Drought evolution characteristics of the Qinghai-Tibet Plateau over the last 100 years based on SPEI

Abstract. The standardized precipitation evapotranspiration index (SPEI) of the Tibetan Plateau was calculated using the CRU4.03 gridded dataset from 1901 to 2018 in this paper. Then, based on the SPEI data, drought on the Qinghai-Tibet Plateau was studied in terms of its spatial and temporal distributions and its changing characteristics over the last 100 years. The results revealed that the precipitation in the southeastern part of the Qinghai-Tibet Plateau has been steadily rising over the last 100 years, in conjunction with only minor temperature shifts. In the northwestern part of the plateau, precipitation has decreased significantly, accompanied by a significant increase in temperature. The drought on the Tibetan Plateau showed a clear gradual increase in aridity from southeast to northwest over the last hundred years. The SPEI also showed distinct seasonal patterns, steadily increasing in spring and summer and decreasing significantly in autumn and winter. In addition, each season had its own spatial characteristics. The northeastern part of the plateau, except the Qaidam Basin, showed a significant aridity trend in all seasons. A wet trend prevailed in the southeastern and southern areas. Drought on the Tibetan Plateau exhibits apparent cyclical oscillations with a main period of 54 years and has different cyclical characteristics in different seasons.

Download Full-text

Dynamics of evapotranspiration and variations in different land-cover regions over the Tibetan Plateau during 1961-2014

Journal of Hydrometeorology ◽

10.1175/jhm-d-20-0074.1 ◽

2021 ◽

Author(s):

Shan Lin ◽

Genxu Wang ◽

Zhaoyong Hu ◽

Kewei Huang ◽

Xiangyang Sun ◽

...

Keyword(s):

Tibetan Plateau ◽

Land Cover ◽

Northwestern Part ◽

The Tibetan Plateau ◽

Southeastern Part ◽

Available Energy ◽

Forest Region ◽

Energy Factors ◽

Term Change ◽

Increasing Trend

AbstractIn this study, the spatiotemporal changes and driving factors of evapotranspiration (ET) over the Tibetan Plateau (TP) are assessed from 1961-2014, based on a revised generalized nonlinear complementary (nonlinear-CR) model. The average annual ET on the TP was 328 mm/year. The highest ET value (711 mm/year) was found in the forest region in the southeastern part of the TP, and the lowest value (151 mm/year) was found in the desert region in the northwestern part of the TP. In terms of the contribution of different sub-regions to the total amount of ET for the whole plateau, the meadow and steppe regions contributed the most to the total amount of ET of TP, accounting for 30% and 18.5%, respectively. The interannual ET presented a significant increasing trend with a value of 0.26 mm/year from 1961 to 2014, and a significant positive ET trend was found over 35% of the region, mainly in the southeastern part of the plateau. The increasing trend of ET in swamp areas was the largest, while that in the desert areas was the smallest. In terms of the seasonality, the ET over the plateau and different land-cover regions increased the most in summer, followed by spring, while the change in ET in winter was not obvious. The energy factors dominated the long-term change in the annual ET over the plateau. In addition, the available energy is the controlling factor for ET changes in humid areas such as forests and shrublands. Energy and water factors together dominate the ET changes in arid areas.

Download Full-text

Three-dimensional structural model of the Qaidam basin: Implications for crustal shortening and growth of the northeast Tibet

Open Geosciences ◽

10.1515/geo-2017-0015 ◽

2017 ◽

Vol 9 (1) ◽

Author(s):

Jianming Guo ◽

Xuebing Wei ◽

Guohui Long ◽

Bo Wang ◽

Hailong Fan ◽

...

Keyword(s):

Tibetan Plateau ◽

Qaidam Basin ◽

Strike Slip ◽

Crustal Thickening ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

Altyn Tagh Fault ◽

Altyn Tagh ◽

History Of ◽

The Tibet Plateau

AbstractThe Qaidam basin, bounded by the Altyn Tagh fault in the north, is located in the northeast of the Tibet plateau, and it has important implications for understanding the history and mechanism of Tibetan plateau formation during the Cenozoic Indo-Eurasia collision. In this study, we constructed the main geological structures and surfaces in three dimensions through the interpolation of regularly spaced 2D seismic sections, constrained by wells data and surface geology of the Qaidam basin in northeast Tibet. Meanwhile the Cenozoic tectonic history of the Qaidam basin was reconstructed and the uplift mechanism of the Tibetan plateau was discussed. This study presents the subsurface data in conjunction with observations and analysis of the stratigraphic and sedimentary evolution. The Cenozoic deformation history of the Qaidam basin shows geologic synchroneity with uplifting history of the Tibet Plateau. It is therefore proposed that the deformation and uplifting in the south and north edges of the Tibet Plateau was almost synchronous. The total shortening and shortening rate during Cenozoic reached 25.5 km and 11.2% respectively across the Qaidam basin, indicating that the loss of the left-lateral strike slip rates of the Altyn Tagh fault has been structurally transformed into local crustal thickening across NW-trending folds and thrust faults. Meanwhile there is an about 11° vertical component along the strike-slip Altyn Tagh fault, the block oblique slip shows one more growth mechanism of the northeast Tibet.

