Spatial Evolution of Snow Melt On the Arctic Coast: A Field Campaign in Utqiaġvik, Alaska

Abstract:

The snow/ice albedo feedback has been identified as one of the key drivers of polar amplification, especially during the spring melt with the return of long daylight hours. From April through June of 2019, the Department of Energy Atmospheric System Research Program and the Atmospheric Radiation Measurement Program (ARM) co-funded a field campaign at the North Slope of Alaska (NSA) ARM facility in Utqiaġvik, Alaska to study simultaneously the evolution of snow melt and surface albedo. Three sites were established with 200-m fixed survey lines. The first site was located approximately one mile from the ocean, at the ARM central facility itself, the second site was established 3-miles further inland in the Barrow Ecological Observatory, and the third site was situated on sea ice in Elson Lagoon. During the observation period, data was regularly collected to examine the relative roles that solar radiation, snow properties and distribution, substrate types and (micro-) topography play in the process of spring melt. Measurements included surface spectral albedo from a high-resolution spectroradiometer, snow stratigraphy, depth, grain size distribution, impurities, as well as melt water and slush level observations. Additionally, pole-mounted photo-surveys were processed into high-resolution digital elevation models (DEM’s) and orthomosaics using structure-from-motion (SfM) techniques.

This poster will summarise the spatial and temporal snow depletion at the three sites over the duration of the field campaign. Using SfM techniques to monitor the evolving snow and ground surfaces greatly expanded our ability to determine snow distribution and surface characteristics throughout the melt, without disturbing the site. This detailed set of snowpack measurements, tied directly to albedo measurements, presents a unique opportunity to improve the understanding of the processes governing the dramatic change in albedo on both tundra and sea ice that takes place every spring in the Arctic.