scholarly journals Distributed Energy Balance Flux Modelling of Mass Balances in the Artesonraju Glacier and Discharge in the Basin of Artesoncocha, Cordillera Blanca, Peru

Climate ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 143
Author(s):  
María Fernanda Lozano Gacha ◽  
Manfred Koch
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Energy Balance Model ◽  
Shortwave Radiation ◽  
Radiative Energy ◽  
Balance Model ◽  
Threshold Temperature ◽  
Mass Balances ◽  
Distributed Energy ◽  
Cordillera Blanca

A distributed energy balance model (DEBAM) is applied to estimate the mass balance of the Artesonraju glacier in the Cordillera Blanca (CB), Peru, and to simulate the ensuing discharge into its respective basin, Artesoncocha. The energy balance model calibrations show that, by using seasonal albedos, reasonable results for mass balances and discharge can be obtained, as witnessed by annually aggregated Nash Sutcliffe coefficients (E) of 0.60–0.87 for discharge and of 0.58–0.71 for mass measurements carried out in the period 2004–2007. Mass losses between −1.42 and −0.45 m.w.e. are calculated for that period. The elevation line altitudes (ELAs), which lie between 5009 and 5050 m.a.s.l., are also well simulated, compared to those measured by the Unidad Glaciologica de Recursos Hídricos del Perú (UGRH). It is demonstrated that the net radiation which drives the energy balance and melting processes is mainly affected by the amount of reflected shortwave radiation from the different surfaces. Moreover, the longwave radiation sinks between 63 and 73% of solar radiative energy in the dry season. Further sensitivity studies indicate that the assumed threshold temperature T0 is crucial in mass balance simulations, as it determines the extension of areas with different albedos. An optimal T0 between 2.6 and 3.8 °C is deduced from these simulations.

scholarly journals Climatic controls and climate proxy potential of Lewis Glacier, Mt. Kenya

2016 ◽  
Vol 10 (1) ◽  
pp. 133-148 ◽  
Author(s):  
R. Prinz ◽  
L. I. Nicholson ◽  
T. Mölg ◽  
W. Gurgiser ◽  
G. Kaser
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Radiative Energy ◽  
Balance Model ◽  
Model Parameters ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Positive Mass ◽  
Current Sensitivity ◽  
Maximum Extent

Abstract. The Lewis Glacier on Mt. Kenya is one of the best studied tropical glaciers and has experienced considerable retreat since a maximum extent in the late 19th century (L19). From distributed mass and energy balance modelling, this study evaluates the current sensitivity of the surface mass and energy balance to climatic drivers, explores climate conditions under which the L19 maximum extent might have been sustained, and discusses the potential for using the glacier retreat to quantify climate change. Multi-year meteorological measurements at 4828 m provide data for input, optimization, and evaluation of a spatially distributed glacier mass balance model to quantify the exchanges of energy and mass at the glacier–atmosphere interface. Currently the glacier loses mass due to the imbalance between insufficient accumulation and enhanced melt, because radiative energy gains cannot be compensated by turbulent energy sinks. Exchanging model input data with synthetic climate scenarios, which were sampled from the meteorological measurements and account for coupled climatic variable perturbations, reveals that the current mass balance is most sensitive to changes in atmospheric moisture (via its impact on solid precipitation, cloudiness, and surface albedo). Positive mass balances result from scenarios with an increase of annual (seasonal) accumulation of 30 % (100 %), compared to values observed today, without significant changes in air temperature required. Scenarios with lower air temperatures are drier and associated with lower accumulation and increased net radiation due to reduced cloudiness and albedo. If the scenarios currently producing positive mass balances are applied to the L19 extent, negative mass balances are the result, meaning that the conditions required to sustain the glacier in its L19 extent are not reflected in today's meteorological observations using model parameters optimized for the present-day glacier. Alternatively, a balanced mass budget for the L19 extent can be achieved by changing both climate and optimized gradients (used to extrapolate the meteorological measurements over the glacier) in a manner that implies a distinctly different coupling between the glacier's local surface-air layer and its surrounding boundary layer. This result underlines the difficulty of deriving palaeoclimates for larger glacier extents on the basis of modern measurements of small glaciers.