Download Full-text

The uplift of the Qinghai-Tibet Plateau: The driver behind the scene

10.31219/osf.io/hpvk7 ◽

2020 ◽

Author(s):

Ruohan Zheng ◽

Wentao Jin ◽

Ting Zeng ◽

Xiaoyong Lu ◽

Haili Ran ◽

...

Keyword(s):

Tibetan Plateau ◽

Northern Hemisphere ◽

Indian Subcontinent ◽

Horizontal Component ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

The Sun ◽

Qinghai Tibet Plateau

During the summer months, the northern hemisphere is tilted to the sun, and the Tibetan plateau and the Indian subcontinent are subjected to the solar pull. It is apparent that the upward component where the Tibetan plateau is subjected to is larger than that of the Indian subcontinent. In contrast, the horizontal component of the solar pull to the Indian subcontinent is larger than that of the Tibetan plateau. Additionally, large masses decelerate more slowly than smaller masses. Collectively these forces propel the Qinghai-Tibet Plateau upward and northeastward.

Download Full-text

Extension of the Upper Yellow River into the Tibet Plateau: Review and New Data

Quaternary ◽

10.3390/quat4020014 ◽

2021 ◽

Vol 4 (2) ◽

pp. 14

Author(s):

Zhengchen Li ◽

Xianyan Wang ◽

Jef Vandenberghe ◽

Huayu Lu

Keyword(s):

Tibetan Plateau ◽

Yellow River ◽

Google Earth ◽

Tibet Plateau ◽

The Yellow River ◽

Published Data ◽

The Tibetan Plateau ◽

Large Lakes ◽

River Terraces ◽

The Tibet Plateau

The Wufo Basin at the margin of the northeastern Tibet Plateau connects the upstream reaches of the Yellow River with the lowland catchment downstream, and the fluvial terrace sequence in this basin provides crucial clues to understand the evolution history of the Yellow River drainage system in relation to the uplift and outgrowth of the Tibetan Plateau. Using field survey and analysis of Digital Elevation Model/Google Earth imagery, we found at least eight Yellow River terraces in this area. The overlying loess of the highest terrace was dated at 1.2 Ma based on paleomagnetic stratigraphy (two normal and two reversal polarities) and the loess-paleosol sequence (12 loess-paleosol cycles). This terrace shows the connections of drainage parts in and outside the Tibetan Plateau through its NE margin. In addition, we review the previously published data on the Yellow River terraces and ancient large lakes in the basins. Based on our new data and previous researches, we conclude that the modern Yellow River, with headwaters in the Tibet Plateau and debouching in the Bohai Sea, should date from at least 1.2 Ma. Ancient large lakes (such as the Hetao and Sanmen Lakes) developed as exorheic systems and flowed through the modern Yellow River at that time.

Download Full-text

Comparing Seasonal Diffences of Black Carbon in Tibetan Plateau transported from South Asia using WRF-Chem

10.5194/egusphere-egu21-6825 ◽

2021 ◽

Author(s):

Shuoqiu Wu ◽

Xiaoyan Ma

Keyword(s):

South Asia ◽

Black Carbon ◽

Carbon Concentration ◽

Wet Deposition ◽

Emission Inventory ◽

Tibet Plateau ◽

Black Carbon Concentration ◽

Different Seasons ◽

Qinghai Tibet Plateau ◽

The Vertical Distribution

The melting of glaciers and snow on the Qinghai-Tibet Plateau, known as the Earth&#8217;s &#8220;Third Pole&#8221; and &#8220;World Water Tower&#8221;, is source of fresh water for hundreds of millions of people in South Asia, Southeast Asia, and East Asia, but it is now suffering from an unprecedented crisis. The black carbon deposited on the surface of the glacier will reduce the snow albedo and absorb more solar radiation, leading to accelerated melting of ice and snow.Previous studies have shown that black carbon from South Asia is one of the main sources of the Qinghai-Tibet Plateau, and the transportation of black carbon to the Qinghai-Tibet Plateau presents obviously seasonal differences.However, the transport of black carbon from South Asia to the Qinghai-Tibet Plateau in different seasons shows a completely opposite trend to wind field conditions.This study uses the WRF-Chem model to study the transmission mechanism of South Asian black carbon to the Tibetan Plateau in April (pre-monsoon), July (summer monsoon) and December (winter monsoon).MIX emission inventory and Peking University's global black carbon emission inventory (PKU-BC) were involved to analyze the seasonal distribution of black carbon concentration, dry and wet deposition in the Qinghai-Tibet Plateau and South Asia, and the distribution of BC concentration and wind field at different altitudes.Combined with the vertical distribution of BC concentration across the Himalayas, the transport mechanism of black carbon in South Asia&#160;to Qinghai-Tibet Plateau in different seasons is studied.In the selected three months, December had the highest surface black carbon concentration in South Asia and the Qinghai-Tibet Plateau, while&#160;July had the lowest black carbon concentration; Mainly because&#160;of&#160;the large amount of wet deposition of black carbon brought about by the heavy precipitation in South Asia in July;According to the vertical distribution of black carbon,black carbon can climb up the hillside and eventually reach the southern slope of the Qinghai-Tibet Plateau&#160;in April. In July, black carbon is mainly distributed below 3km. In December, black carbon can be uplifted to 4-5km, and finally transported into Qinghai-Tibet Plateau.

