scholarly journals Relation between recent glacier variations and climate in the Tien Shan mountains, central Asia

1992 ◽  
Vol 16 ◽  
pp. 11-16 ◽  
Author(s):  
Liu Chaohai ◽  
Han Tianding
Keyword(s):  
Mass Balance ◽  
Central Asia ◽  
Air Temperature ◽  
Little Ice Age ◽  
General Trend ◽  
Summer Temperature ◽  
Tien Shan ◽  
Ice Age ◽  
Climatic Fluctuations ◽  
Tien Shan Mountains

Since the Little Ice Age, most glaciers in the Tien Shan mountains have been retreating. Owing to an increase in precipitation in most parts of the mountains during the late 1950s to early 1970s, the percentage of receding glaciers and the speed of retreat have tended to decrease in the 1970s. However, the general trend of continuous glacier retreat remains unchanged, in part because the summer air temperature shows no tendency to decrease.In the Tien Shan mountains, as the degree of climatic continentality increases the mass balance becomes more dependent on summer temperature, and accumulation and ablation tend to be lower. Therefore, the responses of glaciers to climatic fluctuations in more continental areas are not synchronous with those in less continental areas, and the amplitude of the glacier variations becomes smaller.

scholarly journals Relation between recent glacier variations and climate in the Tien Shan mountains, central Asia

1992 ◽  
Vol 16 ◽  
pp. 11-16 ◽  
Author(s):  
Liu Chaohai ◽  
Han Tianding
Keyword(s):  
Mass Balance ◽  
Central Asia ◽  
Air Temperature ◽  
Little Ice Age ◽  
General Trend ◽  
Summer Temperature ◽  
Tien Shan ◽  
Ice Age ◽  
Climatic Fluctuations ◽  
Tien Shan Mountains

Since the Little Ice Age, most glaciers in the Tien Shan mountains have been retreating. Owing to an increase in precipitation in most parts of the mountains during the late 1950s to early 1970s, the percentage of receding glaciers and the speed of retreat have tended to decrease in the 1970s. However, the general trend of continuous glacier retreat remains unchanged, in part because the summer air temperature shows no tendency to decrease.In the Tien Shan mountains, as the degree of climatic continentality increases the mass balance becomes more dependent on summer temperature, and accumulation and ablation tend to be lower. Therefore, the responses of glaciers to climatic fluctuations in more continental areas are not synchronous with those in less continental areas, and the amplitude of the glacier variations becomes smaller.

scholarly journals Recent Climatic Mass Balance of the Schiaparelli Glacier at the Monte Sarmiento Massif and Reconstruction of Little Ice Age Climate by Simulating Steady-State Glacier Conditions

Geosciences ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 272
Author(s):  
Stephanie Suzanne Weidemann ◽  
Jorge Arigony-Neto ◽  
Ricardo Jaña ◽  
Guilherme Netto ◽  
Inti Gonzalez ◽  
...  
Keyword(s):  
Steady State ◽  
Mass Balance ◽  
Air Temperature ◽  
Little Ice Age ◽  
Similar Rate ◽  
Climatic Conditions ◽  
Ice Age ◽  
Balance Model ◽  
Climate Conditions ◽  
Recent Climate

The Cordillera Darwin Icefield loses mass at a similar rate as the Northern and Southern Patagonian Icefields, showing contrasting individual glacier responses, particularly between the north-facing and south-facing glaciers, which are subject to changing climate conditions. Detailed investigations of climatic mass balance processes on recent glacier behavior are not available for glaciers of the Cordillera Darwin Icefield and surrounding icefields. We therefore applied the coupled snow and ice energy and mass balance model in Python (COSIPY) to assess recent surface energy and mass balance variability for the Schiaparelli Glacier at the Monte Sarmiento Massif. We further used COSIPY to simulate steady-state glacier conditions during the Little Ice Age using information of moraine systems and glacier areal extent. The model is driven by downscaled 6-hourly atmospheric data and high resolution precipitation fields, obtained by using an analytical orographic precipitation model. Precipitation and air temperature offsets to present-day climate were considered to reconstruct climatic conditions during the Little Ice Age. A glacier-wide mean annual climatic mass balance of −1.8 ± 0.36 m w.e. a − 1 was simulated between between April 2000 and March 2017. An air temperature decrease between −0.9 ° C and −1.7 ° C in combination with a precipitation offset of up to +60% to recent climate conditions is necessary to simulate steady-state conditions for Schiaparelli Glacier in 1870.

