scholarly journals Predictions of changes of glacier mass balance in the Nepal Himalaya and Tibetan Plateau: a case study of air temperature increase for three glaciers

1992 ◽  
Vol 16 ◽  
pp. 89-94 ◽  
Author(s):  
Yutaka Ageta ◽  
Tsutomu Kadota
Keyword(s):  
Tibetan Plateau ◽  
Equilibrium State ◽  
Mass Balance ◽  
Air Temperature ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Mountain Areas ◽  
Nepal Himalaya ◽  
Ice Cap

Annual mass exchange differs between maritime and continental glaciers. A common characteristic of these glaciers in Asian high-mountain areas is that most of the annual accumulation occurs in summer. Since variations in mass balance of a summer-accumulation type of glacier are quite sensitive to variations in summer air temperature, shrinkages of such glaciers due to climate warming are predicted by the use of simplified experimental relations between air temperature and mass balance, disregarding variation of other climatic variables such as cloudiness and precipitation. The results predict that both small and large maritime glaciers are more sensitive to warming than a continental ice cap. A small glacier would disappear in a few decades if the air temperature persisted a few degrees above that of an equilibrium state of mass balance.

scholarly journals Predictions of changes of glacier mass balance in the Nepal Himalaya and Tibetan Plateau: a case study of air temperature increase for three glaciers

1992 ◽  
Vol 16 ◽  
pp. 89-94 ◽  
Author(s):  
Yutaka Ageta ◽  
Tsutomu Kadota
Keyword(s):  
Tibetan Plateau ◽  
Equilibrium State ◽  
Mass Balance ◽  
Air Temperature ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Mountain Areas ◽  
Nepal Himalaya ◽  
Ice Cap

Annual mass exchange differs between maritime and continental glaciers. A common characteristic of these glaciers in Asian high-mountain areas is that most of the annual accumulation occurs in summer. Since variations in mass balance of a summer-accumulation type of glacier are quite sensitive to variations in summer air temperature, shrinkages of such glaciers due to climate warming are predicted by the use of simplified experimental relations between air temperature and mass balance, disregarding variation of other climatic variables such as cloudiness and precipitation. The results predict that both small and large maritime glaciers are more sensitive to warming than a continental ice cap. A small glacier would disappear in a few decades if the air temperature persisted a few degrees above that of an equilibrium state of mass balance.

scholarly journals Simulating the effects of mean annual air-temperature changes on permafrost distribution and glacier size: an example from the Upper Engadin, Swiss Alps

1995 ◽  
Vol 21 ◽  
pp. 399-405 ◽  
Author(s):  
Martin Hoelzle ◽  
Wilfried Haeberli
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Swiss Alps ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Mountain Areas ◽  
Model Calculations ◽  
Glacier Terminus ◽  
Time Period ◽  
Mean Annual Air Temperature

Models are developed to simulate changes in permafrost distribution and glacier size in mountain areas. The models exclusively consider equilibrium conditions. As a first application, the simplified assumption is used that one single parameter (mean annual air temperature) is changing. Permafrost distribution patterns are estimated for a test area (Corvatsch-Furtschellas) and for the whole Upper Engadin region (eastern Swiss Alps) using a relation between permafrost occurrence as indicated by BTS (bottom temperature of the winter snow cover) measurements, potential direct solar radiation and mean annual air temperature. Glacier sizes were assessed in the same region with data from the World Glacier Inventory database. The simulations for the glaciers are based on the assumption that an increase or decrease in equilibrium-line altitude (ELA) would lead to a mass-balance change. Model calculations for potential future changes in ELA and mass balance include estimated developments of area, length and volume. Mass changes were also calculated for the time period 1850–1973 on the basis of measured cumulative length change, glacier length and estimated ablation at the glacier terminus. For the time period since 1850, permafrost became inactive or disappeared in about 15% of the area originally underlain by permafrost in the whole Upper Engadin region, and mean annual glacier mass balance was calculated as −0.26 to −0.46 m w.e.a−1 for the larger glaciers in the same area. The estimated loss in glacier volume since 1850 lies between 55% and 66% of the original value. With an assumed increase in mean annual air temperature of +3°C, the area of supposed permafrost occurrence would possibly be reduced by about 65% with respect to present-day conditions and only three glaciers would continue to partially exist.

