scholarly journals Glacier Retreat Across The Chinese Tien Shan Due To Rising Air Temperature

2018 ◽  
Author(s):  
Yanjun Che ◽  
Mingjun Zhang
2016 ◽  
Vol 53 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Sylvain Jobard ◽  
Marc Dzikowski

Reduced meltwater discharge owing to glacier retreat can have severe impacts on downstream water users. To assess these impacts, it is essential to differentiate between water from glacier melt and other sources. We propose a method for doing this on a daily time scale by applying a mixing law to electrical conductivity and proglacial discharge measurements. Daily ablation is then estimated by applying a recession law to the glacier melt component. Testing this method on summer hydrology and meteorology measurements from the Baounet Glacier (France) taken over six consecutive years (2008–2013) allowed us to reconstruct daily ablation during the ablation period. Mean ablation rates ranged from 20 to 30 mm·day−1. Air temperature measurements showed that periods of low ablation during the summer were linked to cooler days and snowfall periods. Comparisons for three consecutive summers showed that the ablation rates obtained by summing calculated daily ablation were statistically similar to the rates recorded by ablation stakes.


2006 ◽  
Vol 43 ◽  
pp. 49-60 ◽  
Author(s):  
Vladimir B. Aizen ◽  
Elena M. Aizen ◽  
Daniel R. Joswiak ◽  
Koji Fujita ◽  
Nozomu Takeuchi ◽  
...  

AbstractSeveral firn/ice cores were recovered from the Siberian Altai (Belukha plateau), central Tien Shan (Inilchek glacier) and the Tibetan Plateau (Zuoqiupu glacier, Bomi) from 1998 to 2003. The comparison analyses of stable-isotope/geochemistry records obtained from these firn/ice cores identified the physical links controlling the climate-related signals at the seasonal-scale variability. The core data related to physical stratigraphy, meteorology and synoptic atmospheric dynamics were the basis for calibration, validation and clustering of the relationships between the firn-/ice-core isotope/ geochemistry and snow accumulation, air temperature and precipitation origin. The mean annual accumulation (in water equivalent) was 106 gcm−2 a−1 at Inilchek glacier, 69 gcm−2 a−1 at Belukha and 196 g cm−2 a−1 at Zuoqiupu. The slopes in regression lines between the δ18O ice-core records and air temperature were found to be positive for the Tien Shan and Altai glaciers and negative for southeastern Tibet, where heavy amounts of isotopically depleted precipitation occur during summer monsoons. The technique of coupling synoptic climatology and meteorological data with δ18O and d-excess in firn-core records was developed to determine climate-related signals and to identify the origin of moisture. In Altai, two-thirds of accumulation from 1984 to 2001 was formed from oceanic precipitation, and the rest of the precipitation was recycled over Aral–Caspian sources. In the Tien Shan, 87% of snow accumulation forms by precipitation originating from the Aral–Caspian closed basin, the eastern Mediterranean and Black Seas, and 13% from the North Atlantic.


1992 ◽  
Vol 16 ◽  
pp. 11-16 ◽  
Author(s):  
Liu Chaohai ◽  
Han Tianding

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.


1992 ◽  
Vol 16 ◽  
pp. 107-114 ◽  
Author(s):  
Hiroyuki Ohno ◽  
Tetsuo Ohata ◽  
Keiji Higuchi

The annual evaporation of a continental-type glacier (43°05’ Ν, 86°48’ E) in the Chinese Tien Shan is estimated, based on data derived from four field observations carried out between summer 1987 and spring 1988, and data from a permanent weather station near the glacier. The evaporation during the melting and non-melting seasons is estimated as 81 mm and negligible, respectively. Assuming that the ablation is equivalent to the annual precipitation (650 mm) in 1987, estimated annual evaporation of 81 mm is 12% of the ablation and consumes 54% of the energy which causes the ablation. It can be said that evaporation suppresses ablation by 50% in comparison with the condition in which there is no evaporation.The influence of fluctuations of air temperature and humidity on the ablation of the glacier were evaluated. Changes in temperature and humidity cause larger changes in ablation of glaciers in a cold and dry climate. The influence of humidity change is very important to glaciers located in a relatively warm environment.


2018 ◽  
Vol 64 (244) ◽  
pp. 300-310 ◽  
Author(s):  
DAIKI SAKAKIBARA ◽  
SHIN SUGIYAMA

ABSTRACTSatellite images were analyzed to measure the frontal positions and ice speeds of 19 marine-terminating outlet glaciers along the coast of Prudhoe Land, northwestern Greenland from 1987 to 2014. All the studied glaciers retreated over the study period at a rate of between 12 and 200 m a−1, with a median (mean) retreat rate of 30 (40) m a−1. The glacier retreat began in the year ~2000, which coincided with an increase in summer mean air temperature from 1.4 to 5.5 °C between 1996 and 2000 in this region. Ice speed near the front of the studied glaciers ranged between 20 and 1740 m a−1 in 2014, and many of them accelerated in the early 2000s. In general, the faster retreat was observed at the glaciers that experienced greater acceleration, as represented by Tracy Glacier, which experienced a retreat of 200 m a−1 and a velocity increase of 930 m a−1 during the study period. A possible interpretation of this observation is that flow acceleration induced dynamic thinning near the termini, resulting in enhanced calving and rapid retreat of the studied glaciers. We hypothesize that atmospheric warming conditions in the late 1990s triggered glacier retreat in northwestern Greenland since 2000.


