scholarly journals Superimposed ice in glacier mass balance on the Tibetan Plateau

1996 ◽  
Vol 42 (142) ◽  
pp. 454-460 ◽  
Author(s):  
Koji Fujita ◽  
Katsumoto Seko ◽  
Yutaka Ageta ◽  
Pu Jianchen ◽  
Yao Tandong

AbstractThe relations between mass balance and meltwater refreezing were examined on the basis of glaciological observations carried out in summer 1993 on Xiao Dongkemadi Glacier, Tanggula Mountains, central Tibetan Plateau. On this glacier, a part of meltwaler refreezes at the snow/ice interface as superimposed ice. The amount of superimposed ice formation was determined by both meltwater supply and temperature condition of the glacier. Snow-layer thickness on the glacier ice body is less than 2 m, even in the higher accumulation zone. About 60% of meltwaler generated in the accumulation zone for the period May–September was trapped at the snow/ice interface by refreezing, and was not discharged out of the glacier. About 26% of accumulated snow to the glacier surface was replaced on the snow/ice interface by refreezing in the accumulation zone. These facts indicate that superimposed ice formation is quite significant for water retention in glaciers under low-precipitation conditions.

1996 ◽  
Vol 42 (142) ◽  
pp. 454-460 ◽  
Author(s):  
Koji Fujita ◽  
Katsumoto Seko ◽  
Yutaka Ageta ◽  
Pu Jianchen ◽  
Yao Tandong

AbstractThe relations between mass balance and meltwater refreezing were examined on the basis of glaciological observations carried out in summer 1993 on Xiao Dongkemadi Glacier, Tanggula Mountains, central Tibetan Plateau. On this glacier, a part of meltwaler refreezes at the snow/ice interface as superimposed ice. The amount of superimposed ice formation was determined by both meltwater supply and temperature condition of the glacier. Snow-layer thickness on the glacier ice body is less than 2 m, even in the higher accumulation zone. About 60% of meltwaler generated in the accumulation zone for the period May–September was trapped at the snow/ice interface by refreezing, and was not discharged out of the glacier. About 26% of accumulated snow to the glacier surface was replaced on the snow/ice interface by refreezing in the accumulation zone. These facts indicate that superimposed ice formation is quite significant for water retention in glaciers under low-precipitation conditions.


2000 ◽  
Vol 31 ◽  
pp. 159-163 ◽  
Author(s):  
Koji Fujita ◽  
Yutaka Ageta ◽  
Pu Jianchen ◽  
Yao Tandong

AbstractData on the mass balance of Xiao Dongkemadi glacier in the Tanggula mountains, central Tibetan Plateau, were obtained over 5 5 years from 1989 to 1995. These are the first continuous mass-balance data for a continental-type glacier on the Tibetan Plateau, where the glacier accumulates during the summer monsoon (summer-accumulation-type glacier). Mass-balance vs altitude profiles were steeper in the negative than in the positive mass-balance years. This is considered to have resulted from the effect of summer accumulation. The annual mass balance is compared with air temperature, precipitation, and black-body temperature in the area including the glacier, which is calculated from infrared radiation observations by theJapanese Geostationary Meteorological Satellite. It was found that the interannual variation in the glacier mass balance was not closely related to maximum monthly mean air temperature, while it did have a relatively good correlation with maximum monthly mean black-body temperature.


2020 ◽  
Vol 12 (5) ◽  
pp. 864 ◽  
Author(s):  
Shaoting Ren ◽  
Massimo Menenti ◽  
Li Jia ◽  
Jing Zhang ◽  
Jingxiao Zhang ◽  
...  

