Dynamics of glacier surface velocity and ice thickness for maritime glaciers in the southeastern Tibetan Plateau

Abstract Most glaciers on the Tibetan Plateau have experienced continuous mass losses in response to global warming. However, the seasonal dynamics of glaciers on the southeastern Tibetan Plateau have rarely been reported in terms of glacier surface elevation and velocity. This paper presents a first attempt to explore the seasonal dynamics of the debris-covered Dagongba Glacier within the southeastern Tibetan Plateau. We use the multitemporal unoccupied aerial vehicle images collected over the lower ablation zone on 8 June and 17 October 2018, and 13 May 2019, and then perform an analysis concerning climatic fluctuations. The results reveal that the mean surface elevation decrease of the Dagongba Glacier during the warm season ( $2.81\pm 0.44$ m) was remarkably higher than the cold season ( $0.72\pm 0.45$ m). Particularly notable glacier surface elevation changes were found around supraglacial lakes and ice cliffs where ice ablation rates were $\sim$ 3 times higher than the average. In addition, a larger longitudinal decline of glacier surface velocity was observed in the warm season than that in the cold season. In terms of further comparative analysis, the Dagongba Glacier experienced a decrease in surface velocity between 1982–83 and 2018–19, with a decrease in the warm season possibly twice as large as that in the cold season.

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Towards ice thickness inversion: an evaluation of global DEMs by ICESat-2 in the glacierized Tibetan Plateau

10.5194/tc-2021-197 ◽

2021 ◽

Author(s):

Wenfeng Chen ◽

Tandong Yao ◽

Guoqing Zhang ◽

Fei Li ◽

Guoxiong Zheng ◽

...

Keyword(s):

Tibetan Plateau ◽

Mean Squared Error ◽

High Elevation ◽

Global Scale ◽

Primary Data ◽

Ice Thickness ◽

The Tibetan Plateau ◽

Glacier Surface ◽

The North ◽

Elevation Model

Abstract. Accurate estimates of regional ice thickness, which are generally produced by ice-thickness inversion models, are crucial for assessments of available freshwater resources and sea level rise. Digital elevation model (DEM) derived surface topography of glaciers is a primary data source for such models. However, the scarce in-situ measurements of glacier surface elevation limit the evaluation of DEM uncertainty, and hence its influence on ice-thickness modelling over the glacierized area of the Tibetan Plateau (TP). Here, we examine the performance over the glacierized TP of six widely used and mainly global-scale DEMs: AW3D30 (30 m), SRTM-GL1 (30 m), NASADEM (30 m), TanDEM-X (90 m), SRTM v4.1 (90 m) and MERIT (90 m) by using ICESat-2 laser altimetry data while considering the effects of glacier dynamics, terrain, and DEM misregistration. The results reveal NASADEM as the best performer, with a small mean error (ME) of −1.0 and a root mean squared error (RMSE) of 12.6 m. A systematic vertical offset existed in AW3D30 (−35.3 ME and 34.9 m RMSE), although it had a similar relative accuracy to NASADEM (~ 13 m STD). TanDEM-X also performs well (−0.1 ME and 15.1 m RMSE), but suffers from serious errors and outliers on steep slopes. SRTM-based DEMs (SRTM-GL1, SRTM v4.1, and MERIT) (all ~ 36 m RMSE) had an inferior performance to NASADEM. However, their errors were reduced in the ablation zone when glacier variations were excluded. Errors in the six DEMs increased from the south-facing to the north-facing aspect and become larger with increasing slope. Misregistration of DEMs relative to ICESat-2 footprint in most glacier areas is small (less than one pixel). An intercomparison of four ice-thickness models: GlabTop2, Open Global Glacier Model (OGGM), Huss-Farinotti (HF), Ice Thickness Inversion Based on Velocity (ITIBOV), show that GlabTop2 is sensitive to the accuracy of both elevation and slope, while OGGM and HF are less sensitive to DEM quality, and ITIBOV is the most sensitive to slope accuracy. Considering the inconsistency of DEMs acquisition dates, NASADEM would be a best choice for ice-thickness estimates over the TP, followed by AW3D30, and TanDEM-X (if steep and high elevation terrain can be avoided). Our assessment figures out the performances of mainly global DEMs over the glacierized TP. This study not only avails the glacier thickness estimation with ice thickness inversion models, but also offered references for other cryosphere studies using DEM.

