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Person

Louis Sass

Physical Scientist

Email: lsass@usgs.gov
Office Phone: 907-786-7460
Fax: 907-786-7150
ORCID: 0000-0003-4677-029X

Location
4210 University Drive
Anchorage , AK 99508-4626
US
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This dataset contains observations of the distribution of end-of-summer snow cover on approximately 3000 glaciers across Alaska and Northwest Canada. The data are provided as: (1) GeoTIFF rasters indicating the spatial extent of end-of-summer snow cover on each glacier's surface in each year (one raster per glacier per year), and (2) yearly tables with the equilibrium line altitude and the accumulation area ratio of the glaciers derived from the snow cover extent geotiffs. Snow cover was identified in Sentinel-2 imagery using a random forest algorithm trained with a manually-created validation dataset. A series of post-processing steps were used to infill missing data from terrain shadowing and cloud cover, and...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2016EF000479/full): Glacier hypsometry provides a first-order approach for assessing a glacier's response to climate forcings. We couple the Randolph Glacier Inventory to a suite of in situ observations and climate model output to examine potential change for the ∼27,000 glaciers in Alaska and northwest Canada through the end of the 21st century. By 2100, based on Representative Concentration Pathways (RCPs) 4.5–8.5 forcings, summer temperatures are predicted to increase between +2.1 and +4.6°C, while solid precipitation (snow) is predicted to decrease by −6 to −11%, despite a +9 to +21% increase in total precipitation. Snow is predicted to undergo a pronounced...
Abstract (from http://onlinelibrary.wiley.com/doi/10.1002/2015JF003539/abstract): A quantitative understanding of snow thickness and snow water equivalent (SWE) on glaciers is essential to a wide range of scientific and resource management topics. However, robust SWE estimates are observationally challenging, in part because SWE can vary abruptly over short distances in complex terrain due to interactions between topography and meteorological processes. In spring 2013, we measured snow accumulation on several glaciers around the Gulf of Alaska using both ground- and helicopter-based ground-penetrating radar surveys, complemented by extensive ground truth observations. We found that SWE can be highly variable (40%...
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