Holocene vegetational and climatic variation in westerly-dominated areas of Central Asia inferred from the Sayram Lake in northern Xinjiang, China

2012 ◽  
Vol 56 (3) ◽  
pp. 339-353 ◽  
Author(s):  
QingFeng Jiang ◽  
JunFeng Ji ◽  
Ji Shen ◽  
Ryo Matsumoto ◽  
GuoBang Tong ◽  
...  
Keyword(s):  
Central Asia ◽  
Climatic Variation ◽  
Northern Xinjiang

scholarly journals Identification of Long-Range Transport Pathways and Potential Source Regions of PM2.5 and PM10 at Akedala Station, Central Asia

Atmosphere ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 1183
Author(s):  
Hanlin Li ◽  
Qing He ◽  
Xinchun Liu
Keyword(s):  
Central Asia ◽  
Transport Pathways ◽  
Air Masses ◽  
Source Areas ◽  
Northern Xinjiang ◽  
Source Regions ◽  
Potential Source ◽  
Western Mongolia ◽  
Pm2.5 And Pm10 ◽  
Eastern Kazakhstan

Cluster analyses, potential source contribution function (PSCF) and concentration-weight trajectory (CWT) were used to identify the main transport pathways and potential source regions with hourly PM2.5 and PM10 concentrations in different seasons from January 2017 to December 2019 at Akedala Station, located in northwest China (Central Asia). The annual mean concentrations of PM2.5 and PM10 were 11.63 ± 9.31 and 19.99 ± 14.39 µg/m3, respectively. The air pollution was most polluted in winter, and the dominant part of PM10 (between 54 to 76%) constituted PM2.5 aerosols in Akedala. Particulate pollution in Akedala can be traced back to eastern Kazakhstan, northern Xinjiang, and western Mongolia. The cluster analyses showed that the Akedala atmosphere was mainly affected by air masses transported from the northwest. The PM2.5 and PM10 mainly came with air masses from the central and eastern regions of Kazakhstan, which are characterized by highly industrialized and semi-arid desert areas. In addition, the analyses of the pressure profile of back-trajectories showed that air mass distribution were mainly distributed above 840 hPa. This indicates that PM2.5 and PM10 concentrations were strongly affected by high altitude air masses. According to the results of the PSCF and CWT methods, the main potential source areas of PM2.5 were very similar to those of PM10. In winter and autumn, the main potential source areas with high weighted PSCF values were located in the eastern regions of Kazakhstan, northern Xinjiang, and western Mongolia. These areas contributed the highest PM2.5 concentrations from 25 to 40 µg/m3 and PM10 concentrations from 30 to 60 µg/m3 in these seasons. In spring and summer, the potential source areas with the high weighted PSCF values were distributed in eastern Kazakhstan, northern Xinjiang, the border between northeast Kazakhstan, and southern Russia. These areas contributed the highest PM2.5 concentrations from 10 to 20 µg/m3 and PM10 concentrations from 20 to 60 µg/m3 in these seasons.

Identification of rock weathering and environmental control in arid catchments (northern Xinjiang) of Central Asia

2013 ◽  
Vol 66 ◽  
pp. 277-294 ◽  
Author(s):  
Bingqi Zhu ◽  
Jingjie Yu ◽  
Xiaoguang Qin ◽  
Patrick Rioual ◽  
Yichi Zhang ◽  
...  
Keyword(s):  
Central Asia ◽  
Environmental Control ◽  
Rock Weathering ◽  
Northern Xinjiang

scholarly journals The earliest Asian bats (Mammalia: Chiroptera) address major gaps in bat evolution

2021 ◽  
Vol 17 (6) ◽  
pp. 20210185
Author(s):  
Matthew F. Jones ◽  
Qiang Li ◽  
Xijun Ni ◽  
K. Christopher Beard
Keyword(s):  
Central Asia ◽  
Junggar Basin ◽  
Placental Mammal ◽  
Early Eocene ◽  
Northern Xinjiang ◽  
Dental Evolution ◽  
Bat Evolution ◽  
Postcranial Anatomy

