As we arrive at the glacier, clouds covered the sun. Although this isn’t ideal for getting a strong signal with the FieldSpec, it did mean we didn’t have to worry about confounding reflections and we could get balanced spectra. Like the one below.
An example of how snow reflects light – we collected this data today!
On the horizontal axis is wavelength (color of light) and on the vertical axis is percent reflectance (how much of that color gets reflected back vs. absorbed). As you can see snow is very bright in the low wavelengths. This is the visible range, showing what we know – snow is bright white! There is a dip near 1000 nm where it absorbs some infra-red light, and snow is effectively “black” (absorbent, not reflective) at higher wavelengths. The big spiky bits near 1300 and 1800 nm are due to interference by water in the atmosphere.
The day was really productive, although I admit not the most interesting if you weren’t there. We established a good protocol for how measurements are taken and recorded and got spectra on at a couple different sites including water-saturated ice, semi-saturated ice, two areas of snow, and some slush. Hopefully tomorrow we’ll get some more snow and unsaturated ice. Most importantly – we now know that we collected some reasonably and useable data!!
As we packed up to head back to town for dinner, the sun came out again. The scenery was beautiful and we just had to keep taking out our cameras to snap some shots. It probably added 30 minutes to our “commute”! Here are a couple – enjoy!