Summer temperature variability inferred from subfossil chironomid assemblages from the south-east margin of the Qinghai–Tibetan Plateau for the last 5000 years

The Holocene ◽  
2017 ◽  
Vol 27 (12) ◽  
pp. 1876-1884 ◽  
Author(s):  
Jie Chang ◽  
Enlou Zhang ◽  
Enfeng Liu ◽  
James Shulmeister

We present a quantitative mean July temperature record spanning the last c. 5000 years from an alpine lake in south-western China. The reconstruction is based on the application of an established chironomid-based inference model using 100 lakes from the region. The reconstructed summer temperature changes are within 2.4°C of modern throughout the record. The results suggest that the summer temperature changes in south-east margin of the Qinghai–Tibetan plateau (QTP) predominantly responds to Asian Summer Monsoon influence, forced by summer insolation until c. 3200 cal. BP. Four cooling events, each separated by c. 500 years (between 3200 and 1600 cal. BP), were observed and these may correspond to the 500-year quasi-periodic solar fluctuation. The most recent cooling period, that is, ‘the Little Ice Age’, appears robust in the Heihai Lake record, providing further evidence that a hemisphere-wide forcing mechanism is possible for this climate event.

2013 ◽  
Vol 80 (1) ◽  
pp. 55-65 ◽  
Author(s):  
Cheng Zhao ◽  
Zhonghui Liu ◽  
Eelco J. Rohling ◽  
Zicheng Yu ◽  
Weiguo Liu ◽  
...  

Arid Central Asia (ACA) lies on a major climatic boundary between the mid-latitude westerlies and the northwestern limit of the Asian summer monsoon, yet only a few high-quality reconstructions exist for its climate history. Here we calibrate a new organic geochemical proxy for lake temperature, and present a 45-yr-resolution temperature record from Hurleg Lake at the eastern margin of the ACA in the northern Tibetan Plateau. Combination with other proxy data from the same samples reveals a distinct warm–dry climate association throughout the record, which contrasts with the warm–wet association found in the Asian monsoon region. This indicates that the climatic boundary between the westerly and the monsoon regimes has remained roughly in the same place throughout the Holocene, at least near our study site. Six millennial-scale cold events are found within the past 9000 yr, which approximately coincide with previously documented events of northern high-latitude cooling and tropical drought. This suggests a connection between the North Atlantic and tropical monsoon climate systems, via the westerly circulation. Finally, we also observe an increase in regional climate variability after the mid-Holocene, which we relate to changes in vegetation (forest) cover in the monsoon region through a land-surface albedo feedback.


The Holocene ◽  
2020 ◽  
Vol 30 (8) ◽  
pp. 1163-1173 ◽  
Author(s):  
Zhe Sun ◽  
Kan Yuan ◽  
Xiaohuan Hou ◽  
Kejia Ji ◽  
Can-Ge Li ◽  
...  

The Asian summer monsoon and the mid-latitude Westerlies are major atmospheric circulation systems which influence the climate of the Tibetan Plateau (TP), and hence the water resources, ecology, and socioeconomic well-being of the region. The interplay between the monsoon and the Westerlies has been investigated on glacial–interglacial, millennial, and decadal scales. However, due to the scarcity of high-resolution climate records from the TP, there is a lack of information on the centennial scale, which is more closely related to the development of civilization. Here we present a decadal-resolution precipitation record covering the past ~3600 years from Ngamring Co in the southern TP. The record suggests the gradual weakening of the Indian Summer Monsoon (ISM) with multiple centennial-scale fluctuations, which are synchronous with temperature changes. Precipitation was relatively high during the Medieval Warm Period (MWP) and low during the Little Ice Age (LIA). A wet Roman Warm Period (RWP) and an abrupt dry spell at 2.8 ka are also identified. Comparisons suggest that an intensified Westerlies penetrated the southern TP during dry intervals, such as during the 2.8 ka event, ~1700–1450 cal yr BP, and the LIA; whereas an intensified monsoon prevailed during warm periods such as the MWP. The centennial-scale oscillations of precipitation in the southern TP during the late Holocene suggest the role of the Westerlies in regulating ISM moisture delivery to the region, which likely resulted from variations in the surface temperature of the North Atlantic together with solar activity.


