气候变化领域集成服务门户(CCPortal): Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years

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DOI	10.5194/tc-12-521-2018
	Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years
	Gardner A.S.; Moholdt G.; Scambos T.; Fahnstock M.; Ligtenberg S.; Van Den Broeke M.; Nilsson J.
发表日期	2018
ISSN	19940416
卷号	12 期号:2
英文摘要	Ice discharge from large ice sheets plays a direct role in determining rates of sea-level rise. We map present-day Antarctic-wide surface velocities using Landsat 7 and 8 imagery spanning 2013-2015 and compare to earlier estimates derived from synthetic aperture radar, revealing heterogeneous changes in ice flow since ∼2008. The new mapping provides complete coastal and inland coverage of ice velocity north of 82.4°S with a mean error of <10myr-1, resulting from multiple overlapping image pairs acquired during the daylight period. Using an optimized flux gate, ice discharge from Antarctica is 1929±40 Gigatons per year (Gtyr-1) in 2015, an increase of 36±15Gtyr-1 from the time of the radar mapping. Flow accelerations across the grounding lines of West Antarctica's Amundsen Sea Embayment, Getz Ice Shelf and Marguerite Bay on the western Antarctic Peninsula, account for 88% of this increase. In contrast, glaciers draining the East Antarctic Ice Sheet have been remarkably constant over the period of observation. Including modeled rates of snow accumulation and basal melt, the Antarctic ice sheet lost ice at an average rate of 183±94Gtyr-1 between 2008 and 2015. The modest increase in ice discharge over the past 7 years is contrasted by high rates of ice sheet mass loss and distinct spatial patters of elevation lowering. The West Antarctic Ice Sheet is experiencing high rates of mass loss and displays distinct patterns of elevation lowering that point to a dynamic imbalance. We find modest increase in ice discharge over the past 7 years, which suggests that the recent pattern of mass loss in Antarctica is part of a longer-term phase of enhanced glacier flow initiated in the decades leading up to the first continent-wide radar mapping of ice flow. © Author(s) 2018.
学科领域	basal melting; discharge; glacier flow; ice flow; ice sheet; Landsat; satellite imagery; sea level change; snow accumulation; synthetic aperture radar; Amundsen Sea; Antarctic Ice Sheet; Antarctic Ice Sheet; Antarctic Peninsula; Antarctica; East Antarctic Ice Sheet; East Antarctica; Getz Ice Shelf; Marguerite Bay; Southern Ocean; West Antarctic Ice Sheet; West Antarctica
语种	英语
scopus关键词	basal melting; discharge; glacier flow; ice flow; ice sheet; Landsat; satellite imagery; sea level change; snow accumulation; synthetic aperture radar; Amundsen Sea; Antarctic Ice Sheet; Antarctic Ice Sheet; Antarctic Peninsula; Antarctica; East Antarctic Ice Sheet; East Antarctica; Getz Ice Shelf; Marguerite Bay; Southern Ocean; West Antarctic Ice Sheet; West Antarctica
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/119222
作者单位	Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, United States; Norwegian Polar Institute, Fram Centre, Tromsø, 9296, Norway; National Snow and Ice Data Center (NSIDC), University of Colorado at Boulder, Boulder, CO 80303, United States; Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK 99775, United States; Institute for Marine and Atmospheric Research Utrecht (IMAU), Utrecht University, Utrecht, Netherlands
推荐引用方式 GB/T 7714	Gardner A.S.,Moholdt G.,Scambos T.,et al. Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years[J],2018,12(2).
APA	Gardner A.S..,Moholdt G..,Scambos T..,Fahnstock M..,Ligtenberg S..,...&Nilsson J..(2018).Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years.Cryosphere,12(2).
MLA	Gardner A.S.,et al."Increased West Antarctic and unchanged East Antarctic ice discharge over the last 7 years".Cryosphere 12.2(2018).