DOI: 10.5194/tc-12-49-2018
Scopus记录号: 2-s2.0-85040528973
论文题名: Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes
作者: Lazeroms W ; M ; J ; , Jenkins A ; , Hilmar Gudmundsson G ; , Van De Wal R ; S ; W
刊名: Cryosphere
ISSN: 19940416
出版年: 2018
卷: 12, 期: 1 起始页码: 49
结束页码: 70
语种: 英语
英文关键词: algorithm
; basal melting
; ice shelf
; ice-ocean interaction
; melting
; meltwater
; modeling
; plume
; sea level change
; temperature effect
; Antarctic Ice Sheet
; Antarctica
; Antarctica
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. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/75446
Appears in Collections: 影响、适应和脆弱性 气候变化与战略
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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
Recommended Citation:
Lazeroms W,M,J,et al. Modelling present-day basal melt rates for Antarctic ice shelves using a parametrization of buoyant meltwater plumes[J]. Cryosphere,2018-01-01,12(1)