气候变化领域集成服务门户(CCPortal): Ocean-driven millennial-scale variability of the Eurasian ice sheet during the last glacial period simulated with a hybrid ice-sheet-shelf model

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DOI	10.5194/cp-15-957-2019
	Ocean-driven millennial-scale variability of the Eurasian ice sheet during the last glacial period simulated with a hybrid ice-sheet-shelf model
	Alvarez-Solas J.; Banderas R.; Robinson A.; Montoya M.
发表日期	2019
ISSN	18149324
起始页码	957
结束页码	979
卷号	15 期号:3
英文摘要	The last glacial period (LGP; ca. 110-10 kyr BP) was marked by the existence of two types of abrupt climatic changes, Dansgaard-Oeschger (DO) and Heinrich (H) events. Although the mechanisms behind these are not fully understood, it is generally accepted that the presence of ice sheets played an important role in their occurrence. While an important effort has been made to investigate the dynamics and evolution of the Laurentide ice sheet (LIS) during this period, the Eurasian ice sheet (EIS) has not received much attention, in particular from a modeling perspective. However, meltwater discharge from this and other ice sheets surrounding the Nordic seas is often implied as a potential cause of ocean instabilities that lead to glacial abrupt climate changes. Thus, a better comprehension of the evolution of the EIS during the LGP is important to understand its role in glacial abrupt climate changes. Here we investigate the response of the EIS to millennial-scale climate variability during the LGP. We use a hybrid, three-dimensional, thermomechanical ice-sheet model that includes ice shelves and ice streams. The model is forced off-line via a novel perturbative approach that, as opposed to conventional methods, clearly differentiates between the spatial patterns of millennial-scale and orbital-scale climate variability. Thus, it provides a more realistic treatment of the forcing at millennial timescales. The effect of both atmospheric and oceanic variations are included. Our results show that the EIS responds with enhanced ice discharge in phase with interstadial warming in the North Atlantic when forced with surface ocean temperatures. Conversely, when subsurface ocean temperatures are used, enhanced ice discharge occurs both during stadials and at the beginning of the interstadials. Separating the atmospheric and oceanic effects demonstrates the major role of the ocean in controlling the dynamics of the EIS on millennial timescales. While the atmospheric forcing alone is only able to produce modest iceberg discharges, warming of the ocean leads to higher rates of iceberg discharges as a result of relatively strong basal melting at the margins of the ice sheet. Our results clearly show the capability of the EIS to react to glacial abrupt climate changes, and highlight the need for stronger constraints on the ice sheet's glacial dynamics and climate-ocean interactions. © 2019 Author(s).
语种	英语
scopus关键词	atmosphere-ocean system; atmospheric forcing; basal melting; climate change; ice sheet; ice shelf; ice stream; ice-ocean interaction; iceberg; interstadial; meltwater; Atlantic Ocean; Atlantic Ocean (North); Eurasia
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146815
作者单位	Departamento de Física de la Tierra y Astrofísica, Facultad de Ciencias Físicas, Universidad Complutense de Madrid (UCM), Madrid, Spain; Instituto de Geociencias (UCM-CSIC), Madrid, Spain
推荐引用方式 GB/T 7714	Alvarez-Solas J.,Banderas R.,Robinson A.,et al. Ocean-driven millennial-scale variability of the Eurasian ice sheet during the last glacial period simulated with a hybrid ice-sheet-shelf model[J],2019,15(3).
APA	Alvarez-Solas J.,Banderas R.,Robinson A.,&Montoya M..(2019).Ocean-driven millennial-scale variability of the Eurasian ice sheet during the last glacial period simulated with a hybrid ice-sheet-shelf model.Climate of the Past,15(3).
MLA	Alvarez-Solas J.,et al."Ocean-driven millennial-scale variability of the Eurasian ice sheet during the last glacial period simulated with a hybrid ice-sheet-shelf model".Climate of the Past 15.3(2019).