scholarly journals A near 90-year record of the evolution of El Morado Glacier and its proglacial lake, Central Chilean Andes

2020 ◽  
Vol 66 (259) ◽  
pp. 846-860 ◽  
Author(s):  
David Farías-Barahona ◽  
Ryan Wilson ◽  
Claudio Bravo ◽  
Sebastián Vivero ◽  
Alexis Caro ◽  
...  
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Central Andes ◽  
Balance Model ◽  
Water Volume ◽  
Glacier Mass Balance ◽  
Severe Drought ◽  
Surface Mass ◽  
Area Loss ◽  
Proglacial Lake

AbstractUsing an ensemble of close- and long-range remote sensing, lake bathymetry and regional meteorological data, we present a detailed assessment of the geometric changes of El Morado Glacier in the Central Andes of Chile and its adjacent proglacial lake between 1932 and 2019. Overall, the results revealed a period of marked glacier down wasting, with a mean geodetic glacier mass balance of −0.39 ± 0.15 m w.e.a−1 observed for the entire glacier between 1955 and 2015 with an area loss of 40% between 1955 and 2019. We estimate an ice elevation change of −1.00 ± 0.17 m a−1 for the glacier tongue between 1932 and 2019. The increase in the ice thinning rates and area loss during the last decade is coincident with the severe drought in this region (2010–present), which our minimal surface mass-balance model is able to reproduce. As a result of the glacier changes observed, the proglacial lake increased in area substantially between 1955 and 2019, with bathymetry data suggesting a water volume of 3.6 million m3 in 2017. This study highlights the need for further monitoring of glacierised areas in the Central Andes. Such efforts would facilitate a better understanding of the downstream impacts of glacier downwasting.

scholarly journals Exploring uncertainty in glacier mass balance modelling with Monte Carlo simulation

2008 ◽  
Vol 2 (3) ◽  
pp. 447-485 ◽  
Author(s):  
H. Machguth ◽  
R. S. Purves ◽  
J. Oerlemans ◽  
M. Hoelzle ◽  
F. Paul
Keyword(s):  
Monte Carlo ◽  
Mass Balance ◽  
Meteorological Data ◽  
Global Radiation ◽  
Systematic Errors ◽  
Uncertainty Assessment ◽  
Balance Model ◽  
Order Estimate ◽  
Glacier Mass Balance ◽  
Data Sets

Abstract. By means of Monte Carlo simulations we calculated uncertainty in modelled cumulative mass balance over 400 days at one particular point on the tongue of Morteratsch Glacier, Switzerland, using a glacier energy balance model of intermediate complexity. Before uncertainty assessment, the model was tuned to observed mass balance for the investigated time period and its robustness was tested by comparing observed and modelled mass balance over 11 years, yielding very small deviations. Both systematic and random uncertainties are assigned to twelve input parameters and their respective values estimated from the literature or from available meteorological data sets. The calculated overall uncertainty in the model output is dominated by systematic errors and amounts to 0.7 m w.e. or approximately 10% of total melt over the investigated time span. In order to provide a first order estimate on variability in uncertainty depending on the quality of input data, we conducted a further experiment, calculating overall uncertainty for different levels of uncertainty in measured global radiation and air temperature. Our results show that the output of a well calibrated model is subject to considerable uncertainties, in particular when applied for extrapolation in time and space where systematic errors are likely to be an important issue.

scholarly journals Exploring uncertainty in glacier mass balance modelling with Monte Carlo simulation

2008 ◽  
Vol 2 (2) ◽  
pp. 191-204 ◽  
Author(s):  
H. Machguth ◽  
R. S. Purves ◽  
J. Oerlemans ◽  
M. Hoelzle ◽  
F. Paul
Keyword(s):  
Monte Carlo ◽  
Mass Balance ◽  
Meteorological Data ◽  
Global Radiation ◽  
Systematic Errors ◽  
Uncertainty Assessment ◽  
Balance Model ◽  
Order Estimate ◽  
Glacier Mass Balance ◽  
Data Sets

