Optical Determination of Snow Microstructure Parameters with the SnowImager instrument

Extensive and reliable ground-truth measurements of snow properties play a crucial role in environmental science to validate models and remote-sensing products. Among the available methods, optics-based approaches offer a good compromise between measurement accuracy and sufficiently large coverage.

We present the technical details of the SnowImager as well as its data products. The SnowImager is a novel, rugged yet portable field instrument that uses near-infrared (NIR) imaging to determine physical snow properties. It enables fast, accurate, and standardized retrieval of two-dimensional specific surface area (SSA) images as well as vertically resolved density profiles, both with millimetre-scale resolution. The SnowImager can be used on vertical snow profiles as well as on the surface scattering layer of sea ice. It was jointly developed by the Swiss federal institute for snow- and avalanche research SLF and Davos Instruments AG.

Providing enhanced snow microstructure characterization, the SnowImager allows better understanding of the processes influenced by the physical properties of snow as well as of their spatial variability. Examples of such fields of use include snow physics, avalanche science and forecasting, meltwater runoff modelling and water storage management, energy balance analysis in climatic models and permafrost studies and albedo observations in systems including snow or a surface scattering layer on sea ice.