scholarly journals Prediction of possible changes in glacio-hydrological characteristics under global warming: southeastern Alaska, U.S.A.

1996 ◽  
Vol 42 (142) ◽  
pp. 407-412 ◽  
Author(s):  
N.V. Davidovich ◽  
M.D. Ananicheva
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Atmospheric Carbon Dioxide ◽  
Climate Model ◽  
Temperature Fields ◽  
Equilibrium Line Altitude ◽  
Mountain Glacier ◽  
Mountain Glaciers ◽  
Glacier Terminus ◽  
Statistical Relationships

Abstract We use the Wetherald and Manabe climate model to predict the response of mountain glaciers to a doubling of atmospheric carbon dioxide. The response is measured in terms of a change in the equilibrium-line altitude (ELA) and the glacier terminus altitude (GTA), net accumulation–ablation on these altitudes and the melt runoff for 12 mountain-glacier regions in southeastern Alaska, U.S.A. The methods we use involve extrapolating climate-model temperature fields to a glacier’s location, and empirical–statistical relationships between air temperature and percentage of solid precipitation, and between summer air temperature and ablation and melt runoff. Our study shows that, under global warming, glaciation in southeastern Alaska will not disappear, but mass exchange of glaciers will be more intensive and the ELA value will increase by 300–760 m, depending on the glacier’s distance from the ocean.

scholarly journals Prediction of possible changes in glacio-hydrological characteristics under global warming: southeastern Alaska, U.S.A.

1996 ◽  
Vol 42 (142) ◽  
pp. 407-412 ◽  
Author(s):  
N.V. Davidovich ◽  
M.D. Ananicheva
Keyword(s):  
Global Warming ◽  
Air Temperature ◽  
Atmospheric Carbon Dioxide ◽  
Climate Model ◽  
Temperature Fields ◽  
Equilibrium Line Altitude ◽  
Mountain Glacier ◽  
Mountain Glaciers ◽  
Glacier Terminus ◽  
Statistical Relationships

AbstractWe use the Wetherald and Manabe climate model to predict the response of mountain glaciers to a doubling of atmospheric carbon dioxide. The response is measured in terms of a change in the equilibrium-line altitude (ELA) and the glacier terminus altitude (GTA), net accumulation–ablation on these altitudes and the melt runoff for 12 mountain-glacier regions in southeastern Alaska, U.S.A. The methods we use involve extrapolating climate-model temperature fields to a glacier’s location, and empirical–statistical relationships between air temperature and percentage of solid precipitation, and between summer air temperature and ablation and melt runoff. Our study shows that, under global warming, glaciation in southeastern Alaska will not disappear, but mass exchange of glaciers will be more intensive and the ELA value will increase by 300–760 m, depending on the glacier’s distance from the ocean.

scholarly journals The Northeast Asia mountain glaciers in the near future by AOGCM scenarios

2010 ◽  
Vol 4 (4) ◽  
pp. 435-445 ◽  
Author(s):  
M. D. Ananicheva ◽  
A. N. Krenke ◽  
R. G. Barry
Keyword(s):  
Mass Balance ◽  
Meteorological Data ◽  
Northeast Asia ◽  
Morphological Structure ◽  
Kamchatka Peninsula ◽  
Baseline Period ◽  
Equilibrium Line Altitude ◽  
Mountain Glaciers ◽  
Glacier System ◽  
Glacier Terminus

Abstract. We studied contrasting glacier systems in continental (Orulgan, Suntar-Khayata and Chersky) mountain ranges, located in the region of the lowest temperatures in the Northern Hemisphere at the boundary of Atlantic and Pacific influences – and maritime ones (Kamchatka Peninsula) – under Pacific influence. Our purpose is to present a simple projection method to assess the main parameters of these glacier regions under climate change. To achieve this, constructed vertical profiles of mass balance (accumulation and ablation) based both on meteorological data for the 1950–1990s (baseline period) and ECHAM4 for 2049–2060 (projected period) are used, the latter – as a climatic scenario. The observations and scenarios were used to define the recent and future equilibrium line altitude and glacier terminus altitude level for each glacier system as well as areas and balance components. The altitudinal distributions of ice areas were determined for present and future, and they were used for prediction of glacier extent versus altitude in the system taking into account the correlation between the ELA and glacier-terminus level change. We tested two hypotheses of ice distribution versus altitude in mountain (valley) glaciers – "linear" and "non-linear". The results are estimates of the possible changes of the areas and morphological structure of northeastern Asia glacier systems and their mass balance characteristics for 2049–2060. Glaciers in the southern parts of northeastern Siberia and those covering small ranges in Kamchatka will likely disappear under the ECHAM4 scenario; the best preservation of glaciers will be on the highest volcanic peaks of Kamchatka. Finally, we compare characteristics of the stability of continental and maritime glacier systems under global warming.

