Summer atmospheric bridging between Europe and East Asia: Influences on drought and wetness on the Tibetan Plateau

2011 ◽  
Vol 236 (1-2) ◽  
pp. 151-157 ◽  
Author(s):  
Xiuhua Zhu ◽  
Oliver Bothe ◽  
Klaus Fraedrich
2007 ◽  
Vol 8 (4) ◽  
pp. 770-789 ◽  
Author(s):  
Guoxiong Wu ◽  
Yimin Liu ◽  
Qiong Zhang ◽  
Anmin Duan ◽  
Tongmei Wang ◽  
...  

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.


2015 ◽  
Vol 112 (18) ◽  
pp. 5625-5630 ◽  
Author(s):  
Jade A. d’Alpoim Guedes ◽  
Hongliang Lu ◽  
Anke M. Hein ◽  
Amanda H. Schmidt

We report directly dated evidence from circa 1400 calibrated years (cal) B.C. for the early use of wheat, barley, and flax as staple crops on the borders of the Tibetan Plateau. During recent years, an increasing amount of data from the Tibetan Plateau and its margins shows that a transition from millets to wheat and barley agriculture took place during the second millennium B.C. Using thermal niche modeling, we refute previous assertions that the ecological characteristics of wheat and barley delayed their spread into East Asia. Rather, we demonstrate that the ability of these crops to tolerate frost and their low growing degree-day requirements facilitated their spread into the high-altitude margins of western China. Following their introduction to this region, these crops rapidly replaced Chinese millets and became the staple crops that still characterize agriculture in this area today.


Author(s):  
Chuan-Chao Wang ◽  
Hui-Yuan Yeh ◽  
Alexander N Popov ◽  
Hu-Qin Zhang ◽  
Hirofumi Matsumura ◽  
...  

The deep population history of East Asia remains poorly understood due to a lack of ancient DNA data and sparse sampling of present-day people. We report genome-wide data from 191 individuals from Mongolia, northern China, Taiwan, the Amur River Basin and Japan dating to 6000 BCE – 1000 CE, many from contexts never previously analyzed with ancient DNA. We also report 383 present-day individuals from 46 groups mostly from the Tibetan Plateau and southern China. We document how 6000-3600 BCE people of Mongolia and the Amur River Basin were from populations that expanded over Northeast Asia, likely dispersing the ancestors of Mongolic and Tungusic languages. In a time transect of 89 Mongolians, we reveal how Yamnaya steppe pastoralist spread from the west by 3300-2900 BCE in association with the Afanasievo culture, although we also document a boy buried in an Afanasievo barrow with ancestry entirely from local Mongolian hunter-gatherers, representing a unique case of someone of entirely non-Yamnaya ancestry interred in this way. The second spread of Yamnaya-derived ancestry came via groups that harbored about a third of their ancestry from European farmers, which nearly completely displaced unmixed Yamnaya-related lineages in Mongolia in the second millennium BCE, but did not replace Afanasievo lineages in western China where Afanasievo ancestry persisted, plausibly acting as the source of the early-splitting Tocharian branch of Indo-European languages. Analyzing 20 Yellow River Basin farmers dating to ∼3000 BCE, we document a population that was a plausible vector for the spread of Sino-Tibetan languages both to the Tibetan Plateau and to the central plain where they mixed with southern agriculturalists to form the ancestors of Han Chinese. We show that the individuals in a time transect of 52 ancient Taiwan individuals spanning at least 1400 BCE to 600 CE were consistent with being nearly direct descendants of Yangtze Valley first farmers who likely spread Austronesian, Tai-Kadai and Austroasiatic languages across Southeast and South Asia and mixing with the people they encountered, contributing to a four-fold reduction of genetic differentiation during the emergence of complex societies. We finally report data from Jomon hunter-gatherers from Japan who harbored one of the earliest splitting branches of East Eurasian variation, and show an affinity among Jomon, Amur River Basin, ancient Taiwan, and Austronesian-speakers, as expected for ancestry if they all had contributions from a Late Pleistocene coastal route migration to East Asia.