1999 ◽  
Vol 45 (151) ◽  
pp. 517-523
Author(s):  
Hou Shugui ◽  
Qin Dahe ◽  
Paul A. Mayewski ◽  
Yang Qinzhao ◽  
Ren Jiawen ◽  
...  

AbstractStable-oxygen-isotope ratios (δ18O) of precipitation and ice-core samples collected from the headwaters of the Urümqi river, Tien Shan, China, were used to test the relationship between δ18O and contemporaneous surface air temperature (Ta). A strong temporal relationship is found between δ18O in precipitation and Ta, particularly for the monthly averages which remove synoptic-scale influences such as changes in condensation level, condensation temperature and moisture sources ( Yao and others, 1996). Linear fits as high as 0.95‰° C-1 for precipitation events and 1.23‰° C-1 for monthly averages are found. Although the δ18O amplitude in ice cores drilled at the nearby Ürümqi glacier No.1(~2 km from the precipitation sampling site) decreased dramatically compared to the precipitation samples, the ice-core records of annually averaged δ18 are still positively correlated with contemporaneous air temperature, especially summer air temperature, at the nearby Daxigou meteorological station. Nevertheless, the relationship between the ice-core δ18O records and contemporaneous air temperature is less significant than that for the precipitation samples due to depositional and post-depositional modification processes, which are highlighted by the successive snow-pit δ18O profiles from the Ürümqi glacier No.1. Our results might extend the application of high-altitude and subtropical ice-core δ18O —Ta records for paleoclimate reconstruction.


1999 ◽  
Vol 45 (151) ◽  
pp. 517-523 ◽  
Author(s):  
Hou Shugui ◽  
Qin Dahe ◽  
Paul A. Mayewski ◽  
Yang Qinzhao ◽  
Ren Jiawen ◽  
...  

AbstractStable-oxygen-isotope ratios(δ18O)of precipitation and ice-core samples collected from the headwaters of the Urümqi river, Tien Shan, China, were used to test the relationship betweenδ18Oand contemporaneous surface air temperature (Ta). A strong temporal relationship is found betweenδ18Oin precipitation andTa,particularly for the monthly averages which remove synoptic-scale influences such as changes in condensation level, condensation temperature and moisture sources ( Yao and others, 1996). Linear fits as high as 0.95‰° C-1for precipitation events and 1.23‰° C-1for monthly averages are found. Although theδ18O amplitude in ice cores drilled at the nearby Ürümqi glacier No.1(~2 km from the precipitation sampling site) decreased dramatically compared to the precipitation samples, the ice-core records of annually averagedδ18are still positively correlated with contemporaneous air temperature, especially summer air temperature, at the nearby Daxigou meteorological station. Nevertheless, the relationship between the ice-coreδ18Orecords and contemporaneous air temperature is less significant than that for the precipitation samples due to depositional and post-depositional modification processes, which are highlighted by the successive snow-pitδ18Oprofiles from the Ürümqi glacier No.1. Our results might extend the application of high-altitude and subtropical ice-coreδ18O—Tarecords for paleoclimate reconstruction.


2006 ◽  
Vol 43 ◽  
pp. 323-328 ◽  
Author(s):  
Tianding Han ◽  
Yongjian Ding ◽  
Baisheng Ye ◽  
Shiyin Liu ◽  
Keqin Jiao

AbstractThe temporal and spatial variations of mass balance on different timescales were analyzed to identify their response to climate change using long-term observed mass-balance data covering the period 1959–2002 at Ürümqi glacier No. 1 at the headwaters of the Ürümqi river, Tien Shan, China. The results show that the accumulated glacier mass balance has decreased by 9599 mm w.e., which is equivalent to about 10 m mean thickness reduction. The negative mass balance has been accentuated in recent years, with a mean mass balance during the period 1997–2002 of –739.6 mm a−1. The glacier mass balance shows a clear periodicity, with positive and negative alternations of 7 and 15 years during the past several decades. Annual mass balance shows a significant negative correlation with summer air temperature from June to August. It is influenced more by annual air temperature than by annual precipitation. The temperature increase preceded the precipitation increase as an influence on the mass balance. Furthermore, monthly mass balance shows a negative correlation with monthly air temperature, significant at the 99% confidence level in July and August. Monthly mass balance is negatively correlated with precipitation in May and August at the 95% confidence level, but positively and insignificantly correlated with precipitation in June and July. The negative relationship between mass balance and precipitation might be related to concurrent increases of precipitation and temperature.


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