Snow and Ice

“Albedo, the ratio of incoming to reflected solar radiation, plays an important role in climate by regulating the amount of shortwave radiation reflected or absorbed and subsequently reradiated as longwave radiation by a surface.” (Burakowski et al., 2015)

Albedo changes are related to light scattering which is caused by changes in particle (crystal size) packing density and foreign materials such as algae or dust on the snow; these things impact the melt rate and can be an indicator of snow/water equivalent, which is important for reservoir management.

The value of VNIR and Full-Range Spectroradiometers for Snow & Ice:

• “Considering the high spatial and temporal variability of albedo and the fact that most snow covered areas are difficult places to reach to perform field measurements, remote sensing is the most suitable tool to determine spatial and temporal variability of snow albedo.” (Dumont et al., 2010)
• “…scientists can distinguish between snow and ice based on their spectral characteristics – the spectral slopes and absorptions are clues to a material’s identity.” (Horodyskyj, 2015)
• “Since light absorption by ice varies substantially depending on wavelength, the spectral distribution of solar radiation after absorption and scattering by snow grains varies within the visible and NIR spectra.” (Aoki et al., 2011)
• “…the range of measurements across the electromagnetic spectrum requires ground measurements of grain size for accurate data interpretation. To fully understand the radiative and convective energy balance in snowy regions, large data sets of ground-based grain size measurements are needed. This is only possible with new techniques allowing for much more rapid acquisition than previously available.” (Berisford et al., 2013)

Maintain accurate data collection of Snow & Ice properties via Ethernet or wireless functionality:

• ASD’s Windows®-compatible RS3™ Spectral Acquisition Software has a user interface that is optimized for field data collection with easy configuration of averaging, field of- view, storage and display of raw, reflectance, radiance and irradiance spectra in ‘real-time’.
• The flexibility, portability, and efficiency of the ASD systems allow you to collect many properties, for example: snow grain size stratigraphy, surface reflectance spectra and broadband albedo, snow physical properties, spectral radiance, snow directional reflectance (HDRF), light absorbing impurities.

Figure 1. Reproduced with permission from Ulyana Horodyskyj. Spectral data characteristics from snow squares of snow and ice; the reflectance signature is characteristic of the morphology of snow and ice and is indicative of other compositional factors such as the degree of contamination by organic and inorganic deposition. (Horodyskyj, U.N., 2013)

The solution

Our ASD spectroradiometers have the added value of being portable and with optimal signal-to-noise design for faster measurements, and wide spectral coverage of 350-2500 nm for determining a variety of compositional and important climatological parameters. We offer different instrument configurations and many accessory options for a variety of set-up and sampling approaches for the most convenient and productive measurement scenarios.

ASD instruments are a practical solution to analyze and discover Snow & Ice composition properties:

• FieldSpec 4 full-range spectroradiometers designed specifically around the challenges researchers face when performing spectral measurements in the field.
• Contact Probe for field measurements of solid materials. Use for snow stratigraphy and grain size studies. 

Ideal for snow & ice applications:

• Portable solution
• Simple, rapid and cost effective real-time measurement (data and analysis in the field)
• Use to ground truth hyperspectral imaging data.

References

^{Aoki, T., Kuchiki, K., Niwano, M., Kodama, Y., Hosaka, M., and Tanaka, T. (2011), Physically based snow albedo model for calculating broadband albedos and the solar heating profile in snowpack for general circulation models, Journal of Geophysical Research(116). D11114, doi:10.1029/2010JD015507}

^{Berisford, D., Molotch, N., Durand, M., Painter, T. (2013), Portable spectral profiler probe for rapid snow grain size stratigraphy, Cold Regions Science and Technology(85), 183–190. doi:10.1016/j.coldregions.2012.09.007 Burakowski, E.A., Ollinger, S.V., Lepine, L., Schaaf, C.B., Wang, Z.,}

^{Dibb, J.E., Hollinger, D.Y., Kim, J.H., Erb, A., Martin, M. (2015), Spatial scaling of reflectance and surface albedo over a mixed-use, temperate forest landscape during snow-covered periods, Remote Sensing of the Environment(158), 465-477. doi:10.1016/j.rse.2014.11.023}

^{Dumont, M., Brissaud, O., Picard, G., Schmitt, B., Gallet, J.-C., and Arnaud, Y. (2010), High-accuracy measurements of snow Bidirectional Reflectance Distribution Function at visible and NIR wavelengths – comparison with modelling results, Atmospheric Chemistry and Physics(10), 2507-2520.doi:10.5194/acp-10-2507-2010}

^{Horodyskyj, U. N. (2013, January 25). Quantifying Spectral Diversity within a MODIS footprint – Ngozumpa and Rongbuk Glaciers, Himalaya.} 

^{Horodyskyj, U. N. (2015, October 27). The Girls on Ice Program learns about spectroscopy: Gulkana Glacier, Alaska.}