Fjord learns to measure snow

Along with all the spectral measurements that we are taking, we are also recording the physical qualities of the snow surface to match these up with the reflectance results. Mainly, this means measuring the snow grain size and density.

Grain size is really easy to measure – we scoop some grains up onto a card with 1 mm, 2 mm, and 3mm grids on it and see (with the help of a little magnifier) how big the grains are. Fjord says these were ~1mm.

Snow density is another very simple thing to measure with the right tools. Fjord demonstrates quite well here. First, you push a metal wedge (of known size!) into the snow, collecting the surface layer.

Then, when the shovel is full, you slide a cover over it so that the wedge is completely full.

You end up with a sample like this…

Which we now weigh…

Once we have a known size and a known mass, we can calculate snow density (density = mass / volume)!

With the help of this data we’ve already noticed that small grain size scatter light more efficiently and provide higher reflectance than coarse grains across all wavelengths!