|Cherkauer, K - UNIV OF WASHINGTON|
|Lettenmaier, D - UNIV OF WASHINGTON|
Submitted to: American Geophysical Union
Publication Type: Abstract Only
Publication Acceptance Date: October 1, 1999
Publication Date: N/A
Technical Abstract: Cold season processes, particularly snow accumulation and ablation and the formation of frozen soil, play an important role in the annual hydrologic cycle. Understanding the spatial distribution of these processes is key in properly modeling the hydrologic response of a basin during the winter and spring. Wind redistributes snow from exposed surfaces to sheltered locations forming snowdrifts and giving the snowpack a topography differen than that of the ground surface. Snow distribution defines the distribution of frozen soil as the snowpack insulates the soil. Snow distribution also impacts the surface energy balance during snow melt; melt occurs most quickly once the pack is discontinuous and sensible heat from the bare regions contributes to the available melt energy. In order to improve the simulation of distributed snow and frozen soil, better observations must be made. During the winters of 1997-1998 and 1998-1999 snowsticks and temperature sensors were installed in fields around University of Minnesota's Rosemount Agricultural Experiment Station (about 25 km south of St. Paul, MN). The snowsticks were used to observe snow depth, while temperature sensors were used to measure soil temperature and frost depth. Data collected from these snowsticks is analyzed to determine the effects of different field conditions (tilled, grass covered, etc.) on snow and frost depth as well as soil temperature. Simulations were run using the variable infiltration capacity (VIC) model to demonstrate that the model captures the basic effects of the different coverage types. The statistical distribution of these observed variables is also investigated to demonstrate the merits of representing the spatial distribution of these properties within the VIC model.