Long-range terrestrial laser scanning measurements of summer and annual mass balances for Urumqi Glacier No. 1, eastern Tien Shan, China

Abstract. The direct glaciological method typically provides in situ observations of annual or seasonal surface mass balance, but can only be implemented through a succession of intensive in situ measurements of measuring networks of stakes and snow pits. This has contributed to glacier surface mass-balance measurements being sparse and often discontinuous in the Tien Shan. Nevertheless, long-term glacier mass-balance measurements are the basis for understanding climate–glacier interactions and projecting future water availability for glacierized catchments in the Tien Shan. Riegl VZ®-6000 long-range terrestrial laser scanning (TLS), typically using class 3B laser beams, is exceptionally well suited for measuring snowy and icy terrain in repeated glacier mapping, and subsequently annual and seasonal geodetic mass balance can be determined. This paper introduces the applied TLS for monitoring summer and annual surface elevation and geodetic mass changes of Urumqi Glacier No. 1 (UG1) as well as delineating accurate glacier boundaries for two consecutive years (2015-17), and discusses the potential of such technology in glaciological applications. Three-dimensional changes of ice and firn/snow bodies and the corresponding densities were considered for the volume-to-mass conversion. UG1 showed pronounced thinning and mass loss for the four investigated periods; glacier-wide geodetic mass balance in the mass-balance year 2015-16 was slightly more negative than in 2016-17. The majority of TLS-derived geodetic elevation changes at individual stakes were slightly positive, but showed a close correlation with the glaciological elevation changes (changes in exposed stake height) of individual stakes (R2 ≥ 0.90). Statistical comparison shows that agreement between the glaciological and geodetic mass balances can be considered satisfying, indicating that the TLS system yields accurate results and has the potential to monitor remote and inaccessible glacier areas where no glaciological measurements are available.

Download Full-text

Long-range terrestrial laser scanning measurements of annual and intra-annual mass balances for Urumqi Glacier No. 1, eastern Tien Shan, China

The Cryosphere ◽

10.5194/tc-13-2361-2019 ◽

2019 ◽

Vol 13 (9) ◽

pp. 2361-2383 ◽

Cited By ~ 8

Author(s):

Chunhai Xu ◽

Zhongqin Li ◽

Huilin Li ◽

Feiteng Wang ◽

Ping Zhou

Keyword(s):

Mass Balance ◽

Long Range ◽

Tien Shan ◽

Glacier Mass Balance ◽

Surface Mass Balance ◽

Mass Balances ◽

Surface Mass ◽

Mass Conversion ◽

Geodetic Mass Balance

Abstract. The direct glaciological method provides in situ observations of annual or seasonal surface mass balance, but can only be implemented through a succession of intensive in situ measurements of field networks of stakes and snow pits. This has contributed to glacier surface mass-balance measurements being sparse and often discontinuous in the Tien Shan. Nevertheless, long-term glacier mass-balance measurements are the basis for understanding climate–glacier interactions and projecting future water availability for glacierized catchments in the Tien Shan. Riegl VZ®-6000 long-range terrestrial laser scanner (TLS), typically using class 3B laser beams, is exceptionally well suited for repeated glacier mapping, and thus determination of annual and seasonal geodetic mass balance. This paper introduces the applied TLS for monitoring summer and annual surface elevation and geodetic mass changes of Urumqi Glacier No. 1 as well as delineating accurate glacier boundaries for 2 consecutive mass-balance years (2015–2017), and discusses the potential of such technology in glaciological applications. Three-dimensional changes of ice and firn–snow bodies and the corresponding densities were considered for the volume-to-mass conversion. The glacier showed pronounced thinning and mass loss for the four investigated periods; glacier-wide geodetic mass balance in the mass-balance year 2015–2016 was slightly more negative than in 2016–2017. Statistical comparison shows that agreement between the glaciological and geodetic mass balances can be considered satisfactory, indicating that the TLS system yields accurate results and has the potential to monitor remote and inaccessible glacier areas where no glaciological measurements are available as the vertical velocity component of the glacier is negligible. For wide applications of the TLS in glaciology, we should use stable scan positions and in-situ-measured densities of snow–firn to establish volume-to-mass conversion.

Download Full-text

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

Remote Sensing ◽

10.3390/rs14020272 ◽

2022 ◽

Vol 14 (2) ◽

pp. 272

Author(s):

Chunhai Xu ◽

Zhongqin Li ◽

Feiteng Wang ◽

Jianxin Mu ◽

Xin Zhang

Keyword(s):

Mass Loss ◽

Mass Balance ◽

Laser Scanning ◽

Mean Value ◽

Tien Shan ◽

Glacier Mass Balance ◽

Topographic Map ◽

Glacier Surface ◽

Elevation Changes ◽

Geodetic Mass Balance

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 km2 (at a rate of 0.006 km2 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.