Abstract. By means of Monte Carlo simulations we calculated uncertainty in modelled cumulative mass balance over 400 days at one particular point on the tongue of Morteratsch Glacier, Switzerland, using a glacier energy balance model of intermediate complexity. Before uncertainty assessment, the model was tuned to observed mass balance for the investigated time period and its robustness was tested by comparing observed and modelled mass balance over 11 years, yielding very small deviations. Both systematic and random uncertainties are assigned to twelve input parameters and their respective values estimated from the literature or from available meteorological data sets. The calculated overall uncertainty in the model output is dominated by systematic errors and amounts to 0.7 m w.e. or approximately 10% of total melt over the investigated time span. In order to provide a first order estimate on variability in uncertainty depending on the quality of input data, we conducted a further experiment, calculating overall uncertainty for different levels of uncertainty in measured global radiation and air temperature. Our results show that the output of a well calibrated model is subject to considerable uncertainties, in particular when applied for extrapolation in time and space where systematic errors are likely to be an important issue.

scholarly journals Relating glacier mass balance to meteorological data by using a seasonal sensitivity characteristic

2000 ◽  
Vol 46 (152) ◽  
pp. 1-6 ◽  
Author(s):  
J. Oerlemans ◽  
B. K. Reichert
Keyword(s):  
Mass Balance ◽  
Climate Sensitivity ◽  
Significant Contribution ◽  
Meteorological Data ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Atmospheric Models ◽  
Temperature And Precipitation ◽  
The Mean ◽  
Sensitivity Characteristic

AbstractWe propose to quantify the climate sensitivity of the mean specific balance B of a glacier by a seasonal sensitivity characteristic (SSC). The SSC gives the dependence of B on monthly anomalies in temperature and precipitation. It is calculated from a mass-balance model. We show and discuss examples for Franz-Josef Glacier (New Zealand), Nigardsbreen (Norway), Hintereisferner (Austria), Peyto Glacier (Canadian Rockies), Abramov Glacier (Kirghizstan) and White Glacier (Canadian Arctic). With regard to the climate sensitivity of B, the SSCs clearly show that summer temperature is the most important factor for glaciers in a dry climate. For glaciers in a wetter climate, spring and fall temperatures also make a significant contribution to the overall sensitivity. The SSC is a 2 × 12 matrix. Multiplying it with monthly perturbations of temperature and precipitation for a particular year yields an estimate of the balance for that year. We show that, with this technique, mass-balance series can be (re)constructed from long meteorological records or from output of atmospheric models.

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.

scholarly journals Glacier evolution in high-mountain Asia under stratospheric sulfate aerosol injection geoengineering

2017 ◽  
Vol 17 (11) ◽  
pp. 6547-6564 ◽  
Author(s):  
Liyun Zhao ◽  
Yi Yang ◽  
Wei Cheng ◽  
Duoying Ji ◽  
John C. Moore
Keyword(s):  
Mass Balance ◽  
Radiative Forcing ◽  
Sulfate Aerosol ◽  
Balance Model ◽  
Climate Projections ◽  
High Mountain ◽  
Glacier Mass Balance ◽  
Volume Loss ◽  
Surface Mass ◽  
Glacier Shrinkage

Abstract. Geoengineering by stratospheric sulfate aerosol injection may help preserve mountain glaciers by reducing summer temperatures. We examine this hypothesis for the glaciers in high-mountain Asia using a glacier mass balance model driven by climate simulations from the Geoengineering Model Intercomparison Project (GeoMIP). The G3 and G4 schemes specify use of stratospheric sulfate aerosols to reduce the radiative forcing under the Representative Concentration Pathway (RCP) 4.5 scenario for the 50 years between 2020 and 2069, and for a further 20 years after termination of geoengineering. We estimate and compare glacier volume loss for every glacier in the region using a glacier model based on surface mass balance parameterization under climate projections from three Earth system models under G3, five models under G4, and six models under RCP4.5 and RCP8.5. The ensemble projections suggest that glacier shrinkage over the period 2010–2069 is equivalent to sea-level rise of 9.0 ± 1.6 mm (G3), 9.8 ± 4.3 mm (G4), 15.5 ± 2.3 mm (RCP4.5), and 18.5 ± 1.7 mm (RCP8.5). Although G3 keeps the average temperature from increasing in the geoengineering period, G3 only slows glacier shrinkage by about 50 % relative to losses from RCP8.5. Approximately 72 % of glaciated area remains at 2069 under G3, as compared with about 30 % for RCP8.5. The widely reported reduction in mean precipitation expected for solar geoengineering is unlikely to be as important as the temperature-driven shift from solid to liquid precipitation for forcing Himalayan glacier change. The termination of geoengineering at 2069 under G3 leads to temperature rise of about 1.3 °C over the period 2070–2089 relative to the period 2050-2069 and corresponding increase in annual mean glacier volume loss rate from 0.17 to 1.1 % yr−1, which is higher than the 0.66 % yr−1 under RCP8.5 during 2070–2089.