Mountain glaciers are excellent indicators of climate change and have an important role in the terrestrial water cycle and food security in many parts of the world. Glaciers are the major water source of rivers and lakes in the Nyainqentanglha Mountains (NM) region, where the glacier area has the second largest extent on the Tibetan Plateau. The potential of the high spatial resolution ZiYuan-3 (ZY-3) Three-Line-Array (TLA) stereo images to retrieve glacier mass balance has not been sufficiently explored. In this study, we optimized the procedure to extract a Digital Elevation Model (DEM) from ZY-3 TLA stereo images and estimated the geodetic mass balance of representative glaciers in the two typical areas of the NM using ZY-3 DEMs and the C-band Shuttle Radar Topography Mission (SRTM) DEM in three periods, i.e., 2000–2013, 2013–2017 and 2000–2017. The results provide detailed information towards better understanding of glacier change and specifically show that: (1) with our new stereo procedure, ZY-3 TLA data can significantly increase point cloud density and decrease invalid data on the glacier surface map to generate a high resolution (5 m) glacier mass balance map; (2) the glacier mass balance in both the Western Nyainqentanglha Mountains (WNM) and Eastern Nyainqentanglha Mountains (ENM) was negative in 2000–2017, and experienced faster mass loss in recent years (2013–2017) in the WNM. Overall, the glaciers in the western and eastern NM show different change patterns since they are influenced by different climate regimes; the glacier mass balances in WNM was –0.22 ± 0.23 m w.e. a−1 and –0.43 ± 0.06 m w.e. a−1 in 2000–2013 and 2013–2017, respectively, while in 2000–2017, it was –0.30 ± 0.19 m w.e. a−1 in the WNM and –0.56 ± 0.20 m w.e. a−1 in the ENM; (3) in the WNM, the glaciers experienced mass loss in 2000–2013 and 2013–2017 in the ablation zone, while in the accumulation zone mass increased in 2000–2013 and a large mass loss occurred in 2013–2017; as regards the ENM, the glacier mass balance was negative in 2000–2017 in both zones; (4) glacier mass balance can be affected by the fractional abundance of debris and glacier slope; (5) the glacier mass balances retrieved by ZY-3 and TanDEM-X data agreed well in the ablation zone, while a large difference occurred in the accumulation zone because of the snow/firn penetration of the X-band SAR signal.


Water ◽  
2016 ◽  
Vol 8 (11) ◽  
pp. 496 ◽  
Author(s):  
Lin Liu ◽  
Liming Jiang ◽  
Yafei Sun ◽  
Hansheng Wang ◽  
Chaolu Yi ◽  
...  

2015 ◽  
Vol 61 (227) ◽  
pp. 447-460 ◽  
Author(s):  
Gao Tanguang ◽  
Kang Shichang ◽  
Lan Cuo ◽  
Zhang Tingjun ◽  
Zhang Guoshuai ◽  
...  

AbstractRunoff estimation in high-altitude glacierized basins is an important issue on the Tibetan Plateau. To investigate glacier mass balance, runoff and water balance in the Qugaqie basin and Zhadang sub-basin in the southern Tibetan Plateau, two glacier models and three snow models were integrated into the spatially distributed hydrological model JAMS/J2K. The results showed that the temperature index method simulated glacier runoff better than the degree-day factor method. The simulated glacier melt volume in the Qugaqie basin in 2006, 2007 and 2008 contributed 58%, 50% and 41%, respectively, to its total runoff. In the Zhadang basin, the glacier melt volume contributed 78% and 66% to its runoff during 2007 and 2008, respectively. Compared with the observation results, the simulated glacier mass balance showed similar variations with slightly higher values, indicating an underestimation of glacier melt volume. The water balance simulation in the upstream areas (705–874 mm) was comparable to that in the downstream areas (1051–1502 mm) and generally lower than the observed results. In both basins, the glacier mass-balance simulation was relatively accurate in the melt season compared to the other seasons.


2013 ◽  
Vol 59 (213) ◽  
pp. 137-148 ◽  
Author(s):  
Guoshuai Zhang ◽  
Shichang Kang ◽  
Koji Fujita ◽  
Eva Huintjes ◽  
Jianqing Xu ◽  
...  