Bats dispersed widely after evolving the capacity for powered flight, and fossil bats are known from the early Eocene of most continents. Until now, however, bats have been conspicuously absent from the early Eocene of mainland Asia. Here, we report two teeth from the Junggar Basin of northern Xinjiang, China belonging to the first known early Eocene bats from Asia, representing arguably the most plesiomorphic bat molars currently recognized. These teeth combine certain bat synapomorphies with primitive traits found in other placental mammals, thereby potentially illuminating dental evolution among stem bats. The Junggar Basin teeth suggest that the dentition of the stem chiropteran family Onychonycteridae is surprisingly derived, although their postcranial anatomy is more primitive than that of any other Eocene bats. Additional comparisons with stem bat families Icaronycteridae and Archaeonycteridae fail to identify unambiguous synapomorphies for the latter taxa, raising the possibility that neither is monophyletic as currently recognized. The presence of highly plesiomorphic bats in the early Eocene of central Asia suggests that this region was an important locus for the earliest, transitional phases of bat evolution, as has been demonstrated for other placental mammal orders including Lagomorpha and Rodentia.

scholarly journals Moisture Transport and Sources of the Extreme Precipitation Over Northern and Southern Xinjiang in the Summer Half-Year During 1979–2018

2021 ◽  
Vol 9 ◽  
Author(s):  
Qin Hu ◽  
Yong Zhao ◽  
Anning Huang ◽  
Pan Ma ◽  
Jing Ming
Keyword(s):  
Central Asia ◽  
Extreme Precipitation ◽  
Arabian Sea ◽  
Dispersion Model ◽  
Particle Dispersion ◽  
Source Areas ◽  
Northern Xinjiang ◽  
Moisture Source ◽  
Summer Half ◽  
Southern Xinjiang

Based on the output data from the Lagrangian flexible particle dispersion model (FLEXPART), we analyze the pathways of moisture to identify the moisture source areas for extreme precipitation in the summer half-year (April–September) over northern and southern Xinjiang, respectively. For both northern and southern Xinjiang, the local evaporation plays a decisive role for extreme precipitation in the summer half-year, of which contribution ratio accounts for 24.5% to northern Xinjiang and 30.2% to southern Xinjiang of all identified source areas. In addition, central Asia and northwestern Asia are the major moisture source areas as well and contribute similarly to extreme precipitation relative to local evaporation. For northern Xinjiang, central Asia surpasses northwestern Asia, and each of them contributes 24.1 and 18.8%, whereas northwestern Asia is somewhat more crucial than central Asia for southern Xinjiang, accounting 22.1 and 19.1%, respectively. Note that the three top-ranked moisture source areas make up a large proportion of total sources. Regarding the remaining source areas that also provide moisture, the contributions are entirely different for southern and northern Xinjiang. Originating from the North Atlantic Ocean, Europe, and the Mediterranean Sea, some water vapor enters northern Xinjiang and converge to precipitate, while this process is barely detectable for extreme precipitation over southern Xinjiang, which is affected by the westerly flow. On the contrary, the Arabian Sea, the Arabian Peninsula, and the Indian Peninsula contribute, even though slightly, to extreme precipitation over southern Xinjiang, which indicates that the meridional transport pathways from the Arabian Sea can carry moisture to this inland region.

scholarly journals Water Vapor from Western Eurasia Promotes Precipitation during the Snow Season in Northern Xinjiang, a Typical Arid Region in Central Asia

Water ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 141 ◽  
Author(s):  
Weiguo Wang ◽  
Hongyi Li ◽  
Jian Wang ◽  
Xiaohua Hao
Keyword(s):  
Water Vapor ◽  
Central Asia ◽  
Water Cycle ◽  
Precipitation Trend ◽  
Vapor Source ◽  
Northern Xinjiang ◽  
The North ◽  
North Polar ◽  
Western Eurasia ◽  
Water Vapor Source

