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Melt-albedo feedback on glaciers is recognized as important processes for understanding glacier behavior and its sensitivity to climate change. This study selected the Muz Taw Glacier in the Altai Mountains to investigate the spatiotemporal variations in albedo and their linkages with mass balance, which will improve our knowledge of the recent acceleration of regional glacier shrinkage. Based on the Landsat-derived albedo, the spatial distribution of ablation-period albedo was characterized by a general increase with elevation, and significant east–west differences at the same elevation. The gap-filling MODIS values captured a nonsignificant negative trend of mean ablation-period albedo since 2000, with a total decrease of approximately 4.2%. From May to September, glacier-wide albedo exhibited pronounced V-shaped seasonal variability. A significant decrease in annual minimum albedo was found from 2000 to 2021, with the rate of approximately −0.30% yr−1 at the 99% confidence level. The bivariate relationship demonstrated that the change of ablation-period albedo explained 82% of the annual mass-balance variability. We applied the albedo method to estimate annual mass balance over the period 2000–2015. Combined with observed values, the average mass balance was −0.82 ± 0.32 m w.e. yr−1 between 2000 and 2020, with accelerated mass loss. [ABSTRACT FROM AUTHOR]

The glaciers in the Sawir Mountains, Altai area, have been experiencing a continuing and accelerating ice loss since 1959, although the snowfall is abundant and evenly distributed over the year. As an attempt to reduce their melting, we carried out two artificial snowfall experiments on the Muz Taw Glacier during 19–22 August 2018. We measured the albedo and mass balance at different sites along the glacier before and after the experiments. Two automatic weather stations (AWSs) were set up at the equilibrium line altitude (ELA) of the glacier as the target area and the forefield as the control area to record the precipitation, respectively. A comparison of the two precipitation records from the two AWSs suggests that natural precipitation could account for up to 21 % of the snowfall received by the glacier during the experiments. Because of the snowfalls, the glacier's surface albedo significantly increased in the middle to upper part; the average mass loss during 18–24 August (after the experiments) decreased by between 32 and 41 mm w.e (14 %–17 %) compared to during 12–18 August (before the experiments); and the mass resulting from the snowfall accounted for between 42 % and 54 % of the total melt during 18–24 August. We also propose a mechanism involving artificial snowfall, albedo, and mass balance, and the feedbacks describing the role of snowfall in reducing the melting of the glacier. The current status of the work is primitive as it is a preliminary trial, and the conclusions need more controlling experiments to validate it against larger spatio-temporal scales in future. [ABSTRACT FROM AUTHOR]

The determination of total glacial volume is important for the observation of climatic change and its consequences such as global sea-level rise. The tongue area of Glacier No. 4 of Sigong River over Mt. Bogda, eastern Tianshan was surveyed by ground-penetrating radar (GPR) and real time kinematic (RTK)-global positioning system (GPS) during the summer campaign 2009. In order to calculate the glacier volume, both co-kriging algorithm and estimation based on the theory of perfectly plastic material were employed. Results indicated that the ice-thickness distribution of the investigated glacier ranges from 0 to 105.0 m, with the mean thickness of 27.6 m in 2009. The corresponding ice volume was ∼0.076 km (∼0.068 km water equivalent). The bedrock topography shows more undulating than the glacier surface. The difference of the calculated ice volume in this study and the estimated value from the empirical formula is large. Therefore, it is urgent to validate the applicability of the existing empirical formula. [ABSTRACT FROM AUTHOR]

Glaciers are not only direct proxy for climate change, but also important water resources for heavy population in Central Asia. In China, many large rivers head from glaciers in mountains. Among those mountains, Qilian Mountain and its surroundings is characterized by small glaciers developed, dense population and extremely dry climate. Glaciers and snow melt water are heavily depended on in that area. Prohibited by limited studies on regional scale glacier behavior and its mechanisms, the significance of glaciers in Qilian Mountain is of debate. In this study, remote sensing, mass balance model and dynamic model are applied to (1) reconstruct area and mass loss of glaciers in the past 50 years and (2) predict them in 21st century, as well as (3) calculate current and future contribution of glaciers to local river stream. The results indicate glaciers in Qilian Mountain are more sensitive to climate change comparing to those glaciers in Tianshan and other mountains in Tibetan Plateau. One of the main reasons for that is the smaller mean glacier size. Certain part of glaciers in Qilian Mountain are predicted to vanish in very near future with climate change scenarios published in IPCC AR5 as climate forcing. We also supply proof for significant contribution of glaciers to local river runoff, even with the coverage of glaciers in the whole mountain range and surroundings less than 5%. [ABSTRACT FROM AUTHOR]