scholarly journals Sensitivities of glacier mass balance and runoff to climate perturbations in Norway

2015 ◽  
Vol 56 (70) ◽  
pp. 79-88 ◽  
Author(s):  
Markus Engelhardt ◽  
Thomas V. Schuler ◽  
Liss M. Andreassen
Keyword(s):  
Mass Balance ◽  
Temperature Change ◽  
Air Temperature ◽  
Annual Runoff ◽  
Precipitation Change ◽  
Glacier Mass Balance ◽  
Northern Norway ◽  
Temperature Range ◽  
Temperature And Precipitation ◽  
Southern Norway

AbstractThis study evaluates sensitivities of glacier mass balance and runoff to both annual and monthly perturbations in air temperature and precipitation at four highly glacierized catchments: Engabreen in northern Norway and Ålfotbreen, Nigardsbreen and Storbreen, which are aligned along a west–east profile in southern Norway. The glacier mass-balance sensitivities to changes in annual air temperature range from 1.74 m w.e. K−1 for Ålfotbreen to 0.55 m w.e. K−1 for Storbreen, the most maritime and the most continental glaciers in this study, respectively. The runoff sensitivities of all catchments are 20–25% per degree temperature change and 6–18% for a 30% precipitation change. A seasonality of the sensitivities becomes apparent. With increasing continentality, the sensitivity of mass balance and runoff to temperature perturbations during summer increases, and the sensitivity of annual runoff to both temperature and precipitation perturbations is constricted towards changes during the ablation period. Comparing sensitivities in northern and southern Norway, as well as the variability across southern Norway, reveals that continentality influences sensitivities more than latitude does.

scholarly journals Atmosphere Driven Mass-Balance Sensitivity of Halji Glacier, Himalayas

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 426
Author(s):  
Anselm Arndt ◽  
Dieter Scherer ◽  
Christoph Schneider
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Reanalysis Dataset ◽  
Monsoon Index ◽  
Temperature And Precipitation ◽  
Ice Surface ◽  
Precipitation Increase ◽  
Precipitation Changes

The COupled Snowpack and Ice surface energy and mass balance model in PYthon (COSIPY) was employed to investigate the relationship between the variability and sensitivity of the mass balance record of the Halji glacier, in the Himalayas, north-western Nepal, over a 40 year period since October 1981 to atmospheric drivers. COSIPY was forced with the atmospheric reanalysis dataset ERA5-Land that has been statistically downscaled to the location of an automatic weather station at the Halji glacier. Glacier mass balance simulations with air temperature and precipitation perturbations were executed and teleconnections investigated. For the mass-balance years 1982 to 2019, a mean annual glacier-wide climatic mass balance of −0.48 meters water equivalent per year (m w.e. a−1) with large interannual variability (standard deviation 0.71 m w.e. a−1) was simulated. This variability is dominated by temperature and precipitation patterns. The Halji glacier is mostly sensitive to summer temperature and monsoon-related precipitation perturbations, which is reflected in a strong correlation with albedo. According to the simulations, the climate sensitivity with respect to either positive or negative air temperature and precipitation changes is nonlinear: A mean temperature increase (decrease) of 1 K would result in a change of the glacier-wide climatic mass balance of −1.43 m w.e. a−1 (0.99m w.e. a−1) while a precipitation increase (decrease) of 10% would cause a change of 0.45m w.e. a−1 (−0.59m w.e. a−1). Out of 22 circulation and monsoon indexes, only the Webster and Yang Monsoon index and Polar/Eurasia index provide significant correlations with the glacier-wide climatic mass balance. Based on the strong dependency of the climatic mass balance from summer season conditions, we conclude that the snow–albedo feedback in summer is crucial for the Halji glacier. This finding is also reflected in the correlation of albedo with the Webster and Yang Monsoon index.

scholarly journals Modeling Glacier Mass Balance and Runoff in the Koxkar River Basin on the South Slope of the Tianshan Mts. during 1959 to 2009, China

2016 ◽  
Author(s):  
Min Xu ◽  
Haidong Han ◽  
Shichang Kang
Keyword(s):  
Mass Balance ◽  
River Basin ◽  
Meteorological Data ◽  
Annual Runoff ◽  
Glacier Mass Balance ◽  
The South ◽  
Temperature And Precipitation ◽  
Western Tianshan ◽  
South Slope ◽  
Hbv Model