Download Full-text

Monitoring glacier albedo as a proxy to derive summer and annual surface mass balances from optical remote-sensing data

The Cryosphere ◽

10.5194/tc-12-271-2018 ◽

2018 ◽

Vol 12 (1) ◽

pp. 271-286 ◽

Cited By ~ 8

Author(s):

Lucas Davaze ◽

Antoine Rabatel ◽

Yves Arnaud ◽

Pascal Sirguey ◽

Delphine Six ◽

...

Keyword(s):

Mass Balance ◽

Surface Albedo ◽

In Situ Measurements ◽

Surface Mass Balance ◽

Mass Balances ◽

Equilibrium Line Altitude ◽

Surface Mass ◽

Minimum Surface ◽

Summer Minimum

Abstract. Less than 0.25 % of the 250 000 glaciers inventoried in the Randolph Glacier Inventory (RGI V.5) are currently monitored with in situ measurements of surface mass balance. Increasing this archive is very challenging, especially using time-consuming methods based on in situ measurements, and complementary methods are required to quantify the surface mass balance of unmonitored glaciers. The current study relies on the so-called albedo method, based on the analysis of albedo maps retrieved from optical satellite imagery acquired since 2000 by the MODIS sensor, on board the TERRA satellite. Recent studies revealed substantial relationships between summer minimum glacier-wide surface albedo and annual surface mass balance, because this minimum surface albedo is directly related to the accumulation–area ratio and the equilibrium-line altitude. On the basis of 30 glaciers located in the French Alps where annual surface mass balance data are available, our study conducted on the period 2000–2015 confirms the robustness and reliability of the relationship between the summer minimum surface albedo and the annual surface mass balance. For the ablation season, the integrated summer surface albedo is significantly correlated with the summer surface mass balance of the six glaciers seasonally monitored. These results are promising to monitor both annual and summer glacier-wide surface mass balances of individual glaciers at a regional scale using optical satellite images. A sensitivity study on the computed cloud masks revealed a high confidence in the retrieved albedo maps, restricting the number of omission errors. Albedo retrieval artifacts have been detected for topographically incised glaciers, highlighting limitations in the shadow correction algorithm, although inter-annual comparisons are not affected by systematic errors.

Download Full-text

Monitoring of glacier albedo from optical remote-sensing data: application to seasonal and annual surface mass balances quantification in the French Alps for the 2000–2015 period

10.5194/tc-2017-49 ◽

2017 ◽

Author(s):

Lucas Davaze ◽

Antoine Rabatel ◽

Yves Arnaud ◽

Pascal Sirguey ◽

Delphine Six ◽

...

Keyword(s):

Mass Balance ◽

Surface Albedo ◽

In Situ Measurements ◽

Surface Mass Balance ◽

Mass Balances ◽

Surface Mass ◽

French Alps ◽

Minimum Surface ◽

Summer Minimum

Abstract. Less than 0.25 % of the 250,000 glaciers inventoried in the Randolph Glacier Inventory (RGI V.5) are currently monitored with in situ measurements of surface mass balance. Increasing this archive is very challenging, especially using time-consuming methods based on in situ measurements, and complementary methods are required to quantify the surface mass balance of unmonitored glaciers. The current study relies on the so-called albedo method, based on the analysis of albedo maps retrieved from optical satellite imagery acquired since 2000 by the MODIS sensor, onboard of TERRA satellite. Recent studies revealed substantial relationships between summer minimum glacier-wide surface albedo and annual surface mass balance, because this minimum surface albedo is directly related to the accumulation-area ratio and the equilibrium-line altitude. On the basis of 30 glaciers located in the French Alps where annual surface mass balance are available, our study conducted on the period 2000–2015 confirms the robustness and reliability of the relationship between the summer minimum surface albedo and the annual surface mass balance. At the seasonal scale, the integrated summer surface albedo is significantly correlated with the summer surface mass balance of the six glaciers seasonally monitored. For the winter season, four of the six glaciers showed a significant correlation when linking the winter surface mass balance and the integrated winter surface albedo, using glacier-dependent thresholds to filter the albedo signal (threshold from 0.53 to 0.76). These results are promising to monitor both annual and seasonal glacier-wide surface mass balances of individual glaciers at a regional scale using optical satellite images. A sensitivity study on the computed cloud masks revealed a high confidence in the retrieved albedo maps, restricting the number of omission errors. Albedo retrieval artifacts have been detected for topographically incised glaciers, highlighting limitations in the shadows correction algorithm, although inter-annual comparisons are not affected by systematic errors.