scholarly journals Climatic controls and climate proxy potential of Lewis Glacier, Mt Kenya

2015 ◽  
Vol 9 (4) ◽  
pp. 3887-3924
Author(s):  
R. Prinz ◽  
L. I. Nicholson ◽  
T. Mölg ◽  
W. Gurgiser ◽  
G. Kaser
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Radiative Energy ◽  
Balance Model ◽  
Model Parameters ◽  
Glacier Mass Balance ◽  
Mass Balances ◽  
Positive Mass ◽  
Current Sensitivity ◽  
Maximum Extent

Abstract. The Lewis Glacier on Mt Kenya is one of the best studied tropical glaciers and has experienced considerable retreat since a maximum extent in the late 19th century (L19). From distributed mass and energy balance modelling, this study evaluates the current sensitivity of the surface mass and energy balance to climatic drivers, explores climate conditions under which the L19 maximum extent might have sustained, and discusses the potential for using the glacier retreat to quantify climate change. Multiyear meteorological measurements at 4828 m provide data for input, optimization and evaluation of a spatially distributed glacier mass balance model to quantify the exchanges of energy and mass at the glacier–atmosphere interface. Currently the glacier loses mass due to the imbalance between insufficient accumulation and enhanced melt, because radiative energy gains cannot be compensated by turbulent energy sinks. Exchanging model input data with synthetic climate scenarios, which were sampled from the meteorological measurements and account for coupled climatic variable perturbations, reveal that the current mass balance is most sensitive to changes in atmospheric moisture (via its impact on solid precipitation, cloudiness and surface albedo). Positive mass balances result from scenarios with an increase of annual (seasonal) accumulation of 30 % (100 %), compared to values observed today, without significant changes in air temperature required. Scenarios with lower air temperatures are drier and associated with lower accumulation and increased net radiation due to reduced cloudiness and albedo. If the scenarios currently producing positive mass balances are applied to the L19 extent, negative mass balances are the result, meaning that the conditions required to sustain the glacier in its L19 extent are not reflected in today's observations. Alternatively, a balanced mass budget for the L19 extent can be explained by changing model parameters that imply a distinctly different coupling between the glacier's local surface-air layer and its surrounding boundary-layer. This result underlines the difficulty of deriving paleoclimates for larger glacier extents on the basis of modern measurements of small glaciers.

Estimation of mass and energy balance of glaciers using a distributed energy balance model over the Chandra river basin (Western Himalaya)

2021 ◽  
Vol 35 (2) ◽  
Author(s):  
Akansha Patel ◽  
Ajanta Goswami ◽  
Jaydeo K. Dharpure ◽  
Meloth Thamban ◽  
Parmanand Sharma ◽  
...  
Keyword(s):  
Energy Balance ◽  
River Basin ◽  
Western Himalaya ◽  
Energy Balance Model ◽  
Balance Model ◽  
Distributed Energy

scholarly journals Climate sensitivity of glaciers in southern Norway: application of an energy-balance model to Nigardsbreen, Hellstugubreen and Alfotbreen

1992 ◽  
Vol 38 (129) ◽  
pp. 223-232 ◽  
Author(s):  
J. Oerlemans
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Climate Sensitivity ◽  
Flow Model ◽  
Energy Balance Model ◽  
Balance Model ◽  
Equilibrium Line Altitude ◽  
Ice Flow ◽  
Calculated Mass ◽  
Southern Norway

AbstractThree glaciers in southern Norway, with very different mass-balance characteristics, are studied with an energy-balance model of the ice/snow surface. The model simulates the observed mass-balance profiles in a satisfactory way, and can thus be used with some confidence in a study of climate sensitivity. Calculated changes in equilibrium-line altitude for a 1 K temperature increase are 110, 108 and 135 m for Nigardsbreen, Hellstugubreen and Alfotbreen, respectively. The corresponding changes in mass balance, averaged over the entire glacier area, are −0.88, −0.715 and −1.11 m year−1 (water equivalent).Runs with an ice-flow model for Nigardsbreen, to which calculated mass-balance profiles arc imposed, predict that the front will advance by 3 km for a 1 K cooling, and will retreat by as much as 6.5 km for a 1 K warming. The response to a 10% increase in precipitation would be a 2 km advance of the snout, whereas a 4 km retreat is predicted for a 10% decrease. This large sensitivity (as compared to many other glaciers) is to a large extent due to the geometry of Nigardsbreen.

