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DOI	10.5194/tc-14-769-2020
	The seasonal evolution of albedo across glaciers and the surrounding landscape of Taylor Valley, Antarctica
	Bergstrom, Anna 1; Gooseff, Michael N.2; Myers, Madeline 3; Doran, Peter T.3; Cross, Julian M.4
通讯作者	Bergstrom, Anna
来源期刊	CRYOSPHERE
ISSN	1994-0416
EISSN	1994-0424
出版年	2020
卷号	14 期号:3 页码:769-788
英文摘要	The McMurdo Dry Valleys (MDVs) of Antarctica are a polar desert ecosystem consisting of alpine glaciers, ice-covered lakes, streams, and expanses of vegetation-free rocky soil. Because average summer temperatures are close to 0 degrees C, the MDV ecosystem in general, and glacier melt dynamics in particular, are both closely linked to the energy balance. A slight increase in incoming radiation or change in albedo can have large effects on the timing and volume of meltwater. However, the seasonal evolution or spatial variability of albedo in the valleys has yet to fully characterized. In this study, we aim to understand the drivers of landscape albedo change within and across seasons. To do so, a box with a camera, GPS, and shortwave radiometer was hung from a helicopter that flew transects four to five times a season along Taylor Valley. Measurements were repeated over three seasons. These data were coupled with incoming radiation measured at six meteorological stations distributed along the valley to calculate the distribution of albedo across individual glaciers, lakes, and soil surfaces. We hypothesized that albedo would decrease throughout the austral summer with ablation of snow patches and increasing sediment exposure on the glacier and lake surfaces. However, small snow events (< 6 mm water equivalent) coupled with ice whitening caused spatial and temporal variability of albedo across the entire landscape. Glaciers frequently followed a pattern of increasing albedo with increasing elevation, as well as increasing albedo moving from east to west laterally across the ablation zone. We suggest that spatial patterns of albedo are a function of landscape morphology trapping snow and sediment, longitudinal gradients in snowfall magnitude, and wind-driven snow redistribution from east to west along the valley. We also compare our albedo measurements to the MODIS albedo product and found that overall the data have reasonable agreement. The mismatch in spatial scale between these two datasets results in variability, which is reduced after a snow event due to albedo following valley-scale gradients of snowfall magnitude. These findings highlight the importance of understanding the spatial and temporal variability in albedo and the close coupling of climate and landscape response. This new understanding of landscape albedo can constrain landscape energy budgets, better predict meltwater generation on from MDV glaciers, and how these ecosystems will respond to changing climate at the landscape scale.
类型	Article
语种	英语
国家	USA
开放获取类型	Green Published, gold
收录类别	SCI-E
WOS记录号	WOS:000518817700001
WOS关键词	MCMURDO DRY VALLEYS ; SURFACE-ENERGY BALANCE ; COVERED LAKE HOARE ; OPTICAL-PROPERTIES ; SEA-ICE ; SPECTRAL ALBEDO ; ABLATION ZONE ; SNOW SURFACE ; MODEL ; MORTERATSCHGLETSCHER
WOS类目	Geography, Physical ; Geosciences, Multidisciplinary
WOS研究方向	Physical Geography ; Geology
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/314293
作者单位	1.Univ Colorado, Dept Geol Sci, Boulder, CO 80305 USA; 2.Univ Colorado, Dept Civil Environm & Architectural Engn, Boulder, CO 80305 USA; 3.Louisiana State Univ, Dept Geol & Geophys, Baton Rouge, LA 70803 USA; 4.Portland State Univ, Dept Geol, Portland, OR 97201 USA
推荐引用方式 GB/T 7714	Bergstrom, Anna,Gooseff, Michael N.,Myers, Madeline,et al. The seasonal evolution of albedo across glaciers and the surrounding landscape of Taylor Valley, Antarctica[J],2020,14(3):769-788.
APA	Bergstrom, Anna,Gooseff, Michael N.,Myers, Madeline,Doran, Peter T.,&Cross, Julian M..(2020).The seasonal evolution of albedo across glaciers and the surrounding landscape of Taylor Valley, Antarctica.CRYOSPHERE,14(3),769-788.
MLA	Bergstrom, Anna,et al."The seasonal evolution of albedo across glaciers and the surrounding landscape of Taylor Valley, Antarctica".CRYOSPHERE 14.3(2020):769-788.