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Landsat-Based Estimation of the Glacier Surface Temperature of Hailuogou Glacier, Southeastern Tibetan Plateau, Between 1990 and 2018

Remote Sensing ◽

10.3390/rs12132105 ◽

2020 ◽

Vol 12 (13) ◽

pp. 2105 ◽

Cited By ~ 3

Author(s):

Haijun Liao ◽

Qiao Liu ◽

Yan Zhong ◽

Xuyang Lu

Keyword(s):

Tibetan Plateau ◽

Surface Temperature ◽

Single Channel ◽

Atmospheric Temperature ◽

Landsat 8 ◽

Glacier Surface ◽

Thermal Dynamics ◽

Mountain Glacier ◽

Southeastern Tibetan Plateau ◽

Ice Water

Glacier surface temperature (GST) is influenced by both the energy flux from the atmosphere above and the thermal dynamics at the ice–water–debris interfaces. However, previous studies on GST are inadequate in time series research and mountain glacier surface temperature retrieval. We evaluate the GST variability at Hailuogou glacier, a temperate glacier located in Southeastern Tibetan Plateau, from 1990 to 2018. We utilized a modified mono-window algorithm to calculate the GST using the Landsat 8 thermal infrared sensor (TIRS) band 10 data and Landsat 5 thematic mapper (TM) band 6 data. Three essential parameters, including the emissivity of ice and snow, atmospheric transmittance, and effective mean atmospheric temperature, were employed in the GST algorithm. The remotely-sensed temperatures were compared with two other single-channel algorithms to validate GST algorithm’s accuracy. Results from different algorithms showed a good agreement, with a mean difference of about 0.6 ℃. Our results showed that the GST of the Hailuogou glacier, both in the upper debris-free part and the lower debris-covered tongue, has experienced a slightly increasing trend at a rate of 0.054 ℃ a−1 during the past decades. Atmospheric warming, expanding debris cover in the lower part, and a darkening debris-free accumulation area are the main causes of the warming of the glacier surface.

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The 2008/09 surge of central Yulinchuan glacier, northern Tibetan Plateau, as monitored by remote sensing

Annals of Glaciology ◽

10.3189/2013aog63a495 ◽

2013 ◽

Vol 54 (63) ◽

pp. 299-310 ◽

Cited By ~ 21

Author(s):

Wanqin Guo ◽

Shiyin Liu ◽

Junfeng Wei ◽

Weijia Bao

Keyword(s):

Remote Sensing ◽

Tibetan Plateau ◽

Longitudinal Velocity ◽

Satellite Image ◽

Surface Velocity ◽

Glacier Surface ◽

Northern Tibetan Plateau ◽

Surface Displacements ◽

Velocity Changes ◽

Length And Area

AbstractThe 2008/09 surge of central Yulinchuan glacier (CYG) on the northwestern slope of Muztag mountain, Tibetan Plateau, is studied based on satellite remote sensing. The widely used cross-correlation feature-tracking method was used to collect satellite image control points and validate their geometric accuracies, as well as to derive glacier surface velocity. Changes in glacier length and area were also retrieved. Results show that the surge of CYG initiated in May 2008 and terminated in July 2009. Two diffluent glacier termini advanced 590 ± 26 m (5.1 ± 0.2% of the 2004 length) and 182 ± 26m (1.8 ± 0.3%), respectively, and glacier area increased by ∼1.41 ± 0.11 km2 (4.6 ± 0.4% of the 2004 area) during this period. The most significant surge period was October 2008 to March 2009, when most of the terminus advances and area increases occurred. The glacier surface drastically crevassed during this time, as much as 1657 ± 297 m of horizontal surface displacements were produced by surge ice, and maximum surface speed reached 13 ± 1.5 m d-1. Results of transverse and longitudinal velocity profiles revealed two surge waves during this surge of CYG.

