The Influence of Mechanical and Thermal Forcing by the Tibetan Plateau on Asian Climate

2007 ◽  
Vol 8 (4) ◽  
pp. 770-789 ◽  
Author(s):  
Guoxiong Wu ◽  
Yimin Liu ◽  
Qiong Zhang ◽  
Anmin Duan ◽  
Tongmei Wang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
East Asia ◽  
South China ◽  
Local Heating ◽  
Lower Troposphere ◽  
Early Spring ◽  
The Tibetan Plateau ◽  
Continental Scale ◽  
The North ◽  
Meridional Winds

Abstract This paper attempts to provide some new understanding of the mechanical as well as thermal effects of the Tibetan Plateau (TP) on the circulation and climate in Asia through diagnosis and numerical experiments. The air column over the TP descends in winter and ascends in summer and regulates the surface Asian monsoon flow. Sensible heating on the sloping lateral surfaces appears from the authors’ experiments to be the major driving source. The retarding and deflecting effects of the TP in winter generate an asymmetric dipole zonal-deviation circulation, with a large anticyclone gyre to the north and a cyclonic gyre to the south. Such a dipole deviation circulation enhances the cold outbreaks from the north over East Asia, results in a dry climate in south Asia and a moist climate over the Indochina peninsula and south China, and forms the persistent rainfall in early spring (PRES) in south China. In summer the TP heating generates a cyclonic spiral zonal-deviation circulation in the lower troposphere, which converges toward and rises over the TP. It is shown that because the TP is located east of the Eurasian continent, in summertime the meridional winds and vertical motions forced by the Eurasian continental-scale heating and the TP local heating are in phase over the eastern and central parts of the continent. The monsoon in East Asia and the dry climate in middle Asia are therefore intensified.

Why Is There an Early Spring Cooling Shift Downstream of the Tibetan Plateau?

2005 ◽  
Vol 18 (22) ◽  
pp. 4660-4668 ◽  
Author(s):  
Jian Li ◽  
Rucong Yu ◽  
Tianjun Zhou ◽  
Bin Wang
Keyword(s):  
Tibetan Plateau ◽  
North Africa ◽  
North Atlantic ◽  
Radiative Forcing ◽  
Temperature Shift ◽  
Early Spring ◽  
Climate Feedback ◽  
The Tibetan Plateau ◽  
The North ◽  
The North Atlantic

Abstract The temperature shift over the eastern flank of the Tibetan Plateau is examined using the last 50 yr of Chinese surface station observations. It was found that a strong cooling shift occurs in early spring (March and April) and late summer (July, August, and September) in contrast to the warming shift in other seasons. The cause of the March–April (MA) cooling is investigated in this study. The MA cooling shift on the lee side of the Tibetan Plateau is found to be not a local phenomenon, but rather it is associated with an eastward extension of a cooling signal originating from North Africa that is related to the North Atlantic Oscillation (NAO) in the previous winter. The midtropospheric westerlies over the North Atlantic and North Africa tend to intensify during positive NAO phases. The enhanced westerlies, after passing over the Tibetan Plateau, result in strengthened ascending motion against the lee side of the plateau, which favors the formation of midlevel stratiform clouds. The increased amount of stratus clouds induces a negative net cloud–radiative forcing, which thereby cools the surface air and triggers a positive cloud–temperature feedback. In this way, the cooling signal from the upstream could “jump” over the Tibetan Plateau and leave a footprint on its lee side. The continental stratiform cloud–climate feedback plays a significant role in the amplification of the cooling shift downstream of the Tibetan Plateau.

scholarly journals Longer Time-Scale Variability of Atmospheric Vertical Motion over the Tibetan Plateau and North Pacific and the Climate in East Asia

Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 630
Author(s):  
Rongxiang Tian ◽  
Yaoming Ma ◽  
Weiqiang Ma ◽  
Xiuyi Zhao ◽  
Duo Zha
Keyword(s):  
Tibetan Plateau ◽  
East Asia ◽  
Negative Correlation ◽  
North Pacific ◽  
Maximum Velocity ◽  
Vertical Motion ◽  
The Tibetan Plateau ◽  
Upward Movement ◽  
The North ◽  
The North Pacific

