气候变化领域集成服务门户(CCPortal): Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet

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DOI	10.5194/tc-12-3813-2018
	Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet
	King M.D.; Howat I.M.; Jeong S.; Noh M.J.; Wouters B.; Noël B.; Van Den Broeke M.R.
发表日期	2018
ISSN	19940416
卷号	12 期号:12
英文摘要	Rapid changes in thickness and velocity have been observed at many marine-terminating glaciers in Greenland, impacting the volume of ice they export, or discharge, from the ice sheet. While annual estimates of ice-sheet-wide discharge have been previously derived, higher-resolution records are required to fully constrain the temporal response of these glaciers to various climatic and mechanical drivers that vary in sub-annual scales. Here we sample outlet glaciers wider than 1 km (N = 230) to derive the first continuous, ice-sheet-wide record of total ice sheet discharge for the 2000-2016 period, resolving a seasonal variability of 6 %. The amplitude of seasonality varies spatially across the ice sheet from 5 % in the southeastern region to 9 % in the northwest region. We analyze seasonal to annual variability in the discharge time series with respect to both modeled meltwater runoff, obtained from RACMO2.3p2, and glacier front position changes over the same period. We find that year-to-year changes in total ice sheet discharge are related to annual front changes (r2 = 0.59, p = 10-4) and that the annual magnitude of discharge is closely related to cumulative front position changes (r2 = 0.79), which show a net retreat of >400 km, or an average retreat of >2 km, at each surveyed glacier. Neither maximum seasonal runoff or annual runoff totals are correlated to annual discharge, which suggests that larger annual quantities of runoff do not relate to increased annual discharge. Discharge and runoff, however, follow similar patterns of seasonal variability with near-coincident periods of acceleration and seasonal maxima. These results suggest that changes in glacier front position drive secular trends in discharge, whereas the impact of runoff is likely limited to the summer months when observed seasonal variations are substantially controlled by the timing of meltwater input. © Author(s) 2018.
学科领域	decadal variation; glacier; ice sheet; meltwater; runoff; seasonal variation; seasonality; Arctic; Greenland; Greenland Ice Sheet
语种	英语
scopus关键词	decadal variation; glacier; ice sheet; meltwater; runoff; seasonal variation; seasonality; Arctic; Greenland; Greenland Ice Sheet
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/119018
作者单位	Byrd Polar and Climate Research Center, Columbus, OH, United States; School of Earth Sciences, Ohio State University, Columbus, OH, United States; Department of Earth System Science, University of California, Irvine, CA, United States; Institute for Marine and Atmospheric research Utrecht, Utrecht University, Utrecht, Netherlands; Faculty of Civil Engineering and Geosciences, Delft University of Technology, Delft, Netherlands
推荐引用方式 GB/T 7714	King M.D.,Howat I.M.,Jeong S.,et al. Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet[J],2018,12(12).
APA	King M.D..,Howat I.M..,Jeong S..,Noh M.J..,Wouters B..,...&Van Den Broeke M.R..(2018).Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet.Cryosphere,12(12).
MLA	King M.D.,et al."Seasonal to decadal variability in ice discharge from the Greenland Ice Sheet".Cryosphere 12.12(2018).