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A large number of Himalayan glacier catchments are under the influence of humid climate with snowfall in winter (November-April) and South-West monsoon in summer (June–September) dominating the regional hydrology
. Such catchments are defined as "Himalayan catchment", where the glacier melt water contributes to the river flow during the period of annual high flows produced by the monsoon. Other two major glacio-hydrological regimes of the Himalaya are winter snow dominated Alpine catchments of the Kashmir and Karakoram region and cold-arid regions of the Ladakh mountain range. Factors influencing the river flow variations in a "Himalayan catchment" were studied in a micro scale glacier catchment in the Garhwal Himalaya, covering an area of 77.8 km2. Discharge data generated from three hydrometric stations established at different altitudes of the Din Gad stream during the summer ablation period of 1998, 1999, 2000, 2001, 2003 and 2004. These data has been analysed along with winter/summer precipitation, temperature and mass balance data of the Dokriani glacier to study the role of the glacier and precipitation in determining the runoff variations along the stream continuum from the glacier snout to 2360 m a.s.l. Study shows that the inter-annual runoff variations in a "Himalayan glacier catchment" is directly linked with the precipitation rather than mass balance changes of the glacier. Study suggest that warming induced initial increase of glacier degraded runoff and subsequent decline is a glaciers mass balance response and cannot be translated as river flow response in a "Himalayan catchment" as suggested by the IPCC, 2007. Study also suggest that the glacier runoff critically influence the headwater river flows during the years of low summer discharge and proposes that the "Himalayan catchment" could experience higher river flows and positive glacier mass balance regime together in association with strong monsoon. This paper intended to highlight the importance of creating credible knowledge on the Himalayan cryospheric processes to develop a global outlook on river flow response to cryospheric change and locally sustainable water resources management strategies.
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Up to now an efficient 3-D geophysical mapping of the subsurface in mountainous environments with rough terrain has not been possible
. A merging approach of several closely spaced 2-D electrical resistivity tomography (ERT) surveys to build up a quasi-3-D model of the electrical resistivity is presented herein as a practical compromise for inferring subsurface characteristics and lithology. The ERT measurements were realised in a small glacier forefield in the Swiss Alps with complex terrain exhibiting a small scale spatial variability of surface substrate.
To build up the grid for the quasi-3-D measurements the ERT surveys were arranged as parallel profiles and perpendicular tie lines. The measured 2-D datasets were collated into one quasi-3-D file. A forward modelling approach - based on studies at a permafrost site below timberline - was used to optimize the geophysical survey design for the mapping of the mountain permafrost distribution in the investigated glacier forefield.
Quasi-3-D geoelectrical imaging is a useful method for mapping of heterogeneous frozen ground conditions and can be considered as a further milestone in the application of near surface geophysics in mountain permafrost environments
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This study provides mapping and analysis of the maximum glacier extent during the "Little Ice Age" in Jotunheimen, Southern Norway, on a regional scale
. Remote sensing techniques were used to map the glacier area at the maximum of the "Little Ice Age" (mid 18th century AD). For validation of the mapping, interpretation of existing glaciochronological studies, analysis of geomorphological maps and our own field measurements using GPS have been applied. The flow length of the glaciers and other inventory data were determined by using a Geographical Information System and a digital elevation model. A total of 233 glaciers existed during the "Little Ice Age" maximum in Jotunheimen, comprising an overall glacier area of about 290 km2. Mean glacier flow length was calculated as about 1.6 km. Until AD 2003, the area shrank by about 35% and the mean flow length decreased by about 34%, compared with the maximum "Little Ice Age" extent.
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Almost a century ago, fears began to be expressed about the possible impact of the rise in atmospheric temperature on mountain glaciers
. The fears led to the initiation of concerted scientific efforts to identify and examine the fluctuations along the front-snout of glaciers. It was believed that such studies, over the next century or so, would enable scientists to establish the relationship between the climate change and the glacier fluctuations.
Monitoring of a glacier, in specific terminology, means the study of glacier growth or degeneration over a specific period of time, laterally, vertically and in its longitudinal profile. Monitoring of glaciers, sensu stricto, is restricted to the study of the glacier snout, i.e., the front end of the glacier. The general belief is that the snout or the lowest extremity of a glacier reflects its health. A glacier in the Himalayas, on average, moves downward at a daily rate of one to three cm along the lower limits. It was the general belief of early glaciologists that the snout, in certain respects, denoted the altitudinal level where the melting of the glacier ice caused by the increased temperature of lower altitudes balanced the glacier’s downward movement. It was believed that the position of a glacier snout would undergo change - both in altitude and appearance - with changes in temperature and snow precipitation. Later studies have revealed that in reality things do not pan out that way. The regional and the local geomorphic features have been observed to have as much influence in the glacier snout fluctuations as the climatic parameters.
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Sublimation plays a decisive role in the surface energy balance of tropical glaciers
. During the dry season low specific humidity and high surface roughness favour the direct transition from ice to vapour and drastically reduce the energy available for melting. However, field measurements are scarce and little is known about the performance of sublimation parametrisations in glacier mass balance and runoff models.
During 15 days in August 2005 sublimation was measured on the tongue of Glaciar Artesonraju (8 58 S, 77 38 W) in the Cordillera Blanca, Peru, using simple lysimeters. Indicating a strong dependence on surface roughness, daily totals of sublimation range from 1–3 kg m−2 for smooth to 2–5 kg m−2 for rough conditions.
Measured sublimation was related to characteristic surface roughness lengths for momentum (zm ) and for the scalar quantities of temperature and water vapour (zs ), using a process-based mass balance model. Input data were provided by automatic weather stations, situated on the glacier tongue at 4750 m ASL and 4810 m ASL, respectively. Under smooth conditions the combination zm =2.0 mm and zs =1.0 mm appeared to be most appropriate, for rough conditions zm =20.0 mm and zs =10.0 mm fitted best.
Extending the sublimation record from April 2004 to December 2005 with the process-based model confirms, that sublimation shows a clear seasonality. 60–90% of the energy available for ablation is consumed by sublimation in the dry season, but only 10–15% in the wet season. The findings are finally used to evaluate the parametrisation of sublimation in the lower-complexity mass balance model ITGG, which has the advantage of requiring precipitation and air temperature as only input data. It turns out that the implementation of mean wind speed is a possible improvement for the representation of sublimation in the ITGG model.
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In this study the authors consider contrasting continental (Orulgan, Suntar-Khayata and Chersky ranges located in the Pole of Cold area at the contact of Atlantic and Pacific influences) and maritime (Kamchatka under the Pacific influence) Russian glacier systems
. Their purpose is to present a simple method for the projection of change of the main parameters of these glacier systems with climate change. To achieve this aim, they constructed vertical profiles of mass balance (accumulation and ablation) based both on meteorological observations for the mid to late 20th century and an ECHAM4 GCM scenario for 2040-2069. The observations and scenario were used for defining the recent and future equilibrium line altitude (ELA) for each glacier system. The altitudinal distributions of the areas covered with glacier ice were determined for present and future states of the glacier systems, taking into account the correlation of the change of the ELA and glacier-termini levels. We also give estimates of the possible changes of the areas and morphological structure of North-eastern Asia glacier systems and their mass balance characteristics from the ECHAM4 scenario. Finally, they compare characteristics of the continental and maritime glacier systems stability under conditions of global warming.
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