Atmospheric water vapor plays an important role in the water cycle, especially in arid Central Asia, where precipitation is invaluable to water resources. Understanding and quantifying the relationship between water vapor source regions and precipitation is a key problem in water resource research in typical arid Central Asia, Northern Xinjiang. However, the relationship between precipitation and water vapor sources is still unclear of snow season. This paper aimed at studying the role of water vapor source supply in the Northern Xinjiang precipitation trend, which was investigated using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model. The results showed that the total water vapor contributed from Western Eurasia and the North Polar area presented upward trends similar to the precipitation change trend, which indicated that the water vapor contribution from the two previous water vapor source regions supplied abundant water vapor and maintained the upward precipitation trend from 1980 to 2017 in Northern Xinjiang. From the climatology of water vapor transport, the region was controlled by midlatitude westerlies and major water vapor input from the western boundary, and the net water vapor flux of this region also showed an annual increasing trend. Western Eurasia had the largest moisture percentage contribution to Northern Xinjiang (48.11%) over the past 38 years. Northern Xinjiang precipitation was correlated with water vapor from Western Eurasia, the North Polar area, and Siberia, and the correlation coefficients were 0.66, 0.45, and 0.57, respectively. These results could aid in better understanding the water cycle process and climate change in this typical arid region of Central Asia.

scholarly journals Temporal and spatial variability in snow cover over the Xinjiang Uygur Autonomous Region, China, from 2001 to 2015

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8861 ◽  
Author(s):  
Wenqian Chen ◽  
Jianli Ding ◽  
Jingzhe Wang ◽  
Junyong Zhang ◽  
Zhe Zhang
Keyword(s):  
Central Asia ◽  
Snow Cover ◽  
Temporal Variations ◽  
Snow Accumulation ◽  
River Valley ◽  
Mountain Glacier ◽  
Northern Xinjiang ◽  
Seasonal Snow ◽  
Ili River Valley ◽  
Seasonal Snow Cover

Xinjiang, China, is a typical arid and semi-arid region of Central Asia that significantly lacks freshwater resources, and the surface runoff in this region is mainly supplied by mountain glacier and snow cover meltwater. Based on the above background and issues of transnational water resources between Xinjiang and Central Asia along the Silk Road Economic Belt, which were highlighted in the major strategy of “The Belt and Road”, this study analysed the spatial and temporal variations in snow cover and snow cover days in the Xinjiang region from 2001 to 2015. The study area includes four subregions: Northern Xinjiang, Southern Xinjiang, Eastern Xinjiang and the Ili River Valley. Moderate-resolution Imaging Spectroradiometer (MODIS) 8-day snow cover data were used after removing clouds by combining MOD10A2 and MYD10A2. The results showed that seasonal snow cover occurred from October to April in most regions of Xinjiang and that this snow cover consisted of two processes: snow accumulation and snow ablation. The maximum snow cover occurred in January, whereas the minimum snow cover occurred from July to August. During the seasonal snow cover period, the snowfall rates in Northern Xinjiang and the Ili River Valley were higher, while the other regions had a low snowfall probability. To study the relationship between altitude and snow cover, the normalized snow elevation correlation index (NSACI) was calculated. The NSACI showed a significant correlation between snow cover and elevation in most regions of Xinjiang and was classified into five grades. Snow cover days did not fluctuate obviously from 2001 to 2015, and a decreasing trend was observed in the four subregions except for the Ili River Valley (nonsignificant decreasing trend). We also observed a correlation between snow cover and temperature and found that the correlations between monthly snow cover and monthly temperature in the four subregions were strongly related to the underlying land type and global warming background, which also suggests that the special topography of Xinjiang greatly influences both snow cover and climate change.

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