气候变化领域集成服务门户(CCPortal): The role of double-diffusive convection in basal melting of Antarctic ice shelves

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DOI	10.1073/pnas.2007541118
	The role of double-diffusive convection in basal melting of Antarctic ice shelves
	Rosevear M.G.; Gayen B.; Galton-Fenzi B.K.
发表日期	2021
ISSN	00278424
卷号	118 期号:6
英文摘要	The Antarctic Ice Sheet loses about half its mass through ocean-driven melting of its fringing ice shelves. However, the ocean processes governing ice shelf melting are not well understood, contributing to uncertainty in projections of Antarctica's contribution to global sea level. We use high-resolution large-eddy simulation to examine ocean-driven melt, in a geophysical-scale model of the turbulent ice shelf-ocean boundary layer, focusing on the ocean conditions observed beneath the Ross Ice Shelf. We quantify the role of double-diffusive convection in determining ice shelf melt rates and oceanic mixed layer properties in relatively warm and low-velocity cavity environments. We demonstrate that double-diffusive convection is the first-order process controlling the melt rate and mixed layer evolution at these flow conditions, even more important than vertical shear due to a mean flow, and is responsible for the step-like temperature and salinity structure, or thermohaline staircase, observed beneath the ice. A robust feature of the multiday simulations is a growing saline diffusive sublayer that drives a time-dependent melt rate. This melt rate is lower than current ice-ocean parameterizations, which consider only shear-controlled turbulent melting, would predict. Our main finding is that double-diffusive convection is an important process beneath ice shelves, yet is currently neglected in ocean-climate models. © 2021 National Academy of Sciences. All rights reserved.
英文关键词	Basal melting of antarctic ice shelves; Double-diffusive convection; Ice-ocean interactions; Large-eddy simulation; Thermohaline staircases
语种	英语
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/180769
作者单位	Institute of Marine and Antarctic Studies, University of Tasmania, Hobart, TAS 7004, Australia; Department of Mechanical Engineering, University of Melbourne, Melbourne, VIC 3010, Australia; Centre for Atmospheric and Oceanic Sciences, Indian Institute of Science, Bengaluru, 560012, India; Australian Antarctic Division, Kingston, TAS 7050, Australia; Australian Antarctic Program Partnership, University of Tasmania, Hobart, TAS 7004, Australia
推荐引用方式 GB/T 7714	Rosevear M.G.,Gayen B.,Galton-Fenzi B.K.. The role of double-diffusive convection in basal melting of Antarctic ice shelves[J],2021,118(6).
APA	Rosevear M.G.,Gayen B.,&Galton-Fenzi B.K..(2021).The role of double-diffusive convection in basal melting of Antarctic ice shelves.Proceedings of the National Academy of Sciences of the United States of America,118(6).
MLA	Rosevear M.G.,et al."The role of double-diffusive convection in basal melting of Antarctic ice shelves".Proceedings of the National Academy of Sciences of the United States of America 118.6(2021).