气候变化领域集成服务门户(CCPortal): Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica

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DOI	10.5194/tc-12-325-2018
	Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica
	Fegyveresi J.M.; Alley R.B.; Muto A.; Orsi A.J.; Spencer M.K.
发表日期	2018
ISSN	19940416
卷号	12 期号:1
英文摘要	Observations at the West Antarctic Ice Sheet (WAIS) Divide site show that near-surface snow is strongly altered by weather-related processes such as strong winds and temperature fluctuations, producing features that are recognizable in the deep ice core. Prominent "glazed" surface crusts develop frequently at the site during summer seasons. Surface, snow pit, and ice core observations made in this study during summer field seasons from 2008-2009 to 2012-2013, supplemented by automated weather station (AWS) data with short-and longwave radiation sensors, revealed that such crusts formed during relatively low-wind, lowhumidity, clear-sky periods with intense daytime sunshine. After formation, such glazed surfaces typically developed cracks in a polygonal pattern likely from thermal contraction at night. Cracking was commonest when several clear days occurred in succession and was generally followed by surface hoar growth; vapor escaping through the cracks during sunny days may have contributed to the high humidity that favored nighttime formation of surface hoar. Temperature and radiation observations show that daytime solar heating often warmed the near-surface snow above the air temperature, contributing to upward mass transfer, favoring crust formation from below, and then surface hoar formation. A simple surface energy calculation supports this observation Subsequent examination of the WDC06A deep ice core revealed that crusts are preserved through the bubbly ice, and some occur in snow accumulated during winters, although not as commonly as in summertime deposits. Although no one has been on site to observe crust formation during winter, it may be favored by greater wintertime wind packing from stronger peak winds, high temperatures and steep temperature gradients from rapid midwinter warmings reaching as high as -15°C, and perhaps longer intervals of surface stability. Time variations in crust occurrence in the core may provide paleoclimatic information, although additional studies are required. Discontinuity and cracking of crusts likely explain why crusts do not produce significant anomalies in other paleoclimatic records. © Author(s) 2018.
学科领域	crack; cracking (fracture); crust; heating; historical record; humidity; longwave radiation; paleoclimate; porosity; snow accumulation; summer; surface energy; surface layer; temperature anomaly; temperature profile; weather; weather station; wind profile; Antarctic Ice Sheet; Antarctica; West Antarctic Ice Sheet; West Antarctica
语种	英语
scopus关键词	crack; cracking (fracture); crust; heating; historical record; humidity; longwave radiation; paleoclimate; porosity; snow accumulation; summer; surface energy; surface layer; temperature anomaly; temperature profile; weather; weather station; wind profile; Antarctic Ice Sheet; Antarctica; 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/119230
作者单位	Terrestrial and Cryospheric Sciences Branch, US Cold Regions Research and Engineering Laboratory (CRREL), Hanover, NH 03755, United States; Dept. of Geosciences, Earth and Environmental Systems Institute, Pennsylvania State University, University Park, PA 16802, United States; Dept. of Earth and Environmental Science, College of Science and Technology, Temple University, Philadelphia, PA 19122, United States; Laboratoire des Sciences du Climat et de l'Environnement (LSCE), IPSL, CEA-CNRS, UVSQ, Université Paris-Saclay, Gif-sur-Yvette, 91191, France; School of Physical Sciences, Lake Superior State University, Sault Sainte Marie, MI 49783, United States
推荐引用方式 GB/T 7714	Fegyveresi J.M.,Alley R.B.,Muto A.,et al. Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica[J],2018,12(1).
APA	Fegyveresi J.M.,Alley R.B.,Muto A.,Orsi A.J.,&Spencer M.K..(2018).Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica.Cryosphere,12(1).
MLA	Fegyveresi J.M.,et al."Surface formation, preservation, and history of low-porosity crusts at the WAIS Divide site, West Antarctica".Cryosphere 12.1(2018).