Subglacial Plumes
Subglacial Plumes
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DOI：
10.1146/annurev-fluid-010719-060252
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
I. Hewitt
中科院分区：
文献类型：
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作者：
I. Hewitt
当冰川冰直接融化到海洋中，或者当冰川下融化的水在深处排放到海洋中时，浮力羽流就会形成。它们在调节从海洋到冰锋的热量传输以及向开阔海洋输出冰川融水方面发挥着关键作用。本文综述了目前对这些羽流动力学的认识，重点介绍了理论发展及其对海底熔融速率的预测。这些预测对海洋温度、冰下流量的大小和空间分布、环境分层以及在冰架下羽流的情况下冰架的几何形状很敏感。然而，目前的理解在很大程度上依赖于熔化和夹带的参数化，而对于这些参数，几乎没有验证的方法。需要新的观测和实验约束来阐明羽流的结构，并给予模型更大的信心。
Buoyant plumes form when glacial ice melts directly into the ocean or when subglacial meltwater is discharged to the ocean at depth. They play a key role in regulating heat transport from the ocean to the ice front, and in exporting glacial meltwater to the open ocean. This review summarises current understanding of the dynamics of these plumes, focussing on theoretical developments and their predictions for submarine melt rates. These predictions are sensitive to ocean temperature, the magnitude and spatial distribution of subglacial discharge, the ambient stratification and, in the case of sub-ice-shelf plumes, the geometry of the ice shelf. However, current understanding relies heavily on parameterisations of melting and entrainment for which there is little in the way of validation. New observational and experimental constraints are needed to elucidate the structure of the plumes and lend greater confidence to the models.