The vertical motion of air is closely related to the amount of precipitation that falls in a particular region. The Tibetan Plateau and the North Pacific are important determinants of the East Asian climate. We use climate diagnosis and statistical analysis to study the vertical motion of the air over the North Pacific and Tibetan Plateau and the relationship between the vertical motion of air over them and the climate in East Asia. Here we show that there is a downward movement of air over the Tibetan Plateau during the winter, with a maximum velocity of downward movement at 500 hPa, whereas there is an upward movement of air with a maximum velocity of upward movement at 600 hPa during the summer. Precipitation in East Asia has a significant negative correlation (The correlation coefficient exceeds −0.463 and confidence level is greater than 99%) with the vertical motion of air over the Tibetan Plateau and the North Pacific during both the winter and summer. There is also a negative correlation of precipitation in the region south of the Yangtze River with the vertical motion of air over the Tibetan Plateau in winter, whereas the area of negative correlation to the vertical motion of air over the North Pacific in winter is located to the east of the Tibetan Plateau and the Yangtze–Huaihe river basin. The research results provide a climatic framework for the vertical motion of air over both the Tibetan Plateau and the North Pacific.

scholarly journals Improvement in the Prediction of Summer Precipitation in the North China−Hetao Region Using the Tropospheric Temperature Over the Tibetan Plateau in Spring

2021 ◽  
Vol 9 ◽  
Author(s):  
Dan Chen ◽  
Sulan Nan ◽  
Ge Liu ◽  
Changyan Zhou ◽  
Renrui Shi ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
East Asia ◽  
North China ◽  
Summer Precipitation ◽  
Asia Pacific ◽  
The Tibetan Plateau ◽  
Tropospheric Temperature ◽  
The North ◽  
The Impact ◽  
The Relationship

We investigated the relationship between the spring tropospheric temperature over the Tibetan Plateau (TPT) and summer precipitation in eastern China on an interannual timescale using the monthly mean ERA-Interim reanalysis dataset, the HadISST dataset and the daily mean precipitation dataset for China. We found that there is a significant positive correlation between the spring TPT and summer precipitation in the North China−Hetao region. The relationship is manifested in the context of the East Asia–Pacific pattern teleconnection. In the high spring TPT index years, the geopotential height anomalies over East Asia and the western North Pacific present a negative phase of the East Asia–Pacific pattern teleconnection in the subsequent summer. This circulation pattern is beneficial for the water vapor transport from the western Pacific to inland, which further transport to the North China−Hetao region from the Yangtze River–Yellow rivers region. Anomalous upward motion occurs in the North China–Hetao region, which increases precipitation. The East Asian subtropical westerly jet shifts further north and the South Asian high weakens and shrinks westward. These conditions all favor an increase in precipitation over the North China–Hetao region. The spring TPT plays an important part in the prediction of summer precipitation in the North China−Hetao region. The improvement in the use of the spring TPT to predict summer precipitation in the North China–Hetao region is examined by comparing the prediction equations with and without the prediction factor of the spring TPT on the basis of the sea surface temperatures in key regions. After considering the impact of the spring TPT, the explanatory variance of the prediction equation for precipitation in the North China–Hetao region increases by 17.3%.

Seismic sedimentological evidence for filling process of western Central Canyon System controlled by the evolution of the Tibetan Plateau and the East Asia monsoon since the Late Miocene, South China Sea

2018 ◽  
Vol 6 (2) ◽  
pp. SD41-SD55
Author(s):  
Dawei Wang ◽  
Hongliu Zeng ◽  
Shiguo Wu ◽  
Weiwei Wang ◽  
Qingping Li ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
South China Sea ◽  
East Asia ◽  
South China ◽  
Late Miocene ◽  
The South China Sea ◽  
The Tibetan Plateau ◽  
The South ◽  
China Sea ◽  
East Asia Monsoon

Three-dimensional blended data, comprised of amplitude and coherence cubes, are used to analyze the evolution of the Central Canyon System (CCS) since the Late Miocene within the western Qiongdongnan Basin (QDNB), South China Sea. The evolution of the canyon since the late Miocene includes two phases and five stages, with a dramatic change of deepwater sediment bodies from early, predominantly axial channel-levee deposits (CLDs) to late, primarily side mass-transport deposits (MTD). During the first and second stages (approximately 5.3–3.7 Ma), axial CLDs derived from the western slope of the South China Sea dominated the sediment bodies within the canyon. The last three stages (3.7 Ma to Recent) were dominated by side MTD, which originated from the northern slope of the South China Sea. Since the canyon was completely filled at 2.4 Ma, axial CLDs only reactivated in the lower strata of the most southern region of the study area. The time of formation of the CCS (approximately 11.6–8.2 Ma) is almost synchronous with the rise of the Himalayas and the first enhancement of the East Asia monsoon during the middle and late Miocene. The change of deepwater deposits within the canyon, which has varied from CLDs to MTDs since 3.7 Ma, is in phase with the further rapid uplift of the entire Tibetan Plateau and the second enhancement of the East Asia monsoon during the middle Pliocene. This evidence suggests that the formation and filling of the canyon should be controlled by the evolution of the Tibetan Plateau and the East Asia monsoon. Tectonics and the East Asia monsoon controlled the evolution of the CCS by changing erosion rates from the Tibetan Plateau, South China Block, and Indochina Peninsula, and sedimentary rates within the Yinggehai Basin and QDNB.

