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Article ; Online: Use of ablation-season albedo as an indicator of annual mass balance of four glaciers in the Tien Shan

Xiaoying Yue / Zhongqin Li / Feiteng Wang / Huilin Li

Frontiers in Earth Science, Vol

2023 Volume 11

Abstract: Glacier mass balance and its sensitivity to climate change depend to a large degree on the albedo and albedo feedback. Although recent increasing studies reconstruct the annual surface mass balance (SMB) based on the relationships between satellite- ... ...

Abstract	Glacier mass balance and its sensitivity to climate change depend to a large degree on the albedo and albedo feedback. Although recent increasing studies reconstruct the annual surface mass balance (SMB) based on the relationships between satellite-derived minimum albedo and annual glaciological mass balance (so-called albedo method), a relationship remains conjectural for Tien Shan glaciers. Accumulation and ablation occur simultaneously in summer, causing different surface processes. We examine this relationship using glaciological mass-balance data and the equilibrium-line altitude (ELA) made on the eastern branch of Urumqi Glacier No. 1 (UG1-E), Tuyuksu, Golubin and Glacier No. 354, and ablation-season (May–September) albedo retrieved from Moderate Resolution Imaging Spectroradiometer (MODIS) images from 2000 to 2021. Compared with minimum ablation-season albedo, we find higher coefficients of determination between mean ablation-season albedo and glaciological mass balance at UG1-E and Tuyuksu. In contrast, for Golubin and Glacier No. 354, glaciological mass balance is higher correlated to minimum ablation-season albedo than mean ablation-season albedo. This difference is related to the glaciological mass-balance time period. The relationship between albedo and glaciological mass balance is obtained over a shorter time for Golubin (8 years) and Glacier No. 354 (9 years) than for UG1-E (20 years) and Tuyuksu (20 years). Non-etheless, based on the correlativity between MODIS-derived mean ablation-season albedo and minimum ablation-season albedo and glaciological mass balance of Golubin and Glacier No. 354 over the 2011–2019 period, the annual SMB for these glaciers can be reconstructed using the albedo method over the period 2000–2010. Comparison with previously reconstructed results indicated that the mass balance derived from albedo is robust for Glacier No. 354, while for Golubin, the results derived from the albedo method only captured the relative changes in mass balance. The current study suggested that ...
Keywords	MODIS albedo ; Tien Shan ; ablation season ; glacier ; mass balance ; Science ; Q
Subject code	550
Language	English
Publishing date	2023-03-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Hydrological response to climate change in a glacierized catchment in eastern Tien Shan, Central Asia

Yufeng Jia / Zhongqin Li / Hongkai Gao / Shengjie Wang / Meiping Sun / Puyu Wang

Journal of Hydrology: Regional Studies, Vol 51, Iss , Pp 101669- (2024)

2024

Abstract: Study region: The headwaters of Urumqi River basin located in eastern Tien Shan Study focus: Glacier shrinkage in recent decades has caused the volume and timing of glacier-fed streamflow to change, which in turn has significantly impacted the water ... ...

Abstract	Study region: The headwaters of Urumqi River basin located in eastern Tien Shan Study focus: Glacier shrinkage in recent decades has caused the volume and timing of glacier-fed streamflow to change, which in turn has significantly impacted the water supply and ecological system in the vast arid land in Central Asia and drawn wide public attention. Based on a glacio-hydrologic degree-day model, the runoff mechanisms and processes of the glacier-fed catchment are revealed. New hydrological insights for the region: The study found that about 51 % glacier coverage of the Urumqi Glacier No.1 catchment (UG1C) generates approximately 76 % glacier runoff, indicating that glacier melt comprises a significant water resource in the region. The different ways that the glacier melts in response to temperature versus precipitation on a daily scale by changing glacier mass balance can effectively stabilize streamflow, showing a strong capacity of the glacier to naturally adjust streamflow beneficially to water utilization by those downstream. Based on the sensitivity of modelled runoff to glacier change by comparing simulations using constant glacier cover that accommodated dynamic changes in glacier area, we found that the maximum volume of ice melt runoff during the past four decades appeared during the period 1996–2019, most likely around 2010.
Keywords	Climate change ; Glacierized catchment ; Ice melt runoff ; Snowmelt runoff ; Glacio-hydrological model ; Physical geography ; GB3-5030 ; Geology ; QE1-996.5
Subject code	550 ; 910
Language	English
Publishing date	2024-02-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Changes in Diversity and Abundance of Ammonia-Oxidizing Archaea and Bacteria along a Glacier Retreating Chronosequence in the Tianshan Mountains, China