scholarly journals Ideal climatic variables for the present-day geometry of the Gregoriev Glacier, Inner Tien Shan, Kyrgyzstan, derived from GPS data and energy-mass balance measurements

2011 ◽  
Vol 5 (2) ◽  
pp. 855-883
Author(s):  
K. Fujita ◽  
N. Takeuchi ◽  
S. A. Nikitin ◽  
A. B. Surazakov ◽  
S. Okamoto ◽  
...  
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Vertical Surface ◽  
Tien Shan ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Differential Gps ◽  
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. Differential GPS surveys reveal a vertical surface deletion 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 modern state are 289 mm and −3.85 °C at the glacier summit (4600 m above sea level, a.s.l.), respectively. The good agreement between the long-term estimated and observed precipitation at a nearby station in the Tien Shan (292 mm at 3614 m a.s.l. for the period 1930–2002) suggests that the glacier dynamics have been regulated by the long-term average accumulation. 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.

scholarly journals Distributed mass-balance and climate sensitivity modelling of Engabreen, Norway

2005 ◽  
Vol 42 ◽  
pp. 395-401 ◽  
Author(s):  
Thomas V. Schuler ◽  
Regine Hock ◽  
Miriam Jackson ◽  
Hallgeir Elvehøy ◽  
Matthias Braun ◽  
...  
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
High Sensitivity ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Index Method ◽  
Temperature And Precipitation ◽  
Simple Mass ◽  
Climate Station ◽  
The Impact

AbstractAssessing the impact of possible climate change on the water resources of glacierized areas requires a reliable model of the climate–glacier-mass-balance relationship. In this study, we simulate the mass-balance evolution of Engabreen, Norway, using a simple mass-balance model based on daily temperature and precipitation data from a nearby climate station. Ablation is calculated using a distributed temperature-index method including potential direct solar radiation, while accumulation is distributed linearly with elevation. The model was run for the period 1974/75–2001/02, for which annual mass-balance measurements and meteorological data are available. Parameter values were determined by a multi-criteria validation including point measurements of mass balance, mass-balance gradients and specific mass balance. The modelled results fit the observed mass balance well. Simple sensitivity experiments indicate a high sensitivity of the mass balance to temperature changes, as expected for maritime glaciers. The results suggest, further, that the mass balance of Engabreen is more sensitive to warming during summer than during winter, while precipitation changes affect almost exclusively the winter balance.

scholarly journals Surface mass balance, thinning and iceberg production, Columbia Glacier, Alaska, 1948–2007

2011 ◽  
Vol 57 (203) ◽  
pp. 431-440 ◽  
Author(s):  
L.A. Rasmussen ◽  
H. Conway ◽  
R.M. Krimmel ◽  
R. Hock
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Balance Model ◽  
Surface Mass Balance ◽  
Mass Balance Model ◽  
Surface Mass ◽  
Surface Ablation ◽  
Positive Balance ◽  
Remarkable Result ◽  
The Difference