Water resources provided by alpine glaciers are an important pillar for people living in the arid regions in the west of China. In this study, the HBV (Hydrologiska Byrans Vattenavdelning) light model was applied to simulate glacier mass balance and runoff in the Koxkar River Basin (KRB) on the south slope of Mt. Tumur, western Tianshan Mts.. Daily temperature and precipitation were calculated by multiple linear regressions and gradient-inverse distance weighting, respectively, based on in-situ observed data by automatic weather stations (AWSs) in the basin (2007–2009) and at four meteorological stations neighbering the basin (1959–2009). Observed daily air temperature and precipitation were taken as input data for the HBV model, which was calibrated using runoff in 2007/08 and 2009/10, and validated in 2008/09 and 2010/11. Generally, the model could simulate runoff very well. The annual glacier mass balance and runoff were calculated using the HBV model driven by interpolated meteorological data for the period of 1959–2009. The simulated glacier mass balance were reasonable when compared with those observed values at nearby glaciers, indicating a decrease trend of mass balance in the basin with an average value of –370.4 mm a-1 since 1959. The annual runoff showed a slight increase trend (5.51 mm a-1). Futher analysis indicated that the runoff is more sensitive to temperature than precipitation amuont in the Koxkar river basin.

scholarly journals Climatic Variables and Mass Balance Of Alpine Glaciers During A Period Of Climate Fluctuation

1990 ◽  
Vol 14 ◽  
pp. 333-333
Author(s):  
David N. Collins
Keyword(s):  
Mass Balance ◽  
Multiple Regression ◽  
Rank Order ◽  
Summer Precipitation ◽  
Climatic Conditions ◽  
Climatic Variables ◽  
Glacier Mass Balance ◽  
Temperature And Precipitation ◽  
Precipitation Regimes ◽  
Precipitation And Temperature

Parameterisation of relationships between climate and glacier mass balance is of considerable importance in understanding and modelling how temporal variability in climate affects the quantity of perennial snow and ice stored in glaciers, and the runoff from glacierised areas. Influences of year-to-year variations in air temperatures are pertinent in the absence of long records of measured energy balance and in view of predictions of future climate scenarios in terms of temperature. Measurements of temperature and precipitation from several stations in Alpine valleys in the Rhone basin, Wallis, Switzerland have been analysed to indicate trends in climate from 1930 to 1988. Actual measurements of mass balance of Griesgletscher, ablation calculated from runoff and net accumulation estimated from totalising rain gauges for Findelengletscher and Gornergletscher beginning in the late 1960s, and runoff from Aletschgletscher since 1930, were taken as annual glaciological responses to climatic variation. Variables to represent climatic elements and interactions between precipitation and temperature were selected according to degree of correlation with glacier response variables, and climate-glacier response relationships were assessed by multiple regression. Subsets of the data representing the coolest (1972–81) and warmest (1943–52) decades were also analysed to indicate whether relationships amongst climatic variables and between climate and mass balance remain the same under contrasting climatic conditions.Overall, mean summer air temperature variables for the months May through September and June through August provide the highest levels of explanation of variance of ablation and mass balance respectively (75–82%). Addition of a precipitation variable (winter, spring or summer) in multiple regression increases explanation to a maximum of 91%. Spring and summer precipitation variables are negatively correlated with ablation. Positive degree days and temperature-summer snow functions provide alternatives to temperature. Event-based analysis of the coolest and warmest years selected by rank order invokes high precipitation in May and low May-June temperatures and summer snowfall events as significant variables.Relationships between climatic variables indicate that warmer-than-average winters have higher precipitation, but at summer and annual time scales precipitation is slightly negatively associated with temperature. At the decadal level, warmer periods appear to be influenced by increased frequency of continental anticyclonic conditions, in an area subject to both maritime and continental influences. These analyses of climatic variables indicate that summer energy inputs dominate glacier mass balance. Relationships between precipitation and temperature are complex and were changeable during a fluctuation of about 1° over 40 years. Effects of a potentially warmer future on the form of precipitation in spring, summer and autumn are not clear, so estimates of changes of mass balance have been calculated for contrasting precipitation regimes.

