HR: 0800h
AN: C21B-0465    [Abstracts]
TI: Distribution and Energy Balance of Shallow Patchy Snow in Complex Terrain
AU: LaMontagne, A
EM: AureleLamontagne@mail.boisestate.edu
AF: Boise State University, Department of Geosciences 1910 University Dr., Boise, ID 83725, United States
AU: * McNamara, J P
EM: jmcnamar@boisestate.edu
AF: Boise State University, Department of Geosciences 1910 University Dr., Boise, ID 83725, United States
AU: Tyler, S W
EM: tylers@unr.edu
AF: University of Nevada, Reno, Dept. of Geological Sciences and Engineering, Reno, NV 89557, United States
AU: Selker, J
EM: selkerj@engr.orst.edu
AF: Oregon State University, Department of Biological and Ecological Engineering rm 210 Gilmore Hall, Corvallis, OR 97331-3906, United States
AB: The extent and energy balances of patchy snow are of great interest when satellite images are used in basin scale snow melt modeling. Problems of accuracy arise when subgrid variability of snow covered area (SCA) occurs on a scale of tens of meters inside a pixel with a scale of hundreds of meters. Warming climate has and is predicted to continue to cause snowlines to rise in lower elevation mountainous areas resulting in deep snowpacks being replaced with shallow subgrid fractional snow cover. This study used basal snow temperatures to show the extent of snow cover and differential melt timing on two aspects of a semi arid watershed in the foothills of Boise, Idaho. As part of the study on the energy balance of shallow patchy snow, distributed temperature sensing (DTS) was used to capture basal snow temperatures across both north and south facing aspects of the Upper Dry Creek experimental watershed in Idaho during a 36 hour melt period following a storm event in March of 2007. Consistent temperatures on the north face reflect a continuous full snow coverage while snow depth decreased by 10 cm. Temperatures on the south facing aspect show initial patchy snow patterns followed by a nearly complete melt by the end of monitoring due to greater solar heating. The instrument used for DTS measurements detects Ramen scattering to yield temperatures with an accuracy of „b0.1„aC and a spatial resolution of 1 meter for the entire length of the cable. The study showed the technology to be a substantial advantage over single point measurements when characterizing soil temperatures in complex terrain with differential solar exposure and melting times.
DE: 0704 Seasonally frozen ground
DE: 0736 Snow (1827, 1863)
DE: 0740 Snowmelt
DE: 0772 Distribution
SC: Cryosphere [C]
MN: 2007 Fall Meeting