气候变化领域集成服务门户(CCPortal): Unprecedented atmospheric conditions (1948-2019) drive the 2019 exceptional melting season over the Greenland ice sheet

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DOI	10.5194/tc-14-1209-2020
	Unprecedented atmospheric conditions (1948-2019) drive the 2019 exceptional melting season over the Greenland ice sheet
	Tedesco M.; Fettweis X.
发表日期	2020
ISSN	19940416
起始页码	1209
结束页码	1223
卷号	14 期号:4
英文摘要	Understanding the role of atmospheric circulation anomalies on the surface mass balance of the Greenland ice sheet (GrIS) is fundamental for improving estimates of its current and future contributions to sea level rise. Here, we show, using a combination of remote sensing observations, regional climate model outputs, reanalysis data, and artificial neural networks, that unprecedented atmospheric conditions (1948-2019) occurring in the summer of 2019 over Greenland promoted new record or close-to-record values of surface mass balance (SMB), runoff, and snowfall. Specifically, runoff in 2019 ranked second within the 1948-2019 period (after 2012) and first in terms of surface mass balance negative anomaly for the hydrological year 1 September 2018-31 August 2019. The summer of 2019 was characterized by an exceptional persistence of anticyclonic conditions that, in conjunction with low albedo associated with reduced snowfall in summer, enhanced the melt-albedo feedback by promoting the absorption of solar radiation and favored advection of warm, moist air along the western portion of the ice sheet towards the north, where the surface melt has been the highest since 1948. The analysis of the frequency of daily 500 hPa geopotential heights obtained from artificial neural networks shows that the total number of days with the five most frequent atmospheric patterns that characterized the summer of 2019 was 5 standard deviations above the 1981-2010 mean, confirming the exceptional nature of the 2019 season over Greenland. © 2020 Author(s).
英文关键词	anticyclone; artificial neural network; atmospheric circulation; climate conditions; remote sensing; runoff; sea level change; seasonal variation; solar radiation; spatiotemporal analysis; Arctic; Greenland; Greenland Ice Sheet
语种	英语
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/202221
作者单位	Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY 10964, United States; NASA Goddard Institute for Space Studies, New York, NY 10025, United States; Department of Geography, University of Liège, Liège, 4000, Belgium
推荐引用方式 GB/T 7714	Tedesco M.,Fettweis X.. Unprecedented atmospheric conditions (1948-2019) drive the 2019 exceptional melting season over the Greenland ice sheet[J],2020,14(4).
APA	Tedesco M.,&Fettweis X..(2020).Unprecedented atmospheric conditions (1948-2019) drive the 2019 exceptional melting season over the Greenland ice sheet.Cryosphere,14(4).
MLA	Tedesco M.,et al."Unprecedented atmospheric conditions (1948-2019) drive the 2019 exceptional melting season over the Greenland ice sheet".Cryosphere 14.4(2020).