scholarly journals Multi-year analysis of distributed glacier mass balance modelling and equilibrium line altitude on King George Island, Antarctic Peninsula

2018 ◽  
Vol 12 (4) ◽  
pp. 1211-1232 ◽  
Author(s):  
Ulrike Falk ◽  
Damián A. López ◽  
Adrián Silva-Busso
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
High Variability ◽  
South Shetland Islands ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Potter Cove ◽  
Shetland Islands ◽  
Ice Cap

Abstract. The South Shetland Islands are located at the northern tip of the Antarctic Peninsula (AP). This region was subject to strong warming trends in the atmospheric surface layer. Surface air temperature increased about 3 K in 50 years, concurrent with retreating glacier fronts, an increase in melt areas, ice surface lowering and rapid break-up and disintegration of ice shelves. The positive trend in surface air temperature has currently come to a halt. Observed surface air temperature lapse rates show a high variability during winter months (standard deviations up to ±1.0K(100m)-1) and a distinct spatial heterogeneity reflecting the impact of synoptic weather patterns. The increased mesocyclonic activity during the wintertime over the past decades in the study area results in intensified advection of warm, moist air with high temperatures and rain and leads to melt conditions on the ice cap, fixating surface air temperatures to the melting point. Its impact on winter accumulation results in the observed negative mass balance estimates. Six years of continuous glaciological measurements on mass balance stake transects as well as 5 years of climatological data time series are presented and a spatially distributed glacier energy balance melt model adapted and run based on these multi-year data sets. The glaciological surface mass balance model is generally in good agreement with observations, except for atmospheric conditions promoting snow drift by high wind speeds, turbulence-driven snow deposition and snow layer erosion by rain. No drift in the difference between simulated mass balance and mass balance measurements can be seen over the course of the 5-year model run period. The winter accumulation does not suffice to compensate for the high variability in summer ablation. The results are analysed to assess changes in meltwater input to the coastal waters, specific glacier mass balance and the equilibrium line altitude (ELA). The Fourcade Glacier catchment drains into Potter cove, has an area of 23.6 km2 and is glacierized to 93.8 %. Annual discharge from Fourcade Glacier into Potter Cove is estimated to q¯=25±6hm3yr-1 with the standard deviation of 8 % annotating the high interannual variability. The average ELA calculated from our own glaciological observations on Fourcade Glacier over the time period 2010 to 2015 amounts to 260±20 m. Published studies suggest rather stable conditions of slightly negative glacier mass balance until the mid-1980s with an ELA of approx. 150 m. The calculated accumulation area ratio suggests dramatic changes in the future extent of the inland ice cap for the South Shetland Islands.

scholarly journals Mass balance of Xiao Dongkemadi glacier on the central Tibetan Plateau from 1989 to 1995

2000 ◽  
Vol 31 ◽  
pp. 159-163 ◽  
Author(s):  
Koji Fujita ◽  
Yutaka Ageta ◽  
Pu Jianchen ◽  
Yao Tandong
Keyword(s):  
Body Temperature ◽  
Tibetan Plateau ◽  
Mass Balance ◽  
Air Temperature ◽  
Black Body ◽  
Glacier Mass Balance ◽  
The Tibetan Plateau ◽  
Central Tibetan Plateau ◽  
Geostationary Meteorological Satellite ◽  
Continuous Mass