2020 ◽  
Author(s):  
Qunfan Zheng ◽  
Huai Zhang

<p>East Asia is a tectonically active area on earth and has a complicated lithospheric deformation due to the western Indo-Asian continental collision and the eastern oceanic subduction mainly from Pacific plate. Till now, mantle dynamics beneath this area is not well understood due to its complex mantle structure, especially in the framework of global spherical mantle convection. Hence, a series of numerical models are conducted in this study to reveal the key controlling parameters in shaping the present-day observed mantle structure beneath East Asia under 3-D global mantle flow models. Global mantle flow models with coarse mesh are firstly applied to give a rough constraint on global mantle convection. The detailed description of upper mantle dynamics of East Asia is left with regional refined mesh. A power-law rheology and absolute plate field are applied subsequently to get a better constraint on the related regional mantle rheological structure and surficial boundary conditions. Thus, the refined and reasonable velocity and stress distributions of upper mantle beneath East Asia at different depths are retrieved based on our 3-D global mantle flow simulations. The derived large shallow mantle flow beneath the Tibetan Plateau causes significant lithospheric shear drag and dynamic topography that result in prominent tectonic evolution of this area. And the Indo–Asian collision may have induced mantle flow beneath the Indian plate and the different velocity structures between the asthenosphere and lithosphere indicate the shear drag of asthenospheric mantle. That may explain the reason that Indo–Asian collision has occurred for 50 Ma, and this collision can still continue to accelerate uplift in the Tibetan plateau. Finally, we also consider the possible implementations of 3-D numerical simulations combined with global lithosphere and deep mantle dynamics so as to discuss the relevant influences.</p>


2017 ◽  
Author(s):  
Hewen Niu ◽  
Shichang Kang ◽  
Hailong Wang ◽  
Rudong Zhang ◽  
Xixi Lu ◽  
...  

Abstract. The high altitude glacierized regions of the Tibetan Plateau (TP) are influenced by carbonaceous aerosols from local sources and long range transport from the adjoining areas. Deposition and accumulation of light-absorbing carbonaceous matters on glacier surfaces can alter the energy balance of glaciers. In this study, two years (December 2014 to December 2016) of continuous observations of carbonaceous aerosols performed in glacierized region of Mt. Yulong (4510 m a.s.l.) and Ganhaizi (GHZ) basin (3054 m a.s.l.) are analyzed. The mass absorption efficiency (MAE) of black carbon (BC) was determined for the first time in Mt. Yulong using a thermal-optical carbon analyzer. The average BC and organic carbon (OC) concentrations were 1.51 ± 0.93 and 2.57 ± 1.32 μg m−3, respectively. The average SOC (secondary OC) concentration, quantified using BC-tracer method, was 1.67 ± 1.15 μg m−3. Monthly mean BC concentrations from monsoon to post-monsoon season were higher than OC in the high altitudes (approximately 5000 m a.s.l.) of Mt. Yulong. The concentrations of carbonaceous matter have distinct spatial and inter-annual variations in this glacierization area. High carbonaceous matter associated with OC (including both SOC and POC) in GHZ basin was mainly contributed from tour bus emissions. The annual mean OC / BC ratio was 2.45 ± 1.96 in Mt. Yulong. Strong photochemical reactions and local tourism activities in monsoon season were the main factors inducing high OC / BC ratios in the Mt. Yulong region. The mean MAE of BC, measured at 632 nm with a thermal-optical protocol under the filter-based method, was 6.82 ± 0.73 m2 g−1, comparable with the results from other studies. Strong seasonal and spatial variations of BC MAE were largely related to the OC and SOC abundance. Source attribution analysis using a global aerosol-climate model, equipped with a BC source tagging technique, suggests that East Asia emissions, including local sources, have the dominant contribution (over 50 %) to annual mean near-surface BC at the two sites. There is also a strong seasonal variation in the regional source apportionment. South Asia has the largest contribution during the pre-monsoon season, while East Asia dominates the monsoon season and post-monsoon season. Results in this study have great implications for accurately evaluating the influences of carbonaceous matter on glacial melting and water resource supply in glacierization areas.


2012 ◽  
Vol 56 (2) ◽  
pp. 301-310 ◽  
Author(s):  
Rui Mao ◽  
DaoYi Gong ◽  
YaPing Shao ◽  
GuangJian Wu ◽  
JingDong Bao

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