How strong is Snow? Spatial correlations of snowpack load bearing capacity and micromechanics from NASA SnowEx SnowMicroPen Data at Grand Mesa, Colorado

Abstract

The mechanical and structural properties of a snowpack, at both the micro- and macro-scales, are critical to understanding how snow cover architecture evolves over each winter. Snow load bearing capacity across a landscape is extremely spatially variable, yet fundamentally important for an array of applications. Such applications include winter vehicle mobility and modeling wildlife movements, among others. In this study, we derive snowpack microstructural and micromechanical properties across Grand Mesa, Colorado using SnowMicroPenetrometer (SMP) penetration force datasets from the NASA SnowEx 2017 and 2020 field campaigns. For the first time, raw SMP data from the SnowEx campaigns are processed and analyzed to derive snow cover microparameters, using empirical and physical methods involving microstructural dimensions of the snow crystal matrix. We propose a newly created equation for an SMP-derived snow load bearing capacity micromechanical parameter. We also refine one technique for identifying top and bottom boundaries of snow profiles in SMP raw data.

The final component of this study involved an analysis of SMP-derived snow microparameter spatial variability across Grand Mesa, Colorado. Results of the statistical analyses for the two different years revealed consistency in spatial relationships. Microparameters that exhibited non-zero cross correlations included snow density, compression strength, load bearing capacity, and microstructural deflection during snow grain bond rupture.