scholarly journals Recent mass balance of Purogangri ice cap, central Tibetan Plateau, by means of differential X-band SAR interferometry

2013 ◽  
Vol 7 (2) ◽  
pp. 1119-1139 ◽  
Author(s):  
N. Neckel ◽  
A. Braun ◽  
J. Kropáček ◽  
V. Hochschild
Keyword(s):  
Tibetan Plateau ◽  
Shuttle Radar Topography Mission ◽  
Climatic Conditions ◽  
Sar Interferometry ◽  
The Tibetan Plateau ◽  
Fine Grid ◽  
Ice Caps ◽  
Ice Cap ◽  
Elevation Data ◽  
Elevation Changes

Abstract. Due to their remoteness, altitude and harsh climatic conditions, little is known about the glaciological parameters of ice caps on the Tibetan Plateau (TP). This study presents an interferometrical approach aiming at surface elevation changes of Purogangri ice cap, located on the central TP. Purogangri ice cap covers an area of 397 ± 9.7 km2 and is the largest ice cap on the TP. Its behavior is determined by dry and cold continental climate suggesting a polar-type glacier regime. We employed data from the actual TerraSAR-X mission and its add-on for Digital Elevation Measurements (TanDEM-X) and compare it with elevation data from the Shuttle Radar Topography Mission (SRTM). These datasets are ideal for this approach as both datasets feature the same wavelength of 3.1 cm and are available at a fine grid spacing. Similar snow conditions can be assumed since the data were acquired in early February 2000 and late January 2012. The trend in glacier extend was extracted using a time series of Landsat data. Our results show a balanced mass budget for the studied time period which is in agreement with previous studies. Additionally, we detected an exceptional fast advance of one glacier tongue in the eastern part of the ice cap between 1999 and 2011.

scholarly journals Recent mass balance of the Purogangri Ice Cap, central Tibetan Plateau, by means of differential X-band SAR interferometry

2013 ◽  
Vol 7 (5) ◽  
pp. 1623-1633 ◽  
Author(s):  
N. Neckel ◽  
A. Braun ◽  
J. Kropáček ◽  
V. Hochschild
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
Sar Interferometry ◽  
Data Sets ◽  
The Tibetan Plateau ◽  
Fine Grid ◽  
Mass Budget ◽  
Ice Cap ◽  
Time Period ◽  
X Band

Abstract. Due to their remoteness, altitude and harsh climatic conditions, little is known about the glaciological parameters of ice caps on the Tibetan Plateau. This study presents a geodetic mass balance estimate of the Purogangri Ice Cap, Tibet's largest ice field between 2000 and 2012. We utilized data from the actual TerraSAR-X mission and its add-on for digital elevation measurements and compared it with elevation data from the Shuttle Radar Topography Mission. The employed data sets are ideal for this approach as both data sets were acquired at X-band at nearly the same time of the year and are available at a fine grid spacing. In order to derive surface elevation changes we employed two different methods. The first method is based on differential synthetic radar interferometry while the second method uses common DEM differencing. Both approaches revealed a slightly negative mass budget of −44 ± 15 and −38 ± 23 mm w.eq. a−1 (millimeter water equivalent) respectively. A slightly negative trend of −0.15 ± 0.01 km2 a−1 in glacier extent was found for the same time period employing a time series of Landsat data. Overall, our results show an almost balanced mass budget for the studied time period. Additionally, we detected one continuously advancing glacier tongue in the eastern part of the ice cap.

scholarly journals Geometric dependency of Tibetan lakes on glacial runoff

2013 ◽  
Vol 17 (10) ◽  
pp. 4061-4077 ◽  
Author(s):  
V. H. Phan ◽  
R. C. Lindenbergh ◽  
M. Menenti
Keyword(s):  
Remote Sensing ◽  
Tibetan Plateau ◽  
Shuttle Radar Topography Mission ◽  
The Tibetan Plateau ◽  
Water Level Changes ◽  
Elevation Data ◽  
Glacial Runoff ◽  
Lake Catchment ◽  
Accurate Quantification ◽  
Do So

