气候变化领域集成服务门户(CCPortal): Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ

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DOI	10.5194/tc-10-597-2016
	Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ
	Muresan I.S.; Khan S.A.; Aschwanden A.; Khroulev C.; Van Dam T.; Bamber J.; Broeke M.R.V.D.; Wouters B.; Kuipers Munneke P.; Kjær K.H.
发表日期	2016
ISSN	19940416
卷号	10 期号:2
英文摘要	Observations over the past 2 decades show substantial ice loss associated with the speed-up of marineterminating glaciers in Greenland. Here we use a regional three-dimensional outlet glacier model to simulate the behaviour of Jakobshavn Isbræ (JI) located in western Greenland. Our approach is to model and understand the recent behaviour of JI with a physical process-based model. Using atmospheric forcing and an ocean parametrization we tune our model to reproduce observed frontal changes of JI during 1990-2014. In our simulations, most of the JI retreat during 1990-2014 is driven by the ocean parametrization used and the glacier's subsequent response, which is largely governed by bed geometry. In general, the study shows significant progress in modelling the temporal variability of the flow at JI. Our results suggest that the overall variability in modelled horizontal velocities is a response to variations in terminus position. The model simulates two major accelerations that are consistent with observations of changes in glacier terminus. The first event occurred in 1998 and was triggered by a retreat of the front and moderate thinning of JI prior to 1998. The second event, which started in 2003 and peaked in the summer 2004, was triggered by the final breakup of the floating tongue. This break-up reduced the buttressing at the JI terminus that resulted in further thinning. As the terminus retreated over a reverse bed slope into deeper water, sustained high velocities over the last decade have been observed at JI. Our model provides evidence that the 1998 and 2003 flow accelerations are most likely initiated by the ocean parametrization used but JI's subsequent dynamic response was governed by its own bed geometry. We are unable to reproduce the observed 2010-2012 terminus retreat in our simulations. We attribute this limitation to either inaccuracies in basal topography or to misrepresentations of the climatic forcings that were applied. Nevertheless, the model is able to simulate the previously observed increase in mass loss through 2014. © 2016 Author(s).
学科领域	atmospheric forcing; climate forcing; geometry; glacier dynamics; marine environment; temporal variation; three-dimensional modeling; topography; Arctic; Greenland; Jakobshavn Glacier
语种	英语
scopus关键词	atmospheric forcing; climate forcing; geometry; glacier dynamics; marine environment; temporal variation; three-dimensional modeling; topography; Arctic; Greenland; Jakobshavn Glacier
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/119687
作者单位	Department of Geodesy, DTU Space, Technical University of Denmark, Kgs. Lyngby, Denmark; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, United States; University of Luxembourg, Faculty of Science, Technology and Communication, Luxembourg, Luxembourg; University of Bristol, School of Geographical Sciences, Bristol, United Kingdom; Institute for Marine and Atmospheric Research Utrecht, Utrecht University, Netherlands; Centre for GeoGenetics, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, Denmark
推荐引用方式 GB/T 7714	Muresan I.S.,Khan S.A.,Aschwanden A.,et al. Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ[J],2016,10(2).
APA	Muresan I.S..,Khan S.A..,Aschwanden A..,Khroulev C..,Van Dam T..,...&Kjær K.H..(2016).Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ.Cryosphere,10(2).
MLA	Muresan I.S.,et al."Modelled glacier dynamics over the last quarter of a century at Jakobshavn Isbræ".Cryosphere 10.2(2016).