AbstractA mass-balance model using upper-air meteorological data for input was calibrated with surface mass balance measured mainly during 1977–78 at 67 sites on Columbia Glacier, Alaska, between 135 and 2645 m a.s.l. Root-mean-square error, model vs measured, is 1.0 m w.e. a−1, with r2 = 0.88. A remarkable result of the analysis was that both precipitation and the factor in the positive degree-day model used to estimate surface ablation were constant with altitude. The model was applied to reconstruct glacier-wide components of surface mass balance over 1948–2007. Surface ablation, 4 km3 ice eq. a−1 (ice equivalent), has changed little throughout the period. From 1948 until about 1981, when drastic retreat began, the surface mass balance was positive but changes in glacier geometry were small, so the positive balance was offset by calving, ∼0.9 km3 ice eq. a−1 . During retreat, volume loss of the glacier accounted for 92% of the iceberg production. Calving increased to ∼4.3 km3 ice eq. a−1 from 1982 to 1995, and after that until 2007 to ∼8.0 km3 ice eq. a−1, which was about twice the loss by surface ablation, whereas prior to retreat it was only about a quarter as much. Calving is calculated as the difference between glacier-wide surface mass balance and geodetically determined volume change.

scholarly journals Reconstructing the annual mass balance of the Echaurren Norte glacier (Central Andes, 33.5° S) using local and regional hydroclimatic data

2016 ◽  
Vol 10 (2) ◽  
pp. 927-940 ◽  
Author(s):  
Mariano H. Masiokas ◽  
Duncan A. Christie ◽  
Carlos Le Quesne ◽  
Pierre Pitte ◽  
Lucas Ruiz ◽  
...  
Keyword(s):  
Mass Balance ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Monthly Precipitation ◽  
Mass Balances ◽  
Positive Mass ◽  
Glacier Surface ◽  
Surface Mass ◽  
The Andes

Abstract. Despite the great number and variety of glaciers in southern South America, in situ glacier mass-balance records are extremely scarce and glacier–climate relationships are still poorly understood in this region. Here we use the longest (>  35 years) and most complete in situ mass-balance record, available for the Echaurren Norte glacier (ECH) in the Andes at  ∼  33.5° S, to develop a minimal glacier surface mass-balance model that relies on nearby monthly precipitation and air temperature data as forcing. This basic model is able to explain 78 % of the variance in the annual glacier mass-balance record over the 1978–2013 calibration period. An attribution assessment identified precipitation variability as the dominant forcing modulating annual mass balances at ECH, with temperature variations likely playing a secondary role. A regionally averaged series of mean annual streamflow records from both sides of the Andes between  ∼  30 and 37° S is then used to estimate, through simple linear regression, this glacier's annual mass-balance variations since 1909. The reconstruction model captures 68 % of the observed glacier mass-balance variability and shows three periods of sustained positive mass balances embedded in an overall negative trend over the past 105 years. The three periods of sustained positive mass balances (centered in the 1920s–1930s, in the 1980s and in the first decade of the 21st century) coincide with several documented glacier advances in this region. Similar trends observed in other shorter glacier mass-balance series suggest that the Echaurren Norte glacier reconstruction is representative of larger-scale conditions and could be useful for more detailed glaciological, hydrological and climatological assessments in this portion of the Andes.

scholarly journals Effect of summer accumulation on glacier mass balance on the Tibetan Plateau revealed by mass-balance model

2000 ◽  
Vol 46 (153) ◽  
pp. 244-252 ◽  
Author(s):  
Koji Fujita ◽  
Yutaka Ageta
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Surface Albedo ◽  
Arid Environment ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
The Tibetan Plateau ◽  
Central Plateau ◽  
Model Calculations ◽  
Surface Mass

AbstractThe characteristics and sensitivities of a cold-based glacier on the Tibetan Plateau, where the summer monsoon provides most of the mass input to glaciers, are discussed using an energy-balance model incorporating the process of water refreezing. The model accurately represents the observational results related to the mass balance of Xiao Dongkemadi glacier on the central plateau during 1992/93. Our data revealed that the mass balance of cold glaciers cannot simply be described by the surface mass/heat balances, because about 20% of infiltrated water is refrozen and thus does not run off from the glacier. Model calculations demonstrate that glaciers in an arid environment can maintain their mass since the monsoon provides precipitation during the melting season. Snowfall in summer keeps surface albedo high and largely restrains ablation. Nevertheless, the calculations also make clear that glaciers on the plateau are more vulnerable than those of other regions because of summer accumulation. In the monsoon climate, warming would cause not only a decrease in accumulation, but also a drastic increase in ablation in combination with surface-albedo lowering. Therefore, although glaciers on and around the plateau can be sustained by summer accumulation, they are more vulnerable to warming than winter-accumulation-type glaciers.

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