scholarly journals A modelling approach to reconstruct Little Ice Age climate from remote-sensing glacier observations in southeastern Tibet

2016 ◽  
Vol 57 (71) ◽  
pp. 359-370 ◽  
Author(s):  
Eva Huintjes ◽  
David Loibl ◽  
Frank Lehmkuhl ◽  
Christoph Schneider
Keyword(s):  
Remote Sensing ◽  
Mass Balance ◽  
Air Temperature ◽  
Little Ice Age ◽  
Global Analysis ◽  
Analysis Data ◽  
Ice Age ◽  
Balance Model ◽  
Glacier Mass Balance ◽  
Southeastern Tibet

AbstractWe use numerical modelling of glacier mass balance combined with recent and past glacier extents to obtain information on Little Ice Age (LIA) climate in southeastern Tibet. We choose two glaciers that have been analysed in a previous study of equilibrium-line altitudes (ELA) and LIA glacier advances with remote-sensing approaches. We apply a physically based surface energy- and mass-balance model that is forced by dynamically downscaled global analysis data. The model is applied to two glacier stages mapped from satellite imagery, modern (1999) and LIA. Precipitation scaling factors (PSF) and air temperature offsets (ATO) are applied to reproduce recent ELA and glacier mass balance (MB) during the LIA. A sensitivity analysis is performed by applying seasonally varying gradients of precipitation and air temperature. The calculated glacier-wide MB estimate for the period 2000–12 is negative for both glaciers (–992±366 kgm–2 a–1 and –1053±258 kgm–2 a–1). Relating recent and LIA PSF/ATO sets suggests a LIA climate with ~8–25% increased precipitation and ~1–2.5°C lower mean air temperature than in the period 2000–12. The results only provide an order of magnitude because deviations in other input parameters are not considered.

scholarly journals Modern and Little Ice Age glaciers in “humid” and “arid” areas of the Tien Shan, Central Asia: two different patterns of fluctuation

1997 ◽  
Vol 24 ◽  
pp. 142-147 ◽  
Author(s):  
O. S. Savoskul
Keyword(s):  
Central Asia ◽  
Little Ice Age ◽  
Tien Shan ◽  
Ice Age ◽  
Equilibrium Line ◽  
Arid Areas ◽  
Glacier Length ◽  
Climate Signals ◽  
Length And Area ◽  
Inner Parts

Patterns of retreat from maximum Little Ice Age (LIA) to present limits are studied at 20 glaciers in the relatively humid northwestern front ranges and arid inner areas of the Tien Shan, Central Asia. The depression of equilibrium-line altitudes has been calculated using several approaches. Data on changes of elevation ranges, glacier length and area are used to compare the patterns of glacier fluctuation. It is found that the large LIA glaciers in the warm and humid northwestern frontal ranges were 1.5–1.9 times larger in area than the modern glaciers; and the LIA glaciers in cold and arid inner parts of the Tien Shan were only 1.03–1.07 times larger. The changes in terminus-to-headwall elevation ranges are about 1.3–1.6 and 1.02–1.10, respectively. The largest LIA glaciers were 1.4–1.9 times longer than modern glaciers in “humid” ranges and only 1.02–1.12 times longer in “arid” areas. The maximum equilibrium-line depressions are approximately 100–200 m in “humid”areas and 20–50 m in “arid”areas. These results suggest that the glaciers in the “humid” areas are likely to be more variable than those in “arid” areas. The differences may be explained either by differences in the sensitivity of glaciers to climate change or by variability of climate signals from one area to another.

scholarly journals Modern and Little Ice Age glaciers in “humid” and “arid” areas of the Tien Shan, Central Asia: two different patterns of fluctuation