AbstractData on the mass balance of Xiao Dongkemadi glacier in the Tanggula mountains, central Tibetan Plateau, were obtained over 5 5 years from 1989 to 1995. These are the first continuous mass-balance data for a continental-type glacier on the Tibetan Plateau, where the glacier accumulates during the summer monsoon (summer-accumulation-type glacier). Mass-balance vs altitude profiles were steeper in the negative than in the positive mass-balance years. This is considered to have resulted from the effect of summer accumulation. The annual mass balance is compared with air temperature, precipitation, and black-body temperature in the area including the glacier, which is calculated from infrared radiation observations by theJapanese Geostationary Meteorological Satellite. It was found that the interannual variation in the glacier mass balance was not closely related to maximum monthly mean air temperature, while it did have a relatively good correlation with maximum monthly mean black-body temperature.

scholarly journals Simulating the effects of mean annual air-temperature changes on permafrost distribution and glacier size: an example from the Upper Engadin, Swiss Alps

1995 ◽  
Vol 21 ◽  
pp. 399-405 ◽  
Author(s):  
Martin Hoelzle ◽  
Wilfried Haeberli
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Swiss Alps ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Mountain Areas ◽  
Model Calculations ◽  
Glacier Terminus ◽  
Time Period ◽  
Mean Annual Air Temperature

Models are developed to simulate changes in permafrost distribution and glacier size in mountain areas. The models exclusively consider equilibrium conditions. As a first application, the simplified assumption is used that one single parameter (mean annual air temperature) is changing.Permafrost distribution patterns are estimated for a test area (Corvatsch-Furtschellas) and for the whole Upper Engadin region (eastern Swiss Alps) using a relation between permafrost occurrence as indicated by BTS (bottom temperature of the winter snow cover) measurements, potential direct solar radiation and mean annual air temperature. Glacier sizes were assessed in the same region with data from the World Glacier Inventory database. The simulations for the glaciers are based on the assumption that an increase or decrease in equilibrium-line altitude (ELA) would lead to a mass-balance change. Model calculations for potential future changes in ELA and mass balance include estimated developments of area, length and volume. Mass changes were also calculated for the time period 1850–1973 on the basis of measured cumulative length change, glacier length and estimated ablation at the glacier terminus.For the time period since 1850, permafrost became inactive or disappeared in about 15% of the area originally underlain by permafrost in the whole Upper Engadin region, and mean annual glacier mass balance was calculated as −0.26 to −0.46 m w.e.a−1 for the larger glaciers in the same area. The estimated loss in glacier volume since 1850 lies between 55% and 66% of the original value. With an assumed increase in mean annual air temperature of +3°C, the area of supposed permafrost occurrence would possibly be reduced by about 65% with respect to present-day conditions and only three glaciers would continue to partially exist.

scholarly journals Reviews and syntheses: How do abiotic and biotic processes respond to climatic variations in the Nam Co catchment (Tibetan Plateau)?

2020 ◽  
Vol 17 (5) ◽  
pp. 1261-1279 ◽  
Author(s):  
Sten Anslan ◽  
Mina Azizi Rad ◽  
Johannes Buckel ◽  
Paula Echeverria Galindo ◽  
Jinlei Kai ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Air Temperature ◽  
Water Availability ◽  
Environmental Changes ◽  
Livestock Grazing ◽  
High Mountain ◽  
The Tibetan Plateau ◽  
Nam Co ◽  
Climatic Fluctuations