Size distribution of PM20 observed to the north of the Tibetan Plateau

2021 ◽  
Vol 18 (2) ◽  
pp. 367-376
Author(s):  
Cheng-long Zhou ◽  
Fan Yang ◽  
Wen Huo ◽  
Ali Mamtimin ◽  
Xing-hua Yang
Keyword(s):  
Tibetan Plateau ◽  
Size Distribution ◽  
The Tibetan Plateau ◽  
The North

scholarly journals Characteristics of Deep Convective Systems and Initiation during Warm Seasons over China and Its Vicinity

2021 ◽  
Vol 13 (21) ◽  
pp. 4289
Author(s):  
Yang Li ◽  
Yubao Liu ◽  
Yun Chen ◽  
Baojun Chen ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
South China ◽  
Warm Season ◽  
Statistical Characteristics ◽  
The Tibetan Plateau ◽  
Spatiotemporal Resolution ◽  
Convective Systems ◽  
Seasonal And Diurnal Variations ◽  
Deep Convective Systems ◽  
Guizhou Plateau

The spatiotemporal statistical characteristics of warm-season deep convective systems, particularly deep convective systems initiation (DCSI), over China and its vicinity are investigated using Himawari-8 geostationary satellite measurements collected during April-September from 2016 to 2020. Based on a satellite brightness temperature multiple-threshold convection identification and tracking method, a total of 47593 deep convective systems with lifetimes of at least 3 h were identified in the region. There are three outstanding local maxima in the region, located in the southwestern, central and eastern Tibetan Plateau and Yunnan-Guizhou Plateau, followed by a region of high convective activities in South China. Most convective systems are developed over the Tibetan Plateau, predominantly eastward-moving, while those developed in Yunnan-Guizhou Plateau and South China mostly move westward and southwestward. The DSCI occurrences become extremely active after the onset of the summer monsoon and tend to reach a maximum in July and August, with a diurnal peak at 11–13 LST in response to the enhanced solar heating and monsoon flows. Several DCSI hotspots are identified in the regions of inland mountains, tropical islands and coastal mountains during daytime, but in basins, plains and coastal areas during nighttime. DCSI over land and oceans exhibits significantly different sub-seasonal and diurnal variations. Oceanic DCSI has an ambiguous diurnal variation, although its sub-seasonal variation is similar to that over land. It is demonstrated that the high spatiotemporal resolution satellite dataset provides rich information for understanding the convective systems over China and vicinity, particularly the complex terrain and oceans where radar observations are sparse or none, which will help to improve the convective systems and initiation nowcasting.

A new species of Cleistocybe (Agaricales, Basidiomycota) from the Tibetan Plateau, China

Phytotaxa ◽  
2018 ◽  
Vol 336 (3) ◽  
pp. 286 ◽  
Author(s):  
HONG-MEI WU ◽  
JIA-QI LUO ◽  
KE WANG ◽  
RUN-CHAO ZHANG ◽  
YI LI ◽  
...  
Keyword(s):  
New Species ◽  
Tibetan Plateau ◽  
Phylogenetic Analyses ◽  
Morphological Observation ◽  
Morphological Description ◽  
The Tibetan Plateau ◽  
Sequence Analyses ◽  
The North ◽  
Close Relationship ◽  
A New Species

During field expeditions to the Tibetan Plateau, a collection of an undescribed species with several basidiomes was found. Morphological observation and DNA sequence analyses of the collection revealed a close relationship with Cleistocybe vernalis, the type species of the genus Cleistocybe. Therefore, a new species is proposed for the fungus with full morphological description accompanied by phylogenetic analyses. The discovery of the species extends the reported distribution of the genus from the north of America and Europe to Asia.