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 Using GRACE and climate model simulations to predict mass loss of Alaskan glaciers through 2100

2016 ◽  
Vol 62 (234) ◽  
pp. 623-639 ◽  
Author(s):  
JOHN WAHR ◽  
EVAN BURGESS ◽  
SEAN SWENSON
Keyword(s):  
Time Series ◽  
Mass Loss ◽  
Sea Level ◽  
Climate Model ◽  
Temperature Fields ◽  
Model Parameters ◽  
Mountain Glaciers ◽  
Grace Data ◽  
Climate Model Simulations ◽  
Loss Rates

ABSTRACTGlaciers in Alaska are currently losing mass at a rate of ~−50 Gt a−1, one of the largest ice loss rates of any regional collection of mountain glaciers on Earth. Existing projections of Alaska's future sea-level contributions tend to be divergent and are not tied directly to regional observations. Here we develop a simple, regional observation-based projection of Alaska's future sea-level contribution. We compute a time series of recent Alaska glacier mass variability using monthly GRACE gravity fields from August 2002 through December 2014. We also construct a three-parameter model of Alaska glacier mass variability based on monthly ERA-Interim snowfall and temperature fields. When these three model parameters are fitted to the GRACE time series, the model explains 94% of the variance of the GRACE data. Using these parameter values, we then apply the model to simulated fields of monthly temperature and snowfall from the Community Earth System Model, to obtain predictions of mass variations through 2100. We conclude that mass loss rates may increase between −80 and −110 Gt a−1 by 2100, with a total sea-level rise contribution of 19 ± 4 mm during the 21st century.

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 How sensitive are mountain glaciers to climate change? Insights from a block model

2018 ◽  
Vol 64 (244) ◽  
pp. 247-258 ◽  
Author(s):  
EVIATAR BACH ◽  
VALENTINA RADIĆ ◽  
CHRISTIAN SCHOOF
Keyword(s):  
Climate Change ◽  
Response Time ◽  
Response Times ◽  
Global Scale ◽  
Surface Slope ◽  
Block Model ◽  
Equilibrium Line Altitude ◽  
Mountain Glacier ◽  
Mountain Glaciers ◽  
Volume Sensitivity

ABSTRACTSimple models of glacier volume evolution are important in understanding features of glacier response to climate change, due to the scarcity of data adequate for running more complex models on a global scale. Two quantities of interest in a glacier's response to climate changes are its response time and its volume sensitivity to changes in the equilibrium line altitude (ELA). We derive a simplified, computationally inexpensive model of glacier volume evolution based on a block model with volume–area–length scaling. After analyzing its steady-state properties, we apply the model to each mountain glacier worldwide and estimate regionally differentiated response times and sensitivities to ELA changes. We use a statistical method from the family of global sensitivity analysis methods to determine the glacier quantities, geometric and climatic, that most influence the model output. The response time is dominated by the climatic setting reflected in the mass-balance gradient in the ablation zone, followed by the surface slope, while volume sensitivity is mainly affected by glacier size, followed by the surface slope.

scholarly journals Retreat of Wurtenkees, European East Alps, since 1850

1997 ◽  
Vol 24 ◽  
pp. 102-105
Author(s):  
W. Schöner ◽  
I. Auer ◽  
R. Böhm ◽  
N. Hammer ◽  
T. Wiesinger
Keyword(s):  
Global Warming ◽  
Mass Balance ◽  
Air Temperature ◽  
Climatic Conditions ◽  
Area Ratio ◽  
Summer Season ◽  
Degree Days ◽  
Equilibrium Line Altitude ◽  
The Mean ◽  
Accumulation Area Ratio

The retreat of Wurtenkees, a glacier of about 1 km2 in the European East Alps, is described by measurement of frontal change, interpretation of maps and a computed mass-balance series. Since 1850, Wurtenkees has been one of the most strongly retreating glaciers in this region. Mass balance has been measured since 1982. Measured values of the accumulation area ratio and the equilibrium-line altitude as well as a degree-days model are used for the description of the activity conditions of the glacier. Under present climatic conditions Wurtenkees would need a lowering of the mean air temperature during the summer season of 1–1.5° C to return to a balanced mass budget. With predicted global warming, the glacier is likely to disappear early in the 21st century.

