A Field Study of Snowpack Ablation at Sagehen Creek Field Station

Preliminary results of a field experiment at Sagehen Creek Field Station, CA during the 2018/2019 winter season are presented. We deployed five flux towers across a subalpine forest/meadow transition zone to compare ablation processes of proximal sites. Differences in longwave and shortwave radiation, air temperature, and sublimation were observed between the five sites, varying with solar aspect, tree density, and other locale-specific parameters. Longwave exitance from snow had a sphere of influence less than 10 m whereas shortwave insolation had a range of influence up to an order of magnitude greater and depended on sun angle and tree height. Sublimation differences between sites were magnified as wind speed increased. Drifted snow caused by an isolated tree was not significant for this warm snow site.