scholarly journals Degree-day glacier mass-balance modelling with applications to glaciers in Iceland, Norway and Greenland

1995 ◽  
Vol 41 (138) ◽  
pp. 345-358 ◽  
Author(s):  
Tómas Jóhannesson ◽  
Oddur Sigurdsson ◽  
Tron Laumann ◽  
Michael Kennett
Keyword(s):  
Mass Balance ◽  
Lapse Rate ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Climate Scenarios ◽  
Mass Balance Model ◽  
Temperature Lapse Rate ◽  
Degree Day ◽  
Firm Evidence ◽  
Good Agreement

AbstractA degree-day glacier mass-balance model is applied to three glaciers in Iceland, Norway and Greenland for which detailed mass-balance measurements are available over a period of several years. Model results are in good agreement with measured variations in the mass balance with elevation over the time periods considered for each glacier. In addition, the model explains 60-80% of the year-to-year variance in the elevation-averaged summer season mass-balance measurements on the glaciers, using a single parameter set for each glacier.The increase in ablation on the glaciers due to a warming of 2° C is predicted to range from about 1 m w.e. year−1at the highest elevations to about 2.5 m w.e. year−1at the lowest elevations. Predicted changes in the winter balance (measured between fixed date) are relatively small, except at the lowest elevations on the Icelandic and Norwegian glaciers where the winter balance is significantly reduced. Equilibrium-line altitudes are raised by 200-300 m on the Icelandic and Norwegian glaciers. Except at the highest elevations, the winter balance of the Icelandic and Norwegian glaciers is predicted to decrease even if the warming is accompanied by a 10% increase in the precipitation.No firm evidence of a climate-related variation in the degree-day factors or in the temperature lapse rate on the same glacier could be found. The model, furthermore, reproduces large variations in the mass balance with elevation and from year to year on each glacier using the same parameter set. We assume, therefore, that these parameters will not change significantly for the climate scenarios considered here.

scholarly journals Degree-day glacier mass-balance modelling with applications to glaciers in Iceland, Norway and Greenland

1995 ◽  
Vol 41 (138) ◽  
pp. 345-358 ◽  
Author(s):  
Tómas Jóhannesson ◽  
Oddur Sigurdsson ◽  
Tron Laumann ◽  
Michael Kennett
Keyword(s):  
Mass Balance ◽  
Lapse Rate ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Climate Scenarios ◽  
Mass Balance Model ◽  
Temperature Lapse Rate ◽  
Degree Day ◽  
Firm Evidence ◽  
Good Agreement

AbstractA degree-day glacier mass-balance model is applied to three glaciers in Iceland, Norway and Greenland for which detailed mass-balance measurements are available over a period of several years. Model results are in good agreement with measured variations in the mass balance with elevation over the time periods considered for each glacier. In addition, the model explains 60-80% of the year-to-year variance in the elevation-averaged summer season mass-balance measurements on the glaciers, using a single parameter set for each glacier.The increase in ablation on the glaciers due to a warming of 2° C is predicted to range from about 1 m w.e. year−1 at the highest elevations to about 2.5 m w.e. year−1 at the lowest elevations. Predicted changes in the winter balance (measured between fixed date) are relatively small, except at the lowest elevations on the Icelandic and Norwegian glaciers where the winter balance is significantly reduced. Equilibrium-line altitudes are raised by 200-300 m on the Icelandic and Norwegian glaciers. Except at the highest elevations, the winter balance of the Icelandic and Norwegian glaciers is predicted to decrease even if the warming is accompanied by a 10% increase in the precipitation.No firm evidence of a climate-related variation in the degree-day factors or in the temperature lapse rate on the same glacier could be found. The model, furthermore, reproduces large variations in the mass balance with elevation and from year to year on each glacier using the same parameter set. We assume, therefore, that these parameters will not change significantly for the climate scenarios considered here.

scholarly journals The response of two Icelandic glaciers to climatic warming computed with a degree-day glacier mass-balance model coupled to a dynamic glacier model

