气候变化领域集成服务门户(CCPortal): Impact of shrubs on winter surface albedo and snow specific surface area at a low arctic site: In situ measurements and simulations

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DOI	10.1175/JCLI-D-19-0318.1
	Impact of shrubs on winter surface albedo and snow specific surface area at a low arctic site: In situ measurements and simulations
	Belke-Brea M.; Domine F.; Barrere M.; Picard G.; Arnaud L.
发表日期	2020
ISSN	0894-8755
起始页码	597
结束页码	609
卷号	33 期号:2
英文摘要	Erect shrubs in the Arctic reduce surface albedo when branches protrude above the snow and modify snow properties, in particular specific surface area (SSA). Important consequences are changes in the land surface-atmosphere energy exchange and the increase of snow melting in autumn, possibly inducing reduced soil thermal insulation and in turn permafrost cooling. Near Umiujaq (56.58N, 76.58W) in the Canadian low Arctic where dwarf birches (Betula glandulosa) are expanding, spectral albedo (400-1080 nm) under diffuse light and vertical profiles of SSA were measured in November and December 2015 at four sites: three with protruding branches and one with only snow. At the beginning of the snow season (8 November), shrub-induced albedo reductions were found to be wavelength dependent and as high as 55% at 500 nm and 18% at 1000 nm, which, integrated over the measurement range (400-1080 nm), corresponds to 70 W m22 of additional absorbed energy. The impact of shrubs is not just snow darkening. They also affect snow SSA in multiple ways, by accumulating snow with high SSA during cold windy precipitation and favoring SSA decrease by inducing melting during warm spells. However, the impact on the radiation budget of direct darkening from shrubs likely dominates over the indirect change in SSA. Spectral albedo was simulated with a linear mixing equation (LME), which fitted well with observed spectra. The average root-mean-square error was 0.009. We conclude that LMEs are a suitable tool to parameterize mixed surface albedo in snow and climate models. © 2019 American Meteorological Society. For information regarding reuse of this content and general copyright information, consult the AMS Copyright Policy (www.ametsoc.org/PUBSReuseLicenses).
英文关键词	Budget control; Climate models; Mean square error; Melting; Solar radiation; Specific surface area; Thermal insulation; Albedo reduction; In-situ measurement; Measurement range; Radiation budget; Root mean square errors; Specific surface area (SSA); Spectral albedos; Vertical profile; Snow; albedo; computer simulation; error analysis; in situ measurement; melting; shrub; snow; winter; Betula glandulosa; Betula nana
语种	英语
来源期刊	Journal of Climate
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/171496
作者单位	Takuvik Joint International Laboratory, Université Laval, CNRS, INSU, Centre d'Études Nordiques, Canada; Department of Geography, Université Laval, Québec City, QC, Canada; Department of Chemistry, Université Laval, Québec City, QC, Canada; Météo-France, CNRS, CNRM, UMR 3589, CEN, Grenoble, France; Université Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble, France
推荐引用方式 GB/T 7714	Belke-Brea M.,Domine F.,Barrere M.,et al. Impact of shrubs on winter surface albedo and snow specific surface area at a low arctic site: In situ measurements and simulations[J],2020,33(2).
APA	Belke-Brea M.,Domine F.,Barrere M.,Picard G.,&Arnaud L..(2020).Impact of shrubs on winter surface albedo and snow specific surface area at a low arctic site: In situ measurements and simulations.Journal of Climate,33(2).
MLA	Belke-Brea M.,et al."Impact of shrubs on winter surface albedo and snow specific surface area at a low arctic site: In situ measurements and simulations".Journal of Climate 33.2(2020).