scholarly journals Simultaneous monitoring of stable oxygen isotope composition in water vapour and precipitation over the central Tibetan Plateau

2015 ◽  
Vol 15 (10) ◽  
pp. 14445-14472 ◽  
Author(s):  
W. Yu ◽  
L. Tian ◽  
Y. Ma ◽  
B. Xu ◽  
D. Qu

Abstract. This study investigated the daily δ18O variations of water vapour (δ18Ov) and precipitation (δ18Op) simultaneously at Nagqu on the central Tibetan Plateau for the first time. The data show that the δ18O tendencies of water vapour coincide strongly with those of associated precipitation. The δ18O values of water vapour affect those of precipitation not only on the same day, but also for the following several days. In turn, the δ18O values of precipitation also affect those of water vapour. Hence, there exists an interaction between δ18Ov and δ18Op, and the interaction decreases gradually with time. During the entire sampling period, the variations of δ18Ov and δ18Op at Nagqu did not appear dependent on temperature, but did seem significantly dependent on the joint contributions of relative humidity, surface pressure, and precipitation amount. In addition, the δ18O changes in water vapour and precipitation can be used to diagnose different atmospheric trajectories, especially the influences of the Indian monsoon and convection. Moreover, intense activities of the Indian monsoon and convection may cause the enrichment of δ18Op relative to δ18Ov at Nagqu (on the central Tibetan Plateau) to differ from that at other stations on the northern Tibetan Plateau. These results indicate that the effects of different moisture sources, including the Indian monsoon and convection currents, need be considered when attempting to interpret paleoclimatic records on the central Tibetan Plateau.

2015 ◽  
Vol 15 (18) ◽  
pp. 10251-10262 ◽  
Author(s):  
W. Yu ◽  
L. Tian ◽  
Y. Ma ◽  
B. Xu ◽  
D. Qu

Abstract. This study investigated daily δ18O variations of water vapour (δ18Ov) and precipitation (δ18Op) simultaneously at Nagqu on the central Tibetan Plateau for the first time. Data show that the δ18O tendencies of water vapour coincide strongly with those of associated precipitation. The δ18O values of precipitation affect those of water vapour not only on the same day, but also for the following several days. In comparison, the δ18O values of local water vapour may only partly contribute to those of precipitation. During the entire sampling period, the variations of δ18Ov and δ18Op at Nagqu did not appear dependent on temperature, but did seem significantly dependent on the joint contributions of relative humidity, pressure, and precipitation amount. In addition, the δ18O changes in water vapour and precipitation can be used to diagnose different moisture sources, especially the influences of the Indian monsoon and convection. Moreover, intense activities of the Indian monsoon and convection may cause the relative enrichment of δ18Op relative to δ18Ov at Nagqu (on the central Tibetan Plateau) to differ from that at other stations on the northern Tibetan Plateau. These results indicate that the effects of different moisture sources, including the Indian monsoon and convection currents, need be considered when attempting to interpret paleoclimatic records on the central Tibetan Plateau.


2008 ◽  
Vol 4 (1) ◽  
pp. 233-248 ◽  
Author(s):  
T. Yao ◽  
K. Duan ◽  
B. Xu ◽  
N. Wang ◽  
X. Guo ◽  
...  

Abstract. Lack of reliable long-term precipitation record from northern Tibetan Plateau has constrained the understanding of precipitation variation in this region. An ice core drilled from the Puruogangri Ice Field on central Tibetan Plateau in the year 2000 helped reveal the precipitation variations since AD 1600. Analysis of the annual accumulation data presented precipitation changes from AD 1600, indicative of wet and dry periods in the past 400 year in the central Tibetan Plateau. Accordingly, the 18th and 20th centuries experienced high precipitation period, whilst the 19th century experienced low precipitation period. Such a feature was consistent with precipitation recorded in ice cores from Dunde and Guliya Glaciers, northern Tibetan Plateau. Besides, the results also pointed to consistency in precipitation-temperature correlation on the northern Tibetan Plateau, in a way that temperature and precipitation were positively correlated. But this feature was contrary to the relationship revealed from Dasuopu ice cores, southern Tibetan Plateau, where temperature and precipitation were negatively correlated. The north-south contrast in precipitation amount and its relationship with temperature may shed light on the reconstruction of Asian monsoon since AD 1600.


2008 ◽  
Vol 4 (3) ◽  
pp. 175-180 ◽  
Author(s):  
T. Yao ◽  
K. Duan ◽  
B. Xu ◽  
N. Wang ◽  
X. Guo ◽  
...  

Abstract. Lack of reliable long-term precipitation record from the northern Tibetan Plateau has constrained our understanding of precipitation variations in this region. We drilled an ice core on the Puruogangri Ice Field in the central Tibetan Plateau in 2000 to reveal the precipitation variations. The well dated part of the core extends back to AD 1600, allowing us to construct a 400-year annual accumulation record. This record shows that the central Tibetan plateau experienced a drier period with an average annual precipitation of ~300 mm in the 19th century, compared to ~450 mm in the wetter periods during 1700–1780 and the 20th century. This pattern agrees with precipitation reconstructions from the Dunde and Guliya ice cores on the northern Plateau but differs from that found in the Dasuopu ice cores from the southern Plateau The north-south contrasts in precipitation reconstruction reveals difference in moisture origin between the south Tibetan Plateau dominated by the Asian monsoon and the north Tibetan Plateau dominated by the continental recycling and the westerlies.