1997 ◽  
Vol 43 (144) ◽  
pp. 321-327 ◽  
Author(s):  
Tómas Jóhannesson
Keyword(s):  
Mass Balance ◽  
Power Plants ◽  
Climate Scenario ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Hydroelectric Power ◽  
Mass Balance Model ◽  
Degree Day ◽  
Ice Cap ◽  
Warming Rate

AbstractA degree-day glacier mass-balance model is coupled to a dynamic glacier model for temperate glaciers. The model is calibrated for two outlet glaciers from the Hofsjökull ice cap in central Iceland. It is forced with a climate scenario that has recently been defined for the Nordic countries for the purpose of outlining the hydrological consequences of future greenhouse warming. The scenario for Iceland specifies a warming rate of 0.25°C per decade in mid-summer and 0.35°C per decade in mid-winter with a sinusoidal variation through the year. The volume of the glaciers is predicted to decrease by approximately 40% over the next century, and the glaciers essentially disappear during the next 200 years. Runoff from the area that is presently covered by the glaciers is predicted to increase by approximately 0.5 m a−1 30 years from now due to the reduction in the volume of the glaciers. The runoff increase reaches a flat maximum of 1.5–2.0 m a−1 100–150 years from now and levels off after that. The predicted runoff increase leads to a significant increase in the discharge of rivers fed by meltwater from the outlet glaciers of the ice cap and may have important consequences for the operation and planning of hydroelectric power plants in Iceland.

scholarly journals The response of two Icelandic glaciers to climatic warming computed with a degree-day glacier mass-balance model coupled to a dynamic glacier model

1997 ◽  
Vol 43 (144) ◽  
pp. 321-327 ◽  
Author(s):  
Tómas Jóhannesson
Keyword(s):  
Mass Balance ◽  
Power Plants ◽  
Climate Scenario ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Hydroelectric Power ◽  
Mass Balance Model ◽  
Degree Day ◽  
Ice Cap ◽  
Warming Rate

AbstractA degree-day glacier mass-balance model is coupled to a dynamic glacier model for temperate glaciers. The model is calibrated for two outlet glaciers from the Hofsjökull ice cap in central Iceland. It is forced with a climate scenario that has recently been defined for the Nordic countries for the purpose of outlining the hydrological consequences of future greenhouse warming. The scenario for Iceland specifies a warming rate of 0.25°C per decade in mid-summer and 0.35°C per decade in mid-winter with a sinusoidal variation through the year. The volume of the glaciers is predicted to decrease by approximately 40% over the next century, and the glaciers essentially disappear during the next 200 years. Runoff from the area that is presently covered by the glaciers is predicted to increase by approximately 0.5 m a−130 years from now due to the reduction in the volume of the glaciers. The runoff increase reaches a flat maximum of 1.5–2.0 m a−1100–150 years from now and levels off after that. The predicted runoff increase leads to a significant increase in the discharge of rivers fed by meltwater from the outlet glaciers of the ice cap and may have important consequences for the operation and planning of hydroelectric power plants in Iceland.

scholarly journals Application of a mass-balance model to a Himalayan glacier

1999 ◽  
Vol 45 (151) ◽  
pp. 559-567 ◽  
Author(s):  
Rijan Bhakta Kayastha ◽  
Tetsuo Ohata ◽  
Yutaka Ageta
Keyword(s):  
Mass Balance ◽  
Surface Albedo ◽  
Balance Model ◽  
Mass Balance Model ◽  
Mass Balances ◽  
Climatic Parameters ◽  
Glacier Surface ◽  
Temperature And Precipitation ◽  
Ice Surface ◽  
Good Agreement

AbstractA mass-balance model based on the energy balance at the snow or ice surface is formulated, with particular attention paid to processes affecting absorption of radiation. The model is applied to a small glacier, Glacier AX010 in the Nepalese Himalaya, and tests of its mass-balance sensitivity to input and climatic parameters are carried out. Calculated and observed area-averaged mass balances of the glacier during summer 1978 (June-September) show good agreement, namely -0.44 and -0.46 m w.e., respectively.Results show the mass balance is strongly sensitive to snow or ice albedo, to the effects of screening by surrounding mountain walls, to areal variations in multiple reflection between clouds and the glacier surface, and to thin snow covers which alter the surface albedo. In tests of the sensitivity of the mass balance to seasonal values of climatic parameters, the mass balance is found to be strongly sensitive to summer air temperature and precipitation but only weakly sensitive to relative humidity.