Metabarcoding of modern sedimentary DNA from the Tibetan Plateau and Siberia as a training dataset for vegetation reconstructions

2021 ◽  
Author(s):  
Weihan Jia ◽  
Kathleen Stoof-Leichsenring ◽  
Sisi Liu ◽  
Kai Li ◽  
Sichao Huang ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Lake Sediments ◽  
Plant Diversity ◽  
Lake Water ◽  
Aquatic Plant ◽  
Freshwater Ecosystems ◽  
The Tibetan Plateau ◽  
Plant Dna ◽  
Continental Scale ◽  
Dna Metabarcoding

<p>Lake sedimentary DNA (<em>sed</em>DNA) is an established tool to trace past changes in vegetation composition and plant diversity. However, little is known about the relationships between sedimentary plant DNA and modern vegetational and environmental conditions. In this study, we investigate i) the relationships between the preservation of sedimentary plant DNA and environmental variables, ii) the modern analogue of ancient plant DNA assemblages archived in lake sediments, and iii) the usability of sedimentary plant DNA for characterization of terrestrial and aquatic plant composition and diversity based on a large dataset of PCR-amplified plant DNA data retrieved from 259 lake surface sediments from the Tibetan Plateau and Siberia. Our results indicate the following: i) Lake-water electrical conductivity and pH are the most important variables for the preservation of plant DNA in lake sediments. We expect the best preservation conditions for sedimentary plant DNA in small deep lakes characterized by high water conductivities (≥100 μS cm<sup>-1</sup>) and neutral to slightly alkaline pH conditions (7–9). ii) Plant DNA metabarcoding is promising for palaeovegetation reconstruction in high mountain regions, where shifts in vegetation are solely captured by the <em>sed</em>DNA-based analogue matching and fossil pollen generally has poor modern analogues. However, the biases in the representation of some taxa could lead to poor analogue conditions. iii) Plant DNA metabarcoding is a reliable proxy to reflect modern vegetation types and climate characteristics at a sub-continental scale. However, the resolution of the <em>trn</em>L P6 loop marker, the incompleteness of the reference library, and the extent of <em>sed</em>DNA preservation are still the main limitations of this method. iv) Plant DNA metabarcoding is a suitable proxy to recover modern aquatic plant diversity, which is mostly affected by July temperature and lake-water conductivity. Ongoing warming might decrease macrophyte richness in the Tibetan Plateau and Siberia, and ultimately threaten the health of these important freshwater ecosystems. To conclude, sedimentary plant DNA presents a high correlation with modern vegetation and may therefore be an important proxy for reconstruction of past vegetation.</p>

“Tiny wiggles” in the Late Miocene red clay deposits in the north‐east of the Tibetan Plateau

2021 ◽  
Author(s):  
Rui Zhang ◽  
Xiaohao Wei ◽  
Vadim A. Kravchinsky ◽  
Leping Yue ◽  
Yan Zheng ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Late Miocene ◽  
The Tibetan Plateau ◽  
Red Clay ◽  
North East ◽  
The North ◽  
Clay Deposits

Melting Ice Rivers

2012 ◽  
Author(s):  
Cheryl Colopy
Keyword(s):  
Global Warming ◽  
Tibetan Plateau ◽  
The Netherlands ◽  
Sea Level ◽  
The Tibetan Plateau ◽  
Mount Everest ◽  
The Past ◽  
The North ◽  
The World ◽  
The Government

From a remote outpost of global warming, a summons crackles over a two-way radio several times a week: . . . Kathmandu, Tsho Rolpa! Babar Mahal, Tsho Rolpa! Kathmandu, Tsho Rolpa! Babar Mahal, Tsho Rolpa! . . . In a little brick building on the lip of a frigid gray lake fifteen thousand feet above sea level, Ram Bahadur Khadka tries to rouse someone at Nepal’s Department of Hydrology and Meteorology in the Babar Mahal district of Kathmandu far below. When he finally succeeds and a voice crackles back to him, he reads off a series of measurements: lake levels, amounts of precipitation. A father and a farmer, Ram Bahadur is up here at this frigid outpost because the world is getting warmer. He and two colleagues rotate duty; usually two of them live here at any given time, in unkempt bachelor quarters near the roof of the world. Mount Everest is three valleys to the east, only about twenty miles as the crow flies. The Tibetan plateau is just over the mountains to the north. The men stay for four months at a stretch before walking down several days to reach a road and board a bus to go home and visit their families. For the past six years each has received five thousand rupees per month from the government—about $70—for his labors. The cold, murky lake some fifty yards away from the post used to be solid ice. Called Tsho Rolpa, it’s at the bottom of the Trakarding Glacier on the border between Tibet and Nepal. The Trakarding has been receding since at least 1960, leaving the lake at its foot. It’s retreating about 200 feet each year. Tsho Rolpa was once just a pond atop the glacier. Now it’s half a kilometer wide and three and a half kilometers long; upward of a hundred million cubic meters of icy water are trapped behind a heap of rock the glacier deposited as it flowed down and then retreated. The Netherlands helped Nepal carve out a trench through that heap of rock to allow some of the lake’s water to drain into the Rolwaling River.

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