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| Titel |
Seasonal controls on snow distribution and aerial ablation at the snow-patch and landscape scales, McMurdo Dry Valleys, Antarctica |
| VerfasserIn |
J. W. Eveland, M. N. Gooseff, D. J. Lampkin, J. E. Barrett, C. D. Takacs-Vesbach |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 7, no. 3 ; Nr. 7, no. 3 (2013-06-11), S.917-931 |
| Datensatznummer |
250017975
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| Publikation (Nr.) |
 copernicus.org/tc-7-917-2013.pdf |
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| Zusammenfassung |
Accumulated snow in the McMurdo Dry Valleys, while limited, has great
ecological significance to subnivian soil environments. Though sublimation
dominates the ablation process in this region, measurable increases in soil
moisture and insulation from temperature extremes provide more favorable
conditions with respect to subnivian soil communities. While precipitation
is not substantial, significant amounts of snow can accumulate, via wind
transport, in topographic lees along the valley bottoms, forming thousands
of discontinuous snow patches. These patches have the potential to act as
significant sources of local meltwater, controlling biogeochemical cycling
and the landscape distribution of microbial communities. Therefore,
determining the spatial and temporal dynamics of snow at multiple scales is
imperative to understanding the broader ecological role of snow in this
region.
High-resolution satellite imagery acquired during the 2009–2010 and
2010–2011 austral summers was used to quantify the distribution of snow
across Taylor and Wright valleys. Extracted snow-covered area from the
imagery was used as the basis for assessing inter-annual variability and
seasonal controls on accumulation and ablation of snow at multiple scales.
In addition to landscape analyses, fifteen 1 km2 plots (3 in each of 5
study regions) were selected to assess the prevalence of snow cover at finer
spatial scales, referred to herein as the snow-patch scale. Results confirm
that snow patches tend to form in the same locations each year with some
minor deviations observed. At the snow-patch scale, neighboring patches
often exhibit considerable differences in aerial ablation rates, and
particular snow patches do not reflect trends for snow-covered area observed
at the landscape scale. These differences are presumably related to
microtopographic influences acting on individual snow patches, such as wind
sheltering and differences in snow depth due to the underlying topography.
This highlights the importance of both the landscape and snow-patch scales
in assessing the effects of snow cover on biogeochemical cycling and
microbial communities. |
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