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Daniel McGrath

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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...
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Assessing the Vulnerability of Alaska’s Glaciers in a Changing Climate
Retreating glaciers are an iconic image of climate change;yet not all glaciers in Alaska are actively retreating, and a few glaciers are even advancing. While this contrasting behavior can be misleading for the casual observer, variable responses between glaciers in a changing climate are expected. Glaciers act as conveyor belts that transport snow and ice from high elevations, where it does not melt, down to low elevations, where it does melt. A change in climate can impact the amount of snow and ice that accumulates (accumulation), the way snow and ice melt (ablation), or the conveyor belt (ice dynamics). While these impacts vary with elevation and glacier shape, glacier changes have major implications for downstream...
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Ice2O: A Continued Assessment of Icefield-to-Ocean Change in the Pacific Coastal Temperate Rainforest
The Gulf of Alaska is one of the most productive marine ecosystems on Earth, supporting salmon fisheries that alone provide large economic benefits to Southeast Alaska. The region also has a vibrant and growing tourism industry. Glaciers are central to many of the area’s natural processes and economic activities, but the rates of glacier loss in Alaska are among the highest on Earth. Glacier loss threatens to significantly change the amount and timing of nutrients delivered by streams to near-shore habitats. Changes in glacier runoff into the ocean may also impact coastal currents that contribute to vibrant nearshore marine ecosystems. Improving our understanding of how ecosystems depend on glaciers and what glacier...
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