AbstractClimate variables that control the annual cycle of the surface energy and mass balance on Zhadang glacier in the central Tibetan Plateau were examined over a 2 year period using a physically based energy-balance model forced by routine meteorological data. The modelled results agree with measured values of albedo, incoming longwave radiation, surface temperature and surface level of the glacier. For the whole observation period, the radiation component dominated (82%) the total surface energy heat fluxes. This was followed by turbulent sensible (10%) and latent heat (6%) fluxes. Subsurface heat flux represented a very minor proportion (2%) of the total heat flux. The sensitivity of specific mass balance was examined by perturbations of temperature (±1 K), relative humidity (±20%) and precipitation (±20%). The results indicate that the specific mass balance is more sensitive to changes in precipitation than to other variables. The main seasonal variations in the energy balance were in the two radiation components (net shortwave radiation and net longwave radiation) and these controlled whether surface melting occurred. A dramatic difference in summer mass balance between 2010 and 2011 indicates that the glacier surface mass balance was closely related to precipitation seasonality and form (proportion of snowfall and rainfall).


2018 ◽  
Vol 10 (10) ◽  
pp. 1547 ◽  
Author(s):  
Eleanor Bash ◽  
Brian Moorman ◽  
Allison Gunther

Current understanding of glacier mass balance changes under changing climate is limited by scarcity of in situ measurements in both time and space, as well as resolution of remote sensing products. Recent innovations in unmanned aerial vehicles (UAVs), as well as structure-from-motion photogrammetry (SfM), have led to increased use of digital imagery to derive topographic data in great detail in many fields, including glaciology. This study tested the capability of UAV surveys to detect surface changes over glacier ice during a three-day period in July 2016. Three UAV imaging missions were conducted during this time over 0.185 km 2 of the ablation area of Fountain Glacier, NU. These were processed with the SfM algorithms in Agisoft Photoscan Professional and overall accuracies of the resulting point clouds ranged from 0.030 to 0.043 m. The high accuracy of point clouds achieved here is primarily a result of a small ground sampling distance (0.018 m), and is also influenced by GPS precision. Glacier surface change was measured through differencing of point clouds and change was compared to ablation stake measurements. Surface change measured with the UAV-SfM method agreed with the coincident ablation stake measurements in most instances, with RMSE values of 0.033, 0.028, and 0.042 m for one-, two-, and three-day periods, respectively. Total specific melt over the study area measured with the UAV was 0.170 m water equivalent (w.e.), while interpolation of ablation measurements resulted in 0.144 m w.e. Using UAVs to measure small changes in glacier surfaces will allow for new investigations of distribution of mass balance measurements.


2015 ◽  
Vol 9 (1) ◽  
pp. 417-440 ◽  
Author(s):  
S. C. Kang ◽  
F. Y. Wang ◽  
U. Morgenstern ◽  
Y. L. Zhang ◽  
B. Grigholm ◽  
...  

Abstract. Two ice cores were retrieved from high elevations (~ 5800 m a.s.l.) at Mt. Nyainqentanglha and Mt. Geladaindong in the southern to inland Tibetan Plateau. The combined analysis of tritium (3H), 210Pb, mercury tracers, along with other chemical records, revealed that the two coring sites had not received net ice accumulation since at least the 1950s and 1980s, respectively, implying an annual ice loss rate of more than several hundred millimeter water equivalent over these periods. Both mass balance modeling at the sites and in situ data from nearby glaciers confirmed a continuously negative mass balance (or mass loss) in the region due to the dramatic warming in the last decades. Along with a recent report on Naimona'nyi Glacier in the Himalaya, the findings suggest that glacier decapitation (i.e., the loss of the accumulation zone) is a wide-spread phenomenon from the southern to inland Tibetan Plateau even at the summit regions. This raises concerns over the rapid rate of glacier ice loss and associated changes in surface glacier runoff, water availability, and sea levels.


Sign in / Sign up

Export Citation Format

Share Document