Download Full-text

Paleolake salinity evolution in the Qaidam Basin (NE Tibetan Plateau) between ~42 and 29 Ma: Links to global cooling and Paratethys sea incursions

10.5194/egusphere-egu21-13526 ◽

2021 ◽

Author(s):

Chengcheng Ye ◽

Yibo Yang ◽

Xiaomin Fang ◽

Weilin Zhang ◽

Chunhui Song ◽

...

Keyword(s):

Climate Change ◽

Tibetan Plateau ◽

Middle Eocene ◽

Qaidam Basin ◽

Regional Climate ◽

Regional Climate Change ◽

Driving Mechanism ◽

The Tibetan Plateau ◽

Early Oligocene ◽

Global Cooling

Global cooling, the early uplift of the Tibetan Plateau, and the retreat of the Paratethys are three main factors that regulate long-term climate change in the Asian interior during the Cenozoic. However, the debated elevation history of the Tibetan Plateau and the overlapping climate effects of the Tibetan Plateau uplift and Paratethys retreat makes it difficult to assess the driving mechanism on regional climate change in a particular period. Some recent progress suggests that precisely dated Paratethys transgression/regression cycles appear to have fluctuated over broad regions with low relief in the northern Tibetan Plateau in the middle Eocene&#8211;early Oligocene, when the global climate was characterized by generally continuous cooling followed by the rapid Eocene&#8211;Oligocene climate transition (EOT). Therefore, a middle Eocene&#8211;early Oligocene record from the Asian interior with unambiguous paleoclimatic implications offers an opportunity to distinguish between the climatic effects of the Paratethys retreat and those of global cooling.Here, we present a complete paleolake salinity record from middle Eocene to early Miocene (~42-29 Ma) in the Qaidam Basin using detailed clay boron content and clay mineralogical investigations. Two independent paleosalimeters, equivalent boron and Couch&#8217;s salinity, collectively present a three-staged salinity evolution, from an oligohaline&#8211;mesohaline environment in the middle Eocene (42-~34 Ma) to a mesosaline environment in late Eocene-early Oligocene (~34-~29 Ma). This clay boron-derived salinity evolution is further supported by the published chloride-based and ostracod-based paleosalinity estimates in the Qaidam Basin. Our quantitative paleolake reconstruction between ~42 and 29 Ma in the Qaidam Basin resembles the hydroclimate change in the neighboring Xining Basin, of which both present good agreement with changes of marine benthic oxygen isotope compositions. We thus speculated that the secular trend of clay boron-derived paleolake salinity in ~42-29 Ma is primarily controlled by global cooling, which regulates regional climate change by influencing the evaporation capacity in the moisture source of Qaidam Basin. Superimposed on this trend, the Paratethys transgression/regression cycles served as an important factor regulating wet/dry fluctuations in the Asian interior between ~42 and ~34 Ma.

Download Full-text

Methane emissions by alpine plant communities in the Qinghai–Tibet Plateau

Biology Letters ◽

10.1098/rsbl.2008.0373 ◽

2008 ◽

Vol 4 (6) ◽

pp. 681-684 ◽

Cited By ~ 67

Author(s):

Guangmin Cao ◽

Xingliang Xu ◽

Ruijun Long ◽

Qilan Wang ◽

Changting Wang ◽

...

Keyword(s):

Plant Communities ◽

Methane Emissions ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

Atmospheric Methane ◽

Closed Chamber ◽

Methane Budget ◽

Alpine Plant Communities ◽

Regional Basis ◽

Qinghai Tibet Plateau

For the first time to our knowledge, we report here methane emissions by plant communities in alpine ecosystems in the Qinghai–Tibet Plateau. This has been achieved through long-term field observations from June 2003 to July 2006 using a closed chamber technique. Strong methane emission at the rate of 26.2±1.2 and 7.8±1.1 μg CH 4 m −2 h −1 was observed for a grass community in a Kobresia humilis meadow and a Potentilla fruticosa meadow, respectively. A shrub community in the Potentilla meadow consumed atmospheric methane at the rate of 5.8±1.3 μg CH 4 m −2 h −1 on a regional basis; plants from alpine meadows contribute at least 0.13 Tg CH 4 yr −1 in the Tibetan Plateau. This finding has important implications with regard to the regional methane budget and species-level difference should be considered when assessing methane emissions by plants.