2016 ◽  
Author(s):  
Xiaoping Wang ◽  
Jiao Ren ◽  
Ping Gong ◽  
Chuanfei Wang ◽  
Yonggang Xue ◽  
...  

Abstract. The Tibetan Plateau (TP) has been contaminated by persistent organic pollutants (POPs), including legacy organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) through atmospheric transport. The exact source regions, transport pathways and time trends of POPs to the TP are not well understood. Here XAD-based passive air samplers (PAS) were deployed at 16 Tibetan background sites from 2007 to 2012 to gain further insight into spatial patterns and temporal trends of OCPs and PCBs. The southeastern TP was characterized by dichlorodiphenyltrichloroethane (DDT) -related chemicals delivered by Indian Monsoon air masses. The northern and northwestern TP displayed the greatest absolute concentration and relative abundance of hexachlorobenzene (HCB) in the atmosphere, caused by the westerly-driven European air masses. The interactions between the DDT polluted Indian monsoon air and the clean westerly winds formed a transition zone in central Tibet where both DDT and HCB were the dominant chemicals. Based on 5-year of continuous sampling, our data indicated declining concentrations of HCB and hexachlorocyclohexanes (HCHs) across the Tibetan region. Inter-annual trends of DDT class chemicals, however, showed less variation during this 5-year sampling period, which may be due to the on-going usage of DDT in India. This paper demonstrates the possibility of using POPs fingerprints to investigate the climate interactions and the validity of using PAS to derive inter-annual atmospheric POPs time trends.


2006 ◽  
Vol 20 (3) ◽  
pp. 505-513 ◽  
Author(s):  
Meixue Yang ◽  
Tandong Yao ◽  
Huijun Wang ◽  
Lide Tian ◽  
Xiaohua Gou

2009 ◽  
Vol 280 (3-4) ◽  
pp. 406-414 ◽  
Author(s):  
Zhangdong Jin ◽  
Mike J. Bickle ◽  
Hazel J. Chapman ◽  
Jimin Yu ◽  
Sumin Wang ◽  
...  

Radiocarbon ◽  
2017 ◽  
Vol 60 (1) ◽  
pp. 137-150 ◽  
Author(s):  
LeLe Ren ◽  
GuangHui Dong ◽  
HaiMing Li ◽  
Dave Rhode ◽  
Rowan K. Flad ◽  
...  

AbstractRecent multidisciplinary research indicates that prehistoric agriculture innovation promoted permanent human settlements of areas up to 3400 m above sea level (asl) in the northern Tibetan Plateau, but when and how ancient humans extensively occupied areas above that altitude remains uncertain. In this paper, we investigated 12 archaeological sites situated above 3600 m asl in the Yushu autonomous prefecture, east-central Tibetan Plateau, to explore this issue. We determined the ages of five sites using the radiocarbon (14C) dating method and identified animal bones sampled from three sites. The dating results show that humans occasionally occupied the Yushu area around 900 BC, and permanently inhabited the area between AD 540 and 1620. Preliminary faunal identifications indicate human-raised livestock including yak, sheep, and horse during the latter period. Stone-constructed tombs and rock painting were found at some investigated sites, suggesting humans perhaps engaged in a pastoral lifestyle during the very late Holocene in the high altitude Yushu area, where nomadic livestock production remains the current primary subsistence strategy focus.


2016 ◽  
Vol 16 (11) ◽  
pp. 6901-6911 ◽  
Author(s):  
Xiaoping Wang ◽  
Jiao Ren ◽  
Ping Gong ◽  
Chuanfei Wang ◽  
Yonggang Xue ◽  
...  

Abstract. The Tibetan Plateau (TP) has been contaminated by persistent organic pollutants (POPs), including legacy organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) through atmospheric transport. The exact source regions, transport pathways and time trends of POPs to the TP are not well understood. Here polystyrene–divinylbenzene copolymer resin (XAD)-based passive air samplers (PASs) were deployed at 16 Tibetan background sites from 2007 to 2012 to gain further insight into spatial patterns and temporal trends of OCPs and PCBs. The southeastern TP was characterized by dichlorodiphenyltrichloroethane (DDT)-related chemicals delivered by Indian monsoon air masses. The northern and northwestern TP displayed the greatest absolute concentration and relative abundance of hexachlorobenzene (HCB) in the atmosphere, caused by the westerly-driven European air masses. The interactions between the DDT polluted Indian monsoon air and the clean westerly winds formed a transition zone in central Tibet, where both DDT and HCB were the dominant chemicals. Based on 5 years of continuous sampling, our data indicated declining concentrations of HCB and hexachlorocyclohexanes (HCHs) across the Tibetan region. Inter-annual trends of DDT class chemicals, however, showed less variation during this 5-year sampling period, which may be due to the ongoing usage of DDT in India. This paper demonstrates the possibility of using POP fingerprints to investigate the climate interactions and the validity of using PAS to derive inter-annual atmospheric POP time trends.


Geology ◽  
2000 ◽  
Vol 28 (8) ◽  
pp. 715-718 ◽  
Author(s):  
Hongbo Zheng ◽  
Christopher McAulay Powell ◽  
Zhisheng An ◽  
Jie Zhou ◽  
Guangrong Dong

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