MEASUREMENT OF SOLID-STATE PRECIPITATION AT THE WATERSHED SCALE IN THE ARCTIC

• Main Authors: Douglas L. Kane, Larry D. Hinzman, James P. Mcnamara, Beau Griggs
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Arctic; Sturm
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.621.812; http://acsys.npolar.no/reports/archive/solidprecip/3_Ext_Abstracts/Kane_exabs.pdf

The closure of water balances, as well as input into hydrologic models, for watersheds in the Arctic require good estimates of the spatially distributed snowpack (Yang and Woo, 1999). Ignoring the under catch of all types of precipitation gauges, snow gauges still perform inadequately when used to predict the snowpack distribution at winter’s end in certain environments. The reason is simple; snow on the ground is susceptible to transportation by the wind along the surface in windy treeless environments (Liston and Sturm, 2002). This results in a very heterogeneous snowpack distribution, with greater quantities collecting in depressions, valley bottoms and leeward sides of ridges. Sublimation losses from the snowpack during the winter are further enhanced during transport. From the forecasting point of view, it is imperative to have a relatively good estimate of the distribution of snow water equivalent (SWE) over the catchment. Because of the heterogeneity of the snow cover, it is very difficult to come up with a single number that represents the average SWE. Because channel networks generally represent depressions in a catchment and shrubs and small trees are more dominant in riparian ecosystems, drifting snow tends to collect in and adjacent to the drainage network. Obviously this enhances runoff and generally reduces evapotranspiration (ET). Hydrologic models for hydrologic forecasting are becoming more complex. This complexity takes two