1997 ◽  
Vol 24 ◽  
pp. 142-147 ◽  
Author(s):  
O. S. Savoskul
Keyword(s):  
Central Asia ◽  
Little Ice Age ◽  
Tien Shan ◽  
Ice Age ◽  
Equilibrium Line ◽  
Arid Areas ◽  
Glacier Length ◽  
Climate Signals ◽  
Length And Area ◽  
Inner Parts

Patterns of retreat from maximum Little Ice Age (LIA) to present limits are studied at 20 glaciers in the relatively humid northwestern front ranges and arid inner areas of the Tien Shan, Central Asia. The depression of equilibrium-line altitudes has been calculated using several approaches. Data on changes of elevation ranges, glacier length and area are used to compare the patterns of glacier fluctuation. It is found that the large LIA glaciers in the warm and humid northwestern frontal ranges were 1.5–1.9 times larger in area than the modern glaciers; and the LIA glaciers in cold and arid inner parts of the Tien Shan were only 1.03–1.07 times larger. The changes in terminus-to-headwall elevation ranges are about 1.3–1.6 and 1.02–1.10, respectively. The largest LIA glaciers were 1.4–1.9 times longer than modern glaciers in “humid” ranges and only 1.02–1.12 times longer in “arid” areas. The maximum equilibrium-line depressions are approximately 100–200 m in “humid”areas and 20–50 m in “arid”areas. These results suggest that the glaciers in the “humid” areas are likely to be more variable than those in “arid” areas. The differences may be explained either by differences in the sensitivity of glaciers to climate change or by variability of climate signals from one area to another.

scholarly journals Glacier dynamics at Helheim and Kangerdlugssuaq glaciers, southeast Greenland, since the Little Ice Age

2014 ◽  
Vol 8 (4) ◽  
pp. 1497-1507 ◽  
Author(s):  
S. A. Khan ◽  
K. K. Kjeldsen ◽  
K. H. Kjær ◽  
S. Bevan ◽  
A. Luckman ◽  
...  
Keyword(s):  
Mass Balance ◽  
Little Ice Age ◽  
Ice Age ◽  
Short Term ◽  
Velocity Change ◽  
Outlet Glacier ◽  
Episodic Events ◽  
Highly Sensitive ◽  
Decadal Scale ◽  
Speed Up

Abstract. Observations over the past decade show significant ice loss associated with the speed-up of glaciers in southeast Greenland from 2003, followed by a deceleration from 2006. These short-term, episodic, dynamic perturbations have a major impact on the mass balance on the decadal scale. To improve the projection of future sea level rise, a long-term data record that reveals the mass balance beyond such episodic events is required. Here, we extend the observational record of marginal thinning of Helheim and Kangerdlugssuaq glaciers from 10 to more than 80 years. We show that, although the frontal portion of Helheim Glacier thinned by more than 100 m between 2003 and 2006, it thickened by more than 50 m during the previous two decades. In contrast, Kangerdlugssuaq Glacier underwent minor thinning of 40–50 m from 1981 to 1998 and major thinning of more than 100 m after 2003. Extending the record back to the end of the Little Ice Age (prior to 1930) shows no thinning of Helheim Glacier from its maximum extent during the Little Ice Age to 1981, while Kangerdlugssuaq Glacier underwent substantial thinning of 230 to 265 m. Comparison of sub-surface water temperature anomalies and variations in air temperature to records of thickness and velocity change suggest that both glaciers are highly sensitive to short-term atmospheric and ocean forcing, and respond very quickly to small fluctuations. On century timescales, however, multiple external parameters (e.g. outlet glacier shape) may dominate the mass change. These findings suggest that special care must be taken in the projection of future dynamic ice loss.

Permafrost warming in the Tien Shan Mountains, Central Asia

2007 ◽  
Vol 56 (3-4) ◽  
pp. 311-327 ◽  
Author(s):  
S.S. Marchenko ◽  
A.P. Gorbunov ◽  
V.E. Romanovsky
Keyword(s):  
Central Asia ◽  
Tien Shan ◽  
Permafrost Warming ◽  
Tien Shan Mountains
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