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 Response of glaciers in northwestern North America to future climate change: an atmosphere/glacier hierarchical modeling approach

2007 ◽  
Vol 46 ◽  
pp. 283-290 ◽  
Author(s):  
Jing Zhang ◽  
Uma S. Bhatt ◽  
Wendell V. Tangborn ◽  
Craig S. Lingle
Keyword(s):  
Mass Balance ◽  
Hierarchical Modeling ◽  
Future Climate ◽  
Balance Model ◽  
Future Climate Change ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Modeling Approach ◽  
Temperature And Precipitation ◽  
South Central

AbstractThe response of glaciers to changing climate is explored with an atmosphere/glacier hierarchical modeling approach, in which global simulations are downscaled with an Arctic MM5 regional model which provides temperature and precipitation inputs to a glacier mass-balance model. The mass balances of Hubbard and Bering Glaciers, south-central Alaska, USA, are simulated for October 1994–September 2004. The comparisons of the mass-balance simulations using dynamically-downscaled vs observed temperature and precipitation data are in reasonably good agreement, when calibration is used to minimize systematic biases in the MM5 downscalings. The responses of the Hubbard (a large tidewater glacier) and Bering (a large surge-type glacier) mass balances to the future climate scenario CCSM3 A1B, a ‘middle-of-the-road’ future climate in which fossil and non-fossil fuels are assumed to be used in balance, are also investigated for the period October 2010–September 2018. Hubbard and Bering Glaciers are projected to have increased accumulation, particularly on the upper glaciers, and greater ablation, particularly on the lower glaciers. The annual net balance for the entire Bering Glacier is projected to be significantly more negative, on average (–2.0ma–1w.e., compared to –1.3ma–1w.e. during the hindcast), and for the entire Hubbard Glacier somewhat less positive (0.3ma–1w.e. compared to 0.4 ma–1w.e. during the hindcast). The Hubbard Glacier mass balances include an estimated iceberg calving flux of 6.5 km3 a–1, which is assumed to remain constant.

scholarly journals Derivation of melt factors from glacier mass-balance records in western Canada

2009 ◽  
Vol 55 (189) ◽  
pp. 123-130 ◽  
Author(s):  
Joseph M. Shea ◽  
R. Dan Moore ◽  
Kerstin Stahl
Keyword(s):  
Mass Balance ◽  
Air Temperature ◽  
Regional Scale ◽  
Predictive Ability ◽  
Lapse Rate ◽  
Sensitivity Analyses ◽  
Glacier Mass Balance ◽  
Mean Values ◽  
Ice Melt ◽  
Standard Deviations

AbstractMelt factors for snow (ks) and ice (ki) were derived from specific mass-balance data and regionally interpolated daily air-temperature series at nine glaciers in the western Cordillera of Canada. Fitted ks and ki were relatively consistent across the region, with mean values (standard deviations) of 3.04 (0.38) and 4.59 (0.59) mm d−1 °C−1, respectively. The interannual variability of melt factors was investigated for two long-term datasets. Calculated annually, snow- and ice-melt factors were relatively stable from year to year; standard deviations for snowmelt factors were 0.48 (17%) and 0.42 (18%) at Peyto and Place Glaciers, respectively, while standard deviations of ice-melt factors were 1.17 (25%) and 0.81 (14%). While fitted values of ks are comparable to those presented in previous observational and modeling studies, fitted ki are substantially and consistently lower across the region. Fitted melt factors were sensitive to the choice of lapse rate used in the air-temperature interpolation. Melt factors fitted to mass-balance data from a single site (Place Glacier) provided reasonable summer balance predictions at most other sites representing both maritime and continental climates, although there was a tendency for under-prediction at several sites. The combination of regionally interpolated air temperatures and a degree-day model appears capable of generating first-order estimates of regional summer balance, which can provide a benchmark against which to judge the predictive ability of more complex (e.g. energy balance) models applied at a regional scale. Mass-balance sensitivity analyses indicate that a temperature increase of 1 K will increase summer ablation in the region by 0.51 m w.e. a−1 on average.

scholarly journals Preliminary results of mass-balance observations of Yala Glacier and analysis of temperature and precipitation gradients in Langtang Valley, Nepal

2014 ◽  
Vol 55 (66) ◽  
pp. 9-14 ◽  
Author(s):  
Prashant Baral ◽  
Rijan B. Kayastha ◽  
Walter W. Immerzeel ◽  
Niraj S. Pradhananga ◽  
Bikas C. Bhattarai ◽  
...  
Keyword(s):  
Climate Change ◽  
Mass Balance ◽  
Lapse Rate ◽  
Convective Precipitation ◽  
Glacier Mass Balance ◽  
Equilibrium Line Altitude ◽  
Temperature And Precipitation ◽  
Meteorological Observations ◽  
The Impact ◽  
Langtang Valley