Climate sensitivity of glaciers in southern Norway: application of an energy-balance model to Nigardsbreen, Hellstugubreen and Alfotbreen

1992 ◽  
Vol 38 (129) ◽  
pp. 223-232 ◽  
Author(s):  
J. Oerlemans
Keyword(s):  
Energy Balance ◽  
Mass Balance ◽  
Climate Sensitivity ◽  
Flow Model ◽  
Energy Balance Model ◽  
Balance Model ◽  
Equilibrium Line Altitude ◽  
Ice Flow ◽  
Calculated Mass ◽  
Southern Norway

AbstractThree glaciers in southern Norway, with very different mass-balance characteristics, are studied with an energy-balance model of the ice/snow surface. The model simulates the observed mass-balance profiles in a satisfactory way, and can thus be used with some confidence in a study of climate sensitivity. Calculated changes in equilibrium-line altitude for a 1 K temperature increase are 110, 108 and 135 m for Nigardsbreen, Hellstugubreen and Alfotbreen, respectively. The corresponding changes in mass balance, averaged over the entire glacier area, are −0.88, −0.715 and −1.11 m year−1(water equivalent).Runs with an ice-flow model for Nigardsbreen, to which calculated mass-balance profiles arc imposed, predict that the front will advance by 3 km for a 1 K cooling, and will retreat by as much as 6.5 km for a 1 K warming. The response to a 10% increase in precipitation would be a 2 km advance of the snout, whereas a 4 km retreat is predicted for a 10% decrease. This large sensitivity (as compared to many other glaciers) is to a large extent due to the geometry of Nigardsbreen.

Modelling mass changes of Dokriani (Central Himalaya) and Chhota Shigri (Western Himalaya) glaciers, India using energy balance approach

2021 ◽  
Author(s):  
Smriti Srivastava ◽  
Mohd Farooq Azam
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Mass Balance ◽  
Western Himalaya ◽  
Reanalysis Data ◽  
Heat Fluxes ◽  
Balance Model ◽  
Mass Balances ◽  
Chhota Shigri Glacier ◽  
Energy Balance Approach

<p>Processes controlling the glacier wastage in the Himalaya are still poorly understood. In the present study, a surface energy-mass balance model is applied to reconstruct the long-term mass balances over 1979-2020 on two benchmark glaciers, Dokriani and Chhota Shigri, located in different climatic regimes. The model is forced with ERA5 reanalysis data and calibrated using field-observed point mass balances. The model is validated against available glacier-wide mass balances. Dokriani and Chhota Shigri glaciers show moderate wastage with a mean value of –0.28 and –0.34 m w.e. a<sup>-1</sup>, respectively over 1979-2020. The mean winter and summer glacier-wide mass balances are 0.44 and –0.72 m w.e. a<sup>-1</sup> for Dokriani Glacier and 0.53 and –0.85 m w.e. a<sup>-1</sup> for Chhota Shigri Glacier, respectively, showing a higher mass turn over on Chhota Shigri Glacier. Net radiation flux is the major component of surface energy balance followed by sensible and latent heat fluxes on both the glaciers. The losses through sublimation is around 10% to the total ablation. Surface albedo is one of the most important drivers controlling the annual mass balance of both Dokriani and Chhota Shigri glacier. Summer mass balance (0.76, p<0.05) mainly controls the annual glacier-wide mass balance on Dokriani Glacier whereas the summer (0.91, p<0.05) and winter (0.78, p<0.05) mass balances together control the annual glacier-wide mass balance on Chhota Shigri Glacier.</p>

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