Abstract. The Tibetan Plateau (TP) is the largest alpine plateau on Earth and plays an important role in global climate dynamics. On the TP, climate change is happening particularly fast, with an increase in air temperature twice the global average. The particular sensitivity of this high mountain environment allows observation and tracking of abiotic and biotic feedback mechanisms. Closed lake systems, such as Nam Co on the central TP, represent important natural laboratories for tracking past and recent climatic changes, as well as geobiological processes and interactions within their respective catchments. This review gives an interdisciplinary overview of past and modern environmental changes using Nam Co as a case study. In the catchment area, ongoing rise in air temperature forces glaciers to melt, contributing to a rise in lake level and changes in water chemistry. Some studies base their conclusions on inconsistent glacier inventories, but an ever-increasing deglaciation and thus higher water availability have persisted over the last few decades. Increasing water availability causes translocation of sediments, nutrients and dissolved organic matter to the lake, as well as higher carbon emissions to the atmosphere. The intensity of grazing has an additional and significant effect on CO2 fluxes, with moderate grazing enhancing belowground allocation of carbon while adversely affecting the C sink potential through reduction of above-surface and subsurface biomass at higher grazing intensities. Furthermore, increasing pressure from human activities and livestock grazing are enhancing grassland degradation processes, thus shaping biodiversity patterns in the lake and catchment. The environmental signal provided by taxon-specific analysis (e.g., diatoms and ostracods) in Nam Co revealed profound climatic fluctuations between warmer–cooler and wetter–drier periods since the late Pleistocene and an increasing input of freshwater and nutrients from the catchment in recent years. Based on the reviewed literature, we outline perspectives to further understand the effects of global warming on geodiversity and biodiversity and their interplay at Nam Co, which acts as a case study for potentially TP-level or even worldwide processes that are currently shaping high mountain areas.

scholarly journals A Surging Glacier Recognized by Remote Sensing on the Zangser Kangri Ice Field, Central Tibetan Plateau

2021 ◽  
Vol 13 (6) ◽  
pp. 1220
Author(s):  
Bowen Jia ◽  
Shugui Hou ◽  
Yetang Wang
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Thermal Emission ◽  
Surface Velocity ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Landsat 8 ◽  
The Tibetan Plateau ◽  
Landsat Images ◽  
Ice Field

A glacier surge, which is quasi-periodic and involves rapid flow, is an abnormal glacier motion. Although some glaciers have been found to be surging, little is known about surging glaciers on the Tibetan Plateau (TP), especially the Central and Northern TP. Here, we found a surging glacier (GLIMS ID: G085885E34389N) on the Zangser Kangri ice field (ZK), Central TP, by means of the digital elevation models (DEMs) from the Shuttle Radar Topography Mission (SRTM), TanDEM-X 90 m, Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) DEMs, and High Mountain Asia 8-m DEM (HMA), combined with Landsat images and the Global Land Ice Velocity Extraction from Landsat 8 (GoLIVE) dataset. This surge event was confirmed by the crevasses, shear margin, and visible advancing snout shown in the Landsat images produced since 2014 and the HMA. The inter-comparison of these DEMs and the surface velocity changes showed that the surge event started between October 2012 and January 2014. The glacier may have also surged in the 1970s, based on a comparison between the topographical map and Landsat images. The glacier mass balance here has been slightly positive from 1999 onward (+0.03 ± 0.06 m w.e.a−1 from 1999 to 2015, +0.02 ± 0.07 m w.e.a−1 from 1999 to December 2011), which may indicate that the ZK is located on the southern edge of the mass balance anomaly on the TP. Combining with other surging glaciers on the Central and Northern TP, the relatively balanced mass condition, large size, and shallow slope can be associated with glacier surges on the Central and Northern TP.

scholarly journals Multi-year analysis of distributed glacier mass balance modelling and equilibrium line altitude on King George Island, Antarctic Peninsula

2017 ◽  
Author(s):  
Ulrike Falk ◽  
Damián A. López ◽  
Adrián Silva-Busso
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Surface Air Temperature ◽  
Equilibrium Line ◽  
South Shetland Islands ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Potter Cove ◽  
Shetland Islands ◽  
Ice Cap