Download Full-text

Glacier-wide summer surface mass-balance calculation: hydrological balance applied to the Argentière and Mer de Glace drainage basins (Mont Blanc)

Journal of Glaciology ◽

10.1017/jog.2018.7 ◽

2018 ◽

Vol 64 (243) ◽

pp. 119-131 ◽

Cited By ~ 1

Author(s):

A. VIANI ◽

T. CONDOM ◽

C. VINCENT ◽

A. RABATEL ◽

B. BACCHI ◽

...

Keyword(s):

Mass Balance ◽

Surface Mass Balance ◽

Mass Balances ◽

Drainage Basins ◽

Mass Balance Calculation ◽

Surface Mass ◽

Hydrological Balance ◽

Good Agreement

ABSTRACTWe present the glacier-wide summer surface mass balances determined by a detailed hydrological balance (sSMBhydro) and the quantification of the uncertainties of the calculations on the Argentière and Mer de Glace-Leschaux drainage basins, located in the upper Arve watershed (French Alps), over the period 1996–2004. The spatial distribution of precipitation within the study area was adjusted using in situ winter mass-balance measurements. The sSMBhydro performance was assessed via a comparison with the summer surface mass balances based on in situ glaciological observations (sSMBglacio). Our results show that the sSMBhydro has an uncertainty of ± 0.67 m w.e. a−1 at Argentière and ± 0.66 m w.e. a−1 at Mer de Glace-Leschaux. Estimates of the Argentière sSMBhydro values are in good agreement with the sSMBglacio values. These time series show almost the same interannual variability. From the marked difference between the sSMBhydro and sSMBglacio values for the Mer de Glace-Leschaux glacier, we suspect a significant role of groundwater fluxes in the hydrological balance. This study underlines the importance of taking into account the groundwater transfers to represent and predict the hydro-glaciological behaviour of a catchment.

Download Full-text

Glacier Surface Mass Balance in the Suntar-Khayata Mountains, Northeastern Siberia

Water ◽

10.3390/w11091949 ◽

2019 ◽

Vol 11 (9) ◽

pp. 1949 ◽

Cited By ~ 1

Author(s):

Yong Zhang ◽

Xin Wang ◽

Zongli Jiang ◽

Junfeng Wei ◽

Hiroyuki Enomoto ◽

...

Keyword(s):

Mass Loss ◽

Mass Balance ◽

Surface Mass Balance ◽

Negative Mass ◽

Glacier Surface ◽

Surface Mass ◽

Northeastern Siberia ◽

Response To Temperature ◽

Rapid Mass

Arctic glaciers comprise a small fraction of the world’s land ice area, but their ongoing mass loss currently represents a large cryospheric contribution to the sea level rise. In the Suntar-Khayata Mountains (SKMs) of northeastern Siberia, in situ measurements of glacier surface mass balance (SMB) are relatively sparse, limiting our understanding of the spatiotemporal patterns of regional mass loss. Here, we present SMB time series for all glaciers in the SKMs, estimated through a glacier SMB model. Our results yielded an average SMB of −0.22 m water equivalents (w.e.) year−1 for the whole region during 1951–2011. We found that 77.4% of these glaciers had a negative mass balance and detected slightly negative mass balance prior to 1991 and significantly rapid mass loss since 1991. The analysis suggests that the rapidly accelerating mass loss was dominated by increased surface melting, while the importance of refreezing in the SMB progressively decreased over time. Projections under two future climate scenarios confirmed the sustained rapid shrinkage of these glaciers. In response to temperature rise, the total present glacier area is likely to decrease by around 50% during the period 2071–2100 under representative concentration pathway 8.5 (RCP8.5).

Download Full-text

Surface elevation changes during 2007–13 on Bowdoin and Tugto Glaciers, northwestern Greenland

Journal of Glaciology ◽

10.1017/jog.2016.106 ◽

2016 ◽

Vol 62 (236) ◽

pp. 1083-1092 ◽

Cited By ~ 14

Author(s):

SHUN TSUTAKI ◽

SHIN SUGIYAMA ◽

DAIKI SAKAKIBARA ◽

TAKANOBU SAWAGAKI

Keyword(s):

Mass Balance ◽

Satellite Observations ◽

Surface Elevation ◽

Surface Mass Balance ◽

Elevation Change ◽

Predominant Role ◽

Ice Dynamics ◽

Surface Mass ◽

Elevation Changes ◽

Negative Surface

ABSTRACTTo quantify recent thinning of marine-terminating outlet glaciers in northwestern Greenland, we carried out field and satellite observations near the terminus of Bowdoin Glacier. These data were used to compute the change in surface elevation from 2007 to 2013 and this rate of thinning was then compared with that of the adjacent land-terminating Tugto Glacier. Comparing DEMs of 2007 and 2010 shows that Bowdoin Glacier is thinning more rapidly (4.1 ± 0.3 m a−1) than Tugto Glacier (2.8 ± 0.3 m a−1). The observed negative surface mass-balance accounts for <40% of the elevation change of Bowdoin Glacier, meaning that the thinning of Bowdoin Glacier cannot be attributable to surface melting alone. The ice speed of Bowdoin Glacier increases down-glacier, reaching 457 m a−1 near the calving front. This flow regime causes longitudinal stretching and vertical compression at a rate of −0.04 a−1. It is likely that this dynamically-controlled thinning has been enhanced by the acceleration of the glacier since 2000. Our measurements indicate that ice dynamics indeed play a predominant role in the rapid thinning of Bowdoin Glacier.

