Testing snowpack layers by Raman spectroscopy

Each of the stratified snow layers in the snowpack is characterized by the morphology and size of the constituent snow grains. Selectively identifying the different snow layers is relevant to determining the stability of the snowpack. We performed on-field Raman spectroscopy measurements in the Monterosa area (Aosta Valley, Italy) to characterize different snowpacks. We observed that the fine features of the Raman spectrum of snow correlate with the snow Specific Surface Area. We clearly distinguished the spectra of aged snow (larger grains, lower specific surface area value) from freshly deposited snow (smaller grains, higher values of specific surface area). Close to the snow melting point, we observed changes in the spectral features of snow associated with the presence of a fraction of liquid water in the snowpack. A portable Raman equipment allows for on-field characterization of the snowpack.