Xiukun Wu / Wei Zhang / Guangxiu Liu / Tuo Chen / Zhongqin Li

Microorganisms, Vol 11, Iss 12, p

2023 Volume 2871

Abstract: Glaciers retreating due to global warming create important new habitats, particularly suitable for studying ecosystem development where nitrogen is a limiting factor. Nitrogen availability mainly results from microbial decomposition and transformation ... ...

Abstract	Glaciers retreating due to global warming create important new habitats, particularly suitable for studying ecosystem development where nitrogen is a limiting factor. Nitrogen availability mainly results from microbial decomposition and transformation processes, including nitrification. AOA and AOB perform the first and rate-limiting step of nitrification. Investigating the abundance and diversity of AOA and AOB is essential for understanding early ecosystem development. The dynamics of AOA and AOB community structure along a soil chronosequence in Tianshan No. 1 Glacier foreland were analyzed using qPCR and clone library methods. The results consistently showed low quantities of both AOA and AOB throughout the chronosequence. Initially, the copy numbers of AOB were higher than those of AOA, but they decreased in later stages. The AOB community was dominated by “Nitrosospira cluster ME”, while the AOA community was dominated by “the soil and sediment 1”. Both communities were potentially connected to supra- and subglacial microbial communities during early stages. Correlation analysis revealed a significant positive correlation between the ratios of AOA and AOB with soil ammonium and total nitrogen levels. These results suggest that variations in abundance and diversity of AOA and AOB along the chronosequences were influenced by ammonium availability during glacier retreat.
Keywords	AOA and AOB ; community structure ; glacier foreland ; chronosequence ; Tianshan No. 1 Glacier ; Biology (General) ; QH301-705.5
Subject code	550
Language	English
Publishing date	2023-11-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Characteristics of Chemical Solutes and Mineral Dust in Ice of the Ablation Area of a Glacier in Tien Shan Mountains, Central Asia

Yunjie Chen / Nozomu Takeuchi / Feiteng Wang / Zhongqin Li

Frontiers in Earth Science, Vol

2022 Volume 10

Abstract: Diverse microbial communities live on glacial surfaces, with abundances and diversities dictated by the chemical and physical conditions of the supraglacial environment. Chemical solutes and mineral dust on glacial surfaces are generally derived from the ...

Abstract	Diverse microbial communities live on glacial surfaces, with abundances and diversities dictated by the chemical and physical conditions of the supraglacial environment. Chemical solutes and mineral dust on glacial surfaces are generally derived from the atmosphere as aerosols, but they can also be supplied from glacial ice. In this study, a 56-m ice core from the ablation area of a mountain glacier in the Tien Shan Mountains of Central Asia was analyzed to characterize the chemical solutes and mineral dust in glacial ice. Soluble chemical ion and mineral dust analysis in the ice core showed that their concentrations varied with depth. The most dominant ion was Ca2+ (mean: 79.8 μEq L−1), followed by Cl−, SO42-, NH4+, and NO3−. The mean dust concentration in the glacial ice was 2.5 ×105 number ml−1. Chemical solute and mineral dust concentrations in the samples indicate that melting glacial ice could potentially affect supraglacial conditions. The annual fluxes of the major ions outcropping from glacial ice were estimated based on their concentrations and the observed melt rate of the ice surface. Consequently, they were comparable to or higher than those from the atmosphere. The mean mass flux of mineral dust from glacial ice was greater than that from the atmosphere. Our results showed that glacial ice supplies chemical solutes and mineral dust to the supraglacial environment and that changing melting rates of glacial ice would affect the chemical conditions on the glacier surface and the growth of photoautotrophs on the ablating ice surface.
Keywords	glacial ice ; ice core ; supraglacial environments ; mineral dust ; soluble ions ; outcropping flux ; Science ; Q
Subject code	290
Language	English
Publishing date	2022-05-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Seasonal Variation in Chemical Composition of Total Suspended Particles During the COVID-19 Pandemic in the Source Area of Urumqi River, Tianshan, China

Cunying Zheng / Zhongqin Li / Xin Zhang / Huimin Jiang / Xi Zhou

Frontiers in Earth Science, Vol

2022 Volume 10

Abstract: The research of atmospheric aerosol in mountain glacier areas has attracted more and more people’s attention. For the first time, a field observation study of total suspended particles (TSPs) for four seasons from September 2019 to August 2020 was ... ...

