉，南极洲西部冰架融化速度加快的原因是，温暖的环极深水(CDW)通过测深槽被输送到大陆架上。这些流入是由一股向东的地下斜坡流(被称为南极斜坡暗流)提供的，它与当地风和潮汐的向西动量输入相反。尽管它对基底融化的研究很重要，但人们对暗流形成的机制以及控制海岸热传输的机制仍不清楚。
在这项研究中，研究人员利用耦合海洋、海冰和冰架组件的高分辨率面向过程，来研究暗流的动力学过程。结果表明，冰架空腔内融水上涌驱动了潜流向冰架的测深导向。因此，基底融化的增加加强了暗流并增强了陆地上的CDW的传输，表明正反馈可能加速未来冰架的融化，并进一步破坏南极西部冰盖的稳定。
附：英文原文
Title: Antarctic Slope Undercurrent and onshore heat transport driven by ice shelf melting
Author: Yidongfang Si, Andrew L. Stewart, Alessandro Silvano, Alberto C. Naveira Garabato
Issue&Volume: 2024-04-17
Abstract: Elevated ice shelf melt rates in West Antarctica have been attributed to transport of warm Circumpolar Deep Water (CDW) onto the continental shelf via bathymetric troughs. These inflows are supplied by an eastward, subsurface slope current (referred to as the Antarctic Slope Undercurrent) that opposes the westward momentum input from local winds and tides. Despite its importance to basal melt, the mechanism via which the undercurrent forms, and thus what controls the shoreward heat transport, remains unclear. In this study, the dynamics of the undercurrent are investigated using high-resolution process-oriented simulations with coupled ocean, sea ice, and ice shelf components. It is shown that the bathymetric steering of the undercurrent toward the ice shelf is driven by upwelling of meltwater within the ice shelf cavity. Increased basal melt therefore strengthens the undercurrent and enhances onshore CDW transport, which indicates a positive feedback that may accelerate future melt of ice shelves, potentially further destabilizing the West Antarctic Ice Sheet.
DOI: adl0601
Source: https://www.science.org/doi/10.1126/sciadv.adl0601