Abstract. The Tibetan Plateau is an essential source of water for Southeast Asia. The runoff from its ~34 000 glaciers, which occupy an area of ~50 000 km2, feeds Tibetan lakes and major Asian rivers like the Indus and Brahmaputra. Reported glacial shrinkage likely has an impact on the runoff. Unfortunately, accurate quantification of glacial changes is difficult over the high-relief Tibetan Plateau. However, it has recently been shown that it is possible to directly assess water level changes of a significant number of the ~900 Tibetan lakes with an area over 1 km2. This paper exploits different remote sensing products to create drainage links between Tibetan glaciers, lakes and rivers. The results allow us to differentiate between lakes with and without outlet. In addition, we introduce the notion of geometric dependency of a lake on glacial runoff, defined as the ratio between the total area of glaciers draining into a lake and the total area of the lake catchment. We determined these dependencies for all ~900 sufficiently large Tibetan lakes. To do so, we combined three remote sensing products: the CAREERI glacier mask product, a lake mask product based on the MODIS MOD44W water product and the HydroSHEDS river network product derived from Shuttle Radar Topography Mission (SRTM) elevation data. Using a drainage network analysis, we determined all drainage links between glaciers and lakes. The results show that 25.3% of the total glacier area directly drains into one of 244 Tibetan lakes. The results also give the geometric dependency of each lake on glacial runoff. For example, there are ten lakes with direct glacial runoff from at least 240 km2 of glacier. Three case studies, including one of the well-studied Nam Tso Lake, demonstrate how the geometric dependency of a lake on glacial runoff can be directly linked to hydrological processes.

scholarly journals Holocene climate variability archived in the Puruogangri ice cap on the central Tibetan Plateau

2006 ◽  
Vol 43 ◽  
pp. 61-69 ◽  
Author(s):  
Lonnie G. Thompson ◽  
Yao Tandong ◽  
Mary E. Davis ◽  
Ellen Mosley-Thompson ◽  
Tracy A. Mashiotta ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Ice Core ◽  
Ice Cores ◽  
The Tibetan Plateau ◽  
Climate History ◽  
Ice Caps ◽  
Ice Cap ◽  
Monsoon System ◽  
The Tropics ◽  
Ice Core Records

AbstractTwo ice cores (118.4 and 214.7 m in length) were collected in 2000 from the Puruogangri ice cap in the center of the Tibetan Plateau (TP) in a joint US-Chinese collaborative project. These cores yield paleoclimatic and environmental records extending through the Middle Holocene, and complement previous ice-core histories from the Dunde and Guliya ice caps in northeast and northwest Tibet, respectively, and Dasuopu glacier in the Himalaya. The high-resolution Puruogangri climate record since AD 1600 details regional temperature and moisture variability. The post-1920 period is characterized by above-average annual net balance, contemporaneous with the greatest 18O enrichment of the last 400 years, consistent with the isotopically inferred warming observed in other TP ice-core records. On longer timescales the aerosol history reveals large and abrupt events, one of which is dated ∼4.7 kyr BP and occurs close to the time of a drought that extended throughout the tropics and may have been associated with centuries-long weakening of the Asian/Indian/African monsoon system. The Puruogangri climate history, combined with the other TP ice-core records, has the potential to provide valuable information on variations in the strength of the monsoon across the TP during the Holocene.

scholarly journals Understanding habitat selection of the Vulnerable wild yak Bos mutus on the Tibetan Plateau

Oryx ◽  
2016 ◽  
Vol 51 (2) ◽  
pp. 361-369 ◽  
Author(s):  
Xuchang Liang ◽  
Aili Kang ◽  
Nathalie Pettorelli
Keyword(s):  
Habitat Selection ◽  
Tibetan Plateau ◽  
Growing Season ◽  
Species Distribution Modelling ◽  
Climatic Conditions ◽  
Habitat Availability ◽  
The Tibetan Plateau ◽  
Limited Effect ◽  
Distribution Modelling ◽  
Selection Of

AbstractWe tested a series of hypotheses on drivers of habitat selection by the Vulnerable wild yak Bos mutus, combining distribution-wide sighting data with species distribution modelling approaches. The results indicate that climatic conditions are of paramount importance in shaping the wild yak's distribution on the Tibetan Plateau. Habitat selection patterns were seasonal, with yaks appearing to select areas closer to villages during the vegetation-growing season. Unexpectedly, our index of forage quantity had a limited effect in determining the distribution of the species. Overall, our results suggest that expected changes in climate for this region could have a significant impact on habitat availability for wild yaks, and we call for more attention to be focused on the unique wildlife in this ecosystem.

scholarly journals Observations of widespread accelerated thinning in the upper reaches of Svalbard glaciers

