New shortwave infrared albedo measurements for snow specific surface area retrieval
Journal of Glaciology
Snow grain-size characterization, its vertical and temporal evolution is a key parameter for the improvement and validation of snow and radiative transfer models (optical and microwave) as well as for remote-sensing retrieval methods. We describe two optical methods, one active and one passive shortwave infrared, for field determination of the specific surface area (SSA) of snow grains. We present a new shortwave infrared (SWIR) camera approach. This new method is compared with a SWIR laserbased system measuring snow albedo with an integrating sphere (InfraRed Integrating Sphere (IRIS)). Good accuracy (10%) and reproducibility in SSA measurements are obtained using the IRIS system on snow samples having densities greater than 200 kg m–3, validated against X-ray microtomography measurements. The SWIRcam approach shows improved sensitivity to snow SSA when compared to a near-infrared camera, giving a better contrast of the snow stratigraphy in a snow pit.
Montpetit, Benoit; Royer, A; Langlois, A; Cliché, P; Roy, A; Champollion, N; Picard, G; Domine, F; and Obbard, Rachel, "New shortwave infrared albedo measurements for snow specific surface area retrieval" (2012). Open Dartmouth: Faculty Open Access Articles. 101.