2014 ◽  
Vol 119 (14) ◽  
pp. 8552-8567 ◽  
Author(s):  
Guoqing Zhang ◽  
Tandong Yao ◽  
Hongjie Xie ◽  
Jun Qin ◽  
Qinghua Ye ◽  
...  

2017 ◽  
Author(s):  
Hui Sun ◽  
Xiaodong Liu ◽  
Zaitao Pan

Abstract. While dust aerosols emitted from major Asian sources such as Taklimakan and Gobi Deserts have been shown to have strong effect on Asian monsoon and climate, the role of dust emitted from Tibetan Plateau (TP) itself, where aerosols can directly interact with the TP heat pump because of their physical proximity both in location and elevation, has not been examined. This study uses the dust coupled RegCM4.1 regional climate model to simulate the spatiotemporal distribution of dust aerosols originating in the TP and their radiative effects on the East Asian summer monsoon (EASM) during both heavy and light dust years. Two 20-year simulations with and without the dust emission from TP showed that direct radiative cooling in the mid-troposphere induced by the TP locally produced dust aerosols resulted in an overall anticyclonic circulation anomaly in the low-troposphere centered over the TP region. The northeasterly anomaly in the EASM region reduces its strength considerably. The simulations found a significant negative correlation between the TP column dust load produced by local emissions and the corresponding anomaly in the EASM index (R=−0.41). The locally generated TP dust can cause surface cooling far downstream in eastern Mongolia and northeastern China through stationery Rossby wave propagation. Although contribution to the total Asian dust source from within TP (mainly Qaidam Basin) is relatively small, its impacts on Asian monsoon and climate seems disproportionately large, likely owning to its higher elevation within TP itself.


2016 ◽  
Vol 12 (2) ◽  
pp. 201-211 ◽  
Author(s):  
W. An ◽  
S. Hou ◽  
W. Zhang ◽  
Y. Wang ◽  
Y. Liu ◽  
...  

Abstract. Stable oxygen isotopic records in ice cores provide valuable information about past temperature, especially for regions with scarce instrumental measurements. This paper presents the δ18O result of an ice core drilled to bedrock from Mt. Zangser Kangri (ZK), a remote area on the northern Tibetan Plateau (TP). We reconstructed the temperature series for 1951–2008 from the δ18O records. In addition, we combined the ZK δ18O records with those from three other ice cores in the northern TP (Muztagata, Puruogangri, and Geladaindong) to reconstruct a regional temperature history for the period 1951–2002 (RTNTP). The RTNTP showed significant warming at 0.51 ± 0.07 °C (10 yr)−1 since 1970, a higher rate than the trend of instrumental records of the northern TP (0.43 ± 0.08 °C (10 yr)−1) and the global temperature trend (0.27 ± 0.03°C (10 yr)−1) at the same time. In addition, the ZK temperature record, with extra length until 2008, seems to suggest that the rapid elevation-dependent warming continued for this region during the last decade, when the mean global temperature showed very little change. This could provide insights into the behavior of the recent warming hiatus at higher elevations, where instrumental climate records are lacking.


2009 ◽  
Vol 6 (6) ◽  
pp. 10849-10881
Author(s):  
J. Hong ◽  
J. Kim

Abstract. The Tibetan Plateau is a critical region in the research of biosphere-atmosphere interactions on both regional and global scales due to its relation to Asian summer monsoon and El Niño. The unique environment on the Plateau provides valuable information for the evaluation of the models' surface energy partitioning associated with the summer monsoon. In this study, we investigated the surface energy partitioning on this important area through comparative analysis of two biosphere models constrained by the in-situ observation data. Indeed, the characteristics of the Plateau provide a unique opportunity to clarify the structural deficiencies of biosphere models as well as new insight into the surface energy partitioning on the Plateau. Our analysis showed that the observed inconsistency between the two biosphere models was mainly related to: 1) the parameterization for soil evaporation; 2) the way to deal with roughness lengths of momentum and scalars; and 3) the parameterization of subgrid velocity scale for aerodynamic conductance. Our study demonstrates that one should carefully interpret the modeling results on the Plateau especially during the pre-monsoon period.


Sign in / Sign up

Export Citation Format

Share Document