Measurement Date 13th April 2008 18th May 2008 29th May 2008 31st May 2008 02nd June 2008
Volume of Snow (km3) 13.91 23.87 26.39 22.47 19.65
Average Density of Snow (kg m-3) 422.0 519.0 581.8 626.1 702.5
Total Weight (tonnes) 5,942,069 12,412,105 15,402,051 13,947,382 13,910,871
Table 3.2 The volume, density, and weight of snow within the Tobredalen study area. The snow pits changed in depth, snow density, and water content during the progression of spring melt (Figure 3.7). The snow temperature was initially buffered from air temperature changes by the insulating properties of the air held in the snow structure, and a high albedo. The surface heating and melt of the upper snow layers resulted in seepage of water down the snow pit profile, and downstream, resulting in the increase in density over time (Figure 3.8). At the end of the Pit 1 monitoring, 02nd June 2008, the infiltration of melt-water homogenised the temperatures throughout the profile, and resulted in the highest snow densities and standing water at the base of the pit. A similar process occurred at each of the snow pits (Figures 3.9 and 3.10) Transect 1 Snow Pit Temperatures 13th April-2nd June
1.6
Height above ground (m)
1.4 1.2 13/04/2008
1
25/05/2008 29/05/2008
0.8
02/06/2008
0.6 0.4 0.2 0 -10
-8
-6
-4
-2
0
2
o
Temperature ( C)
Figure 3.7 The change in snow pit depth and temperatures at Transect 1, shown during every other sampling date.