Download Full-text

Quantifying mass balance processes on the Southern Patagonia Icefield

The Cryosphere ◽

10.5194/tc-9-25-2015 ◽

2015 ◽

Vol 9 (1) ◽

pp. 25-35 ◽

Cited By ~ 47

Author(s):

M. Schaefer ◽

H. Machguth ◽

M. Falvey ◽

G. Casassa ◽

E. Rignot

Keyword(s):

Mass Balance ◽

Reanalysis Data ◽

Ice Thickness ◽

Surface Mass Balance ◽

Mass Balances ◽

Surface Mass ◽

Mass Losses ◽

Southern Patagonia ◽

Spatially Distributed ◽

The Individual

Abstract. We present surface mass balance simulations of the Southern Patagonia Icefield (SPI) driven by downscaled reanalysis data. The simulations were evaluated and interpreted using geodetic mass balances, measured point balances and a complete velocity field of the icefield for spring 2004. The high measured accumulation of snow of up to 15.4 m w.e. yr−1 (meters water equivalent per year) as well as the high measured ablation of up to 11 m w.e. yr−1 is reproduced by the model. The overall modeled surface mass balance was positive and increasing during 1975–2011. Subtracting the surface mass balance from geodetic balances, calving fluxes were inferred. Mass losses of the SPI due to calving were strongly increasing from 1975–2000 to 2000–2011 and higher than losses due to surface melt. Calving fluxes were inferred for the individual glacier catchments and compared to fluxes estimated from velocity data. Measurements of ice thickness and flow velocities at the glaciers' front and spatially distributed accumulation measurements can help to reduce the uncertainties of the different terms in the mass balance of the Southern Patagonia Icefield.

Download Full-text

Surface mass balance modeling of mountain glaciers in the Caucasus and in the High Mountain Asia

10.5194/egusphere-egu2020-4257 ◽

2020 ◽

Author(s):

Oleg Rybak ◽

Elena Rybak ◽

Victor Popovnin ◽

Afanasy Gubanov ◽

Rysbek Satylkanov ◽

...

Keyword(s):

Energy Balance ◽

Mass Balance ◽

Tien Shan ◽

Surface Mass Balance ◽

Mountain Glacier ◽

Model Calculations ◽

Suggested Approach ◽

Surface Mass ◽

Mountain Glaciers ◽

Energy Balance Approach

&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160; The most significant quantity characterizing current state of a mountain glacier is its surface mass balance (SMB). SMB responds to changing climatic conditions and therefore determines present and future behavior of the glacier. Formulation of SMB in terms of a mathematical model allows better understanding complex processes of the atmospheric impact on glacier dynamics. After several decades of development, common universal modeling principles and approaches have been elaborated. At present, most of the newly developed models are quite similar with only varying details mostly concerning parameterization of heat fluxes.SMB is an interplay between positive (accumulation) and negative (ablation) components. Ablation is formulated either using temperature-index (positive degree day) approach or surface energy balance calculation (or combination of both). Both these approaches are based on genuine physical principles and that is why they can be easily transformed into computational algorithms. Results of ablation model calculations are relatively easily constrained by observations. In contrast, evaluation of accumulation is much more dependent on poorly constrained factors such as local atmospheric circulation, snow-storm transport (including post-depositional) and avalanche feeding.Our approach to simulate components of SMB is based on energy balance approach and emulation of meteorological conditions using a simple stochastic weather generator. To validate the model, we use observed SMB data from several mountain glaciers in different environmental conditions &#8211; Djankuat (Central Caucasus), Tuyuksu (Zailiyski Alatau), Sary-Tor and Karabatkak (Inner Tien Shan). Suggested approach allows to easily construct an ensemble of numerical experiments and implement Monte Carlo method for the SMB evaluation. This possibility is especially significant for simulation of future states of glaciers according to one or another climatic scenario on a coupled ice flow-SMB model.The reported study was funded by RFBR, project number 20-05-00681 (&#8220;Evolution of glaciation of Inner Tien Shan under climate change and technogenic influence&#8221;)

Download Full-text