气候变化领域集成服务门户(CCPortal): Interannual snow accumulation variability on glaciers derived from repeat, spatially extensive ground-penetrating radar surveys

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DOI	10.5194/tc-12-3617-2018
	Interannual snow accumulation variability on glaciers derived from repeat, spatially extensive ground-penetrating radar surveys
	McGrath D.; Sass L.; O'Neel S.; McNeil C.; Candela S.G.; Baker E.H.; Marshall H.-P.
发表日期	2018
ISSN	19940416
卷号	12 期号:11
英文摘要	There is significant uncertainty regarding the spatiotemporal distribution of seasonal snow on glaciers, despite being a fundamental component of glacier mass balance. To address this knowledge gap, we collected repeat, spatially extensive high-frequency ground-penetrating radar (GPR) observations on two glaciers in Alaska during the spring of 5 consecutive years. GPR measurements showed steep snow water equivalent (SWE) elevation gradients at both sites; continental Gulkana Glacier's SWE gradient averaged 115 mm 100 mĝ'1 and maritime Wolverine Glacier's gradient averaged 440 mm 100 mĝ'1 (over > 1000 m). We extrapolated GPR point observations across the glacier surface using terrain parameters derived from digital elevation models as predictor variables in two statistical models (stepwise multivariable linear regression and regression trees). Elevation and proxies for wind redistribution had the greatest explanatory power, and exhibited relatively time-constant coefficients over the study period. Both statistical models yielded comparable estimates of glacier-wide average SWE (1 % average difference at Gulkana, 4 % average difference at Wolverine), although the spatial distributions produced by the models diverged in unsampled regions of the glacier, particularly at Wolverine. In total, six different methods for estimating the glacier-wide winter balance average agreed within ±11 %. We assessed interannual variability in the spatial pattern of snow accumulation predicted by the statistical models using two quantitative metrics. Both glaciers exhibited a high degree of temporal stability, with ĝ1/485 % of the glacier area experiencing less than 25 % normalized absolute variability over this 5-year interval. We found SWE at a sparse network (3 stakes per glacier) of long-term glaciological stake sites to be highly correlated with the GPR-derived glacier-wide average. We estimate that interannual variability in the spatial pattern of winter SWE accumulation is only a small component (4 %-10 % of glacier-wide average) of the total mass balance uncertainty and thus, our findings support the concept that sparse stake networks effectively measure interannual variability in winter balance on glaciers, rather than some temporally varying spatial pattern of snow accumulation. © Author(s) 2018.
学科领域	annual variation; frequency analysis; glacier mass balance; ground penetrating radar; parameterization; prediction; quantitative analysis; snow accumulation; spatiotemporal analysis; uncertainty analysis; Alaska; Gulkana Glacier; United States; Gulo gulo
语种	英语
scopus关键词	annual variation; frequency analysis; glacier mass balance; ground penetrating radar; parameterization; prediction; quantitative analysis; snow accumulation; spatiotemporal analysis; uncertainty analysis; Alaska; Gulkana Glacier; United States; Gulo gulo
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/119030
作者单位	Department of Geosciences, Colorado State University, Fort Collins, CO, United States; U.S. Geological Survey Alaska Science Center, Anchorage, AK, United States; School of Earth Sciences and Byrd Polar Research Center, Ohio State University, Columbus, OH, United States; Department of Geosciences, Boise State University, Boise, ID, United States
推荐引用方式 GB/T 7714	McGrath D.,Sass L.,O'Neel S.,et al. Interannual snow accumulation variability on glaciers derived from repeat, spatially extensive ground-penetrating radar surveys[J],2018,12(11).
APA	McGrath D..,Sass L..,O'Neel S..,McNeil C..,Candela S.G..,...&Marshall H.-P..(2018).Interannual snow accumulation variability on glaciers derived from repeat, spatially extensive ground-penetrating radar surveys.Cryosphere,12(11).
MLA	McGrath D.,et al."Interannual snow accumulation variability on glaciers derived from repeat, spatially extensive ground-penetrating radar surveys".Cryosphere 12.11(2018).