Abstract The Spiti Valley is located in the Trans-Himalayan terrain of India, from where non-geometrical microliths have been discovered. While the Siwalik Hills have been subjected to extensive prehistoric surveys, this is the first evidence of lithic tools discovered in the Trans-Himalayan region of Himachal Pradesh, India. Due to its topographical and intense climatic features, the Trans-Himalayan region has generally been regarded as a barrier since prehistoric times. However, Dzamathang cannot be considered as an isolated site in the Trans-Himalayas. In fact, in the adjoining areas of Ladakh, Tibet and Nepal, similar lithics have been reported from several sites and been assigned to the Middle and Upper Palaeolithic. The discovery of this site suggests that the Trans-Himalayan zone may have acted as a possible route rather than a barrier during human migration. Large numbers of lithics have been recovered in the Dzamathang area of the Spiti Valley. Based on the collection of the artefacts from the surface, this paper tries to understand the geological and geographical setting of the area, particularly concerning prehistoric settlements in the Trans-Himalayas. This assemblage consists of assorted artefacts, which include a unifacial chopper, microlithic cores, flakes, blades, bladelets, burin and a large amount of debitage fragments. The majority of artefacts are on quartzite or quartzarenite. Future surveys will be targeted at recovering primary context sites for excavations and absolute dating.

Abstract The Himalaya are often referred to as the third pole of the Earth because they host the largest areal extent of glaciation outside the polar regions. Estimating the volume of these glaciers is challenging because the ice thickness of most of the glaciers is not accurately known. Depth profiling of the north-facing Hamtah and Parang glaciers was carried out using ground-penetrating radar surveys. The 6 km long Hamtah glacier and the 2.5 km long Parang glacier, with average widths of 350 and 250 m, respectively, are located in different U-shaped valleys. The depth of the ice–bedrock interface varied from 35 to 95 m in the Hamtah glacier and from 40 to 140 m in the Parang glacier. The valley profiles and ground-penetrating radar data were combined to obtain the volumes of the glaciers. The total volumes of ice in the Parang and Hamtah glaciers were estimated to be 0.179 and 0.375 km 3 , respectively. Shape analyses of different parts of these glaciers suggest that mathematical equations can be used to describe their sequential development. The retreat rates of the Parang and Hamtah glaciers were estimated to be 11.04 and 16.10 m a −1 , respectively.

Abstract This article describes an attempt to map snow cover accurately from other land covers using Moderate Resolution Imaging Spectrometer (MODIS) data of 500 m spatial resolution. The workflow includes reflectance modelling, computing snow-cover fraction (SCF) and establishing an empirical relationship between the SCF and normalized difference snow index (NDSI) to map snow cover at operational level. Regression relationships have been developed between the SCF derived from the linear mixture model (LMM) and snow obtained from the NDSI based on two criteria, namely: SCF greater than 0.0 and SCF greater than 0.1. The best regression equation has been selected by examining respective graph plots using statistical measures of mean absolute error, correlation coefficient, root mean square error (RMSE) and uncertainty analysis. The results have been validated against the actual SCF obtained from a high-resolution 15 m Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) visible and near infrared (VNIR) scene and covering a substantial range of snow cover of the same area. The selected regression model SCF = 0.25 + 0.35 × NDSI has been tested on other areas and validation efforts show that the pixel-level SCF relationship provides useful results as measured in independent tests against actual SCF obtained from ASTER scene.

Abstract We describe a time series of meteorological parameters and surface energy balance components of a seasonal snow cover from an automatic weather station (4863 m a.s.l., 32.28° N, 77.58° E), for a winter season from 1 December 2012 to 30 March 2013, located on a moraine close to the equilibrium line altitude of Chhota Shigri glacier, Himachal Pradesh, India. The analysis shows that for over 80% of the time in winter, the snow surface was at a cooling phase. During late winter however, the surface had some positive residual energy which induced some melt during peak hours of the day. The net all-wave radiation was mostly negative during winter because of the high reflective property of snow and reduced incoming longwave radiation due to low cloud. The sensible heat flux heats the surface at night and enhances the cooling during day. The latent heat flux is always negative, showing that the surface is losing mass through sublimation processes (−0.83 mm w.e./day). A correlation between the energy fluxes and temperature shows a distinct relationship between fluxes. A comparison between the two studies performed on- and off-glacier reveals a significant difference in some parameters. A higher value (−1.08 mm/day) of sublimation rate at 4863 m a.s.l. shows that a large amount of energy available at the surface was used in sublimation processes. A comparatively lower albedo, relative humidity and net longwave radiation and higher latent heat flux, wind speed and net shortwave radiation yield a distinctive surface energy balance, highlighting the need for a large number of stations at different zones to achieve a coherent picture of energy balance in the region.