Download Full-text

Evaluation of Noah-MP Land-Model Uncertainties over Sparsely Vegetated Sites on the Tibet Plateau

Atmosphere ◽

10.3390/atmos11050458 ◽

2020 ◽

Vol 11 (5) ◽

pp. 458

Author(s):

Guo Zhang ◽

Fei Chen ◽

Yueli Chen ◽

Jianduo Li ◽

Xindong Peng

Keyword(s):

Heat Flux ◽

Organic Matter ◽

Soil Organic Matter ◽

Tibetan Plateau ◽

Sensible Heat Flux ◽

Limiting Factors ◽

Tibet Plateau ◽

The Tibetan Plateau ◽

Annual Total ◽

The Impact

The water budget and energy exchange over the Tibetan Plateau (TP) region play an important role on the Asian monsoon. However, it is not well presented in the current land surface models (LSMs). In this study, uncertainties in the Noah with multiparameterization (Noah-MP) LSM are assessed through physics ensemble simulations in three sparsely vegetated sites located in the central TP. The impact of soil organic matter on energy flux and water cycles, along with the influence of uncertainties in precipitation are explored using observations at those sites during the third Tibetan Plateau Experiment from 1August2014 to31July2015. The greatest uncertainties are in the subprocesses of the canopy resistance, soil moisture limiting factors for evaporation, runoff (RNF) and ground water, and surface-layer parameterization. These uncertain subprocesses do not change across the different precipitation datasets. More precipitation can increase the annual total net radiation (Rn), latent heat flux (LH) and RNF, but decrease sensible heat flux (SH). Soil organic matter enlarges the annual total LH by ~26% but lessens the annual total Rn, SH, and RNF by ~7%, 7%, and 39%, respectively. Its effect on the LH and RNF at the Nagqu site, which has a sand soil texture type, is greater than that at the other two sites with sandy loam. This study highlights the importance of precipitation uncertainties and the effect of soil organic matter on the Noah-MP land-model simulations. It provides a guidance to improve the Noah-MP LSM further and hence the land-atmosphere interactions simulated by weather and climate models over the TP region.

Download Full-text

Neoproterozoic Amdo and Jiayuqiao microblocks in the Tibetan Plateau: Implications for Rodinia reconstruction

Geological Society of America Bulletin ◽

10.1130/b35632.1 ◽

2020 ◽

Author(s):

Yiming Liu ◽

Yuhua Wang ◽

Sanzhong Li ◽

M. Santosh ◽

Runhua Guo ◽

...

Keyword(s):

Tibetan Plateau ◽

South China ◽

Tectonic Setting ◽

Parental Magma ◽

Tibet Plateau ◽

Geochemical Data ◽

The Tibetan Plateau ◽

South China Craton ◽

Neoproterozoic Magmatism ◽

T Values

The Tibetan Plateau is composed of several microblocks, the tectonic affinity and paleogeographic correlations of which remain enigmatic. We investigated the Amdo and Jiayuqiao microblocks in central Tibet Plateau with a view to understand their tectonic setting and paleogeographic position within the Neoproterozoic supercontinent Rodinia. We present zircon U-Pb and Lu-Hf isotope, and whole-rock geochemical data on Neoproterozoic granitic gneisses from these microblocks. Zircon grains from the Jiayuqiao granitic gneiss yielded an age of 857 ± 9 Ma with variable εHf(t) values (−8.9 to 4.0). The Amdo granitic gneisses yielded ages of 893 ± 5 Ma, 807 ± 5 Ma, and 767 ± 11 Ma, with εHf(t) values in the range of −4.9 to 3.5. Geochemically, the granitoids belong to high-K calc-alkaline series, with the protolith derived from partial melting of ancient crustal components. The ascending parental magma of the Amdo granitoids experienced significant mantle contamination as compared to the less contaminated magmas that generated the Jiayuqiao intrusions. In contrast to the Lhasa, Himalaya, South China, and Tarim blocks, we suggest that the Amdo and Jiayuqiao microblocks probably formed a unified block during the Neoproterozoic and were located adjacent to the southwestern part of South China craton. The Neoproterozoic magmatism was probably associated with the subduction of the peripheral ocean under the South China craton and the delamination of lithospheric mantle beneath the Jiangnan orogen.

Download Full-text