scholarly journals Development of a Water and Enthalpy Budget-based Glacier mass balance Model (WEB-GM) and its preliminary validation

2017 ◽  
Vol 53 (4) ◽  
pp. 3146-3178 ◽  
Author(s):  
Baohong Ding ◽  
Kun Yang ◽  
Wei Yang ◽  
Xiaobo He ◽  
Yingying Chen ◽  
...  
Keyword(s):  
Mass Balance ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Mass Balance Model ◽  
Preliminary Validation

scholarly journals Forcing a Distributed Glacier Mass Balance Model with the Regional Climate Model REMO. Part I: Climate Model Evaluation

2010 ◽  
Vol 23 (6) ◽  
pp. 1589-1606 ◽  
Author(s):  
Sven Kotlarski ◽  
Frank Paul ◽  
Daniela Jacob
Keyword(s):  
Regional Climate Model ◽  
Mass Balance ◽  
Climate Model ◽  
Regional Climate ◽  
Global Radiation ◽  
High Elevation ◽  
Balance Model ◽  
Future Climate Change ◽  
Glacier Mass Balance ◽  
Mass Balance Model

Abstract A coupling interface between the regional climate model REMO and a distributed glacier mass balance model is presented in a series of two papers. The first part describes and evaluates the reanalysis-driven regional climate simulation that is used to force a mass balance model for two glaciers of the Swiss mass balance network. The detailed validation of near-surface air temperature, precipitation, and global radiation for the European Alps shows that the basic spatial and temporal patterns of all three parameters are reproduced by REMO. Compared to the Climatic Research Unit (CRU) dataset, the Alpine mean temperature is underestimated by 0.34°C. Annual precipitation shows a positive bias of 17% (30%) with respect to the uncorrected gridded ALP-IMP (CRU) dataset. A number of important and systematic model biases arise in high-elevation regions, namely, a negative temperature bias in winter, a bias of seasonal precipitation (positive or negative, depending on gridbox altitude and season), and an underestimation of springtime and overestimation of summertime global radiation. These can be expected to have a strong effect on the simulated glacier mass balance. It is recommended to account for these shortcomings by applying correction procedures before using the RCM output for subsequent mass balance modeling. Despite the obvious model deficiencies in high-elevation regions, the new interface broadens the scope of application of glacier mass balance models and will allow for a straightforward assessment of future climate change impacts.

scholarly journals Modelling 60 years of glacier mass balance and runoff for Chhota Shigri Glacier, Western Himalaya, Northern India

2017 ◽  
Vol 63 (240) ◽  
pp. 618-628 ◽  
Author(s):  
MARKUS ENGELHARDT ◽  
AL. RAMANATHAN ◽  
TRUDE EIDHAMMER ◽  
PANKAJ KUMAR ◽  
OSKAR LANDGREN ◽  
...  
Keyword(s):  
Mass Balance ◽  
Global Radiation ◽  
Western Himalaya ◽  
Snow Accumulation ◽  
Balance Model ◽  
Model Parameters ◽  
Glacier Mass Balance ◽  
Mass Balance Model ◽  
Glacier Melt ◽  
Chhota Shigri Glacier

