气候变化领域集成服务门户(CCPortal): Dynamic influence of pinning points on marine ice-sheet stability: A numerical study in Dronning Maud Land, East Antarctica

CCPortal

DOI	10.5194/tc-10-2623-2016
	Dynamic influence of pinning points on marine ice-sheet stability: A numerical study in Dronning Maud Land, East Antarctica
	Favier L.; Pattyn F.; Berger S.; Drews R.
发表日期	2016
ISSN	19940416
卷号	10 期号:6
英文摘要	The East Antarctic ice sheet is likely more stable than its West Antarctic counterpart because its bed is largely lying above sea level. However, the ice sheet in Dronning Maud Land, East Antarctica, contains marine sectors that are in contact with the ocean through overdeepened marine basins interspersed by grounded ice promontories and ice rises, pinning and stabilising the ice shelves. In this paper, we use the ice-sheet model BISICLES to investigate the effect of sub-ice-shelf melting, using a series of scenarios compliant with current values, on the ice-dynamic stability of the outlet glaciers between the Lazarev and Roi Baudouin ice shelves over the next millennium. Overall, the sub-ice-shelf melting substantially impacts the sea-level contribution. Locally, we predict a short-term rapid grounding-line retreat of the overdeepened outlet glacier Hansenbreen, which further induces the transition of the bordering ice promontories into ice rises. Furthermore, our analysis demonstrated that the onset of the marine ice-sheet retreat and subsequent promontory transition into ice rise is controlled by small pinning points, mostly uncharted in pan-Antarctic datasets. Pinning points have a twofold impact on marine ice sheets. They decrease the ice discharge by buttressing effect, and they play a crucial role in initialising marine ice sheets through data assimilation, leading to errors in ice-shelf rheology when omitted. Our results show that unpinning increases the sea-level rise by 10ĝ€%, while omitting the same pinning point in data assimilation decreases it by 10ĝ€ %, but the more striking effect is in the promontory transition time, advanced by two centuries for unpinning and delayed by almost half a millennium when the pinning point is missing in data assimilation. Pinning points exert a subtle influence on ice dynamics at the kilometre scale, which calls for a better knowledge of the Antarctic margins.
学科领域	data assimilation; data set; discharge; glacier; ice sheet; ice shelf; numerical model; rheology; sea level change; Antarctica; East Antarctica; Queen Maud Land
语种	英语
scopus关键词	data assimilation; data set; discharge; glacier; ice sheet; ice shelf; numerical model; rheology; sea level change; Antarctica; East Antarctica; Queen Maud Land
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/119552
作者单位	Laboratoire de Glaciologie, DGES, Université Libre de Bruxelles, Brussels, Belgium
推荐引用方式 GB/T 7714	Favier L.,Pattyn F.,Berger S.,et al. Dynamic influence of pinning points on marine ice-sheet stability: A numerical study in Dronning Maud Land, East Antarctica[J],2016,10(6).
APA	Favier L.,Pattyn F.,Berger S.,&Drews R..(2016).Dynamic influence of pinning points on marine ice-sheet stability: A numerical study in Dronning Maud Land, East Antarctica.Cryosphere,10(6).
MLA	Favier L.,et al."Dynamic influence of pinning points on marine ice-sheet stability: A numerical study in Dronning Maud Land, East Antarctica".Cryosphere 10.6(2016).