Monday, April 11, 2016

Fair Weather...

We couldn’t ask for two more perfect days.  With brilliant warm sunny days we collected nearly a thousand snow depth measurements at intensive sites and along transects that cross the Teller NGEE watershed. As we climbed out of the site in the helicopter at 8pm, we could see the faint tracks of the tens of thousands of footsteps along remarkably straight survey lines that form the Teller snow grid. 

Every ten meters along kilometers of transects we collected snow depth measurements in order to quantify the spatial patterns of snow distribution in relation to vegetation type, slope, aspect, topography and elevation. For each transect Bob and Cathy set up a directional bearing using hand held gps, Lily Cohen (UAF) paced off distance using a three-meter-long avalanche probe, Cathy measured snow depth with a thaw probe and Bob Busey collected high resolution position data with the Trimble differential GPS rover.  

Given the depth and density of the snow pack we adjusted our snow density measurement goal from 40 sites to 10, and noticed that within just two warm days the snowpack had gotten significantly more “rotten” and wet.  In the mornings water in the snow pack froze into icy layers that were difficult to penetrate with the snowpack density tube, but by the afternoon the snow was so soft we struggled to stay upright, expending significant effort extracting ourselves from thigh deep postholes, even though we wore snowshoes or skis. On Saturday we will install two temporary mini-meteorology stations to track changes in the snow pack and radiation balance in anticipation of snowmelt, which will start soon if temperatures continue to stay warm.