Arctic Perennial Snowfields are Shrinking

Lead researcher Molly Tedesche records measurements at a snowfield, high in the Brooks Range.

Chris Ciancibelli

Snowfields serve as habitat for a variety of wildlife, especially caribou that find relief from insect harassment there. Snowfields also influence hydrology, vegetation, permafrost, and protect valuable archaeological artifacts. A new study shows perennial snowfields in Gates of the Arctic National Park and Preserve are decreasing. Equilibrium areas, or bright areas, of the snowfields are shrinking, while ablation areas, or dark areas, are growing. Hydrologists and ecologists may use the information in this study, and others like it, to plan for ecological shifts, changes in water supplies for Arctic communities, and climate change adaptation. Local people who depend on caribou as a subsistence resource may be impacted as the caribou travel farther or change their routes to access existing snowfields. Archaeologists may prioritize areas where snowfields have recently retreated for exploration in order to document and protect newly exposed cultural resources.

Lead author Molly Tedesche was a Young Leaders in Climate Change intern with the park in 2015 when she conducted this research.

Extent Changes in the Perennial Snowfields of Gates of the Arctic National Park and Preserve, Alaska

Abstract

Perennial snowfields in Gates of the Arctic National Park and Preserve (GAAR) in the central Brooks Range of Alaska are a critical component of the cryosphere. They serve as habitat for an array of wildlife, including caribou, a species that is crucial as a food and cultural resource for rural subsistence hunters and Native Alaskans. Snowfields also influence hydrology, vegetation, permafrost, and have the potential to preserve valuable archaeological artifacts. By deriving time series maps using cloud computing and supervised classification of Landsat satellite imagery, we calculated areas and evaluated extent changes. We also derived changes in elevations of the perennial snowfields that remained stable for at least four years. For the study period of 1985 to 2017, we found that total areas of perennial snowfields in GAAR are decreasing, with most of the notable changes in the latter half of the study period. Equilibrium areas, or bright areas, of the snowfields are shrinking, while ablation, or dark areas, are growing. We also found that the snowfields occur at higher elevations over time. Climate change may be altering the distribution, elevation, and extent of perennial snowfields in GAAR, which could affect caribou populations and subsistence lifestyles in rural Alaska.

Tedesche, M. E., E. D. Trochim, S. R. Fassnacht, and G. J. Wolken. 2019. Extent Changes in the Perennial Snowfields of Gates of the Arctic National Park and Preserve, Alaska. Hydrology 6, 53.