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Frontal ablation and temporal variations in surface velocity of Livingston Island ice cap, Antarctica

The Cryosphere Discussions ◽

10.5194/tcd-7-4207-2013 ◽

2013 ◽

Vol 7 (4) ◽

pp. 4207-4240 ◽

Cited By ~ 2

Author(s):

B. Osmanoglu ◽

M. I. Corcuera ◽

F. J. Navarro ◽

M. Braun ◽

R. Hock

Keyword(s):

Mass Balance ◽

Ablation Rate ◽

Surface Velocity ◽

South Shetland Islands ◽

Ice Thickness ◽

Western Coast ◽

Glacier Surface ◽

Ice Cap ◽

Livingston Island ◽

Frontal Ablation

Abstract. Frontal ablation from marine-terminating glaciers and ice caps covering the islands off the western coast of the Antarctic Peninsula is poorly known. Here we estimate the frontal ablation from the ice cap of Livingston Island, the second largest island in the South Shetland Islands archipelago, using glacier surface velocities obtained from intensity offset tracking of PALSAR-1 imagery and glacier ice thickness inferred from principles of glacier dynamics and calibrated against ground-penetrating radar (GPR) measurements of ice thickness. Using 21 SAR images acquired between October 2007 and January 2011, we obtain surface velocities of up to 250 m yr−1 and an average frontal ablation rate of about 509 &pm; 381 Mt yr−1, equivalent to a specific mass change of −0.7 &pm; 0.5 m w.e. yr−1 over the area of the ice cap (697 km2). A rough estimate of the surface mass balance of the ice cap gives 0.1 &pm; 0.1 m w.e. yr−1, resulting in a~total mass balance for Livingston Island ice cap of −0.6 &pm; 0.5 m w.e. yr−1. We find that frontal ablation and surface ablation contribute equal shares to total ablation. We also find large changes in frontal ablation rate (of ∼237 Mt yr−1) due to temporal variability in surface velocities. This highlights the importance of taking into account the seasonality in ice velocities when computing frontal ablation with a flux-gate approach.

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Spatiotemporal variability of surface velocities of monsoon temperate glaciers in the Kangri Karpo Mountains, southeastern Tibetan Plateau

Journal of Glaciology ◽

10.1017/jog.2020.98 ◽

2020 ◽

pp. 1-6

Author(s):

Kunpeng Wu ◽

Shiyin Liu ◽

Junli Xu ◽

Yu Zhu ◽

Qiao Liu ◽

...

Keyword(s):

Tibetan Plateau ◽

Feature Tracking ◽

Phase Correlation ◽

Surface Velocity ◽

Spatiotemporal Variability ◽

Glacier Mass Balance ◽

Landsat Images ◽

Ice Flow ◽

Southeastern Tibetan Plateau ◽

The Past

Abstract Influenced by the Indian monsoon, the Kangri Karpo Mountains (KKM) of the southeastern Tibetan Plateau is the most humid part of the plateau, and one of the most important regions with numerous monsoon temperate glaciers. Glacier mass balance estimates have been strongly negative in the KKM over recent decades, but the spatiotemporal characteristics of surface velocity are poorly understood. Using phase-correlation feature tracking on Landsat images, this study estimates spatiotemporal variabilities of monsoon temperate glaciers for the period of 1988–2019. Results show that a significant slowdown was observed below an elevation of 4900 m, while an accelerated ice flow was found at an elevation of 4900–5800 m over the past 30 years. The trend of slowdown was −0.1 m a−1 dec−1 during 1988–2000, and then it increased to −0.5 m a−1 dec−1 during 2001–2019.

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In-situ automatic observations of ice thickness of seas

Metrology and Measurement Systems ◽

10.2478/v10178-012-0051-6 ◽

2012 ◽

Vol 19 (3) ◽

pp. 583-592 ◽

Cited By ~ 1

Author(s):

Yinke Dou ◽

Xiaomin Chang

Keyword(s):

Sea Ice ◽

New Technologies ◽

Capacitive Sensor ◽

Automatic Monitoring ◽

Ice Thickness ◽

In Situ Observation ◽

Glacier Surface ◽

Sea Ice Thickness ◽

Surface Ice

Abstract Ice thickness is one of the most critical physical indicators in the ice science and engineering. It is therefore very necessary to develop in-situ automatic observation technologies of ice thickness. This paper proposes the principle of three new technologies of in-situ automatic observations of sea ice thickness and provides the findings of laboratory applications. The results show that the in-situ observation accuracy of the monitor apparatus based on the Magnetostrictive Delay Line (MDL) principle can reach ±2 mm, which has solved the “bottleneck” problem of restricting the fine development of a sea ice thermodynamic model, and the resistance accuracy of monitor apparatus with temperature gradient can reach the centimeter level and research the ice and snow substance balance by automatically measuring the glacier surface ice and snow change. The measurement accuracy of the capacitive sensor for ice thickness can also reach ±4 mm and the capacitive sensor is of the potential for automatic monitoring the water level under the ice and the ice formation and development process in water. Such three new technologies can meet different needs of fixed-point ice thickness observation and realize the simultaneous measurement in order to accurately judge the ice thickness.