ABSTRACTGlacier mass balance and runoff are simulated from 1955 to 2014 for the catchment (46% glacier cover) containing Chhota Shigri Glacier (Western Himalaya) using gridded data from three regional climate models: (1) the Rossby Centre regional atmospheric climate model v.4 (RCA4); (2) the REgional atmosphere MOdel (REMO); and (3) the Weather Research and Forecasting Model (WRF). The input data are downscaled to the simulation grid (300 m) and calibrated with point measurements of temperature and precipitation. Additional input is daily potential global radiation calculated using a DEM at a resolution of 30 m. The mass-balance model calculates daily snow accumulation, melt and runoff. The model parameters are calibrated with available mass-balance measurements and results are validated with geodetic measurements, other mass-balance model results and run-off measurements. Simulated annual mass balances slightly decreased from −0.3 m w.e. a−1 (1955–99) to −0.6 m w.e. a−1 for 2000–14. For the same periods, mean runoff increased from 2.0 m3 s−1 (1955–99) to 2.4 m3 s−1 (2000–14) with glacier melt contributing about one-third to the runoff. Monthly runoff increases are greatest in July, due to both increased snow and glacier melt, whereas slightly decreased snowmelt in August and September was more than compensated by increased glacier melt.

scholarly journals Mass-balance model parameter transferability on a tropical glacier

2013 ◽  
Vol 59 (217) ◽  
pp. 845-858 ◽  
Author(s):  
Wolfgang Gurgiser ◽  
Thomas Mölg ◽  
Lindsey Nicholson ◽  
Georg Kaser
Keyword(s):  
Mass Balance ◽  
The Other ◽  
Balance Model ◽  
Small Scale ◽  
Model Parameters ◽  
Glacier Mass Balance ◽  
Ablation Zone ◽  
Model Errors ◽  
Mass Balance Model ◽  
Cumulative Mass

AbstractWe explore the small-scale spatial and temporal transferability of model parameters between two points in the ablation zone of tropical Glaciar Shallap, Cordillera Blanca, Peru (9°S, −77° W; ∼4800 m a.s.l.) in order to provide a robust assessment of the performance of a process-based glacier mass-balance model. Relative surface height change is calculated at hourly time-steps, and cumulative values are compared to surface height measurements made at irregular intervals (14–64 days) over the course of two continuous hydrological years (August 2006–August 2008). Best-performing parameter combinations were determined for each point from the outcome of 1000 model simulations for which parameters were varied randomly within a defined range. With these parameter combinations measurements for a specific location and time-span are well reproduced. Transferring the parameter combination as optimized for one location to the other location in the ablation zone increases the errors of modeled cumulative mass balance by 5–1326 mm ice eq.a−1. Transferring the parameter combinations as optimized for one year to the other year increases the modeled errors in cumulative mass balance by 18–3179 mm ice eq.a−1. Model errors generally increase during periods with frequent snowfall and snow cover. This could reflect either the inherent difficulty of modeling complex snow processes, or the inability of the model to correctly capture the pattern of albedo evolution at this site. The magnitude of errors associated with parameter transfer in space and time highlights the need for improving model performance for robust climatological and/or hydrological analyses on tropical glaciers.

scholarly journals Favorable climatic regime for maintaining the present-day geometry of the Gregoriev Glacier, Inner Tien Shan

2011 ◽  
Vol 5 (3) ◽  
pp. 539-549 ◽  
Author(s):  
K. Fujita ◽  
N. Takeuchi ◽  
S. A. Nikitin ◽  
A. B. Surazakov ◽  
S. Okamoto ◽  
...  
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Tien Shan ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Current State ◽  
Climatic Regime ◽  
Good Agreement

Abstract. We conducted 2 yr (2005–2007) of in situ meteorological and glaciological observations on the Gregoriev Glacier, a flat-top glacier within the Inner Tien Shan, Kyrgyzstan. Relative carrier-phase GPS surveys reveal a vertical lowering at the summit of the glacier. Based on snow density data and an energy-mass balance model, we estimate that the annual precipitation and summer mean temperature required to maintain the glacier in the current state are 289 mm and −3.8 °C at the glacier summit (4600 m a.s.l.), respectively. The good agreement between dynamically derived precipitation and the long-term observed precipitation at a nearby station in the Tien Shan (296 mm at 3614 m a.s.l. for the period 1930–2002) suggests that the glacier has been in a near steady-state in terms of mass supply. The glacier mass-balance, reconstructed based on meteorological data from the Tien Shan station for the past 80 yr, explains the observed fluctuations in glacier extent, particularly the negative mass balance in the 1990s.

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