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 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 Surface energy and mass balance at Purogangri ice cap, central Tibetan Plateau, 2001–2011

2015 ◽  
Vol 61 (230) ◽  
pp. 1048-1060 ◽  
Author(s):  
Eva Huintjes ◽  
Niklas Neckel ◽  
Volker Hochschild ◽  
Christoph Schneider
Keyword(s):  
Tibetan Plateau ◽  
Surface Energy ◽  
Mass Loss ◽  
Mass Balance ◽  
High Surface ◽  
Shortwave Radiation ◽  
Balance Model ◽  
The Tibetan Plateau ◽  
Analysis Model ◽  
Ice Cap

AbstractMost glaciers on the Tibetan Plateau are difficult to assess as they are located in remote regions at high altitude. This study focuses on the surface energy-balance (SEB) and mass-balance (MB) characteristics of Purogangri ice cap (PIC). A ‘COupled Snowpack and Ice surface energy and MAss balance model’ (COSIMA) is applied without observational data from the ground. The model is forced by a meteorological dataset from the High Asia Refined analysis. Model results for annual surface-elevation changes and MB agree well with the results of a previous remote-sensing estimate. Low surface velocities of 0.026 ± 0.012 m d−1 were measured by repeat-pass InSAR. This finding supports the validation of the steady-state COSIMA against satellite-derived surface changes. Overall MB of PIC for the period 2001–11 is nearly balanced (−44 kg m−2 a−1). Analysis of the model-derived SEB/MB components reveals that a significant amount of snowfall in spring is responsible for high surface albedo throughout the year. Thus, the average surface energy loss through net longwave radiation is larger than the energy gain through net shortwave radiation. The dry continental climate favours mass loss through sublimation, which accounts for 66% of the total mass loss.

scholarly journals Energy and mass balance characteristics of the Guliya ice cap in the West Kunlun Mountains, Tibetan Plateau

2019 ◽  
Vol 159 ◽  
pp. 71-85 ◽  
Author(s):  
Shenghai Li ◽  
Tandong Yao ◽  
Wusheng Yu ◽  
Wei Yang ◽  
Meilin Zhu
Keyword(s):  
Tibetan Plateau ◽  
Mass Balance ◽  
The West ◽  
Ice Cap ◽  
Kunlun Mountains ◽  
West Kunlun

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 Note on the application of planar-fit rotation for non-omnidirectional sonic anemometers

2013 ◽  
Vol 6 (2) ◽  
pp. 221-229 ◽  
Author(s):  
M. Li ◽  
W. Babel ◽  
K. Tanaka ◽  
T. Foken
Keyword(s):  
Tibetan Plateau ◽  
Friction Velocity ◽  
Sonic Anemometer ◽  
Data Sets ◽  
The Tibetan Plateau ◽  
Open Part ◽  
Scalar Fluxes ◽  
Sonic Anemometers ◽  
Wind Velocities

Abstract. For non-omnidirectional sonic anemometers like the Kaijo-Denki DAT 600 TR61A probe, it is shown that separate planar-fit rotations must be used for the undisturbed (open part of the sonic anemometer) and the disturbed sector. This increases the friction velocity while no effect on the scalar fluxes was found. In the disturbed sector, irregular values of − u′w′ < 0 were detected for low wind velocities. Up to a certain extent these results can be transferred to the CSAT3 sonic anemometer (Campbell Scientific Ltd). This study was done for data sets from the Naqu-BJ site on the Tibetan Plateau.

scholarly journals A new map of permafrost distribution on the Tibetan Plateau

2017 ◽  
Vol 11 (6) ◽  
pp. 2527-2542 ◽  
Author(s):  
Defu Zou ◽  
Lin Zhao ◽  
Yu Sheng ◽  
Ji Chen ◽  
Guojie Hu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Spatial Data ◽  
Land Surface ◽  
Future Research ◽  
Data Sets ◽  
The Tibetan Plateau ◽  
Freezing And Thawing ◽  
Frozen Ground ◽  
Distribution Maps ◽  
Spatial Data Sets

Abstract. The Tibetan Plateau (TP) has the largest areas of permafrost terrain in the mid- and low-latitude regions of the world. Some permafrost distribution maps have been compiled but, due to limited data sources, ambiguous criteria, inadequate validation, and deficiency of high-quality spatial data sets, there is high uncertainty in the mapping of the permafrost distribution on the TP. We generated a new permafrost map based on freezing and thawing indices from modified Moderate Resolution Imaging Spectroradiometer (MODIS) land surface temperatures (LSTs) and validated this map using various ground-based data sets. The soil thermal properties of five soil types across the TP were estimated according to an empirical equation and soil properties (moisture content and bulk density). The temperature at the top of permafrost (TTOP) model was applied to simulate the permafrost distribution. Permafrost, seasonally frozen ground, and unfrozen ground covered areas of 1.06  ×  106 km2 (0.97–1.15  ×  106 km2, 90 % confidence interval) (40 %), 1.46  ×  106 (56 %), and 0.03  ×  106 km2 (1 %), respectively, excluding glaciers and lakes. Ground-based observations of the permafrost distribution across the five investigated regions (IRs, located in the transition zones of the permafrost and seasonally frozen ground) and three highway transects (across the entire permafrost regions from north to south) were used to validate the model. Validation results showed that the kappa coefficient varied from 0.38 to 0.78 with a mean of 0.57 for the five IRs and 0.62 to 0.74 with a mean of 0.68 within the three transects. Compared with earlier studies, the TTOP modelling results show greater accuracy. The results provide more detailed information on the permafrost distribution and basic data for use in future research on the Tibetan Plateau permafrost.

scholarly journals Diachronous Tibetan Plateau landscape evolution derived from lava field geomorphology

Geology ◽  
2020 ◽  
Vol 48 (3) ◽  
pp. 263-267 ◽  
Author(s):  
Robert Law ◽  
Mark B. Allen
Keyword(s):  
Tibetan Plateau ◽  
Landscape Evolution ◽  
Tectonic Geomorphology ◽  
Normal Faults ◽  
Data Sets ◽  
The Tibetan Plateau ◽  
Northern Tibetan Plateau ◽  
Tectonic Processes ◽  
Stepwise Evolution

Abstract Evolution of the Tibetan Plateau is important for understanding continental tectonics because of the plateau’s exceptional elevation (∼5 km above sea level) and crustal thickness (∼70 km). Patterns of long-term landscape evolution can constrain tectonic processes, but have been hard to quantify, in contrast to established data sets for strain, exhumation, and paleo-elevation. This study analyzes the relief of the bases and tops of 17 Cenozoic lava fields on the central and northern Tibetan Plateau. Analyzed fields have typical lateral dimensions of tens of kilometers, and so have an appropriate scale for interpreting tectonic geomorphology. Fourteen of the fields have not been deformed since eruption. One field is cut by normal faults; two others are gently folded, with limb dips &lt;6°. Relief of the bases and tops of the fields is comparable to that of modern, internally drained parts of the plateau, and distinctly lower than that of externally drained regions. The lavas preserve a record of underlying low-relief bedrock landscapes at the time they were erupted, which have undergone little change since. There is an overlap in each area between younger published low-temperature thermochronology ages and the age of the oldest eruption in each area, here interpreted as the transition between the end of significant (&gt;3 km) exhumation and plateau landscape development. This diachronous process took place between ∼32.5°N and ∼36.5°N and between ca. 40 Ma and ca. 10 Ma, advancing northwards at a long-term rate of ∼15 km/m.y. Results are consistent with incremental northward growth of the plateau, rather than a stepwise evolution or synchronous uplift.

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.

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