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Combining SAR interferometry and the equation of continuity to estimate the three-dimensional glacier surface-velocity vector

Journal of Glaciology ◽

10.3189/s0022143000001398 ◽

1999 ◽

Vol 45 (151) ◽

pp. 533-538 ◽

Cited By ~ 2

Author(s):

Niels Reeh ◽

Søren Nørvang Madsen ◽

Johan Jakob Mohr

Keyword(s):

Steady State ◽

Mass Balance ◽

Vertical Velocity ◽

Velocity Vector ◽

Thickness Distribution ◽

Vertical Surface ◽

Horizontal Velocity ◽

Sar Interferometry ◽

Surface Velocity ◽

Ice Thickness

AbstractUntil now, an assumption of surface-parallel glacier flow has been used to express the vertical velocity component in terms of the horizontal velocity vector, permitting all three velocity components to be determined from synthetic aperture radar interferometry. We discuss this assumption, which neglects the influence of the local mass balance and a possible contribution to the vertical velocity arising if the glacier is not in steady state. We find that the mass-balance contribution to the vertical surface velocity is not always negligible as compared to the surface-slope contribution. Moreover, the vertical velocity contribution arising if the ice sheet is not in steady state can be significant. We apply the principle of mass conservation to derive an equation relating the vertical surface velocity to the horizontal velocity vector. This equation, valid for both steady-state and non-steady-state conditions, depends on the ice-thickness distribution. Replacing the surface-parallel-flow assumption with a correct relationship between the surface velocity components requires knowledge of additional quantities such as surface mass balance or ice thickness.

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Tectonics of the Southeastern Tibetan Plateau and Its Adjacent Foreland

10.1130/mem210 ◽

2013 ◽

Cited By ~ 8

Author(s):

B.C. Burchfiel ◽

Chen Zhiliang

Keyword(s):

Tibetan Plateau ◽

Southeastern Tibetan Plateau

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Short-term Variations in Strain and Surface Tilt on Storglaciären, Kebnekaise, Northern Sweden

Journal of Glaciology ◽

10.3189/s0022143000004512 ◽

1989 ◽

Vol 35 (120) ◽

pp. 201-208 ◽

Cited By ~ 29

Author(s):

Peter Jansson ◽

Roger LeB. Hooke

Keyword(s):

Water Pressure ◽

High Water ◽

Ice Thickness ◽

Gradual Change ◽

Short Term ◽

Glacier Surface ◽

Vertical Movements ◽

Bed Topography ◽

The Waves ◽

Local Uplift

AbstractTiltmeters that can detect changes in slope of a glacier surface as small as 0.1 μ rad have been used on Storglaciären. The records obtained to date have been from the upper part of the ablation area, where the bed of the glacier is overdeepened. A total of 82 d of records has been obtained for various time periods between early June and early September.There is generally a gradual change in inclination of the glacier surface over periods of several days, but these changes do not appear to be systematic. In particular, they are not consistent with vertical movements of stakes located 2–3 ice thicknesses away from the tiltmeters. This suggests that the tiltmeters are sensing disturbances over areas with diameters comparable to the local ice thickness.Superimposed on these trends are diurnal signals suggesting rises and falls of the surface just up-glacier from the riegel that bounds the overdeepening on its down-glacier end. These may be due to waves of high water pressure originating in a crevassed area near the equilibrium line. If this interpretation is correct, the waves apparently move down-glacier at speeds of 20–60 m h−1and become sufficiently focused, either by the bed topography or by conduit constrictions, to result in local uplift of the surface. Also observed are abrupt tilts towards the glacier center line shortly after the beginning of heavy rainstorms. These appear to be due to longitudinal stretching as the part of the glacier below the riegel accelerates faster than that above. Water entering the glacier by way of a series of crevasses over the riegel is believed to be responsible for this differential acceleration. In June 1987, a dramatic event was registered, probably reflecting the initial summer acceleration of the glacier.

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