Written By Leena Leppänen, Finnish Meteorological Institute, Arctic Research, Sodankylä, Finland. 2017 Winning Goetz Instrument Support Program Project Title: "Spectral reflectance of snow in Sodankylä, Finland"
ASD's QualitySpec® Trek (QST) was used for reflectance measurements of natural snowpack in Sodankylä. A total of 163 spectrums were measured, including 6 test measurements in the beginning. Usually, measurements were made in Intensive Observation Area (IOA) where snow pit measurements are made weekly in addition to several automatic measurements of snow and meteorological properties (Figure 1).
Figure 1. IOA measurement field. Location of snow pit area is marked with red circle. Snow pits were made to the same area but different spot every measurement occasion. Snowpack is suspected to be homogenous in that area.
The manual snow pit measurements includes definition of layers and for each measurement of grain size and type, hardness and wetness, and density profile and specific surface area (SSA) profile with IceCube, snow depth and bulk snow water equivalent (SWE). Automatic snow measurements at the site are snow depth, SWE, snow temperature profile every 10 cm, and snowfall intensity with particle size. More information about snow pit measurements and snow conditions in Sodankylä can be found from Leppänen et al. 2016.
Vertical profiles from snowpack were measured with QST to research vertical variability of reflectance in snowpack (Figure 3a). Measurements were made approximately every 2-3 cm, and 4-5 cm in depth hoar layer where coarse grains existed. Snowpack surface was measured also from top (Figure 3b). Forest snow pit profiles were measured for research of horizontal spatial variability (Figures 2a, 2b).