Abstract	The research of atmospheric aerosol in mountain glacier areas has attracted more and more people’s attention. For the first time, a field observation study of total suspended particles (TSPs) for four seasons from September 2019 to August 2020 was carried out at the Tianshan Glaciological Station in the source area of Urumqi River, East Tianshan Mountains, China. The TSPs presented typical seasonal characteristics of high in autumn and low in winter, with the annual average value of 181 ± 170 μg m−3. Concentrations of Ca2+, SO42−, NO3−, Cl−, NH4+ and K+, OC, EC were elevated in autumn. The influence of stationary source emissions was stronger than mobile sources, which was explained by the average ratio of NO3−/SO42− (0.31 ± 0.17). The concentration of secondary organic carbon (SOC) was higher in summer and autumn, especially in summer, indicating that secondary formation processes of organic aerosols were frequent in summer. Impact of fossil fuel combustion sources were evident over the Glaciers, corroborated by the diagnostic mass ratios of OC/EC (0–21.4, 3.38) and K+/EC (0–0.31, 0.08). The factor analysis illustrated that aerosols were mainly affected by rock salt, dust, coal combustion, and automobile exhaust. The local sources made significant contributions to TSPs in the source of Urumqi River by the results of Results of Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model and potential source contribution function (PSCF).
Keywords	organic and elemental carbon ; water-soluble inorganic ions ; seasonal variation ; backward trajectory ; potential source contribution function (PSCF) ; Science ; Q
Subject code	550
Language	English
Publishing date	2022-05-01T00:00:00Z
Publisher	Frontiers Media S.A.
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Spatio-Temporal Changes of Mass Balance in the Ablation Area of the Muz Taw Glacier, Sawir Mountains, from Multi-Temporal Terrestrial Geodetic Surveys

Chunhai Xu / Zhongqin Li / Feiteng Wang / Jianxin Mu

Remote Sensing, Vol 13, Iss 1465, p

2021 Volume 1465

Abstract: The glaciers in the Sawir Mountains are an important freshwater resource, and glaciers have been experiencing a continuing retreat over the past few decades. However, studies on detailed glacier mass changes are currently sparse. Here, we present the ... ...

Abstract	The glaciers in the Sawir Mountains are an important freshwater resource, and glaciers have been experiencing a continuing retreat over the past few decades. However, studies on detailed glacier mass changes are currently sparse. Here, we present the high-precision evolution of annual surface elevation and geodetic mass changes in the ablation area of the Muz Taw Glacier (Sawir Mountains, China) over the latest three consecutive mass-balance years (2017–2020) based on multi-temporal terrestrial geodetic surveys. Our results revealed clearly surface lowering and negative geodetic mass changes, and the spatial changing patterns were generally similar for the three periods with the most negative surface lowering (approximately −5.0 to −4.0 m a −1 ) around the glacier terminus. The gradient of altitudinal elevation changes was commonly steep at the low elevations and gentle in the upper-elevation parts, and reduced surface lowering was observed at the glacier terminus. Resulting emergence velocities ranged from 0.11 to 0.86 m a −1 with pronounced spatial variability, which was mainly controlled by surface slope, ice thickness, and the movement of tributary glaciers. Meanwhile, emergence velocities slightly compensated the surface ablation at the ablation area with a proportion of 14.9%, and dynamic thickening had small contributions to glacier surface evolution. Limited annual precipitation and glacier accumulation may result in these weak contributions. Higher-resolution surveys at the seasonal and monthly scales are required to get insight into the mass balance processes and their mechanism.
Keywords	glacier mass balance ; glacier dynamics ; terrestrial laser scanning ; mountain glacier ; Sawir Mountains ; Science ; Q
Subject code	550
Language	English
Publishing date	2021-04-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Geodetic Mass Balance of Haxilegen Glacier No. 51, Eastern Tien Shan, from 1964 to 2018

Chunhai Xu / Zhongqin Li / Feiteng Wang / Jianxin Mu / Xin Zhang

Remote Sensing, Vol 14, Iss 272, p

2022 Volume 272

Abstract: The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Tien Shan, China) is one of the very few well-measured glaciers, and comprehensive ... ...