2012 ◽  
Vol 6 (2) ◽  
pp. 1085-1115 ◽  
Author(s):  
T. D. James ◽  
T. Murray ◽  
N. E. Barrand ◽  
H. J. Sykes ◽  
A. J. Fox ◽  
...  
Keyword(s):  
Mass Loss ◽  
High Spatial Resolution ◽  
Entire Surface ◽  
Svalbard Archipelago ◽  
Ice Caps ◽  
Mountain Glaciers ◽  
Decadal Scale ◽  
Before And After ◽  
Elevation Data ◽  
Elevation Changes

Abstract. The measured rise in eustatic sea level over the 20th century was dominated by mass loss from the world's mountain glaciers and ice caps, and predictions suggest that these fresh water reservoirs will remain significant into the 21st century. However, estimates of this mass transfer to the ocean are based on a limited number of observations extrapolated to represent not only regional changes but often changes across individual glaciers. Combining high resolution elevation data from contemporary laser-altimetry surveys and archived aerial photography makes it possible to measure historical changes across a glacier's entire surface. Here we present a high spatial resolution time-series for six Arctic glaciers in the Svalbard Archipelago spanning 1961 to 2005. We find increasing thinning rates before and after 1990 with elevation losses occurring most notably in the glaciers' upper reaches. In the absence of a clear meteorological driver, we recommend further investigation into a possible albedo amplification of prevailing meteorological trends to explain these higher elevation changes, which could have important consequences on the region's mass balance due to the sensitivity of its hypsometric distribution. However, the strong influence of decadal-scale variability, while explaining lower rates of mass loss reported in earlier studies, highlights that caution must be exercised when interpreting thinning rates when averaged over long periods.

Marine Isotope Stage 3 paleotemperature inferred from reconstructing the Die Shan ice cap, northeastern Tibetan Plateau

2018 ◽  
Vol 89 (2) ◽  
pp. 494-504 ◽  
Author(s):  
Hang Cui ◽  
Jie Wang ◽  
Beibei Yu ◽  
Zhenbo Hu ◽  
Pan Yao ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Last Glacial Maximum ◽  
Glacial Maximum ◽  
Marine Isotope Stage ◽  
The Tibetan Plateau ◽  
Equilibrium Line Altitude ◽  
Last Glacial ◽  
Mis 3 ◽  
Ice Cap ◽  
Northeastern Tibetan Plateau

AbstractGlacial extent mapping and dating indicate that the local last glacial maximum (LLGM) of the northeastern Tibetan Plateau occurred during mid-Marine Isotope Stage (MIS) 3. This is asynchronous with the global last glacial maximum (LGM) that occurred during MIS 2. The causes underlying this asynchronicity are the subject of ongoing debate, and paleoclimatic reconstructions are a key to advancing understanding of the climatic influence on the spatial and temporal patterns of paleoglaciation. We used multiple methods to reconstruct the equilibrium-line altitude (ELA) of the Die Shan paleo-ice cap on the northeastern Tibetan Plateau, and to infer past temperature for ice maximum positions believed to be mid-MIS 3 in age, based on regional correlation. Geomorphic ELA reconstructions combined with an energy and mass balance model yield a paleo-ELA of 4117±31 m asl (786 m lower than present) with temperature depressions of 3.8 to ~4.6°C compared to the present. This is less than the LGM reconstruction of temperature depression inferred from other climatic proxy records on the Tibetan Plateau and suggests that the LLGM glacial advance was a product of lower temperatures and slightly reduced precipitation compared to present, whereas the LGM was a more restricted advance in which much colder conditions were combined with much lower precipitation.

scholarly journals Monitoring glacial thickness changes in the Tibetan Plateau derived from ICESat data

2016 ◽  
Vol 19 (2) ◽  
pp. 130-137
Author(s):  
Vu Hien Phan ◽  
Roderik Lindenbergh ◽  
Massimo Menenti
Keyword(s):  
Tibetan Plateau ◽  
Average Rate ◽  
Weather Conditions ◽  
Mountain Range ◽  
The Tibetan Plateau ◽  
Thickness Change ◽  
Shuttle Radar Topographic Mission ◽  
Elevation Changes ◽  
Water Mass Balance ◽  
The Impact

