In-situ monitoring of the time evolution of the effective thermal conductivity of snow

Abstract: We report on a 3-month long time series of in-situ measurements of the effective thermal conductivity (k eff) of snow at 6 heights in an Alpine snowpack in the Mont-Blanc mountain range, France, at an altitude of 2400m. Measurements were carried out automatically every 2days using heated-needle probes embedded in the snowpack. The experimental procedure used is presented in detail and demonstrates the applicability of single heated-needle probes for the evaluation of k eff in snow, both for long-term measurements within the snowpack and occasional use in the field. Results based on 139 automatically collected data show k eff values ranging between 0.04 and 0.35Wm−1 K−1, and a consistent pattern of effective thermal conductivity increase throughout the measurements campaign. The temporal rate of change of k eff varies up to 0.01W m− 1 K−1day−1, with maximum values just after snowfall. [ABSTRACT FROM AUTHOR]