C43A-0363:
Reconciling Measured and Modeled Distributed Snowpack Temperatures and Subsurface Heat Fluxes
Thursday, 18 December 2014
Hendrik Huwald1, Chad W Higgins2, Marc Diebold1, Michael Lehning1,3, Sian R Williams4, John Steven Selker2 and Marc B Parlange1,5, (1)EPFL Swiss Federal Institute of Technology Lausanne, Lausanne, Switzerland, (2)Oregon State University, Corvallis, OR, United States, (3)SLF / WSL, Davos Dorf, Switzerland, (4)Imperial College London, London, United Kingdom, (5)University of British Columbia, Civil Engineering, Vancouver, BC, Canada
Abstract:
While many common snow cover models allow for spatially distributed representation of the snow pack, most in-situ measurement techniques determining snow properties and state variables are invasive, destructive, and in most cases single point measurements. Fiber optic distributed temperature sensing (FO-DTS) provides a way to obtain hundreds of data points in the snow at a time in various problem-adapted configurations with cable lengths of several hundred meters. We present several experiments employing different geometrical FO cable arrangements in the snow in an attempt to obtain small-scale statistical information on snow temperature distribution and variability and the resulting subsurface (conductive) heat fluxes. The spatially distributed conductive heat fluxes are computed based on the Fourier heat equation using snow temperature and snow depth data, and an effective snow thermal conductivity derived from collocated density measurements. The temperature measurements and the simple heat flux calculations are then compared to corresponding results from the detailed SNOWPACK model. These comparisons investigate the closure of the local energy balance and show the relation between DTS temperatures and model estimations of snow thermal conductivity and conductive heat fluxes.
