Masters Thesis Defense - Pat Curley
- Tuesday, November 17, 2015 at 4:10pm
- Roberts Hall - view map
The Influence of Solar Radiation in Snow on Near Surface Energy Balance in Complex Topography
Once snow reaches the ground it begins to change. It may be thermodynamically metamorphosed into a weak layer, which could lead to slab avalanches. The effect of local weather, topography, and snow depth on this process can be estimated with a first principle one-dimensional energy balance equation in conjunction with a topographic mesh model. This work focused on the effect of solar radiation on surface and near surface temperatures as well as the effect of varying the resolution of the topographic model. To do this, the commercially available software RadThermRT (RTRT) was used. A solar radiation attenuation coefficient was developed based on wavelength, snow grain size, and snow density from published literature. This code was then used to calculate results from twelve hour radiation recrystallization experiments carried out in a cold lab with homogenous snow. Finally, conditions for metamorphic events were calculated and qualitatively affirmed in the field at the Yellowstone Club ski area. This work demonstrates that solar radiation has a significant effect on the surface temperature as well as temperature at depth, and weak layer metamorphic events can be modeled. For radiation recrystallization events, strong positive-knee-shaped gradients were successfully modeled on congruous slopes. RTRT and measured results agreed within 2˚C.