Abstract. The South Shetland Islands are located at the northern tip of the Antarctic Peninsula (AP). This region was subject to strong warming trends in the atmospheric surface layer. Surface air temperature increased about 3 K in 50 years, concurrent with retreating glacier fronts, an increase in melt areas, ice surface lowering and rapid break-up and disintegration of ice shelves. The positive trend in surface air temperature has currently come to a halt. Observed surface air temperature lapse rates show a high variability during winter months (standard deviations up to −1 K/100 m), and a distinct spatial heterogeneity reflecting the impact of synoptic weather patterns. The increased mesocyclonic activity during the winter time over the past decades in the study area results in intensified advection of warm, moist air with high temperatures and rain, and leads to melt conditions on the ice cap, fixating surface air temperatures to the melting point. Its impact on winter accumulation results in the observed negative mass balance estimates. Six years of continuous glaciological measurements on mass balance stake transects as well as five years of climatological data time series are presented and a spatially distributed glacier energy balance melt model adapted and run based on these multi-year data sets. The glaciological surface mass balance model is generally in good agreement with observations, except for atmospheric conditions promoting snow drift by high wind speeds, turbulence-driven snow deposition and snow layer erosion by rain. No drift can be seen over the course of the 5-year model run period. The winter accumulation does not suffice to compensate for the high variability in summer ablation. The results are analysed to assess changes in melt water input to the coastal waters, specific glacier mass balance and the equilibrium line altitude. The Fourcade Glacier catchment drains into Potter cove, has an area of 23.6 km2 and is to 93.8 % glacierized. Annual discharge from Fourcade Glacier into Potter Cove is estimated to q = 25 ± 6 hm3 per year with the standard deviation of 8% annotating the high interannual variability. The average equilibrium line altitude (ELA) calculated from own glaciological observations on Fourcade Glacier over the time period 2010 to 2015 amounts to ELA = 260 ± 20 m. Published studies suggest rather stable conditions of slightly negative glacier mass balance until the mid 80's with an ELA of approx. 150 m. The calculated accumulation area ratio suggests dramatic changes in the future extent of the inland ice cap for the South Shetland Islands.

scholarly journals The climatic mass balance of Svalbard glaciers: a 10-year simulation with a coupled atmosphere–glacier mass balance model

2016 ◽  
Vol 10 (3) ◽  
pp. 1089-1104 ◽  
Author(s):  
Kjetil S. Aas ◽  
Thorben Dunse ◽  
Emily Collier ◽  
Thomas V. Schuler ◽  
Terje K. Berntsen ◽  
...  
Keyword(s):  
Mass Balance ◽  
Detailed Comparison ◽  
Balance Model ◽  
Climate Projections ◽  
Glacier Mass Balance ◽  
Grid Spacing ◽  
Satellite Measurements ◽  
Mean Values ◽  
Ice Cap ◽  
A Site

Abstract. In this study we simulate the climatic mass balance of Svalbard glaciers with a coupled atmosphere–glacier model with 3 km grid spacing, from September 2003 to September 2013. We find a mean specific net mass balance of −257 mm w.e. yr−1, corresponding to a mean annual mass loss of about 8.7 Gt, with large interannual variability. Our results are compared with a comprehensive set of mass balance, meteorological, and satellite measurements. Model temperature biases of 0.19 and −1.9 °C are found at two glacier automatic weather station sites. Simulated climatic mass balance is mostly within about 100 mm w.e. yr−1 of stake measurements, and simulated winter accumulation at the Austfonna ice cap shows mean absolute errors of 47 and 67 mm w.e. yr−1 when compared to radar-derived values for the selected years 2004 and 2006. Comparison of modeled surface height changes from 2003 to 2008, and satellite altimetry reveals good agreement in both mean values and regional differences. The largest deviations from observations are found for winter accumulation at Hansbreen (up to around 1000 mm w.e. yr−1), a site where sub-grid topography and wind redistribution of snow are important factors. Comparison with simulations using 9 km grid spacing reveal considerable differences on regional and local scales. In addition, 3 km grid spacing allows for a much more detailed comparison with observations than what is possible with 9 km grid spacing. Further decreasing the grid spacing to 1 km appears to be less significant, although in general precipitation amounts increase with resolution. Altogether, the model compares well with observations and offers possibilities for studying glacier climatic mass balance on Svalbard both historically as well as based on climate projections.

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