气候变化领域集成服务门户(CCPortal): Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes

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DOI	10.5194/tc-12-49-2018
	Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes
	Lazeroms W.M.J.; Jenkins A.; Hilmar Gudmundsson G.; Van De Wal R.S.W.
发表日期	2018
ISSN	19940416
卷号	12 期号:1
英文摘要	Basal melting below ice shelves is a major factor in mass loss from the Antarctic Ice Sheet, which can contribute significantly to possible future sea-level rise. Therefore, it is important to have an adequate description of the basal melt rates for use in ice-dynamical models. Most current ice models use rather simple parametrizations based on the local balance of heat between ice and ocean. In this work, however, we use a recently derived parametrization of the melt rates based on a buoyant meltwater plume travelling upward beneath an ice shelf. This plume parametrization combines a non-linear ocean temperature sensitivity with an inherent geometry dependence, which is mainly described by the grounding-line depth and the local slope of the ice-shelf base. For the first time, this type of parametrization is evaluated on a two-dimensional grid covering the entire Antarctic continent. In order to apply the essentially one-dimensional parametrization to realistic ice-shelf geometries, we present an algorithm that determines effective values for the grounding-line depth and basal slope in any point beneath an ice shelf. Furthermore, since detailed knowledge of temperatures and circulation patterns in the ice-shelf cavities is sparse or absent, we construct an effective ocean temperature field from observational data with the purpose of matching (area-averaged) melt rates from the model with observed present-day melt rates. Our results qualitatively replicate large-scale observed features in basal melt rates around Antarctica, not only in terms of average values, but also in terms of the spatial pattern, with high melt rates typically occurring near the grounding line. The plume parametrization and the effective temperature field presented here are therefore promising tools for future simulations of the Antarctic Ice Sheet requiring a more realistic oceanic forcing. © Author(s) 2018.
学科领域	algorithm; basal melting; ice shelf; ice-ocean interaction; melting; meltwater; modeling; plume; sea level change; temperature effect; Antarctic Ice Sheet; Antarctica; Antarctica
语种	英语
scopus关键词	algorithm; basal melting; ice shelf; ice-ocean interaction; melting; meltwater; modeling; plume; sea level change; temperature effect; Antarctic Ice Sheet; Antarctica; Antarctica
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119244
作者单位	Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Utrecht, Netherlands; British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom
推荐引用方式 GB/T 7714	Lazeroms W.M.J.,Jenkins A.,Hilmar Gudmundsson G.,et al. Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes[J],2018,12(1).
APA	Lazeroms W.M.J.,Jenkins A.,Hilmar Gudmundsson G.,&Van De Wal R.S.W..(2018).Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes.Cryosphere,12(1).
MLA	Lazeroms W.M.J.,et al."Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes".Cryosphere 12.1(2018).