AbstractMonitoring the glacier mass balance of summer-accumulation-type Himalayan glaciers is critical to not only assess the impact of climate change on the volume of such glaciers but also predict the downstream water availability and the global sea-level change in future. To better understand the change in meteorological parameters related to glacier mass balance and runoff in a glacierized basin and to assess the highly heterogeneous glacier responses to climate change in the Nepal Himalaya and nearby ranges, the Cryosphere Monitoring Project (CMP) carries out meteorological observations in Langtang Valley and mass-balance measurements on Yala Glacier, a debris-free glacier in the same valley. A negative annual mass balance of –0.89m w.e. and the rising equilibrium-line altitude of Yala Glacier indicate a continuation of a secular trend toward more negative mass balances. Lower temperature lapse rate during the monsoon, the effect of convective precipitation associated with mesoscale thermal circulation in the local precipitation and the occurrence of distinct diurnal cycles of temperature and precipitation at different stations in the valley are other conclusions of this comprehensive scientific study initiated by CMP which aims to yield multi-year glaciological, hydrological and meteorological observations in the glacierized Langtang River basin.

scholarly journals ICESat laser altimetry over small mountain glaciers

2016 ◽  
Author(s):  
D. Treichler ◽  
A. Kääb
Keyword(s):  
Mass Balance ◽  
Glacier Mass Balance ◽  
Srtm Dem ◽  
Elevation Change ◽  
Laser Altimetry ◽  
Glacier Surface ◽  
Mountain Glaciers ◽  
Southern Norway ◽  
Spatially Varying

Abstract. Using sparsely glaciated southern Norway as a case study, we assess the potential and limitations of ICESat laser altimetry for analysing regional glacier elevation change in rough mountain terrain. Differences between ICESat GLAS elevations and reference elevation data are plotted over time to derive a glacier surface elevation trend for the ICESat acquisition period 2003–2008. We find spatially varying biases between ICESat and three tested digital elevation models (DEMs): the Norwegian national DEM, SRTM DEM and a high resolution LiDAR DEM. For regional glacier elevation change, the spatial inconsistency of reference DEMs – a result of spatio-temporal merging – has the potential to significantly affect or dilute trends. Elevation uncertainties of all three tested DEMs exceed ICESat elevation uncertainty by an order of magnitude, and are thus limiting the accuracy of the method, rather than ICESat uncertainty. After correction of reference elevation bias, we find that ICESat provides a robust and realistic estimate of a moderately negative glacier mass balance of around −0.30 m ± 0.06 ice per year. This regional estimate agrees well with the heterogeneous but overall negative in-situ glacier mass balance observed in the area. ICESat matches glacier size distribution of the study area well and measures also small ice patches not commonly monitored in-situ. The sample is large enough for spatial and thematic subsetting. Vertical offsets to ICESat elevations vary for different glaciers in southern Norway due to spatially inconsistent reference DEM age. We introduce a per-glacier correction that removes these spatially varying offsets, and considerably increases trend significance. Only after application of this correction do individual campaigns also fit to observed in-situ glacier mass balance. Our correction has the potential to improve glacier trend significance also for other causes of spatially varying vertical offsets, for instance due to radar penetration into ice and snow for the SRTM DEM, or as a consequence from mosaicking and merging that is common for national or global DEMs.

scholarly journals Predicted response of Storglaciären, Sweden, to climatic warming

1997 ◽  
Vol 24 ◽  
pp. 217-222 ◽  
Author(s):  
Keith A. Brugger
Keyword(s):  
Mass Balance ◽  
Surface Profile ◽  
Summer Temperature ◽  
Glacier Mass Balance ◽  
Climatic Warming ◽  
Temperature And Precipitation ◽  
Precipitation Increase ◽  
Dependent Model ◽  
Glacier Flow ◽  
Comparable Magnitude

A time-dependent model of glacier flow was used to predict the response of Storglaciären, a small valley glacier in northern Sweden, to different warming scenarios by imposing two possible climatic forcings: one in which temperature alone increases (T model), and one in which both temperature and precipitation increase (TP model). A range of possible changes in temperature and/or precipitation was related to changes in glacier mass balance through a multiple linear correlation of mean specific net balance with mean summer temperature and mean specific winter balance. The T model was run with mass-balance perturbations in the form of linear increases from the recent (1980–89) mean summer temperature of 1, 2 and 4°C over the next 100 years. Perturbations for the TP model also used linear increases in precipitation of 10, 20 and 50% over current mean winter values in addition to increases in temperature. Results of the modeling suggest that initial changes in the glacier‘s profile due to increases in temperature, or in both temperature and precipitation, are of comparable magnitude to those that might be expected as the glacier completes its response under the existing climate. Changes in the glacier‘s surface profile and terminus position that can, with some certainty, be attributed to climatic warming may only become apparent several decades after warming has begun.

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