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This study describes time series analysis of snow-melt, radiation data and energy balance for a seasonal snow cover at Dhundi field station of SASE, which lies in Pir Panjal range of the N-W Himalaya, for a winter season from 13 January to 12 April 2005. The analysis shows that mean snow surface temperature remains very close to the melting temperature of snow. It was found close to −1 • C for the complete observational period which makes the snow pack at Dhundi moist from its beginning. The average air temperature over this period was found to be 3.5 • C with hourly average variation from −5.5 • C to 13 • C. The snow surface at this station received a mean short wave radiation of 430 W m −2 , out of which 298 W m −2 was reflected back by the snow surface with mean albedo value of 0.70. The high average temperature and more absorption of solar radiation resulted in higher thermal state of the snowpack which was further responsible for faster and higher densification of the snowpack. Net radiation energy was the major component of surface energy budget with a mean value of 83 W m −2 . Bulk transfer model was used to calculate turbulent fluxes. The net energy was utilized for satisfying cold content and snow-melt by using measured snow surface temperature and density of snow pack. The mean square error between calculated and measured daily snow-melt was found to be approximately 6.6 mm of water equivalent.

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Stratigraphic boundaries at fine-to-coarse transitions in snow can introduce impeding layers to infiltrating water. In our present investigation, such impeding horizons were observed within sub-freezing homogeneous snow as a consequence of subsurface melting caused by the penetration of solar radiation. This new texture impeded the further downward flow of meltwater at fine-to-coarse transitions, leading to the formation of low-permeability melt-freeze crusts following multiple meltfreeze cycles. In this work, a large sub-freezing (-68C) homogeneous sample, consisting of small rounded grains, was periodically exposed to intense radiation generated by a sun simulator. Due to the penetration of shortwave radiation into the snow, subsurface melting caused the growth of melt-freeze polycrystals from clustered rounded crystals. Variations in mass growth (%) of melt-freeze polycrystals and mass loss (%) of grain clusters were studied within the sub-freezing snow with respect to different melt-freeze cycles. In this work, we study the growth of melt-freeze polycrystals in the top and bottom sub-layers with respect to collective saturation. Saturation profiles from the snow were recorded with a parallel-probe saturation profiler (PPSP) device, sampling at vertical intervals of 7 mm, after each melting cycle. Intrinsic permeabilities across different stratified sub-layers were monitored in relation to saturation as a function of different melt-freeze cycles. Our observations revealed that there is a significant decrease in intrinsic permeability for the first few top sub-layers. Also, permeability in the second topmost sub-layer was less than that in the topmost sub-layer directly interacting with the radiation. These results support the evolution of a new coarse grain texture within the homogeneous snow that subsequently converts into a layer of low permeability. In the various transects of the snow sample, two melt-freeze crusts and one ice crust were manually identified through stratigraphic mapping. A correlation was also established between the saturation spikes recorded with the help of the PPSP and corresponding depth positions of the crusts.