00637nas a2200169   4500008004100000245013500041210006900176260001200245300001400257490000600271100002100277700002500298700002500323700002200348700003300370856006400403       2013                        eng d00aSeasonal controls on snow distribution and aerial ablation at the snow-patch and landscape scales, McMurdo Dry Valleys, Antarctica0 aSeasonal controls on snow distribution and aerial ablation at th  c09/2013  a917 - 9310 v71 aEveland, Jeffery1 aGooseff, Michael, N.1 aLampkin, Derrick, J.1 aBarrett, John, E.1 aTakacs-Vesbach, Cristina, D.  uhttp://www.the-cryosphere.net/7/917/2013/tc-7-917-2013.html00619nas a2200169   4500008004100000245011800041210006900159260001200228300001600240490000700256100002100263700002500284700002500309700002200334700003300356856006000389       2013                        eng d00aSpatial and temporal patterns of snow accumulation and aerial ablation across the McMurdo Dry Valleys, Antarctica0 aSpatial and temporal patterns of snow accumulation and aerial ab  c09/2013  a2864 - 28750 v271 aEveland, Jeffery1 aGooseff, Michael, N.1 aLampkin, Derrick, J.1 aBarrett, John, E.1 aTakacs-Vesbach, Cristina, D.  uhttp://onlinelibrary.wiley.com/doi/10.1002/hyp.9407/pdf03506nas a2200133   4500008004100000245006900041210006700110260004000177490000900217520305100226100002103277700002503298856004903323       2012                        eng d00aSnow dynamics in a polar desert, McMurdo Dry Valleys, Antarctica0 aSnow dynamics in a polar desert McMurdo Dry Valleys Antarctica  bPennsylvania State Universityc20120 vM.S.3 a<p>Snow in the McMurdo Dry Valleys is rare source of moisture for subnivian soils (beneath snow) in a cold desert ecosystem. While sublimation dominates the ablation process, measurable increases in soil moisture are expected to provide more favorable conditions for subnivian soil communities. In addition, snow cover insulates the underlying soil from temperature extremes. Quantifying the spatial distribution and ablation patterns of seasonal snow is necessary to understand these dynamics. Annual snowfall varies spatially ranging from 3 to 50 mm of snow water equivalent, with greater amounts occurring at the coast. Despite receiving very little precipitation, significant amounts of snow can accumulate (via aeolian redistribution) in topographic lees at the valley bottoms, forming thousands of discontinuous patches (typically 1-100 m<sup>2</sup> in area). These patches have the potential to act as fertility islands, controlling the landscape distribution of microbial communities, and biogeochemical cycling.</p><p>High resolution imagery acquired during the 2009-2010 and 2010-2011 austral summers was used to quantify the distribution of snow across Taylor and Wright Valleys. An object-based classification was used to extract snow-covered area from the imagery. Coupled with topographic parameters, unique distribution patterns were characterized for 5 regions within the neighboring valleys. Time lapses of snow distribution during each season in each region provide insight into spatially characterizing the aerial ablation rates (change in area of landscape covered by snow) across the valleys. The distribution of snow-covered area during the 2009-2010 austral summer is used as a baseline for seasonal comparison. The surrounding regions of Lake Fryxell, Lake Hoare, Lake Bonney, Lake Brownworth, and Lake Vanda exhibited losses of snow-covered area of 9.61 km<sup>2</sup> (-93%), 1.63 km<sup>2</sup> (-72%), 1.07 km<sup>2</sup> (-97%), 2.60 km<sup>2</sup> (-82%), and 0.25 km<sup>2</sup> (- 96%) respectively, as measured from peak accumulation in October to mid-January during the&nbsp;2009-2010 season. Differences in aerial ablation rates within and across local regions suggest that both topographic variation and regional microclimates influence the ablation of seasonal snow cover. Elevation has shown to be the strongest control over aerial ablation. Fifteen 1 km<sup>2</sup> plots (3 in each region) were selected to assess the prevalence of snow cover at smaller scales. Results confirm that snow patches form in the same locations each year with some minor deviations observed. Stable isotopes from snow patches also provide insights into temporal and spatial processes associated with ablation. At the snow patch scale, neighboring patches often exhibit considerable differences in aerial ablation rates, presumably controlled by snow depth. 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.</p>1 aEveland, Jeffery1 aGooseff, Michael, N.  uhttps://etda.libraries.psu.edu/catalog/12680