气候变化领域集成服务门户(CCPortal): Ocean melting of the Zachariae Isstrøm and nioghalvfjerdsfjorden glaciers, northeast Greenland

CCPortal

DOI	10.1073/pnas.2015483118
	Ocean melting of the Zachariae Isstrøm and nioghalvfjerdsfjorden glaciers, northeast Greenland
	An L.; Rignot E.; Wood M.; Willis J.K.; Mouginot J.; Khan S.A.
发表日期	2021
ISSN	00278424
卷号	118 期号:2
英文摘要	Zachariae Isstrøm (ZI) and Nioghalvfjerdsfjorden (79N) are marine-terminating glaciers in northeast Greenland that hold an ice volume equivalent to a 1.1-m global sea level rise. ZI lost its floating ice shelf, sped up, retreated at 650 m/y, and experienced a 5-gigaton/y mass loss. Glacier 79N has been more stable despite its exposure to the same climate forcing. We analyze the impact of ocean thermal forcing on the glaciers. A three-dimensional inversion of airborne gravity data reveals an 800-m-deep, broad channel that allows subsurface, warm, Atlantic Intermediate Water (AIW) (+1.25◦C) to reach the front of ZI via two sills at 350-m depth. Subsurface ocean temperature in that channel has warmed by 1.3±0.5◦C since 1979. Using an ocean model, we calculate a rate of ice removal at the grounding line by the ocean that increased from 108 m/y to 185 m/y in 1979-2019. Observed ice thinning caused a retreat of its flotation line to increase from 105 m/y to 217 m/y, for a combined grounding line retreat of 13 km in 41 y that matches independent observations within 14%. In contrast, the limited access of AIW to 79N via a narrower passage yields lower grounded ice removal (53 m/y to 99 m/y) and thinning-induced retreat (27 m/y to 50 m/y) for a combined retreat of 4.4 km, also within 12% of observations. Ocean-induced removal of ice at the grounding line, modulated by bathymetric barriers, is therefore a main driver of ice sheet retreat, but it is not incorporated in most ice sheet models. © This open access article is distributed under Creative Commons Attribution-NonCommercialNoDerivatives License 4.0 (CC BY-NC-ND).
英文关键词	Climate; Glaciology; Greenland; Ice-ocean interaction; Sea level
语种	英语
scopus关键词	Article; Atlantic Ocean; climate change; conductance; deglaciation; environmental impact; environmental protection; flotation; Greenland; heat loss; ice sheet; measurement accuracy; ocean current; priority journal; salinity; satellite imagery; seasonal variation; snowmelt runoff; steady state; summer; water temperature; winter
来源期刊	Proceedings of the National Academy of Sciences of the United States of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/181081
作者单位	Department of Earth System Science, University of California, Irvine, CA 92617, United States; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, United States; Department of Civil and Environmental Engineering, University of California, Irvine, CA 92617, United States; University of Grenoble Alpes, CNRS, Institut de Recherche pour le Développement, Grenoble Institute of Engineering, Institute of Environmental Geosciences, Grenoble, 38031, France; National Space Institute, Geodesy and Earth Observation, Technical University of Denmark, Lyngby, 2800, Denmark
推荐引用方式 GB/T 7714	An L.,Rignot E.,Wood M.,et al. Ocean melting of the Zachariae Isstrøm and nioghalvfjerdsfjorden glaciers, northeast Greenland[J],2021,118(2).
APA	An L.,Rignot E.,Wood M.,Willis J.K.,Mouginot J.,&Khan S.A..(2021).Ocean melting of the Zachariae Isstrøm and nioghalvfjerdsfjorden glaciers, northeast Greenland.Proceedings of the National Academy of Sciences of the United States of America,118(2).
MLA	An L.,et al."Ocean melting of the Zachariae Isstrøm and nioghalvfjerdsfjorden glaciers, northeast Greenland".Proceedings of the National Academy of Sciences of the United States of America 118.2(2021).