Monitoring glacier changes is essential for estimating the water mass balance of the Tibetan Plateau. Recent research indicates that glaciers at individual regions on the Tibetan Plateau and surroundings are shrinking and thinning during the last decades. Studies considering large regions often ignored however the impact of locally varying weather conditions and terrain characteristics on glacial evolution, i.e. the impact of orographic precipitation and variation in solar radiation. Our hypothesis is therefore that adjacent glaciers of opposite orientation change in a different way. In this study, we exploit Ice Cloud and land Elevation Satellite (ICESat)/ Geoscience Laser Altimetry System (GLAS) data in combination with the NASA Shuttle Radar Topographic Mission (SRTM) digital elevation model (DEM) and the Global Land Ice Measurements from Space (GLIMS) glacier mask to estimate glacial thickness change trends between 2003 and 2009 on the whole Tibetan Plateau. The results show that 90 glacial areas could be distinguished. Most of observed glacial areas on the Tibetan Plateau are thinning, except for some glaciers in the Northwest. In general, glacial elevations on the whole Tibetan Plateau decreased at an average rate of -0.17 ± 0.47 meters per year (m a-1) between 2003 and 2009, taking together glaciers of any size, distribution, and location of the observed glacial area. Moreover, the results show that glacial elevation changes indeed strongly depend on the relative position in a mountain range.

scholarly journals Surface-area changes of glaciers in the Tibetan Plateau interior area since the 1970s using recent Landsat images and historical maps

2014 ◽  
Vol 55 (66) ◽  
pp. 213-222 ◽  
Author(s):  
Wei Junfeng ◽  
Liu Shiyin ◽  
Guo Wanqin ◽  
Yao Xiaojun ◽  
Xu Junli ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Reduction Rate ◽  
Topographic Maps ◽  
The Tibetan Plateau ◽  
Historical Maps ◽  
Landsat Images ◽  
Glacier Shrinkage ◽  
Ice Caps ◽  
The North ◽  
Regional Gradient

AbstractThe Tibetan Plateau interior area (TPIA), often termed the Qangtang Plateau, is distinguished by many dome-like mountains higher than 6000 ma.s.l. These mountains provide favourable conditions for the development of ice caps and glaciers of extreme continental/subpolar type. According to historical topographic maps (1959–80) and recent Landsat images (2004–11), continuous retreat was observed and the glacierized part of this area decreased by 9.5% (0.27% a–1) with respect to the total glacier area of 8036.4 km2 in the 1970s. Glaciers in the Zhari Namco basin have experienced the highest area shrinkage, with a reduction rate of 0.72% a–1, while the smallest reduction occurred in Bangong Co (0.12% a–1) and Dogai Coying basins (0.11% a–1). A regional gradient of area loss was found, with a larger decrease in the south and a smaller decrease in the north of the plateau. Comparisons indicate glaciers have experienced smaller shrinkage in the TPIA than in surrounding regions. Glacier shrinkage in the TPIA is mainly attributed to an increase in air temperature, while precipitation, glacier size and positive difference of glaciation also played an important role.

Estimation of the ELA on Hardangerjøkulen, Norway, during the 1995/96 winter season using repeat-pass SAR coherence

2002 ◽  
Vol 34 ◽  
pp. 349-354 ◽  
Author(s):  
R. E. J. Kelly
Keyword(s):  
Winter Season ◽  
Sar Interferometry ◽  
Synthetic Aperture ◽  
Equilibrium Line Altitude ◽  
Ice Caps ◽  
Complementary Method ◽  
Ice Cap ◽  
Southern Norway ◽  
Surface Ice ◽  
Good Agreement

AbstractThis paper demonstrates the utility of European Remote-sensing Satellite (ERS) synthetic aperture radar (SAR) interferometry for monitoring the transient snow-line (TSL) on Hardangerjøkulen ice cap, southern Norway, during the 1995/96 winter. The study shows how coherence information (an interferometry product) over the ice cap can be used to locate the TSL after the summer melt season. Spatial variations in coherence over the ice cap between successive ERS tandem-phase passes from summer to winter are related to surface and volume snow stability and surface ice stability. Temporal differences of coherence images between winter and summer are investigated using histogram analysis. A histogram threshold is found for the 1995/96 winter that can be used to identify the location of the TSL and then estimate the equilibrium-line altitude (ELA). The result shows good agreement (0.5%) with the field-estimated ELA from the Norwegian Water and Energy Administration. Themethod appears to be straightforward for this ice cap and it is envisaged that it could be a useful complementary method on other ice caps where repeat-pass SAR data are available.

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