Abstract	The eastern Tien Shan hosts substantial mid-latitude glaciers, but in situ glacier mass balance records are extremely sparse. Haxilegen Glacier No. 51 (eastern Tien Shan, China) is one of the very few well-measured glaciers, and comprehensive glaciological measurements were implemented from 1999 to 2011 and re-established in 2017. Mass balance of Haxilegen Glacier No. 51 (1999–2015) has recently been reported, but the mass balance record has not extended to the period before 1999. Here, we used a 1:50,000-scale topographic map and long-range terrestrial laser scanning (TLS) data to calculate the area, volume, and mass changes for Haxilegen Glacier No. 51 from 1964 to 2018. Haxilegen Glacier No. 51 lost 0.34 km 2 (at a rate of 0.006 km 2 a −1 or 0.42% a −1 ) of its area during the period 1964–2018. The glacier experienced clearly negative surface elevation changes and geodetic mass balance. Thinning occurred almost across the entire glacier surface, with a mean value of −0.43 ± 0.12 m a −1 . The calculated average geodetic mass balance was −0.36 ± 0.12 m w.e. a −1 . Without considering the error bounds of mass balance estimates, glacier mass loss over the past 50 years was in line with the observed and modeled mass balance (−0.37 ± 0.22 m w.e. a −1 ) that was published for short time intervals since 1999 but was slightly less negative than glacier mass loss in the entire eastern Tien Shan. Our results indicate that Riegl VZ ® -6000 TLS can be widely used for mass balance measurements of unmonitored individual glaciers.
Keywords	glacier mass balance ; remote sensing ; TLS ; eastern Tien Shan ; Science ; Q
Subject code	333
Language	English
Publishing date	2022-01-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Multi-Temporal Variations in Surface Albedo on Urumqi Glacier No.1 in Tien Shan, under Arid and Semi-Arid Environment

Xiaoying Yue / Zhongqin Li / Huilin Li / Feiteng Wang / Shuang Jin

Remote Sensing, Vol 14, Iss 808, p

2022 Volume 808

Abstract: Surface albedo exerts substantial control over the energy available for glacier melting. For Urumqi Glacier No.1 in the Tien Shan Mountains, China, represented as a “summer accumulation” glacier, the variations in albedo driven by surface processes are ... ...

Abstract	Surface albedo exerts substantial control over the energy available for glacier melting. For Urumqi Glacier No.1 in the Tien Shan Mountains, China, represented as a “summer accumulation” glacier, the variations in albedo driven by surface processes are complex and still poorly understood. In this study, we examined the interannual trends in ablation-period albedo from 2000 to 2021 using MOD10A1 products, evaluated the variation in bare-ice albedo retrieved from 13 end-of-summer Landsat images obtained between 2002 and 2019, and investigated the seasonal variation and diurnal cycle of surface albedo collected near the equilibrium line of the glacier by an AWS from September 2018 to August 2021. During the period of 2000–2021, the average ablation-period albedo presented a slight but not statistically significant downward trend, with a total decrease of 1.87%. Specifically, the decrease in glacier albedo was quicker in July than that in August, and there was a slight increase in May and June. The blackening phenomenon was shown on the east branch glacier, but not on the west branch glacier. For seasonal variability, a bimodal pattern was demonstrated, different from the unimodal seasonal variation in other midlatitude glaciers. The albedo peaks occurred in December and April or May. Under clear sky conditions, the diurnal cycle presented three patterns: a symmetric pattern, an asymmetric pattern, and a progressive decreasing pattern. Air temperature and solid precipitation are the main drivers of variations in glacier albedo, but in different periods of the ablation season, two climate variables affect albedo to varying degrees. The effect of surface albedo reduction enhanced glacier melting by about 20% over the past 20 years. The short-term increase in albedo caused by summer snowfall can considerably reduce glacier melting by as much as 80% in June.
Keywords	surface albedo ; temporal variability ; MOD10A1 ; Landsat bare-ice albedo ; semi-arid glacier environment ; Tien Shan ; Science ; Q
Subject code	550
Language	English
Publishing date	2022-02-01T00:00:00Z
Publisher	MDPI AG
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Tempo-spatial changes of ecological vulnerability in the arid area based on ordered weighted average model

Xingran Cai / Zhongqin Li / Yanqing Liang

Ecological Indicators, Vol 133, Iss , Pp 108398- (2021)

2021

Abstract: Ecological environment in the arid areas of Northwest China is very vulnerable. Ecological vulnerability is considered to be one of the important indicators to measure the status and evolutions of the regional ecological environment and has become a key ... ...