scholarly journals Little Ice Age climate reconstruction from ensemble reanalysis of Alpine glacier fluctuations

2014 ◽  
Vol 8 (2) ◽  
pp. 639-650 ◽  
Author(s):  
M. P. Lüthi
Keyword(s):  
Atlantic Multidecadal Oscillation ◽  
Ice Age ◽  
Macroscopic Model ◽  
Radiative Cooling ◽  
Equilibrium Line Altitude ◽  
Alpine Glacier ◽  
Mountain Glaciers ◽  
Glacier Terminus ◽  
History Of ◽  
The Alps

Abstract. Mountain glaciers sample a combination of climate fields – temperature, precipitation and radiation – by accumulation and melting of ice. Flow dynamics acts as a transfer function that maps volume changes to a length response of the glacier terminus. Long histories of terminus positions have been assembled for several glaciers in the Alps. Here I analyze terminus position histories from an ensemble of seven glaciers in the Alps with a macroscopic model of glacier dynamics to derive a history of glacier equilibrium line altitude (ELA) for the time span 400–2010 C.E. The resulting climatic reconstruction depends only on records of glacier variations. The reconstructed ELA history is similar to recent reconstructions of Alpine summer temperature and Atlantic Multidecadal Oscillation (AMO) index, but bears little resemblance to reconstructed precipitation variations. Most reconstructed low-ELA periods coincide with large explosive volcano eruptions, hinting at a direct effect of volcanic radiative cooling on mass balance. The glacier advances during the LIA, and the retreat after 1860, can thus be mainly attributed to temperature and volcanic radiative cooling.

scholarly journals Little Ice Age climate reconstruction from ensemble reanalysis of Alpine glacier fluctuations

2013 ◽  
Vol 7 (5) ◽  
pp. 5147-5175 ◽  
Author(s):  
M. P. Lüthi
Keyword(s):  
Little Ice Age ◽  
Ice Age ◽  
Macroscopic Model ◽  
Volume Changes ◽  
Equilibrium Line Altitude ◽  
Alpine Glacier ◽  
Mountain Glaciers ◽  
Glacier Terminus ◽  
History Of ◽  
The Alps

Abstract. Mountain glaciers sample a combination of climate parameters – temperature, precipitation and radiation – by their rate of volume accumulation and loss. Flow dynamics acts as transfer function which maps volume changes to a length response of the glacier terminus. Long histories of terminus positions have been assembled for several glaciers in the Alps. Here I analyze terminus position histories from an ensemble of seven glaciers in the Alps with a macroscopic model of glacier dynamics to derive a history of glacier equilibrium line altitude (ELA) for the time span 400–2010 C.E. The resulting climatic reconstruction depends only on records of glacier variations. The reconstructed ELA history is similar to recent reconstructions of Alpine summer temperature and Atlantic Meridional Oscillation (AMO) index. Most reconstructed low-ELA periods coincide with large explosive volcano eruptions, hinting to mass balance reduction by volcanic radiative cooling. The glacier advances during the LIA, and the retreat after 1860 are thus explained by temperature and volcanic cooling alone.

scholarly journals Retreat of Wurtenkees, European East Alps, since 1850

1997 ◽  
Vol 24 ◽  
pp. 102-105 ◽  
Author(s):  
W. Schöner ◽  
I. Auer ◽  
R. Böhm ◽  
N. Hammer ◽  
T. Wiesinger
Keyword(s):  
Global Warming ◽  
Mass Balance ◽  
Air Temperature ◽  
Climatic Conditions ◽  
Area Ratio ◽  
Summer Season ◽  
Degree Days ◽  
Equilibrium Line Altitude ◽  
The Mean ◽  
Accumulation Area Ratio

The retreat of Wurtenkees, a glacier of about 1 km2 in the European East Alps, is described by measurement of frontal change, interpretation of maps and a computed mass-balance series. Since 1850, Wurtenkees has been one of the most strongly retreating glaciers in this region. Mass balance has been measured since 1982. Measured values of the accumulation area ratio and the equilibrium-line altitude as well as a degree-days model are used for the description of the activity conditions of the glacier. Under present climatic conditions Wurtenkees would need a lowering of the mean air temperature during the summer season of 1–1.5° C to return to a balanced mass budget. With predicted global warming, the glacier is likely to disappear early in the 21st century.

Sign in / Sign up

Export Citation Format

Share Document