Field investigation of efficient thermal conductivity of snow cover on Spitsbergen

This paper presents results of field investigations of coefficient of efficient thermal conductivity of snow with different structures and densities. Observations were performed in spring of 2013 in the vicinity of meteorological station Barentsburg. The data obtained were processed by means of the Fourier technique that allowed deriving relationship between thermal conductivity and snow temperature in regimes of cooling and warming of the snow cover surface. It was found that coefficient of efficient thermal conductivity increases with rising of the snow temperature in the regime of the snow surface cooling, and it does decrease under regime of warming. This can be possibly caused by the following: under the snow surface warming a water vapor flux moves inward, and when the snow temperature drops the water vapor condensation grows. That results in additional temperature rise and creates effect of growth of thermal conductivity at the lower temperature. When the snow surface cools down this effect is absent, and when the snow temperature drops a contribution of water vapor diffusion into thermal conductivity also decreases, and as a result, the coefficient drops too. Average value of coefficient of efficient thermal conductivity of the depth hoar with density of 280 kg/m3 is 0.12 W/(mK) that in 3–4 times smaller than the same coefficient of granular and frozen together snow with density of 370–390 kg/m3.