Abstract	Ecological environment in the arid areas of Northwest China is very vulnerable. Ecological vulnerability is considered to be one of the important indicators to measure the status and evolutions of the regional ecological environment and has become a key measure in the study of ecological change. However, studies on the ecological vulnerability in the whole arid areas of Northwest China on the county scale are currently sparse. Here, according to vegetation, land use type, topography, climate and socio-economic data, we present the spatial and temporal evolution of ecological vulnerability in the arid areas of Northwest China over the period 2000–2018 by structuring a “pressure (P)-sensitivity (S)-restoration (R)” ecological vulnerability evaluation index system and using an ordered weighted average (OWA) model. Our results suggested that the overall ecological vulnerability in the arid areas of Northwest China was dominated by the severe level from 2000 to 2018 with an average multi-year ecological vulnerability index of 0.48, which appeared a slight downward trend with the implementation of ecological restoration measures. Ecological vulnerability exhibited a significant “stepped” differentiation feature, and the eastern and western regions were markedly lower than that of the central region. Gravity center of the ecological vulnerability index has a significant spatial difference, which developed in the shape of “Z” direction between Heshuo county and Tuokexun county. Our study revealed the dynamic changes of ecological vulnerability at the county scale and provided decision-making information for the formulation of targeted ecological vulnerability management measures. Under the background of climate change and the new normal of social economy, the dynamic monitoring of ecological vulnerability and effective identification of vulnerability factors still require in-depth research.
Keywords	Ecological vulnerability ; Ordered weighted average (OWA) ; Spatiotemporal pattern ; The arid areas of Northwest China ; Ecology ; QH540-549.5
Subject code	720
Language	English
Publishing date	2021-12-01T00:00:00Z
Publisher	Elsevier
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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Article ; Online: Rapid mass losses of Urumqi River Basin glaciers, eastern Tianshan Mountains revealed from multi-temporal DEMs, 1964–2021

Puyu Wang / Hongliang Li / Zhongqin Li / Liping Xu / Fengchen Yu / Jie He / Yuping Dai / Ping Zhou / Jianxin Mu / Xiaoying Yue

International Journal of Digital Earth, Vol 17, Iss

2024 Volume 1

Abstract: ABSTRACTGlacier volume changes have remarkable impacts on regional water resources; however, their estimation uncertainties remain large. In this study, the surface elevations of seven glaciers at the headwaters of the Urumqi River exhibited obvious ... ...

Abstract	ABSTRACTGlacier volume changes have remarkable impacts on regional water resources; however, their estimation uncertainties remain large. In this study, the surface elevations of seven glaciers at the headwaters of the Urumqi River exhibited obvious thinning at the rate of 0.32 m a−1 from 1964 to 2021. Correlations between the ice volume change (dV) derived from surface elevation conversion and the area change (dS) were established for valley, cirque, and hanging glaciers. The ice volumes of valley, cirque, and hanging glaciers in the Urumqi River Basin decreased by 0.99 km3, 0.18 km3, and 0.59 km3, respectively, and the total ice volume decreased by 1.76 km3 during 1964–2021. Ice volume losses are accelerating. The correlation between dV and dS for valley glaciers produced a large estimation difference for the ice volume change of Urumqi Glacier No. 1 (UG1) compared with the glaciological mass balance (15%), while the estimation differences of ice volume changes for the three types of glaciers in the Urumqi River Basin were within acceptable limits (10%) based on the geodetic results. This new method has vast potential in estimating ice volume changes at the basin or regional scale, or even across western China.
Keywords	Multi-temporal DEMs ; ice volume change ; glacier area change ; Urumqi River ; Tianshan Mountains ; Mathematical geography. Cartography ; GA1-1776
Subject code	550
Language	English
Publishing date	2024-12-01T00:00:00Z
Publisher	Taylor & Francis Group
Document type	Article ; Online
Database	BASE - Bielefeld Academic Search Engine (life sciences selection)

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